From a787870924dbd6f321661e06d4ec1c7a408c9ccf Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 14 Aug 2013 14:55:40 +0200 Subject: sched, arch: Create asm/preempt.h In order to prepare to per-arch implementations of preempt_count move the required bits into an asm-generic header and use this for all archs. Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-h5j0c1r3e3fk015m30h8f1zx@git.kernel.org Signed-off-by: Ingo Molnar --- include/asm-generic/preempt.h | 54 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 include/asm-generic/preempt.h (limited to 'include/asm-generic') diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h new file mode 100644 index 000000000000..a1fc6590a743 --- /dev/null +++ b/include/asm-generic/preempt.h @@ -0,0 +1,54 @@ +#ifndef __ASM_PREEMPT_H +#define __ASM_PREEMPT_H + +#include + +/* + * We mask the PREEMPT_NEED_RESCHED bit so as not to confuse all current users + * that think a non-zero value indicates we cannot preempt. + */ +static __always_inline int preempt_count(void) +{ + return current_thread_info()->preempt_count & ~PREEMPT_NEED_RESCHED; +} + +static __always_inline int *preempt_count_ptr(void) +{ + return ¤t_thread_info()->preempt_count; +} + +/* + * We now loose PREEMPT_NEED_RESCHED and cause an extra reschedule; however the + * alternative is loosing a reschedule. Better schedule too often -- also this + * should be a very rare operation. + */ +static __always_inline void preempt_count_set(int pc) +{ + *preempt_count_ptr() = pc; +} + +/* + * We fold the NEED_RESCHED bit into the preempt count such that + * preempt_enable() can decrement and test for needing to reschedule with a + * single instruction. + * + * We invert the actual bit, so that when the decrement hits 0 we know we both + * need to resched (the bit is cleared) and can resched (no preempt count). + */ + +static __always_inline void set_preempt_need_resched(void) +{ + *preempt_count_ptr() &= ~PREEMPT_NEED_RESCHED; +} + +static __always_inline void clear_preempt_need_resched(void) +{ + *preempt_count_ptr() |= PREEMPT_NEED_RESCHED; +} + +static __always_inline bool test_preempt_need_resched(void) +{ + return !(*preempt_count_ptr() & PREEMPT_NEED_RESCHED); +} + +#endif /* __ASM_PREEMPT_H */ -- cgit v1.3-14-g43fede From 01028747559ac6c6f642a7bbd2875cc4f66b2feb Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 14 Aug 2013 14:55:46 +0200 Subject: sched: Create more preempt_count accessors We need a few special preempt_count accessors: - task_preempt_count() for when we're interested in the preemption count of another (non-running) task. - init_task_preempt_count() for properly initializing the preemption count. - init_idle_preempt_count() a special case of the above for the idle threads. With these no generic code ever touches thread_info::preempt_count anymore and architectures could choose to remove it. Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-jf5swrio8l78j37d06fzmo4r@git.kernel.org Signed-off-by: Ingo Molnar --- include/asm-generic/preempt.h | 14 ++++++++++++++ include/trace/events/sched.h | 2 +- kernel/sched/core.c | 7 +++---- 3 files changed, 18 insertions(+), 5 deletions(-) (limited to 'include/asm-generic') diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h index a1fc6590a743..8100b1ec1715 100644 --- a/include/asm-generic/preempt.h +++ b/include/asm-generic/preempt.h @@ -27,6 +27,20 @@ static __always_inline void preempt_count_set(int pc) *preempt_count_ptr() = pc; } +/* + * must be macros to avoid header recursion hell + */ +#define task_preempt_count(p) \ + (task_thread_info(p)->preempt_count & ~PREEMPT_NEED_RESCHED) + +#define init_task_preempt_count(p) do { \ + task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \ +} while (0) + +#define init_idle_preempt_count(p, cpu) do { \ + task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \ +} while (0) + /* * We fold the NEED_RESCHED bit into the preempt count such that * preempt_enable() can decrement and test for needing to reschedule with a diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 2e7d9947a10d..613381bcde40 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -100,7 +100,7 @@ static inline long __trace_sched_switch_state(struct task_struct *p) /* * For all intents and purposes a preempted task is a running task. */ - if (task_thread_info(p)->preempt_count & PREEMPT_ACTIVE) + if (task_preempt_count(p) & PREEMPT_ACTIVE) state = TASK_RUNNING | TASK_STATE_MAX; #endif diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ee61f5affd20..0ba4e4192390 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -983,7 +983,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu) * ttwu() will sort out the placement. */ WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && - !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); + !(task_preempt_count(p) & PREEMPT_ACTIVE)); #ifdef CONFIG_LOCKDEP /* @@ -1723,8 +1723,7 @@ void sched_fork(struct task_struct *p) p->on_cpu = 0; #endif #ifdef CONFIG_PREEMPT_COUNT - /* Want to start with kernel preemption disabled. */ - task_thread_info(p)->preempt_count = PREEMPT_DISABLED; + init_task_preempt_count(p); #endif #ifdef CONFIG_SMP plist_node_init(&p->pushable_tasks, MAX_PRIO); @@ -4217,7 +4216,7 @@ void init_idle(struct task_struct *idle, int cpu) raw_spin_unlock_irqrestore(&rq->lock, flags); /* Set the preempt count _outside_ the spinlocks! */ - task_thread_info(idle)->preempt_count = PREEMPT_ENABLED; + init_idle_preempt_count(idle, cpu); /* * The idle tasks have their own, simple scheduling class: -- cgit v1.3-14-g43fede From bdb43806589096ac4272fe1307e789846ac08d7c Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 10 Sep 2013 12:15:23 +0200 Subject: sched: Extract the basic add/sub preempt_count modifiers Rewrite the preempt_count macros in order to extract the 3 basic preempt_count value modifiers: __preempt_count_add() __preempt_count_sub() and the new: __preempt_count_dec_and_test() And since we're at it anyway, replace the unconventional $op_preempt_count names with the more conventional preempt_count_$op. Since these basic operators are equivalent to the previous _notrace() variants, do away with the _notrace() versions. Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-ewbpdbupy9xpsjhg960zwbv8@git.kernel.org Signed-off-by: Ingo Molnar --- arch/mips/mm/init.c | 5 +- arch/x86/kernel/traps.c | 4 +- include/asm-generic/preempt.h | 35 ++++++++++++++ include/linux/hardirq.h | 8 ++-- include/linux/preempt.h | 106 +++++++++++++++++++----------------------- include/linux/sched.h | 5 -- include/linux/uaccess.h | 8 +--- kernel/context_tracking.c | 2 +- kernel/sched/core.c | 29 +++++------- kernel/softirq.c | 14 +++--- 10 files changed, 113 insertions(+), 103 deletions(-) (limited to 'include/asm-generic') diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index e205ef598e97..12156176c7ca 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -124,7 +124,7 @@ void *kmap_coherent(struct page *page, unsigned long addr) BUG_ON(Page_dcache_dirty(page)); - inc_preempt_count(); + pagefault_disable(); idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1); #ifdef CONFIG_MIPS_MT_SMTC idx += FIX_N_COLOURS * smp_processor_id() + @@ -193,8 +193,7 @@ void kunmap_coherent(void) write_c0_entryhi(old_ctx); EXIT_CRITICAL(flags); #endif - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); } void copy_user_highpage(struct page *to, struct page *from, diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 8c8093b146ca..729aa779ff75 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -88,7 +88,7 @@ static inline void conditional_sti(struct pt_regs *regs) static inline void preempt_conditional_sti(struct pt_regs *regs) { - inc_preempt_count(); + preempt_count_inc(); if (regs->flags & X86_EFLAGS_IF) local_irq_enable(); } @@ -103,7 +103,7 @@ static inline void preempt_conditional_cli(struct pt_regs *regs) { if (regs->flags & X86_EFLAGS_IF) local_irq_disable(); - dec_preempt_count(); + preempt_count_dec(); } static int __kprobes diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h index 8100b1ec1715..82d958fc3823 100644 --- a/include/asm-generic/preempt.h +++ b/include/asm-generic/preempt.h @@ -65,4 +65,39 @@ static __always_inline bool test_preempt_need_resched(void) return !(*preempt_count_ptr() & PREEMPT_NEED_RESCHED); } +/* + * The various preempt_count add/sub methods + */ + +static __always_inline void __preempt_count_add(int val) +{ + *preempt_count_ptr() += val; +} + +static __always_inline void __preempt_count_sub(int val) +{ + *preempt_count_ptr() -= val; +} + +static __always_inline bool __preempt_count_dec_and_test(void) +{ + return !--*preempt_count_ptr(); +} + +/* + * Returns true when we need to resched -- even if we can not. + */ +static __always_inline bool need_resched(void) +{ + return unlikely(test_preempt_need_resched()); +} + +/* + * Returns true when we need to resched and can (barring IRQ state). + */ +static __always_inline bool should_resched(void) +{ + return unlikely(!*preempt_count_ptr()); +} + #endif /* __ASM_PREEMPT_H */ diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 1e041063b226..d9cf963ac832 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -33,7 +33,7 @@ extern void rcu_nmi_exit(void); #define __irq_enter() \ do { \ account_irq_enter_time(current); \ - add_preempt_count(HARDIRQ_OFFSET); \ + preempt_count_add(HARDIRQ_OFFSET); \ trace_hardirq_enter(); \ } while (0) @@ -49,7 +49,7 @@ extern void irq_enter(void); do { \ trace_hardirq_exit(); \ account_irq_exit_time(current); \ - sub_preempt_count(HARDIRQ_OFFSET); \ + preempt_count_sub(HARDIRQ_OFFSET); \ } while (0) /* @@ -62,7 +62,7 @@ extern void irq_exit(void); lockdep_off(); \ ftrace_nmi_enter(); \ BUG_ON(in_nmi()); \ - add_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \ + preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \ rcu_nmi_enter(); \ trace_hardirq_enter(); \ } while (0) @@ -72,7 +72,7 @@ extern void irq_exit(void); trace_hardirq_exit(); \ rcu_nmi_exit(); \ BUG_ON(!in_nmi()); \ - sub_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \ + preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \ ftrace_nmi_exit(); \ lockdep_on(); \ } while (0) diff --git a/include/linux/preempt.h b/include/linux/preempt.h index df8e245e8729..2343d8715299 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -18,97 +18,86 @@ #include #if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER) - extern void add_preempt_count(int val); - extern void sub_preempt_count(int val); +extern void preempt_count_add(int val); +extern void preempt_count_sub(int val); +#define preempt_count_dec_and_test() ({ preempt_count_sub(1); should_resched(); }) #else -# define add_preempt_count(val) do { *preempt_count_ptr() += (val); } while (0) -# define sub_preempt_count(val) do { *preempt_count_ptr() -= (val); } while (0) +#define preempt_count_add(val) __preempt_count_add(val) +#define preempt_count_sub(val) __preempt_count_sub(val) +#define preempt_count_dec_and_test() __preempt_count_dec_and_test() #endif -#define inc_preempt_count() add_preempt_count(1) -#define dec_preempt_count() sub_preempt_count(1) - -#ifdef CONFIG_PREEMPT - -asmlinkage void preempt_schedule(void); - -#define preempt_check_resched() \ -do { \ - if (unlikely(!*preempt_count_ptr())) \ - preempt_schedule(); \ -} while (0) - -#ifdef CONFIG_CONTEXT_TRACKING - -void preempt_schedule_context(void); - -#define preempt_check_resched_context() \ -do { \ - if (unlikely(!