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-rw-r--r--arch/arc/kernel/devtree.c24
-rw-r--r--arch/arc/kernel/entry.S14
-rw-r--r--arch/arc/kernel/process.c23
-rw-r--r--arch/arc/kernel/setup.c7
-rw-r--r--arch/arc/kernel/signal.c2
-rw-r--r--arch/arc/kernel/smp.c2
-rw-r--r--arch/arc/kernel/stacktrace.c21
-rw-r--r--arch/arc/kernel/unaligned.c2
8 files changed, 60 insertions, 35 deletions
diff --git a/arch/arc/kernel/devtree.c b/arch/arc/kernel/devtree.c
index fffdb5e41b20..e32b54abff51 100644
--- a/arch/arc/kernel/devtree.c
+++ b/arch/arc/kernel/devtree.c
@@ -17,6 +17,28 @@
#include <asm/clk.h>
#include <asm/mach_desc.h>
+#ifdef CONFIG_SERIAL_EARLYCON
+
+static unsigned int __initdata arc_base_baud;
+
+unsigned int __init arc_early_base_baud(void)
+{
+ return arc_base_baud/16;
+}
+
+static void __init arc_set_early_base_baud(unsigned long dt_root)
+{
+ unsigned int core_clk = arc_get_core_freq();
+
+ if (of_flat_dt_is_compatible(dt_root, "abilis,arc-tb10x"))
+ arc_base_baud = core_clk/3;
+ else
+ arc_base_baud = core_clk;
+}
+#else
+#define arc_set_early_base_baud(dt_root)
+#endif
+
static const void * __init arch_get_next_mach(const char *const **match)
{
static const struct machine_desc *mdesc = __arch_info_begin;
@@ -56,5 +78,7 @@ const struct machine_desc * __init setup_machine_fdt(void *dt)
if (clk)
arc_set_core_freq(of_read_ulong(clk, len/4));
+ arc_set_early_base_baud(dt_root);
+
return mdesc;
}
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 83a046a7cd06..d868289c5a26 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -736,16 +736,20 @@ ENTRY(ret_from_fork)
; put last task in scheduler queue
bl @schedule_tail
- ; If kernel thread, jump to its entry-point
ld r9, [sp, PT_status32]
brne r9, 0, 1f
- jl.d [r14]
- mov r0, r13 ; arg to payload
+ jl.d [r14] ; kernel thread entry point
+ mov r0, r13 ; (see PF_KTHREAD block in copy_thread)
1:
- ; special case of kernel_thread entry point returning back due to
- ; kernel_execve() - pretend return from syscall to ret to userland
+ ; Return to user space
+ ; 1. Any forked task (Reach here via BRne above)
+ ; 2. First ever init task (Reach here via return from JL above)
+ ; This is the historic "kernel_execve" use-case, to return to init
+ ; user mode, in a round about way since that is always done from
+ ; a kernel thread which is executed via JL above but always returns
+ ; out whenever kernel_execve (now inline do_fork()) is involved
b ret_from_exception
END(ret_from_fork)
diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c
index fdd89715d2d3..98c00a2d4dd9 100644
--- a/arch/arc/kernel/process.c
+++ b/arch/arc/kernel/process.c
@@ -192,29 +192,6 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
return 0;
}
-/*
- * API: expected by schedular Code: If thread is sleeping where is that.
- * What is this good for? it will be always the scheduler or ret_from_fork.
- * So we hard code that anyways.
- */
-unsigned long thread_saved_pc(struct task_struct *t)
-{
- struct pt_regs *regs = task_pt_regs(t);
- unsigned long blink = 0;
-
- /*
- * If the thread being queried for in not itself calling this, then it
- * implies it is not executing, which in turn implies it is sleeping,
- * which in turn implies it got switched OUT by the schedular.
- * In that case, it's kernel mode blink can reliably retrieved as per
- * the picture above (right above pt_regs).