*preempt_count_ptr())) \ - preempt_schedule_context(); \ -} while (0) -#else - -#define preempt_check_resched_context() preempt_check_resched() - -#endif /* CONFIG_CONTEXT_TRACKING */ - -#else /* !CONFIG_PREEMPT */ - -#define preempt_check_resched() do { } while (0) -#define preempt_check_resched_context() do { } while (0) - -#endif /* CONFIG_PREEMPT */ +#define __preempt_count_inc() __preempt_count_add(1) +#define __preempt_count_dec() __preempt_count_sub(1) +#define preempt_count_inc() preempt_count_add(1) +#define preempt_count_dec() preempt_count_sub(1) #ifdef CONFIG_PREEMPT_COUNT #define preempt_disable() \ do { \ - inc_preempt_count(); \ + preempt_count_inc(); \ barrier(); \ } while (0) #define sched_preempt_enable_no_resched() \ do { \ barrier(); \ - dec_preempt_count(); \ + preempt_count_dec(); \ } while (0) -#define preempt_enable_no_resched() sched_preempt_enable_no_resched() +#define preempt_enable_no_resched() sched_preempt_enable_no_resched() +#ifdef CONFIG_PREEMPT +asmlinkage void preempt_schedule(void); #define preempt_enable() \ do { \ - preempt_enable_no_resched(); \ - preempt_check_resched(); \ + barrier(); \ + if (unlikely(preempt_count_dec_and_test())) \ + preempt_schedule(); \ } while (0) -/* For debugging and tracer internals only! */ -#define add_preempt_count_notrace(val) \ - do { *preempt_count_ptr() += (val); } while (0) -#define sub_preempt_count_notrace(val) \ - do { *preempt_count_ptr() -= (val); } while (0) -#define inc_preempt_count_notrace() add_preempt_count_notrace(1) -#define dec_preempt_count_notrace() sub_preempt_count_notrace(1) +#define preempt_check_resched() \ +do { \ + if (should_resched()) \ + preempt_schedule(); \ +} while (0) + +#else +#define preempt_enable() preempt_enable_no_resched() +#define preempt_check_resched() do { } while (0) +#endif #define preempt_disable_notrace() \ do { \ - inc_preempt_count_notrace(); \ + __preempt_count_inc(); \ barrier(); \ } while (0) #define preempt_enable_no_resched_notrace() \ do { \ barrier(); \ - dec_preempt_count_notrace(); \ + __preempt_count_dec(); \ } while (0) -/* preempt_check_resched is OK to trace */ +#ifdef CONFIG_PREEMPT + +#ifdef CONFIG_CONTEXT_TRACKING +asmlinkage void preempt_schedule_context(void); +#else +#define preempt_schedule_context() preempt_schedule() +#endif + #define preempt_enable_notrace() \ do { \ - preempt_enable_no_resched_notrace(); \ - preempt_check_resched_context(); \ + barrier(); \ + if (unlikely(__preempt_count_dec_and_test())) \ + preempt_schedule_context(); \ } while (0) +#else +#define preempt_enable_notrace() preempt_enable_no_resched_notrace() +#endif #else /* !CONFIG_PREEMPT_COUNT */ @@ -118,10 +107,11 @@ do { \ * that can cause faults and scheduling migrate into our preempt-protected * region. */ -#define preempt_disable() barrier() +#define preempt_disable() barrier() #define sched_preempt_enable_no_resched() barrier() -#define preempt_enable_no_resched() barrier() -#define preempt_enable() barrier() +#define preempt_enable_no_resched() barrier() +#define preempt_enable() barrier() +#define preempt_check_resched() do { } while (0) #define preempt_disable_notrace() barrier() #define preempt_enable_no_resched_notrace() barrier() diff --git a/include/linux/sched.h b/include/linux/sched.h index 9fa151fb968e..06ac17c7e639 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2409,11 +2409,6 @@ static inline int signal_pending_state(long state, struct task_struct *p) return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p); } -static inline int need_resched(void) -{ - return unlikely(test_preempt_need_resched()); -} - /* * cond_resched() and cond_resched_lock(): latency reduction via * explicit rescheduling in places that are safe. The return diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 5ca0951e1855..9d8cf056e661 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -15,7 +15,7 @@ */ static inline void pagefault_disable(void) { - inc_preempt_count(); + preempt_count_inc(); /* * make sure to have issued the store before a pagefault * can hit. @@ -30,11 +30,7 @@ static inline void pagefault_enable(void) * the pagefault handler again. */ barrier(); - dec_preempt_count(); - /* - * make sure we do.. - */ - barrier(); + preempt_count_dec(); preempt_check_resched(); } diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index 247091bf0587..013161f1c807 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -111,7 +111,7 @@ void context_tracking_user_enter(void) * instead of preempt_schedule() to exit user context if needed before * calling the scheduler. */ -void __sched notrace preempt_schedule_context(void) +asmlinkage void __sched notrace preempt_schedule_context(void) { enum ctx_state prev_ctx; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0ba4e4192390..9c84a9ab1892 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2219,7 +2219,7 @@ notrace unsigned long get_parent_ip(unsigned long addr) #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ defined(CONFIG_PREEMPT_TRACER)) -void __kprobes add_preempt_count(int val) +void __kprobes preempt_count_add(int val) { #ifdef CONFIG_DEBUG_PREEMPT /* @@ -2228,7 +2228,7 @@ void __kprobes add_preempt_count(int val) if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) return; #endif - add_preempt_count_notrace(val); + __preempt_count_add(val); #ifdef CONFIG_DEBUG_PREEMPT /* * Spinlock count overflowing soon? @@ -2239,9 +2239,9 @@ void __kprobes add_preempt_count(int val) if (preempt_count() == val) trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); } -EXPORT_SYMBOL(add_preempt_count); +EXPORT_SYMBOL(preempt_count_add); -void __kprobes sub_preempt_count(int val) +void __kprobes preempt_count_sub(int val) { #ifdef CONFIG_DEBUG_PREEMPT /* @@ -2259,9 +2259,9 @@ void __kprobes sub_preempt_count(int val) if (preempt_count() == val) trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); - sub_preempt_count_notrace(val); + __preempt_count_sub(val); } -EXPORT_SYMBOL(sub_preempt_count); +EXPORT_SYMBOL(preempt_count_sub); #endif @@ -2525,9 +2525,9 @@ asmlinkage void __sched notrace preempt_schedule(void) return; do { - add_preempt_count_notrace(PREEMPT_ACTIVE); + __preempt_count_add(PREEMPT_ACTIVE); __schedule(); - sub_preempt_count_notrace(PREEMPT_ACTIVE); + __preempt_count_sub(PREEMPT_ACTIVE); /* * Check again in case we missed a preemption opportunity @@ -2554,11 +2554,11 @@ asmlinkage void __sched preempt_schedule_irq(void) prev_state = exception_enter(); do { - add_preempt_count(PREEMPT_ACTIVE); + __preempt_count_add(PREEMPT_ACTIVE); local_irq_enable(); __schedule(); local_irq_disable(); - sub_preempt_count(PREEMPT_ACTIVE); + __preempt_count_sub(PREEMPT_ACTIVE); /* * Check again in case we missed a preemption opportunity @@ -3798,16 +3798,11 @@ SYSCALL_DEFINE0(sched_yield) return 0; } -static inline int should_resched(void) -{ - return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); -} - static void __cond_resched(void) { - add_preempt_count(PREEMPT_ACTIVE); + __preempt_count_add(PREEMPT_ACTIVE); __schedule(); - sub_preempt_count(PREEMPT_ACTIVE); + __preempt_count_sub(PREEMPT_ACTIVE); } int __sched _cond_resched(void) diff --git a/kernel/softirq.c b/kernel/softirq.c index a90de70cf1f3..3e88612fc87e 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -100,13 +100,13 @@ static void __local_bh_disable(unsigned long ip, unsigned int cnt) raw_local_irq_save(flags); /* - * The preempt tracer hooks into add_preempt_count and will break + * The preempt tracer hooks into preempt_count_add and will break * lockdep because it calls back into lockdep after SOFTIRQ_OFFSET * is set and before current->softirq_enabled is cleared. * We must manually increment preempt_count here and manually * call the trace_preempt_off later. */ - add_preempt_count_notrace(cnt); + __preempt_count_add(cnt); /* * Were softirqs turned off above: */ @@ -120,7 +120,7 @@ static void __local_bh_disable(unsigned long ip, unsigned int cnt) #else /* !CONFIG_TRACE_IRQFLAGS */ static inline void __local_bh_disable(unsigned long ip, unsigned int cnt) { - add_preempt_count(cnt); + preempt_count_add(cnt); barrier(); } #endif /* CONFIG_TRACE_IRQFLAGS */ @@ -139,7 +139,7 @@ static void __local_bh_enable(unsigned int cnt) if (softirq_count() == cnt) trace_softirqs_on(_RET_IP_); - sub_preempt_count(cnt); + preempt_count_sub(cnt); } /* @@ -169,12 +169,12 @@ static inline void _local_bh_enable_ip(unsigned long ip) * Keep preemption disabled until we are done with * softirq processing: */ - sub_preempt_count(SOFTIRQ_DISABLE_OFFSET - 1); + preempt_count_sub(SOFTIRQ_DISABLE_OFFSET - 1); if (unlikely(!in_interrupt() && local_softirq_pending())) do_softirq(); - dec_preempt_count(); + preempt_count_dec(); #ifdef CONFIG_TRACE_IRQFLAGS local_irq_enable(); #endif @@ -360,7 +360,7 @@ void irq_exit(void) account_irq_exit_time(current); trace_hardirq_exit(); - sub_preempt_count(HARDIRQ_OFFSET); + preempt_count_sub(HARDIRQ_OFFSET); if (!in_interrupt() && local_softirq_pending()) invoke_softirq(); -- cgit v1.3-14-g43fede From 1a338ac32ca630f67df25b4a16436cccc314e997 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 14 Aug 2013 14:51:00 +0200 Subject: sched, x86: Optimize the preempt_schedule() call Remove the bloat of the C calling convention out of the preempt_enable() sites by creating an ASM wrapper which allows us to do an asm("call ___preempt_schedule") instead. calling.h bits by Andi Kleen Suggested-by: Linus Torvalds Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-tk7xdi1cvvxewixzke8t8le1@git.kernel.org [ Fixed build error. ] Signed-off-by: Ingo Molnar --- arch/x86/include/asm/calling.h | 50 ++++++++++++++++++++++++++++++++++++++++ arch/x86/include/asm/preempt.h | 10 ++++++++ arch/x86/kernel/Makefile | 2 ++ arch/x86/kernel/i386_ksyms_32.c | 7 ++++++ arch/x86/kernel/preempt.S | 25 ++++++++++++++++++++ arch/x86/kernel/x8664_ksyms_64.c | 7 ++++++ include/asm-generic/preempt.h | 10 ++++++++ include/linux/preempt.h | 13 ++++------- 8 files changed, 116 insertions(+), 8 deletions(-) create mode 100644 arch/x86/kernel/preempt.S (limited to 'include/asm-generic') diff --git a/arch/x86/include/asm/calling.h b/arch/x86/include/asm/calling.h index 0fa675033912..cb4c73bfeb48 100644 --- a/arch/x86/include/asm/calling.h +++ b/arch/x86/include/asm/calling.h @@ -48,6 +48,8 @@ For 32-bit we have the following conventions - kernel is built with #include +#ifdef CONFIG_X86_64 + /* * 64-bit system call stack frame layout defines and helpers, * for assembly code: @@ -192,3 +194,51 @@ For 32-bit we have the following conventions - kernel is built with .macro icebp .byte 0xf1 .endm + +#else /* CONFIG_X86_64 */ + +/* + * For 32bit only simplified versions of SAVE_ALL/RESTORE_ALL. These + * are different from the entry_32.S versions in not changing the segment + * registers. So only suitable for in kernel use, not when transitioning + * from or to user space. The resulting stack frame is not a standard + * pt_regs frame. The main use case is calling C code from assembler + * when all the registers need to be preserved. + */ + + .macro SAVE_ALL + pushl_cfi %eax + CFI_REL_OFFSET eax, 0 + pushl_cfi %ebp + CFI_REL_OFFSET ebp, 0 + pushl_cfi %edi + CFI_REL_OFFSET edi, 0 + pushl_cfi %esi + CFI_REL_OFFSET esi, 0 + pushl_cfi %edx + CFI_REL_OFFSET edx, 0 + pushl_cfi %ecx + CFI_REL_OFFSET ecx, 0 + pushl_cfi %ebx + CFI_REL_OFFSET ebx, 0 + .endm + + .macro RESTORE_ALL + popl_cfi %ebx + CFI_RESTORE ebx + popl_cfi %ecx + CFI_RESTORE ecx + popl_cfi %edx + CFI_RESTORE edx + popl_cfi %esi + CFI_RESTORE esi + popl_cfi %edi + CFI_RESTORE edi + popl_cfi %ebp + CFI_RESTORE ebp + popl_cfi %eax + CFI_RESTORE eax + .endm + +#endif /* CONFIG_X86_64 */ + diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h index 1309942b95e5..1de41690ff99 100644 --- a/arch/x86/include/asm/preempt.h +++ b/arch/x86/include/asm/preempt.h @@ -95,4 +95,14 @@ static __always_inline bool should_resched(void) return unlikely(!__this_cpu_read_4(__preempt_count)); } +#ifdef CONFIG_PREEMPT + extern asmlinkage void ___preempt_schedule(void); +# define __preempt_schedule() asm ("call ___preempt_schedule") + extern asmlinkage void preempt_schedule(void); +# ifdef CONFIG_CONTEXT_TRACKING + extern asmlinkage void ___preempt_schedule_context(void); +# define __preempt_schedule_context() asm ("call ___preempt_schedule_context") +# endif +#endif + #endif /* __ASM_PREEMPT_H */ diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index a5408b965c9d..9b0a34e2cd79 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -36,6 +36,8 @@ obj-y += tsc.o io_delay.o rtc.o obj-y += pci-iommu_table.o obj-y += resource.o +obj-$(CONFIG_PREEMPT) += preempt.o + obj-y += process.o obj-y += i387.o xsave.o obj-y += ptrace.o diff --git a/arch/x86/kernel/i386_ksyms_32.c b/arch/x86/kernel/i386_ksyms_32.c index 0fa69127209a..05fd74f537d6 100644 --- a/arch/x86/kernel/i386_ksyms_32.c +++ b/arch/x86/kernel/i386_ksyms_32.c @@ -37,3 +37,10 @@ EXPORT_SYMBOL(strstr); EXPORT_SYMBOL(csum_partial); EXPORT_SYMBOL(empty_zero_page); + +#ifdef CONFIG_PREEMPT +EXPORT_SYMBOL(___preempt_schedule); +#ifdef CONFIG_CONTEXT_TRACKING +EXPORT_SYMBOL(___preempt_schedule_context); +#endif +#endif diff --git a/arch/x86/kernel/preempt.S b/arch/x86/kernel/preempt.S new file mode 100644 index 000000000000..ca7f0d58a87d --- /dev/null +++ b/arch/x86/kernel/preempt.S @@ -0,0 +1,25 @@ + +#include +#include +#include +#include + +ENTRY(___preempt_schedule) + CFI_STARTPROC + SAVE_ALL + call preempt_schedule + RESTORE_ALL + ret + CFI_ENDPROC + +#ifdef CONFIG_CONTEXT_TRACKING + +ENTRY(___preempt_schedule_context) + CFI_STARTPROC + SAVE_ALL + call preempt_schedule_context + RESTORE_ALL + ret + CFI_ENDPROC + +#endif diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c index b014d9414d08..040681928e9d 100644 --- a/arch/x86/kernel/x8664_ksyms_64.c +++ b/arch/x86/kernel/x8664_ksyms_64.c @@ -66,3 +66,10 @@ EXPORT_SYMBOL(empty_zero_page); #ifndef CONFIG_PARAVIRT EXPORT_SYMBOL(native_load_gs_index); #endif + +#ifdef CONFIG_PREEMPT +EXPORT_SYMBOL(___preempt_schedule); +#ifdef CONFIG_CONTEXT_TRACKING +EXPORT_SYMBOL(___preempt_schedule_context); +#endif +#endif diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h index 82d958fc3823..5dc14ed3791c 100644 --- a/include/asm-generic/preempt.h +++ b/include/asm-generic/preempt.h @@ -100,4 +100,14 @@ static __always_inline bool should_resched(void) return unlikely(!*preempt_count_ptr()); } +#ifdef CONFIG_PREEMPT +extern asmlinkage void preempt_schedule(void); +#define __preempt_schedule() preempt_schedule() + +#ifdef CONFIG_CONTEXT_TRACKING +extern asmlinkage void preempt_schedule_context(void); +#define __preempt_schedule_context() preempt_schedule_context() +#endif +#endif /* CONFIG_PREEMPT */ + #endif /* __ASM_PREEMPT_H */ diff --git a/include/linux/preempt.h b/include/linux/preempt.h index 2343d8715299..a3d9dc8c2c00 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -50,18 +50,17 @@ do { \ #define preempt_enable_no_resched() sched_preempt_enable_no_resched() #ifdef CONFIG_PREEMPT -asmlinkage void preempt_schedule(void); #define preempt_enable() \ do { \ barrier(); \ if (unlikely(preempt_count_dec_and_test())) \ - preempt_schedule(); \ + __preempt_schedule(); \ } while (0) #define preempt_check_resched() \ do { \ if (should_resched()) \ - preempt_schedule(); \ + __preempt_schedule(); \ } while (0) #else @@ -83,17 +82,15 @@ do { \ #ifdef CONFIG_PREEMPT -#ifdef CONFIG_CONTEXT_TRACKING -asmlinkage void preempt_schedule_context(void); -#else -#define preempt_schedule_context() preempt_schedule() +#ifndef CONFIG_CONTEXT_TRACKING +#define __preempt_schedule_context() __preempt_schedule() #endif #define preempt_enable_notrace() \ do { \ barrier(); \ if (unlikely(__preempt_count_dec_and_test())) \ - preempt_schedule_context(); \ + __preempt_schedule_context(); \ } while (0) #else #define preempt_enable_notrace() preempt_enable_no_resched_notrace() -- cgit v1.3-14-g43fede From 75f93fed50c2abadbab6ef546b265f51ca975b27 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 27 Sep 2013 17:30:03 +0200 Subject: sched: Revert need_resched() to look at TIF_NEED_RESCHED Yuanhan reported a serious throughput regression in his pigz benchmark. Using the ftrace patch I found that several idle paths need more TLC before we can switch the generic need_resched() over to preempt_need_resched. The preemption paths benefit most from preempt_need_resched and do indeed use it; all other need_resched() users don't really care that much so reverting need_resched() back to tif_need_resched() is the simple and safe solution. Reported-by: Yuanhan Liu Signed-off-by: Peter Zijlstra Cc: Fengguang Wu Cc: Huang Ying Cc: lkp@linux.intel.com Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20130927153003.GF15690@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar --- arch/x86/include/asm/preempt.h | 8 -------- include/asm-generic/preempt.h | 8 -------- include/linux/sched.h | 5 +++++ 3 files changed, 5 insertions(+), 16 deletions(-) (limited to 'include/asm-generic') diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h index 1de41690ff99..8729723636fd 100644 --- a/arch/x86/include/asm/preempt.h +++ b/arch/x86/include/asm/preempt.h @@ -79,14 +79,6 @@ static __always_inline bool __preempt_count_dec_and_test(void) GEN_UNARY_RMWcc("decl", __preempt_count, __percpu_arg(0), "e"); } -/* - * Returns true when we need to resched -- even if we can not. - */ -static __always_inline bool need_resched(void) -{ - return unlikely(test_preempt_need_resched()); -} - /* * Returns true when we need to resched and can (barring IRQ state). */ diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h index 5dc14ed3791c..ddf2b420ac8f 100644 --- a/include/asm-generic/preempt.h +++ b/include/asm-generic/preempt.h @@ -84,14 +84,6 @@ static __always_inline bool __preempt_count_dec_and_test(void) return !--*preempt_count_ptr(); } -/* - * Returns true when we need to resched -- even if we can not. - */ -static __always_inline bool need_resched(void) -{ - return unlikely(test_preempt_need_resched()); -} - /* * Returns true when we need to resched and can (barring IRQ state). */ diff --git a/include/linux/sched.h b/include/linux/sched.h index b09798b672f3..2ac5285db434 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2577,6 +2577,11 @@ static inline bool __must_check current_clr_polling_and_test(void) } #endif +static __always_inline bool need_resched(void) +{ + return unlikely(tif_need_resched()); +} + /* * Thread group CPU time accounting. */ -- cgit v1.3-14-g43fede From 1a49123b34346154ffd70f0b60dce007f1605676 Mon Sep 17 00:00:00 2001 From: Zhang Yanfei Date: Thu, 3 Oct 2013 19:38:14 +0800 Subject: __page_to_pfn: Fix typo in comment Fix typo in __page_to_pfn comment: s/encorded/encoded. Signed-off-by: Zhang Yanfei Signed-off-by: Jiri Kosina --- include/asm-generic/memory_model.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/asm-generic') diff --git a/include/asm-generic/memory_model.h b/include/asm-generic/memory_model.h index aea9e45efce6..14909b0b9cae 100644 --- a/include/asm-generic/memory_model.h +++ b/include/asm-generic/memory_model.h @@ -53,7 +53,7 @@ #elif defined(CONFIG_SPARSEMEM) /* - * Note: section's mem_map is encorded to reflect its start_pfn. + * Note: section's mem_map is encoded to reflect its start_pfn. * section[i].section_mem_map == mem_map's address - start_pfn; */ #define __page_to_pfn(pg) \ -- cgit v1.3-14-g43fede From d468bf9ecaabd3bf3a6134e5a369ced82b1d1ca1 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Tue, 24 Sep 2013 11:54:38 +0200 Subject: gpio: add API to be strict about GPIO IRQ usage It is currently often possible in many GPIO drivers to request a GPIO line to be used as IRQ after calling gpio_to_irq() and, as the gpiolib is not aware of this, set the same line to output and start driving it, with undesired side effects. As it is a bogus usage scenario to request a line flagged as output to used as IRQ, we introduce APIs to let gpiolib track the use of a line as IRQ, and also set this flag from the userspace ABI. The API is symmetric so that lines can also be flagged from .irq_enable() and unflagged from IRQ by .irq_disable(). The debugfs file is altered so that we see if a line is reserved for IRQ. Cc: Enric Balletbo i Serra Cc: Grant Likely Cc: Jean-Christophe PLAGNIOL-VILLARD Cc: Santosh Shilimkar Acked-by: Alexandre Courbot Reviewed-by: Stephen Warren Reviewed-by: Javier Martinez Canillas Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 88 ++++++++++++++++++++++++++++++++++++++++++++-- include/asm-generic/gpio.h | 3 ++ include/linux/gpio.h | 12 +++++++ 3 files changed, 101 insertions(+), 2 deletions(-) (limited to 'include/asm-generic') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4fc28603a742..1014cb5e10b0 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -60,6 +60,7 @@ struct gpio_desc { #define FLAG_ACTIVE_LOW 6 /* sysfs value has active low */ #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ +#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ #define ID_SHIFT 16 /* add new flags before this one */ @@ -96,6 +97,8 @@ static int gpiod_get_value(const struct gpio_desc *desc); static void gpiod_set_value(struct gpio_desc *desc, int value); static int gpiod_cansleep(const struct gpio_desc *desc); static int gpiod_to_irq(const struct gpio_desc *desc); +static int gpiod_lock_as_irq(struct gpio_desc *desc); +static void gpiod_unlock_as_irq(struct gpio_desc *desc); static int gpiod_export(struct gpio_desc *desc, bool direction_may_change); static int gpiod_export_link(struct device *dev, const char *name, struct gpio_desc *desc); @@ -162,6 +165,17 @@ static struct gpio_desc *gpio_to_desc(unsigned gpio) return &gpio_desc[gpio]; } +/** + * Convert an offset on a certain chip to a corresponding descriptor + */ +static struct gpio_desc *gpiochip_offset_to_desc(struct gpio_chip *chip, + unsigned int offset) +{ + unsigned int gpio = chip->base + offset; + + return gpio_to_desc(gpio); +} + /** * Convert a GPIO descriptor to the integer namespace. * This should disappear in the future but is needed since we still @@ -428,6 +442,7 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, desc->flags &= ~GPIO_TRIGGER_MASK; if (!gpio_flags) { + gpiod_unlock_as_irq(desc); ret = 0; goto free_id; } @@ -466,6 +481,12 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, if (ret < 0) goto free_id; + ret = gpiod_lock_as_irq(desc); + if (ret < 0) { + gpiod_warn(desc, "failed to flag the GPIO for IRQ\n"); + goto free_id; + } + desc->flags |= gpio_flags; return 0; @@ -1730,6 +1751,14 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value) return -EINVAL; } + /* GPIOs used for IRQs shall not be set as output */ + if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) { + gpiod_err(desc, + "%s: tried to set a GPIO tied to an IRQ as output\n", + __func__); + return -EIO; + } + /* Open drain pin should not be driven to 1 */ if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags)) return gpiod_direction_input(desc); @@ -2050,6 +2079,58 @@ int __gpio_to_irq(unsigned gpio) } EXPORT_SYMBOL_GPL(__gpio_to_irq); +/** + * gpiod_lock_as_irq() - lock a GPIO to be used as IRQ + * @gpio: the GPIO line to lock as used for IRQ + * + * This is used directly by GPIO drivers that want to lock down + * a certain GPIO line to be used as IRQs, for example in the + * .to_irq() callback of their gpio_chip, or in the .irq_enable() + * of its irq_chip implementation if the GPIO is known from that + * code. + */ +static int gpiod_lock_as_irq(struct gpio_desc *desc) +{ + if (!desc) + return -EINVAL; + + if (test_bit(FLAG_IS_OUT, &desc->flags)) { + gpiod_err(desc, + "%s: tried to flag a GPIO set as output for IRQ\n", + __func__); + return -EIO; + } + + set_bit(FLAG_USED_AS_IRQ, &desc->flags); + return 0; +} + +int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset) +{ + return gpiod_lock_as_irq(gpiochip_offset_to_desc(chip, offset)); +} +EXPORT_SYMBOL_GPL(gpio_lock_as_irq); + +/** + * gpiod_unlock_as_irq() - unlock a GPIO used as IRQ + * @gpio: the GPIO line to unlock from IRQ usage + * + * This is used directly by GPIO drivers that want to indicate + * that a certain GPIO is no longer used exclusively for IRQ. + */ +static void gpiod_unlock_as_irq(struct gpio_desc *desc) +{ + if (!desc) + return; + + clear_bit(FLAG_USED_AS_IRQ, &desc->flags); +} + +void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) +{ + return gpiod_unlock_as_irq(gpiochip_offset_to_desc(chip, offset)); +} +EXPORT_SYMBOL_GPL(gpio_unlock_as_irq); /* There's no value in making it easy to inline GPIO calls that may sleep. * Common examples include ones connected to I2C or SPI chips. @@ -2091,6 +2172,7 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) unsigned gpio = chip->base; struct gpio_desc *gdesc = &chip->desc[0]; int is_out; + int is_irq; for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) @@ -2098,12 +2180,14 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) gpiod_get_direction(gdesc); is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); - seq_printf(s, " gpio-%-3d (%-20.20s) %s %s", + is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags); + seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s", gpio, gdesc->label, is_out ? "out" : "in ", chip->get ? (chip->get(chip, i) ? "hi" : "lo") - : "? "); + : "? ", + is_irq ? "IRQ" : " "); seq_printf(s, "\n"); } } diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index bde646995d10..b309a5c0019e 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -192,6 +192,9 @@ extern int __gpio_cansleep(unsigned gpio); extern int __gpio_to_irq(unsigned gpio); +extern int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset); +extern void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset); + extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); extern int gpio_request_array(const struct gpio *array, size_t num); extern void gpio_free_array(const struct gpio *array, size_t num); diff --git a/include/linux/gpio.h b/include/linux/gpio.h index 552e3f46e4a3..a06ec3e85ba3 100644 --- a/include/linux/gpio.h +++ b/include/linux/gpio.h @@ -204,6 +204,18 @@ static inline int gpio_to_irq(unsigned gpio) return -EINVAL; } +static inline int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset) +{ + WARN_ON(1); + return -EINVAL; +} + +static inline void gpio_unlock_as_irq(struct gpio_chip *chip, + unsigned int offset) +{ + WARN_ON(1); +} + static inline int irq_to_gpio(unsigned irq) { /* irq can never have been returned from gpio_to_irq() */ -- cgit v1.3-14-g43fede From 586a87e6edc936d6d3c3585af504b33b9c3f0a06 Mon Sep 17 00:00:00 2001 From: Christian Ruppert Date: Tue, 15 Oct 2013 15:37:54 +0200 Subject: pinctrl/gpio: non-linear GPIO ranges accesible from gpiolib This patch adds the infrastructure required to register non-linear gpio ranges through gpiolib and the standard GPIO device tree bindings. Signed-off-by: Christian Ruppert Signed-off-by: Linus Walleij --- Documentation/devicetree/bindings/gpio/gpio.txt | 40 +++++++++++++++- drivers/gpio/gpiolib-of.c | 63 +++++++++++++++++++++---- drivers/gpio/gpiolib.c | 47 ++++++++++++++++++ drivers/pinctrl/core.c | 14 ++++++ include/asm-generic/gpio.h | 10 ++++ include/linux/gpio.h | 10 ++++ include/linux/pinctrl/pinctrl.h | 3 ++ 7 files changed, 177 insertions(+), 10 deletions(-) (limited to 'include/asm-generic') diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt index 6cec6ff20d2e..0c85bb6e3a80 100644 --- a/Documentation/devicetree/bindings/gpio/gpio.txt +++ b/Documentation/devicetree/bindings/gpio/gpio.txt @@ -87,8 +87,10 @@ controllers. The gpio-ranges property described below represents this, and contains information structures as follows: gpio-range-list ::= [gpio-range-list] - single-gpio-range ::= + single-gpio-range ::= | + numeric-gpio-range ::= + named-gpio-range ::= '<0 0>' gpio-phandle : phandle to pin controller node. gpio-base : Base GPIO ID in the GPIO controller pinctrl-base : Base pinctrl pin ID in the pin controller @@ -97,6 +99,19 @@ contains information structures as follows: The "pin controller node" mentioned above must conform to the bindings described in ../pinctrl/pinctrl-bindings.txt. +In case named gpio ranges are used (ranges with both and + set to 0), the property gpio-ranges-group-names contains one string +for every single-gpio-range in gpio-ranges: + gpiorange-names-list ::= [gpiorange-names-list] + gpiorange-name : Name of the pingroup associated to the GPIO range in + the respective pin controller. + +Elements of gpiorange-names-list corresponding to numeric ranges contain +the empty string. Elements of gpiorange-names-list corresponding to named +ranges contain the name of a pin group defined in the respective pin +controller. The number of pins/GPIOs in the range is the number of pins in +that pin group. + Previous versions of this binding required all pin controller nodes that were referenced by any gpio-ranges property to contain a property named #gpio-range-cells with value <3>. This requirement is now deprecated. @@ -104,7 +119,7 @@ However, that property may still exist in older device trees for compatibility reasons, and would still be required even in new device trees that need to be compatible with older software. -Example: +Example 1: qe_pio_e: gpio-controller@1460 { #gpio-cells = <2>; @@ -117,3 +132,24 @@ Example: Here, a single GPIO controller has GPIOs 0..9 routed to pin controller pinctrl1's pins 20..29, and GPIOs 10..19 routed to pin controller pinctrl2's pins 50..59. + +Example 2: + + gpio_pio_i: gpio-controller@14B0 { + #gpio-cells = <2>; + compatible = "fsl,qe-pario-bank-e", "fsl,qe-pario-bank"; + reg = <0x1480 0x18>; + gpio-controller; + gpio-ranges = <&pinctrl1 0 20 10>, + <&pinctrl2 10 0 0>, + <&pinctrl1 15 0 10>, + <&pinctrl2 25 0 0>; + gpio-ranges-group-names = "", + "foo", + "", + "bar"; + }; + +Here, three GPIO ranges are defined wrt. two pin controllers. pinctrl1 GPIO +ranges are defined using pin numbers whereas the GPIO ranges wrt. pinctrl2 +are named "foo" and "bar". diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 0dfaf20e4dad..e78760921bd7 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -190,10 +190,15 @@ static void of_gpiochip_add_pin_range(struct gpio_chip *chip) struct of_phandle_args pinspec; struct pinctrl_dev *pctldev; int index = 0, ret; + const char *name; + static const char group_names_propname[] = "gpio-ranges-group-names"; + struct property *group_names; if (!np) return; + group_names = of_find_property(np, group_names_propname, NULL); + for (;; index++) { ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, index, &pinspec); @@ -204,14 +209,56 @@ static void of_gpiochip_add_pin_range(struct gpio_chip *chip) if (!pctldev) break; - ret = gpiochip_add_pin_range(chip, - pinctrl_dev_get_devname(pctldev), - pinspec.args[0], - pinspec.args[1], - pinspec.args[2]); - - if (ret) - break; + if (pinspec.args[2]) { + if (group_names) { + ret = of_property_read_string_index(np, + group_names_propname, + index, &name); + if (strlen(name)) { + pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n", + np->full_name); + break; + } + } + /* npins != 0: linear range */ + ret = gpiochip_add_pin_range(chip, + pinctrl_dev_get_devname(pctldev), + pinspec.args[0], + pinspec.args[1], + pinspec.args[2]); + if (ret) + break; + } else { + /* npins == 0: special range */ + if (pinspec.args[1]) { + pr_err("%s: Illegal gpio-range format.\n", + np->full_name); + break; + } + + if (!group_names) { + pr_err("%s: GPIO group range requested but no %s property.\n", + np->full_name, group_names_propname); + break; + } + + ret = of_property_read_string_index(np, + group_names_propname, + index, &name); + if (ret) + break; + + if (!strlen(name)) { + pr_err("%s: Group name of GPIO group range cannot be the empty string.\n", + np->full_name); + break; + } + + ret = gpiochip_add_pingroup_range(chip, pctldev, + pinspec.args[0], name); + if (ret) + break; + } } } diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 86ef3461ec06..b83b7e491f76 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1319,6 +1319,53 @@ EXPORT_SYMBOL_GPL(gpiochip_find); #ifdef CONFIG_PINCTRL +/** + * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping + * @chip: the gpiochip to add the range for + * @pinctrl: the dev_name() of the pin controller to map to + * @gpio_offset: the start offset in the current gpio_chip number space + * @pin_group: name of the pin group inside the pin controller + */ +int gpiochip_add_pingroup_range(struct gpio_chip *chip, + struct pinctrl_dev *pctldev, + unsigned int gpio_offset, const char *pin_group) +{ + struct gpio_pin_range *pin_range; + int ret; + + pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); + if (!pin_range) { + pr_err("%s: GPIO chip: failed to allocate pin ranges\n", + chip->label); + return -ENOMEM; + } + + /* Use local offset as range ID */ + pin_range->range.id = gpio_offset; + pin_range->range.gc = chip; + pin_range->range.name = chip->label; + pin_range->range.base = chip->base + gpio_offset; + pin_range->pctldev = pctldev; + + ret = pinctrl_get_group_pins(pctldev, pin_group, + &pin_range->range.pins, + &pin_range->range.npins); + if (ret < 0) + return ret; + + pinctrl_add_gpio_range(pctldev, &pin_range->range); + + pr_debug("GPIO chip %s: created GPIO range %d->%d ==> %s PINGRP %s\n", + chip->label, gpio_offset, + gpio_offset + pin_range->range.npins - 1, + pinctrl_dev_get_devname(pctldev), pin_group); + + list_add_tail(&pin_range->node, &chip->pin_ranges); + + return 0; +} +EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range); + /** * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping * @chip: the gpiochip to add the range for diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index 92f86ab30a13..5ee61a470016 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -462,6 +462,20 @@ struct pinctrl_dev *pinctrl_find_and_add_gpio_range(const char *devname, } EXPORT_SYMBOL_GPL(pinctrl_find_and_add_gpio_range); +int pinctrl_get_group_pins(struct pinctrl_dev *pctldev, const char *pin_group, + const unsigned **pins, unsigned *num_pins) +{ + const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; + int gs; + + gs = pinctrl_get_group_selector(pctldev, pin_group); + if (gs < 0) + return gs; + + return pctlops->get_group_pins(pctldev, gs, pins, num_pins); +} +EXPORT_SYMBOL_GPL(pinctrl_get_group_pins); + /** * pinctrl_find_gpio_range_from_pin() - locate the GPIO range for a pin * @pctldev: the pin controller device to look in diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index bde646995d10..523f40525535 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -228,6 +228,9 @@ struct gpio_pin_range { int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, unsigned int gpio_offset, unsigned int pin_offset, unsigned int npins); +int gpiochip_add_pingroup_range(struct gpio_chip *chip, + struct pinctrl_dev *pctldev, + unsigned int gpio_offset, const char *pin_group); void gpiochip_remove_pin_ranges(struct gpio_chip *chip); #else @@ -239,6 +242,13 @@ gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, { return 0; } +static inline int +gpiochip_add_pingroup_range(struct gpio_chip *chip, + struct pinctrl_dev *pctldev, + unsigned int gpio_offset, const char *pin_group) +{ + return 0; +} static inline void gpiochip_remove_pin_ranges(struct gpio_chip *chip) diff --git a/include/linux/gpio.h b/include/linux/gpio.h index 552e3f46e4a3..b8d0e53a802f 100644 --- a/include/linux/gpio.h +++ b/include/linux/gpio.h @@ -80,6 +80,7 @@ static inline int irq_to_gpio(unsigned int irq) #include #include #include +#include struct device; struct gpio_chip; @@ -220,6 +221,15 @@ gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, return -EINVAL; } +static inline int +gpiochip_add_pingroup_range(struct gpio_chip *chip, + struct pinctrl_dev *pctldev, + unsigned int gpio_offset, const char *pin_group) +{ + WARN_ON(1); + return -EINVAL; +} + static inline void gpiochip_remove_pin_ranges(struct gpio_chip *chip) { diff --git a/include/linux/pinctrl/pinctrl.h b/include/linux/pinctrl/pinctrl.h index 5979147d2bda..fefb88663975 100644 --- a/include/linux/pinctrl/pinctrl.h +++ b/include/linux/pinctrl/pinctrl.h @@ -144,6 +144,9 @@ extern struct pinctrl_dev *pinctrl_find_and_add_gpio_range(const char *devname, extern struct pinctrl_gpio_range * pinctrl_find_gpio_range_from_pin(struct pinctrl_dev *pctldev, unsigned int pin); +extern int pinctrl_get_group_pins(struct pinctrl_dev *pctldev, + const char *pin_group, const unsigned **pins, + unsigned *num_pins); #ifdef CONFIG_OF extern struct pinctrl_dev *of_pinctrl_get(struct device_node *np); -- cgit v1.3-14-g43fede From eb3057df732c304622aee77c450761746939a2dc Mon Sep 17 00:00:00 2001 From: Frantisek Hrbata Date: Mon, 14 Oct 2013 18:08:46 +1030 Subject: kernel: add support for init_array constructors This adds the .init_array section as yet another section with constructors. This is needed because gcc could add __gcov_init calls to .init_array or .ctors section, depending on gcc (and binutils) version . v2: - reuse mod->ctors for .init_array section for modules, because gcc uses .ctors or .init_array, but not both at the same time v3: - fail to load if that does happen somehow. Signed-off-by: Frantisek Hrbata Signed-off-by: Rusty Russell --- include/asm-generic/vmlinux.lds.h | 1 + kernel/module.c | 20 ++++++++++++++++++-- 2 files changed, 19 insertions(+), 2 deletions(-) (limited to 'include/asm-generic') diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 83e2c31e8b00..bc2121fa9132 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -473,6 +473,7 @@ #define KERNEL_CTORS() . = ALIGN(8); \ VMLINUX_SYMBOL(__ctors_start) = .; \ *(.ctors) \ + *(.init_array) \ VMLINUX_SYMBOL(__ctors_end) = .; #else #define KERNEL_CTORS() diff --git a/kernel/module.c b/kernel/module.c index 947105fd4cab..5c9cf84017d5 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2708,7 +2708,7 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags) return 0; } -static void find_module_sections(struct module *mod, struct load_info *info) +static int find_module_sections(struct module *mod, struct load_info *info) { mod->kp = section_objs(info, "__param", sizeof(*mod->kp), &mod->num_kp); @@ -2738,6 +2738,18 @@ static void find_module_sections(struct module *mod, struct load_info *info) #ifdef CONFIG_CONSTRUCTORS mod->ctors = section_objs(info, ".ctors", sizeof(*mod->ctors), &mod->num_ctors); + if (!mod->ctors) + mod->ctors = section_objs(info, ".init_array", + sizeof(*mod->ctors), &mod->num_ctors); + else if (find_sec(info, ".init_array")) { + /* + * This shouldn't happen with same compiler and binutils + * building all parts of the module. + */ + printk(KERN_WARNING "%s: has both .ctors and .init_array.\n", + mod->name); + return -EINVAL; + } #endif #ifdef CONFIG_TRACEPOINTS @@ -2776,6 +2788,8 @@ static void find_module_sections(struct module *mod, struct load_info *info) info->debug = section_objs(info, "__verbose", sizeof(*info->debug), &info->num_debug); + + return 0; } static int move_module(struct module *mod, struct load_info *info) @@ -3233,7 +3247,9 @@ static int load_module(struct load_info *info, const char __user *uargs, /* Now we've got everything in the final locations, we can * find optional sections. */ - find_module_sections(mod, info); + err = find_module_sections(mod, info); + if (err) + goto free_unload; err = check_module_license_and_versions(mod); if (err) -- cgit v1.3-14-g43fede From 79a9becda8940deb2274b5aa4577c86d52ee7ecb Mon Sep 17 00:00:00 2001 From: Alexandre Courbot Date: Thu, 17 Oct 2013 10:21:36 -0700 Subject: gpiolib: export descriptor-based GPIO interface This patch exports the gpiod_* family of API functions, a safer alternative to the legacy GPIO interface. Differences between the gpiod and legacy gpio APIs are: - gpio works with integers, whereas gpiod operates on opaque handlers which cannot be forged or used before proper acquisition - gpiod get/set functions are aware of the active low state of a GPIO - gpio consumers should now include to access the new interface, whereas chips drivers will use The legacy gpio API is now built as inline functions on top of gpiod. Signed-off-by: Alexandre Courbot Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 422 ++++++++++++++++++++++-------------------- include/asm-generic/gpio.h | 222 +++++++--------------- include/linux/gpio.h | 11 +- include/linux/gpio/consumer.h | 238 ++++++++++++++++++++++++ include/linux/gpio/driver.h | 127 +++++++++++++ 5 files changed, 658 insertions(+), 362 deletions(-) create mode 100644 include/linux/gpio/consumer.h create mode 100644 include/linux/gpio/driver.h (limited to 'include/asm-generic') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d66139dc410d..224abdc4b095 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -16,16 +16,11 @@ #define CREATE_TRACE_POINTS #include -/* Optional implementation infrastructure for GPIO interfaces. +/* Implementation infrastructure for GPIO interfaces. * - * Platforms may want to use this if they tend to use very many GPIOs - * that aren't part of a System-On-Chip core; or across I2C/SPI/etc. - * - * When kernel footprint or instruction count is an issue, simpler - * implementations may be preferred. The GPIO programming interface - * allows for inlining speed-critical get/set operations for common - * cases, so that access to SOC-integrated GPIOs can sometimes cost - * only an instruction or two per bit. + * The GPIO programming interface allows for inlining speed-critical + * get/set operations for common cases, so that access to SOC-integrated + * GPIOs can sometimes cost only an instruction or two per bit. */ @@ -57,7 +52,7 @@ struct gpio_desc { #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ #define FLAG_TRIG_FALL 4 /* trigger on falling edge */ #define FLAG_TRIG_RISE 5 /* trigger on rising edge */ -#define FLAG_ACTIVE_LOW 6 /* sysfs value has active low */ +#define FLAG_ACTIVE_LOW 6 /* value has active low */ #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ @@ -81,29 +76,8 @@ static LIST_HEAD(gpio_chips); static DEFINE_IDR(dirent_idr); #endif -/* - * Internal gpiod_* API using descriptors instead of the integer namespace. - * Most of this should eventually go public. - */ static int gpiod_request(struct gpio_desc *desc, const char *label); static void gpiod_free(struct gpio_desc *desc); -static int gpiod_direction_input(struct gpio_desc *desc); -static int gpiod_direction_output(struct gpio_desc *desc, int value); -static int gpiod_get_direction(const struct gpio_desc *desc); -static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce); -static int gpiod_get_value_cansleep(const struct gpio_desc *desc); -static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value); -static int gpiod_get_value(const struct gpio_desc *desc); -static void gpiod_set_value(struct gpio_desc *desc, int value); -static int gpiod_cansleep(const struct gpio_desc *desc); -static int gpiod_to_irq(const struct gpio_desc *desc); -static int gpiod_lock_as_irq(struct gpio_desc *desc); -static void gpiod_unlock_as_irq(struct gpio_desc *desc); -static int gpiod_export(struct gpio_desc *desc, bool direction_may_change); -static int gpiod_export_link(struct device *dev, const char *name, - struct gpio_desc *desc); -static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value); -static void gpiod_unexport(struct gpio_desc *desc); #ifdef CONFIG_DEBUG_FS #define gpiod_emerg(desc, fmt, ...) \ @@ -157,13 +131,14 @@ static int gpio_chip_hwgpio(const struct gpio_desc *desc) /** * Convert a GPIO number to its descriptor */ -static struct gpio_desc *gpio_to_desc(unsigned gpio) +struct gpio_desc *gpio_to_desc(unsigned gpio) { if (WARN(!gpio_is_valid(gpio), "invalid GPIO %d\n", gpio)) return NULL; else return &gpio_desc[gpio]; } +EXPORT_SYMBOL_GPL(gpio_to_desc); /** * Convert an offset on a certain chip to a corresponding descriptor @@ -181,10 +156,11 @@ static struct gpio_desc *gpiochip_offset_to_desc(struct gpio_chip *chip, * This should disappear in the future but is needed since we still * use GPIO numbers for error messages and sysfs nodes */ -static int desc_to_gpio(const struct gpio_desc *desc) +int desc_to_gpio(const struct gpio_desc *desc) { return desc - &gpio_desc[0]; } +EXPORT_SYMBOL_GPL(desc_to_gpio); /* Warn when drivers omit gpio_request() calls -- legal but ill-advised @@ -219,16 +195,15 @@ static int gpio_ensure_requested(struct gpio_desc *desc) return 0; } -static struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) +/** + * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs + * @desc: descriptor to return the chip of + */ +struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) { return desc ? desc->chip : NULL; } - -/* caller holds gpio_lock *OR* gpio is marked as requested */ -struct gpio_chip *gpio_to_chip(unsigned gpio) -{ - return gpiod_to_chip(gpio_to_desc(gpio)); -} +EXPORT_SYMBOL_GPL(gpiod_to_chip); /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ static int gpiochip_find_base(int ngpio) @@ -254,8 +229,15 @@ static int gpiochip_find_base(int ngpio) } } -/* caller ensures gpio is valid and requested, chip->get_direction may sleep */ -static int gpiod_get_direction(const struct gpio_desc *desc) +/** + * gpiod_get_direction - return the current direction of a GPIO + * @desc: GPIO to get the direction of + * + * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error. + * + * This function may sleep if gpiod_cansleep() is true. + */ +int gpiod_get_direction(const struct gpio_desc *desc) { struct gpio_chip *chip; unsigned offset; @@ -281,6 +263,7 @@ static int gpiod_get_direction(const struct gpio_desc *desc) } return status; } +EXPORT_SYMBOL_GPL(gpiod_get_direction); #ifdef CONFIG_GPIO_SYSFS @@ -365,17 +348,10 @@ static ssize_t gpio_value_show(struct device *dev, mutex_lock(&sysfs_lock); - if (!test_bit(FLAG_EXPORT, &desc->flags)) { + if (!test_bit(FLAG_EXPORT, &desc->flags)) status = -EIO; - } else { - int value; - - value = !!gpiod_get_value_cansleep(desc); - if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) - value = !value; - - status = sprintf(buf, "%d\n", value); - } + else + status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc)); mutex_unlock(&sysfs_lock); return status; @@ -398,9 +374,7 @@ static ssize_t gpio_value_store(struct device *dev, status = kstrtol(buf, 0, &value); if (status == 0) { - if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) - value = !value; - gpiod_set_value_cansleep(desc, value != 0); + gpiod_set_value_cansleep(desc, value); status = size; } } @@ -790,7 +764,7 @@ static struct class gpio_class = { /** - * gpio_export - export a GPIO through sysfs + * gpiod_export - export a GPIO through sysfs * @gpio: gpio to make available, already requested * @direction_may_change: true if userspace may change gpio direction * Context: arch_initcall or later @@ -804,7 +778,7 @@ static struct class gpio_class = { * * Returns zero on success, else an error. */ -static int gpiod_export(struct gpio_desc *desc, bool direction_may_change) +int gpiod_export(struct gpio_desc *desc, bool direction_may_change) { unsigned long flags; int status; @@ -882,12 +856,7 @@ fail_unlock: status); return status; } - -int gpio_export(unsigned gpio, bool direction_may_change) -{ - return gpiod_export(gpio_to_desc(gpio), direction_may_change); -} -EXPORT_SYMBOL_GPL(gpio_export); +EXPORT_SYMBOL_GPL(gpiod_export); static int match_export(struct device *dev, const void *data) { @@ -895,7 +864,7 @@ static int match_export(struct device *dev, const void *data) } /** - * gpio_export_link - create a sysfs link to an exported GPIO node + * gpiod_export_link - create a sysfs link to an exported GPIO node * @dev: device under which to create symlink * @name: name of the symlink * @gpio: gpio to create symlink to, already exported @@ -905,8 +874,8 @@ static int match_export(struct device *dev, const void *data) * * Returns zero on success, else an error. */ -static int gpiod_export_link(struct device *dev, const char *name, - struct gpio_desc *desc) +int gpiod_export_link(struct device *dev, const char *name, + struct gpio_desc *desc) { int status = -EINVAL; @@ -937,15 +906,10 @@ static int gpiod_export_link(struct device *dev, const char *name, return status; } - -int gpio_export_link(struct device *dev, const char *name, unsigned gpio) -{ - return gpiod_export_link(dev, name, gpio_to_desc(gpio)); -} -EXPORT_SYMBOL_GPL(gpio_export_link); +EXPORT_SYMBOL_GPL(gpiod_export_link); /** - * gpio_sysfs_set_active_low - set the polarity of gpio sysfs value + * gpiod_sysfs_set_active_low - set the polarity of gpio sysfs value * @gpio: gpio to change * @value: non-zero to use active low, i.e. inverted values * @@ -956,7 +920,7 @@ EXPORT_SYMBOL_GPL(gpio_export_link); * * Returns zero on success, else an error. */ -static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) +int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) { struct device *dev = NULL; int status = -EINVAL; @@ -987,20 +951,15 @@ unlock: return status; } - -int gpio_sysfs_set_active_low(unsigned gpio, int value) -{ - return gpiod_sysfs_set_active_low(gpio_to_desc(gpio), value); -} -EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low); +EXPORT_SYMBOL_GPL(gpiod_sysfs_set_active_low); /** - * gpio_unexport - reverse effect of gpio_export() + * gpiod_unexport - reverse effect of gpio_export() * @gpio: gpio to make unavailable * * This is implicit on gpio_free(). */ -static void gpiod_unexport(struct gpio_desc *desc) +void gpiod_unexport(struct gpio_desc *desc) { int status = 0; struct device *dev = NULL; @@ -1033,12 +992,7 @@ static void gpiod_unexport(struct gpio_desc *desc) pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), status); } - -void gpio_unexport(unsigned gpio) -{ - gpiod_unexport(gpio_to_desc(gpio)); -} -EXPORT_SYMBOL_GPL(gpio_unexport); +EXPORT_SYMBOL_GPL(gpiod_unexport); static int gpiochip_export(struct gpio_chip *chip) { @@ -1145,27 +1099,6 @@ static inline void gpiochip_unexport(struct gpio_chip *chip) { } -static inline int gpiod_export(struct gpio_desc *desc, - bool direction_may_change) -{ - return -ENOSYS; -} - -static inline int gpiod_export_link(struct device *dev, const char *name, - struct gpio_desc *desc) -{ - return -ENOSYS; -} - -static inline int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) -{ - return -ENOSYS; -} - -static inline void gpiod_unexport(struct gpio_desc *desc) -{ -} - #endif /* CONFIG_GPIO_SYSFS */ /* @@ -1677,7 +1610,16 @@ EXPORT_SYMBOL_GPL(gpiochip_is_requested); * rely on gpio_request() having been called beforehand. */ -static int gpiod_direction_input(struct gpio_desc *desc) +/** + * gpiod_direction_input - set the GPIO direction to input + * @desc: GPIO to set to input + * + * Set the direction of the passed GPIO to input, such as gpiod_get_value() can + * be called safely on it. + * + * Return 0 in case of success, else an error code. + */ +int gpiod_direction_input(struct gpio_desc *desc) { unsigned long flags; struct gpio_chip *chip; @@ -1734,14 +1676,19 @@ fail: gpiod_dbg(desc, "%s status %d\n", __func__, status); return status; } +EXPORT_SYMBOL_GPL(gpiod_direction_input); -int gpio_direction_input(unsigned gpio) -{ - return gpiod_direction_input(gpio_to_desc(gpio)); -} -EXPORT_SYMBOL_GPL(gpio_direction_input); - -static int gpiod_direction_output(struct gpio_desc *desc, int value) +/** + * gpiod_direction_output - set the GPIO direction to input + * @desc: GPIO to set to output + * @value: initial output value of the GPIO + * + * Set the direction of the passed GPIO to output, such as gpiod_set_value() can + * be called safely on it. The initial value of the output must be specified. + * + * Return 0 in case of success, else an error code. + */ +int gpiod_direction_output(struct gpio_desc *desc, int value) { unsigned long flags; struct gpio_chip *chip; @@ -1814,22 +1761,17 @@ fail: gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status); return status; } - -int gpio_direction_output(unsigned gpio, int value) -{ - return gpiod_direction_output(gpio_to_desc(gpio), value); -} -EXPORT_SYMBOL_GPL(gpio_direction_output); +EXPORT_SYMBOL_GPL(gpiod_direction_output); /** - * gpio_set_debounce - sets @debounce time for a @gpio + * gpiod_set_debounce - sets @debounce time for a @gpio * @gpio: the gpio to set debounce time * @debounce: debounce time is microseconds * * returns -ENOTSUPP if the controller does not support setting * debounce. */ -static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) +int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) { unsigned long flags; struct gpio_chip *chip; @@ -1871,12 +1813,19 @@ fail: return status; } +EXPORT_SYMBOL_GPL(gpiod_set_debounce); -int gpio_set_debounce(unsigned gpio, unsigned debounce) +/** + * gpiod_is_active_low - test whether a GPIO is active-low or not + * @desc: the gpio descriptor to test + * + * Returns 1 if the GPIO is active-low, 0 otherwise. + */ +int gpiod_is_active_low(const struct gpio_desc *desc) { - return gpiod_set_debounce(gpio_to_desc(gpio), debounce); + return test_bit(FLAG_ACTIVE_LOW, &desc->flags); } -EXPORT_SYMBOL_GPL(gpio_set_debounce); +EXPORT_SYMBOL_GPL(gpiod_is_active_low); /* I/O calls are only valid after configuration completed; the relevant * "is this a valid GPIO" error checks should already have been done. @@ -1900,7 +1849,7 @@ EXPORT_SYMBOL_GPL(gpio_set_debounce); * that the GPIO was actually requested. */ -static int _gpiod_get_value(const struct gpio_desc *desc) +static int _gpiod_get_raw_value(const struct gpio_desc *desc) { struct gpio_chip *chip; int value; @@ -1914,33 +1863,54 @@ static int _gpiod_get_value(const struct gpio_desc *desc) } /** - * __gpio_get_value() - return a gpio's value - * @gpio: gpio whose value will be returned - * Context: any + * gpiod_get_raw_value() - return a gpio's raw value + * @desc: gpio whose value will be returned * - * This is used directly or indirectly to implement gpio_get_value(). - * It returns the zero or nonzero value provided by the associated - * gpio_chip.get() method; or zero if no such method is provided. + * Return the GPIO's raw value, i.e. the value of the physical line disregarding + * its ACTIVE_LOW status. + * + * This function should be called from contexts where we cannot sleep, and will + * complain if the GPIO chip functions potentially sleep. */ -static int gpiod_get_value(const struct gpio_desc *desc) +int gpiod_get_raw_value(const struct gpio_desc *desc) { if (!desc) return 0; /* Should be using gpio_get_value_cansleep() */ WARN_ON(desc->chip->can_sleep); - return _gpiod_get_value(desc); + return _gpiod_get_raw_value(desc); } +EXPORT_SYMBOL_GPL(gpiod_get_raw_value); -int __gpio_get_value(unsigned gpio) +/** + * gpiod_get_value() - return a gpio's value + * @desc: gpio whose value will be returned + * + * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into + * account. + * + * This function should be called from contexts where we cannot sleep, and will + * complain if the GPIO chip functions potentially sleep. + */ +int gpiod_get_value(const struct gpio_desc *desc) { - return gpiod_get_value(gpio_to_desc(gpio)); + int value; + if (!desc) + return 0; + /* Should be using gpio_get_value_cansleep() */ + WARN_ON(desc->chip->can_sleep); + + value = _gpiod_get_raw_value(desc); + if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + value = !value; + + return value; } -EXPORT_SYMBOL_GPL(__gpio_get_value); +EXPORT_SYMBOL_GPL(gpiod_get_value); /* * _gpio_set_open_drain_value() - Set the open drain gpio's value. - * @gpio: Gpio whose state need to be set. - * @chip: Gpio chip. + * @desc: gpio descriptor whose state need to be set. * @value: Non-zero for setting it HIGH otherise it will set to LOW. */ static void _gpio_set_open_drain_value(struct gpio_desc *desc, int value) @@ -1966,9 +1936,8 @@ static void _gpio_set_open_drain_value(struct gpio_desc *desc, int value) } /* - * _gpio_set_open_source() - Set the open source gpio's value. - * @gpio: Gpio whose state need to be set. - * @chip: Gpio chip. + * _gpio_set_open_source_value() - Set the open source gpio's value. + * @desc: gpio descriptor whose state need to be set. * @value: Non-zero for setting it HIGH otherise it will set to LOW. */ static void _gpio_set_open_source_value(struct gpio_desc *desc, int value) @@ -1993,7 +1962,7 @@ static void _gpio_set_open_source_value(struct gpio_desc *desc, int value) __func__, err); } -static void _gpiod_set_value(struct gpio_desc *desc, int value) +static void _gpiod_set_raw_value(struct gpio_desc *desc, int value) { struct gpio_chip *chip; @@ -2008,62 +1977,70 @@ static void _gpiod_set_value(struct gpio_desc *desc, int value) } /** - * __gpio_set_value() - assign a gpio's value - * @gpio: gpio whose value will be assigned + * gpiod_set_raw_value() - assign a gpio's raw value + * @desc: gpio whose value will be assigned * @value: value to assign - * Context: any * - * This is used directly or indirectly to implement gpio_set_value(). - * It invokes the associated gpio_chip.set() method. + * Set the raw value of the GPIO, i.e. the value of its physical line without + * regard for its ACTIVE_LOW status. + * + * This function should be called from contexts where we cannot sleep, and will + * complain if the GPIO chip functions potentially sleep. */ -static void gpiod_set_value(struct gpio_desc *desc, int value) +void gpiod_set_raw_value(struct gpio_desc *desc, int value) { - if (!desc) return; /* Should be using gpio_set_value_cansleep() */ WARN_ON(desc->chip->can_sleep); - _gpiod_set_value(desc, value); + _gpiod_set_raw_value(desc, value); } +EXPORT_SYMBOL_GPL(gpiod_set_raw_value); -void __gpio_set_value(unsigned gpio, int value) +/** + * gpiod_set_value() - assign a gpio's value + * @desc: gpio whose value will be assigned + * @value: value to assign + * + * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into + * account + * + * This function should be called from contexts where we cannot sleep, and will + * complain if the GPIO chip functions potentially sleep. + */ +void gpiod_set_value(struct gpio_desc *desc, int value) { - return gpiod_set_value(gpio_to_desc(gpio), value); + if (!desc) + return; + /* Should be using gpio_set_value_cansleep() */ + WARN_ON(desc->chip->can_sleep); + if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + value = !value; + _gpiod_set_raw_value(desc, value); } -EXPORT_SYMBOL_GPL(__gpio_set_value); +EXPORT_SYMBOL_GPL(gpiod_set_value); /** - * __gpio_cansleep() - report whether gpio value access will sleep - * @gpio: gpio in question - * Context: any + * gpiod_cansleep() - report whether gpio value access may sleep + * @desc: gpio to check * - * This is used directly or indirectly to implement gpio_cansleep(). It - * returns nonzero if access reading or writing the GPIO value can sleep. */ -static int gpiod_cansleep(const struct gpio_desc *desc) +int gpiod_cansleep(const struct gpio_desc *desc) { if (!desc) return 0; - /* only call this on GPIOs that are valid! */ return desc->chip->can_sleep; } - -int __gpio_cansleep(unsigned gpio) -{ - return gpiod_cansleep(gpio_to_desc(gpio)); -} -EXPORT_SYMBOL_GPL(__gpio_cansleep); +EXPORT_SYMBOL_GPL(gpiod_cansleep); /** - * __gpio_to_irq() - return the IRQ corresponding to a GPIO - * @gpio: gpio whose IRQ will be returned (already requested) - * Context: any + * gpiod_to_irq() - return the IRQ corresponding to a GPIO + * @desc: gpio whose IRQ will be returned (already requested) * - * This is used directly or indirectly to implement gpio_to_irq(). - * It returns the number of the IRQ signaled by this (input) GPIO, - * or a negative errno. + * Return the IRQ corresponding to the passed GPIO, or an error code in case of + * error. */ -static int gpiod_to_irq(const struct gpio_desc *desc) +int gpiod_to_irq(const struct gpio_desc *desc) { struct gpio_chip *chip; int offset; @@ -2074,12 +2051,7 @@ static int gpiod_to_irq(const struct gpio_desc *desc) offset = gpio_chip_hwgpio(desc); return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO; } - -int __gpio_to_irq(unsigned gpio) -{ - return gpiod_to_irq(gpio_to_desc(gpio)); -} -EXPORT_SYMBOL_GPL(__gpio_to_irq); +EXPORT_SYMBOL_GPL(gpiod_to_irq); /** * gpiod_lock_as_irq() - lock a GPIO to be used as IRQ @@ -2091,7 +2063,7 @@ EXPORT_SYMBOL_GPL(__gpio_to_irq); * of its irq_chip implementation if the GPIO is known from that * code. */ -static int gpiod_lock_as_irq(struct gpio_desc *desc) +int gpiod_lock_as_irq(struct gpio_desc *desc) { if (!desc) return -EINVAL; @@ -2106,6 +2078,7 @@ static int gpiod_lock_as_irq(struct gpio_desc *desc) set_bit(FLAG_USED_AS_IRQ, &desc->flags); return 0; } +EXPORT_SYMBOL_GPL(gpiod_lock_as_irq); int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset) { @@ -2120,13 +2093,14 @@ EXPORT_SYMBOL_GPL(gpio_lock_as_irq); * This is used directly by GPIO drivers that want to indicate * that a certain GPIO is no longer used exclusively for IRQ. */ -static void gpiod_unlock_as_irq(struct gpio_desc *desc) +void gpiod_unlock_as_irq(struct gpio_desc *desc) { if (!desc) return; clear_bit(FLAG_USED_AS_IRQ, &desc->flags); } +EXPORT_SYMBOL_GPL(gpiod_unlock_as_irq); void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) { @@ -2134,37 +2108,89 @@ void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) } EXPORT_SYMBOL_GPL(gpio_unlock_as_irq); -/* There's no value in making it easy to inline GPIO calls that may sleep. - * Common examples include ones connected to I2C or SPI chips. +/** + * gpiod_get_raw_value_cansleep() - return a gpio's raw value + * @desc: gpio whose value will be returned + * + * Return the GPIO's raw value, i.e. the value of the physical line disregarding + * its ACTIVE_LOW status. + * + * This function is to be called from contexts that can sleep. */ - -static int gpiod_get_value_cansleep(const struct gpio_desc *desc) +int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) { might_sleep_if(extra_checks); if (!desc) return 0; - return _gpiod_get_value(desc); + return _gpiod_get_raw_value(desc); } +EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep); -int gpio_get_value_cansleep(unsigned gpio) +/** + * gpiod_get_value_cansleep() - return a gpio's value + * @desc: gpio whose value will be returned + * + * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into + * account. + * + * This function is to be called from contexts that can sleep. + */ +int gpiod_get_value_cansleep(const struct gpio_desc *desc) { - return gpiod_get_value_cansleep(gpio_to_desc(gpio)); + int value; + + might_sleep_if(extra_checks); + if (!desc) + return 0; + + value = _gpiod_get_raw_value(desc); + if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + value = !value; + + return value; } -EXPORT_SYMBOL_GPL(gpio_get_value_cansleep); +EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep); -static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) +/** + * gpiod_set_raw_value_cansleep() - assign a gpio's raw value + * @desc: gpio whose value will be assigned + * @value: value to assign + * + * Set the raw value of the GPIO, i.e. the value of its physical line without + * regard for its ACTIVE_LOW status. + * + * This function is to be called from contexts that can sleep. + */ +void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) { might_sleep_if(extra_checks); if (!desc) return; - _gpiod_set_value(desc, value); + _gpiod_set_raw_value(desc, value); } +EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep); -void gpio_set_value_cansleep(unsigned gpio, int value) +/** + * gpiod_set_value_cansleep() - assign a gpio's value + * @desc: gpio whose value will be assigned + * @value: value to assign + * + * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into + * account + * + * This function is to be called from contexts that can sleep. + */ +void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) { - return gpiod_set_value_cansleep(gpio_to_desc(gpio), value); + might_sleep_if(extra_checks); + if (!desc) + return; + + if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + value = !value; + _gpiod_set_raw_value(desc, value); } -EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); +EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep); #ifdef CONFIG_DEBUG_FS diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index b309a5c0019e..00f8f0a9edcd 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -10,6 +10,8 @@ #ifdef CONFIG_GPIOLIB #include +#include +#include /* Platforms may implement their GPIO interface with library code, * at a small performance cost for non-inlined operations and some @@ -49,122 +51,11 @@ struct module; struct device_node; struct gpio_desc; -/** - * struct gpio_chip - abstract a GPIO controller - * @label: for diagnostics - * @dev: optional device providing the GPIOs - * @owner: helps prevent removal of modules exporting active GPIOs - * @list: links gpio_chips together for traversal - * @request: optional hook for chip-specific activation, such as - * enabling module power and clock; may sleep - * @free: optional hook for chip-specific deactivation, such as - * disabling module power and clock; may sleep - * @get_direction: returns direction for signal "offset", 0=out, 1=in, - * (same as GPIOF_DIR_XXX), or negative error - * @direction_input: configures signal "offset" as input, or returns error - * @get: returns value for signal "offset"; for output signals this - * returns either the value actually sensed, or zero - * @direction_output: configures signal "offset" as output, or returns error - * @set_debounce: optional hook for setting debounce time for specified gpio in - * interrupt triggered gpio chips - * @set: assigns output value for signal "offset" - * @to_irq: optional hook supporting non-static gpio_to_irq() mappings; - * implementation may not sleep - * @dbg_show: optional routine to show contents in debugfs; default code - * will be used when this is omitted, but custom code can show extra - * state (such as pullup/pulldown configuration). - * @base: identifies the first GPIO number handled by this chip; or, if - * negative during registration, requests dynamic ID allocation. - * @ngpio: the number of GPIOs handled by this controller; the last GPIO - * handled is (base + ngpio - 1). - * @desc: array of ngpio descriptors. Private. - * @can_sleep: flag must be set iff get()/set() methods sleep, as they - * must while accessing GPIO expander chips over I2C or SPI - * @names: if set, must be an array of strings to use as alternative - * names for the GPIOs in this chip. Any entry in the array - * may be NULL if there is no alias for the GPIO, however the - * array must be @ngpio entries long. A name can include a single printk - * format specifier for an unsigned int. It is substituted by the actual - * number of the gpio. - * - * A gpio_chip can help platforms abstract various sources of GPIOs so - * they can all be accessed through a common programing interface. - * Example sources would be SOC controllers, FPGAs, multifunction - * chips, dedicated GPIO expanders, and so on. - * - * Each chip controls a number of signals, identified in method calls - * by "offset" values in the range 0..(@ngpio - 1). When those signals - * are referenced through calls like gpio_get_value(gpio), the offset - * is calculated by subtracting @base from the gpio number. - */ -struct gpio_chip { - const char *label; - struct device *dev; - struct module *owner; - struct list_head list; - - int (*request)(struct gpio_chip *chip, - unsigned offset); - void (*free)(struct gpio_chip *chip, - unsigned offset); - int (*get_direction)(struct gpio_chip *chip, - unsigned offset); - int (*direction_input)(struct gpio_chip *chip, - unsigned offset); - int (*get)(struct gpio_chip *chip, - unsigned offset); - int (*direction_output)(struct gpio_chip *chip, - unsigned offset, int value); - int (*set_debounce)(struct gpio_chip *chip, - unsigned offset, unsigned debounce); - - void (*set)(struct gpio_chip *chip, - unsigned offset, int value); - - int (*to_irq)(struct gpio_chip *chip, - unsigned offset); - - void (*dbg_show)(struct seq_file *s, - struct gpio_chip *chip); - int base; - u16 ngpio; - struct gpio_desc *desc; - const char *const *names; - unsigned can_sleep:1; - unsigned exported:1; - -#if defined(CONFIG_OF_GPIO) - /* - * If CONFIG_OF is enabled, then all GPIO controllers described in the - * device tree automatically may have an OF translation - */ - struct device_node *of_node; - int of_gpio_n_cells; - int (*of_xlate)(struct gpio_chip *gc, - const struct of_phandle_args *gpiospec, u32 *flags); -#endif -#ifdef CONFIG_PINCTRL - /* - * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally - * describe the actual pin range which they serve in an SoC. This - * information would be used by pinctrl subsystem to configure - * corresponding pins for gpio usage. - */ - struct list_head pin_ranges; -#endif -}; - -extern const char *gpiochip_is_requested(struct gpio_chip *chip, - unsigned offset); -extern struct gpio_chip *gpio_to_chip(unsigned gpio); - -/* add/remove chips */ -extern int gpiochip_add(struct gpio_chip *chip); -extern int __must_check gpiochip_remove(struct gpio_chip *chip); -extern struct gpio_chip *gpiochip_find(void *data, - int (*match)(struct gpio_chip *chip, - void *data)); - +/* caller holds gpio_lock *OR* gpio is marked as requested */ +static inline struct gpio_chip *gpio_to_chip(unsigned gpio) +{ + return gpiod_to_chip(gpio_to_desc(gpio)); +} /* Always use the library code for GPIO management calls, * or when sleeping may be involved. @@ -172,25 +63,52 @@ extern struct gpio_chip *gpiochip_find(void *data, extern int gpio_request(unsigned gpio, const char *label); extern void gpio_free(unsigned gpio); -extern int gpio_direction_input(unsigned gpio); -extern int gpio_direction_output(unsigned gpio, int value); +static inline int gpio_direction_input(unsigned gpio) +{ + return gpiod_direction_input(gpio_to_desc(gpio)); +} +static inline int gpio_direction_output(unsigned gpio, int value) +{ + return gpiod_direction_output(gpio_to_desc(gpio), value); +} -extern int gpio_set_debounce(unsigned gpio, unsigned debounce); +static inline int gpio_set_debounce(unsigned gpio, unsigned debounce) +{ + return gpiod_set_debounce(gpio_to_desc(gpio), debounce); +} -extern int gpio_get_value_cansleep(unsigned gpio); -extern void gpio_set_value_cansleep(unsigned gpio, int value); +static inline int gpio_get_value_cansleep(unsigned gpio) +{ + return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio)); +} +static inline void gpio_set_value_cansleep(unsigned gpio, int value) +{ + return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value); +} /* A platform's code may want to inline the I/O calls when * the GPIO is constant and refers to some always-present controller, * giving direct access to chip registers and tight bitbanging loops. */ -extern int __gpio_get_value(unsigned gpio); -extern void __gpio_set_value(unsigned gpio, int value); +static inline int __gpio_get_value(unsigned gpio) +{ + return gpiod_get_raw_value(gpio_to_desc(gpio)); +} +static inline void __gpio_set_value(unsigned gpio, int value) +{ + return gpiod_set_raw_value(gpio_to_desc(gpio), value); +} -extern int __gpio_cansleep(unsigned gpio); +static inline int __gpio_cansleep(unsigned gpio) +{ + return gpiod_cansleep(gpio_to_desc(gpio)); +} -extern int __gpio_to_irq(unsigned gpio); +static inline int __gpio_to_irq(unsigned gpio) +{ + return gpiod_to_irq(gpio_to_desc(gpio)); +} extern int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset); extern void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset); @@ -199,19 +117,30 @@ extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *labe extern int gpio_request_array(const struct gpio *array, size_t num); extern void gpio_free_array(const struct gpio *array, size_t num); -#ifdef CONFIG_GPIO_SYSFS - /* * A sysfs interface can be exported by individual drivers if they want, * but more typically is configured entirely from userspace. */ -extern int gpio_export(unsigned gpio, bool direction_may_change); -extern int gpio_export_link(struct device *dev, const char *name, - unsigned gpio); -extern int gpio_sysfs_set_active_low(unsigned gpio, int value); -extern void gpio_unexport(unsigned gpio); +static inline int gpio_export(unsigned gpio, bool direction_may_change) +{ + return gpiod_export(gpio_to_desc(gpio), direction_may_change); +} -#endif /* CONFIG_GPIO_SYSFS */ +static inline int gpio_export_link(struct device *dev, const char *name, + unsigned gpio) +{ + return gpiod_export_link(dev, name, gpio_to_desc(gpio)); +} + +static inline int gpio_sysfs_set_active_low(unsigned gpio, int value) +{ + return gpiod_sysfs_set_active_low(gpio_to_desc(gpio), value); +} + +static inline void gpio_unexport(unsigned gpio) +{ + gpiod_unexport(gpio_to_desc(gpio)); +} #ifdef CONFIG_PINCTRL @@ -281,31 +210,4 @@ static inline void gpio_set_value_cansleep(unsigned gpio, int value) #endif /* !CONFIG_GPIOLIB */ -#ifndef CONFIG_GPIO_SYSFS - -struct device; - -/* sysfs support is only available with gpiolib, where it's optional */ - -static inline int gpio_export(unsigned gpio, bool direction_may_change) -{ - return -ENOSYS; -} - -static inline int gpio_export_link(struct device *dev, const char *name, - unsigned gpio) -{ - return -ENOSYS; -} - -static inline int gpio_sysfs_set_active_low(unsigned gpio, int value) -{ - return -ENOSYS; -} - -static inline void gpio_unexport(unsigned gpio) -{ -} -#endif /* CONFIG_GPIO_SYSFS */ - #endif /* _ASM_GENERIC_GPIO_H */ diff --git a/include/linux/gpio.h b/include/linux/gpio.h index a06ec3e85ba3..c691df044458 100644 --- a/include/linux/gpio.h +++ b/include/linux/gpio.h @@ -16,14 +16,17 @@ #define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW) #define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH) +/* Gpio pin is active-low */ +#define GPIOF_ACTIVE_LOW (1 << 2) + /* Gpio pin is open drain */ -#define GPIOF_OPEN_DRAIN (1 << 2) +#define GPIOF_OPEN_DRAIN (1 << 3) /* Gpio pin is open source */ -#define GPIOF_OPEN_SOURCE (1 << 3) +#define GPIOF_OPEN_SOURCE (1 << 4) -#define GPIOF_EXPORT (1 << 4) -#define GPIOF_EXPORT_CHANGEABLE (1 << 5) +#define GPIOF_EXPORT (1 << 5) +#define GPIOF_EXPORT_CHANGEABLE (1 << 6) #define GPIOF_EXPORT_DIR_FIXED (GPIOF_EXPORT) #define GPIOF_EXPORT_DIR_CHANGEABLE (GPIOF_EXPORT | GPIOF_EXPORT_CHANGEABLE) diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h new file mode 100644 index 000000000000..2088eb50421c --- /dev/null +++ b/include/linux/gpio/consumer.h @@ -0,0 +1,238 @@ +#ifndef __LINUX_GPIO_CONSUMER_H +#define __LINUX_GPIO_CONSUMER_H + +#include +#include + +#ifdef CONFIG_GPIOLIB + +struct device; +struct gpio_chip; + +/** + * Opaque descriptor for a GPIO. These are obtained using gpiod_get() and are + * preferable to the old integer-based handles. + * + * Contrary to integers, a pointer to a gpio_desc is guaranteed to be valid + * until the GPIO is released. + */ +struct gpio_desc; + +int gpiod_get_direction(const struct gpio_desc *desc); +int gpiod_direction_input(struct gpio_desc *desc); +int gpiod_direction_output(struct gpio_desc *desc, int value); + +/* Value get/set from non-sleeping context */ +int gpiod_get_value(const struct gpio_desc *desc); +void gpiod_set_value(struct gpio_desc *desc, int value); +int gpiod_get_raw_value(const struct gpio_desc *desc); +void gpiod_set_raw_value(struct gpio_desc *desc, int value); + +/* Value get/set from sleeping context */ +int gpiod_get_value_cansleep(const struct gpio_desc *desc); +void gpiod_set_value_cansleep(struct gpio_desc *desc, int value); +int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc); +void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value); + +int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce); + +int gpiod_is_active_low(const struct gpio_desc *desc); +int gpiod_cansleep(const struct gpio_desc *desc); + +int gpiod_to_irq(const struct gpio_desc *desc); + +/* Convert between the old gpio_ and new gpiod_ interfaces */ +struct gpio_desc *gpio_to_desc(unsigned gpio); +int desc_to_gpio(const struct gpio_desc *desc); +struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc); + +#else /* CONFIG_GPIOLIB */ + +static inline struct gpio_desc *__must_check gpiod_get(struct device *dev, + const char *con_id) +{ + return ERR_PTR(-ENOSYS); +} +static inline struct gpio_desc *__must_check gpiod_get_index(struct device *dev, + const char *con_id, + unsigned int idx) +{ + return ERR_PTR(-ENOSYS); +} +static inline void gpiod_put(struct gpio_desc *desc) +{ + might_sleep(); + + /* GPIO can never have been requested */ + WARN_ON(1); +} + +static inline struct gpio_desc *__must_check devm_gpiod_get(struct device *dev, + const char *con_id) +{ + return ERR_PTR(-ENOSYS); +} +static inline +struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev, + const char *con_id, + unsigned int idx) +{ + return ERR_PTR(-ENOSYS); +} +static inline void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) +{ + might_sleep(); + + /* GPIO can never have been requested */ + WARN_ON(1); +} + + +static inline int gpiod_get_direction(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} +static inline int gpiod_direction_input(struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} +static inline int gpiod_direction_output(struct gpio_desc *desc, int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} + + +static inline int gpiod_get_value(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline void gpiod_set_value(struct gpio_desc *desc, int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} +static inline int gpiod_get_raw_value(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline void gpiod_set_raw_value(struct gpio_desc *desc, int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} + +static inline int gpiod_get_value_cansleep(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} +static inline int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, + int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} + +static inline int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} + +static inline int gpiod_is_active_low(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline int gpiod_cansleep(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} + +static inline int gpiod_to_irq(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -EINVAL; +} + +static inline struct gpio_desc *gpio_to_desc(unsigned gpio) +{ + return ERR_PTR(-EINVAL); +} +static inline int desc_to_gpio(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -EINVAL; +} +static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return ERR_PTR(-ENODEV); +} + + +#endif /* CONFIG_GPIOLIB */ + +#if IS_ENABLED(CONFIG_GPIOLIB) && IS_ENABLED(CONFIG_GPIO_SYSFS) + +int gpiod_export(struct gpio_desc *desc, bool direction_may_change); +int gpiod_export_link(struct device *dev, const char *name, + struct gpio_desc *desc); +int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value); +void gpiod_unexport(struct gpio_desc *desc); + +#else /* CONFIG_GPIOLIB && CONFIG_GPIO_SYSFS */ + +static inline int gpiod_export(struct gpio_desc *desc, + bool direction_may_change) +{ + return -ENOSYS; +} + +static inline int gpiod_export_link(struct device *dev, const char *name, + struct gpio_desc *desc) +{ + return -ENOSYS; +} + +static inline int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) +{ + return -ENOSYS; +} + +static inline void gpiod_unexport(struct gpio_desc *desc) +{ +} + +#endif /* CONFIG_GPIOLIB && CONFIG_GPIO_SYSFS */ + +#endif diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h new file mode 100644 index 000000000000..5dc172c72f0f --- /dev/null +++ b/include/linux/gpio/driver.h @@ -0,0 +1,127 @@ +#ifndef __LINUX_GPIO_DRIVER_H +#define __LINUX_GPIO_DRIVER_H + +#include + +struct device; +struct gpio_desc; + +/** + * struct gpio_chip - abstract a GPIO controller + * @label: for diagnostics + * @dev: optional device providing the GPIOs + * @owner: helps prevent removal of modules exporting active GPIOs + * @list: links gpio_chips together for traversal + * @request: optional hook for chip-specific activation, such as + * enabling module power and clock; may sleep + * @free: optional hook for chip-specific deactivation, such as + * disabling module power and clock; may sleep + * @get_direction: returns direction for signal "offset", 0=out, 1=in, + * (same as GPIOF_DIR_XXX), or negative error + * @direction_input: configures signal "offset" as input, or returns error + * @direction_output: configures signal "offset" as output, or returns error + * @get: returns value for signal "offset"; for output signals this + * returns either the value actually sensed, or zero + * @set: assigns output value for signal "offset" + * @set_debounce: optional hook for setting debounce time for specified gpio in + * interrupt triggered gpio chips + * @to_irq: optional hook supporting non-static gpio_to_irq() mappings; + * implementation may not sleep + * @dbg_show: optional routine to show contents in debugfs; default code + * will be used when this is omitted, but custom code can show extra + * state (such as pullup/pulldown configuration). + * @base: identifies the first GPIO number handled by this chip; or, if + * negative during registration, requests dynamic ID allocation. + * @ngpio: the number of GPIOs handled by this controller; the last GPIO + * handled is (base + ngpio - 1). + * @desc: array of ngpio descriptors. Private. + * @can_sleep: flag must be set iff get()/set() methods sleep, as they + * must while accessing GPIO expander chips over I2C or SPI + * @names: if set, must be an array of strings to use as alternative + * names for the GPIOs in this chip. Any entry in the array + * may be NULL if there is no alias for the GPIO, however the + * array must be @ngpio entries long. A name can include a single printk + * format specifier for an unsigned int. It is substituted by the actual + * number of the gpio. + * + * A gpio_chip can help platforms abstract various sources of GPIOs so + * they can all be accessed through a common programing interface. + * Example sources would be SOC controllers, FPGAs, multifunction + * chips, dedicated GPIO expanders, and so on. + * + * Each chip controls a number of signals, identified in method calls + * by "offset" values in the range 0..(@ngpio - 1). When those signals + * are referenced through calls like gpio_get_value(gpio), the offset + * is calculated by subtracting @base from the gpio number. + */ +struct gpio_chip { + const char *label; + struct device *dev; + struct module *owner; + struct list_head list; + + int (*request)(struct gpio_chip *chip, + unsigned offset); + void (*free)(struct gpio_chip *chip, + unsigned offset); + int (*get_direction)(struct gpio_chip *chip, + unsigned offset); + int (*direction_input)(struct gpio_chip *chip, + unsigned offset); + int (*direction_output)(struct gpio_chip *chip, + unsigned offset, int value); + int (*get)(struct gpio_chip *chip, + unsigned offset); + void (*set)(struct gpio_chip *chip, + unsigned offset, int value); + int (*set_debounce)(struct gpio_chip *chip, + unsigned offset, + unsigned debounce); + + int (*to_irq)(struct gpio_chip *chip, + unsigned offset); + + void (*dbg_show)(struct seq_file *s, + struct gpio_chip *chip); + int base; + u16 ngpio; + struct gpio_desc *desc; + const char *const *names; + unsigned can_sleep:1; + unsigned exported:1; + +#if defined(CONFIG_OF_GPIO) + /* + * If CONFIG_OF is enabled, then all GPIO controllers described in the + * device tree automatically may have an OF translation + */ + struct device_node *of_node; + int of_gpio_n_cells; + int (*of_xlate)(struct gpio_chip *gc, + const struct of_phandle_args *gpiospec, u32 *flags); +#endif +#ifdef CONFIG_PINCTRL + /* + * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally + * describe the actual pin range which they serve in an SoC. This + * information would be used by pinctrl subsystem to configure + * corresponding pins for gpio usage. + */ + struct list_head pin_ranges; +#endif +}; + +extern const char *gpiochip_is_requested(struct gpio_chip *chip, + unsigned offset); + +/* add/remove chips */ +extern int gpiochip_add(struct gpio_chip *chip); +extern int __must_check gpiochip_remove(struct gpio_chip *chip); +extern struct gpio_chip *gpiochip_find(void *data, + int (*match)(struct gpio_chip *chip, void *data)); + +/* lock/unlock as IRQ */ +int gpiod_lock_as_irq(struct gpio_desc *desc); +void gpiod_unlock_as_irq(struct gpio_desc *desc); + +#endif -- cgit v1.3-14-g43fede From ce3959604878c1c693979ec552069dc8bdb5ccde Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 13 Oct 2013 17:23:53 -0400 Subject: constify copy_siginfo_to_user{,32}() Signed-off-by: Al Viro --- arch/arm64/kernel/signal32.c | 2 +- arch/ia64/kernel/signal.c | 2 +- arch/mips/kernel/signal32.c | 2 +- arch/parisc/kernel/signal32.c | 2 +- arch/parisc/kernel/signal32.h | 2 +- arch/powerpc/kernel/signal_32.c | 2 +- arch/s390/kernel/compat_signal.c | 2 +- arch/sparc/kernel/signal32.c | 2 +- arch/tile/kernel/compat_signal.c | 2 +- arch/x86/ia32/ia32_signal.c | 2 +- fs/binfmt_elf.c | 2 +- include/asm-generic/siginfo.h | 2 +- include/linux/compat.h | 2 +- kernel/signal.c | 2 +- 14 files changed, 14 insertions(+), 14 deletions(-) (limited to 'include/asm-generic') diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c index e393174fe859..07da8c0fde2e 100644 --- a/arch/arm64/kernel/signal32.c +++ b/arch/arm64/kernel/signal32.c @@ -150,7 +150,7 @@ static inline int get_sigset_t(sigset_t *set, return 0; } -int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from) +int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from) { int err; diff --git a/arch/ia64/kernel/signal.c b/arch/ia64/kernel/signal.c index 3637e03d2282..33cab9a8adff 100644 --- a/arch/ia64/kernel/signal.c +++ b/arch/ia64/kernel/signal.c @@ -105,7 +105,7 @@ restore_sigcontext (struct sigcontext __user *sc, struct sigscratch *scr) } int -copy_siginfo_to_user (siginfo_t __user *to, siginfo_t *from) +copy_siginfo_to_user (siginfo_t __user *to, const siginfo_t *from) { if (!access_ok(VERIFY_WRITE, to, sizeof(siginfo_t))) return -EFAULT; diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c index 57de8b751627..1905a419aa46 100644 --- a/arch/mips/kernel/signal32.c +++ b/arch/mips/kernel/signal32.c @@ -314,7 +314,7 @@ SYSCALL_DEFINE3(32_sigaction, long, sig, const struct compat_sigaction __user *, return ret; } -int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from) +int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from) { int err; diff --git a/arch/parisc/kernel/signal32.c b/arch/parisc/kernel/signal32.c index 6c6a271a6140..984abbee71ca 100644 --- a/arch/parisc/kernel/signal32.c +++ b/arch/parisc/kernel/signal32.c @@ -319,7 +319,7 @@ copy_siginfo_from_user32 (siginfo_t *to, compat_siginfo_t __user *from) } int -copy_siginfo_to_user32 (compat_siginfo_t __user *to, siginfo_t *from) +copy_siginfo_to_user32 (compat_siginfo_t __user *to, const siginfo_t *from) { compat_uptr_t addr; compat_int_t val; diff --git a/arch/parisc/kernel/signal32.h b/arch/parisc/kernel/signal32.h index 72ab41a51f32..af51d4ccee42 100644 --- a/arch/parisc/kernel/signal32.h +++ b/arch/parisc/kernel/signal32.h @@ -34,7 +34,7 @@ struct compat_ucontext { /* ELF32 signal handling */ -int copy_siginfo_to_user32 (compat_siginfo_t __user *to, siginfo_t *from); +int copy_siginfo_to_user32 (compat_siginfo_t __user *to, const siginfo_t *from); int copy_siginfo_from_user32 (siginfo_t *to, compat_siginfo_t __user *from); /* In a deft move of uber-hackery, we decide to carry the top half of all diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index bebdf1a1a540..149cd583d061 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -891,7 +891,7 @@ static long restore_tm_user_regs(struct pt_regs *regs, #endif #ifdef CONFIG_PPC64 -int copy_siginfo_to_user32(struct compat_siginfo __user *d, siginfo_t *s) +int copy_siginfo_to_user32(struct compat_siginfo __user *d, const siginfo_t *s) { int err; diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c index 1389b637dae5..44b25269a970 100644 --- a/arch/s390/kernel/compat_signal.c +++ b/arch/s390/kernel/compat_signal.c @@ -49,7 +49,7 @@ typedef struct __u32 gprs_high[NUM_GPRS]; } rt_sigframe32; -int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from) +int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from) { int err; diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c index b524f91dd0e5..ee789d2ef05d 100644 --- a/arch/sparc/kernel/signal32.c +++ b/arch/sparc/kernel/signal32.c @@ -68,7 +68,7 @@ struct rt_signal_frame32 { /* __siginfo_rwin_t * */u32 rwin_save; } __attribute__((aligned(8))); -int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from) +int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from) { int err; diff --git a/arch/tile/kernel/compat_signal.c b/arch/tile/kernel/compat_signal.c index 85e00b2f39bf..19c04b5ce408 100644 --- a/arch/tile/kernel/compat_signal.c +++ b/arch/tile/kernel/compat_signal.c @@ -49,7 +49,7 @@ struct compat_rt_sigframe { struct compat_ucontext uc; }; -int copy_siginfo_to_user32(struct compat_siginfo __user *to, siginfo_t *from) +int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *from) { int err; diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c index 665a730307f2..220675795e08 100644 --- a/arch/x86/ia32/ia32_signal.c +++ b/arch/x86/ia32/ia32_signal.c @@ -34,7 +34,7 @@ #include #include -int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from) +int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from) { int err = 0; bool ia32 = test_thread_flag(TIF_IA32); diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 864154972670..a6f8cb498b0e 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1374,7 +1374,7 @@ static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) } static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata, - siginfo_t *siginfo) + const siginfo_t *siginfo) { mm_segment_t old_fs = get_fs(); set_fs(KERNEL_DS); diff --git a/include/asm-generic/siginfo.h b/include/asm-generic/siginfo.h index b685d3bd32e2..3d1a3af5cf59 100644 --- a/include/asm-generic/siginfo.h +++ b/include/asm-generic/siginfo.h @@ -32,6 +32,6 @@ static inline void copy_siginfo(struct siginfo *to, struct siginfo *from) #endif -extern int copy_siginfo_to_user(struct siginfo __user *to, struct siginfo *from); +extern int copy_siginfo_to_user(struct siginfo __user *to, const struct siginfo *from); #endif diff --git a/include/linux/compat.h b/include/linux/compat.h index 345da00a86e0..78cdf51ff5ba 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -362,7 +362,7 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask, long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, unsigned long bitmap_size); int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from); -int copy_siginfo_to_user32(struct compat_siginfo __user *to, siginfo_t *from); +int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *from); int get_compat_sigevent(struct sigevent *event, const struct compat_sigevent __user *u_event); long compat_sys_rt_tgsigqueueinfo(compat_pid_t tgid, compat_pid_t pid, int sig, diff --git a/kernel/signal.c b/kernel/signal.c index ded28b91fa53..940b30ee9a30 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2723,7 +2723,7 @@ COMPAT_SYSCALL_DEFINE2(rt_sigpending, compat_sigset_t __user *, uset, #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER -int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from) +int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from) { int err; -- cgit v1.3-14-g43fede From ec778edf97dcaa517e5b0eea6f1a9ba9d476e4a8 Mon Sep 17 00:00:00 2001 From: Cody P Schafer Date: Tue, 12 Nov 2013 15:09:48 -0800 Subject: bitops/find: clarify and extend documentation Add return value documentation and clarify the units of the @size parameter. Signed-off-by: Cody P Schafer Cc: Arnd Bergmann Cc: Cody P Schafer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/bitops/find.h | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'include/asm-generic') diff --git a/include/asm-generic/bitops/find.h b/include/asm-generic/bitops/find.h index 71c778033f57..998d4d544f18 100644 --- a/include/asm-generic/bitops/find.h +++ b/include/asm-generic/bitops/find.h @@ -7,6 +7,9 @@ * @addr: The address to base the search on * @offset: The bitnumber to start searching at * @size: The bitmap size in bits + * + * Returns the bit number for the next set bit + * If no bits are set, returns @size. */ extern unsigned long find_next_bit(const unsigned long *addr, unsigned long size, unsigned long offset); @@ -18,6 +21,9 @@ extern unsigned long find_next_bit(const unsigned long *addr, unsigned long * @addr: The address to base the search on * @offset: The bitnumber to start searching at * @size: The bitmap size in bits + * + * Returns the bit number of the next zero bit + * If no bits are zero, returns @size. */ extern unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, unsigned long offset); @@ -28,9 +34,10 @@ extern unsigned long find_next_zero_bit(const unsigned long *addr, unsigned /** * find_first_bit - find the first set bit in a memory region * @addr: The address to start the search at - * @size: The maximum size to search + * @size: The maximum number of bits to search * * Returns the bit number of the first set bit. + * If no bits are set, returns @size. */ extern unsigned long find_first_bit(const unsigned long *addr, unsigned long size); @@ -38,9 +45,10 @@ extern unsigned long find_first_bit(const unsigned long *addr, /** * find_first_zero_bit - find the first cleared bit in a memory region * @addr: The address to start the search at - * @size: The maximum size to search + * @size: The maximum number of bits to search * * Returns the bit number of the first cleared bit. + * If no bits are zero, returns @size. */ extern unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size); -- cgit v1.3-14-g43fede