- */
- if (t != current && t->state != TASK_RUNNING)
- blink = *((unsigned int *)regs - 1);
-
- return blink;
-}
-
int elf_check_arch(const struct elf32_hdr *x)
{
unsigned int eflags;
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index 252bf603db9c..900f68a70088 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -412,6 +412,11 @@ static int show_cpuinfo(struct seq_file *m, void *v)
char *str;
int cpu_id = ptr_to_cpu(v);
+ if (!cpu_online(cpu_id)) {
+ seq_printf(m, "processor [%d]\t: Offline\n", cpu_id);
+ goto done;
+ }
+
str = (char *)__get_free_page(GFP_TEMPORARY);
if (!str)
goto done;
@@ -429,7 +434,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
free_page((unsigned long)str);
done:
- seq_printf(m, "\n\n");
+ seq_printf(m, "\n");
return 0;
}
diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c
index cb3142a2d40b..114234e83caa 100644
--- a/arch/arc/kernel/signal.c
+++ b/arch/arc/kernel/signal.c
@@ -104,7 +104,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
struct pt_regs *regs = current_pt_regs();
/* Always make any pending restarted system calls return -EINTR */
- current_thread_info()->restart_block.fn = do_no_restart_syscall;
+ current->restart_block.fn = do_no_restart_syscall;
/* Since we stacked the signal on a word boundary,
* then 'sp' should be word aligned here. If it's
diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
index 20ebb602ea2f..6a400b1b0b62 100644
--- a/arch/arc/kernel/smp.c
+++ b/arch/arc/kernel/smp.c
@@ -221,7 +221,7 @@ static void ipi_send_msg_one(int cpu, enum ipi_msg_type msg)
* and read back old value
*/
do {
- new = old = *ipi_data_ptr;
+ new = old = ACCESS_ONCE(*ipi_data_ptr);
new |= 1U << msg;
} while (cmpxchg(ipi_data_ptr, old, new) != old);
diff --git a/arch/arc/kernel/stacktrace.c b/arch/arc/kernel/stacktrace.c
index 9ce47cfe2303..92320d6f737c 100644
--- a/arch/arc/kernel/stacktrace.c
+++ b/arch/arc/kernel/stacktrace.c
@@ -43,6 +43,10 @@ static void seed_unwind_frame_info(struct task_struct *tsk,
struct pt_regs *regs,
struct unwind_frame_info *frame_info)
{
+ /*
+ * synchronous unwinding (e.g. dump_stack)
+ * - uses current values of SP and friends
+ */
if (tsk == NULL && regs == NULL) {
unsigned long fp, sp, blink, ret;
frame_info->task = current;
@@ -61,12 +65,17 @@ static void seed_unwind_frame_info(struct task_struct *tsk,
frame_info->regs.r63 = ret;
frame_info->call_frame = 0;
} else if (regs == NULL) {
+ /*
+ * Asynchronous unwinding of sleeping task
+ * - Gets SP etc from task's pt_regs (saved bottom of kernel
+ * mode stack of task)
+ */
frame_info->task = tsk;
- frame_info->regs.r27 = KSTK_FP(tsk);
- frame_info->regs.r28 = KSTK_ESP(tsk);
- frame_info->regs.r31 = KSTK_BLINK(tsk);
+ frame_info->regs.r27 = TSK_K_FP(tsk);
+ frame_info->regs.r28 = TSK_K_ESP(tsk);
+ frame_info->regs.r31 = TSK_K_BLINK(tsk);
frame_info->regs.r63 = (unsigned int)__switch_to;
/* In the prologue of __switch_to, first FP is saved on stack
@@ -83,6 +92,10 @@ static void seed_unwind_frame_info(struct task_struct *tsk,
frame_info->call_frame = 0;
} else {
+ /*
+ * Asynchronous unwinding of intr/exception
+ * - Just uses the pt_regs passed
+ */
frame_info->task = tsk;
frame_info->regs.r27 = regs->fp;
@@ -95,7 +108,7 @@ static void seed_unwind_frame_info(struct task_struct *tsk,
#endif
-static noinline unsigned int
+notrace noinline unsigned int
arc_unwind_core(struct task_struct *tsk, struct pt_regs *regs,
int (*consumer_fn) (unsigned int, void *), void *arg)
{
diff --git a/arch/arc/kernel/unaligned.c b/arch/arc/kernel/unaligned.c
index 7ff5b5c183bb..74db59b6f392 100644
--- a/arch/arc/kernel/unaligned.c
+++ b/arch/arc/kernel/unaligned.c
@@ -12,6 +12,7 @@
*/
#include <linux/types.h>
+#include <linux/perf_event.h>
#include <linux/ptrace.h>
#include <linux/uaccess.h>
#include <asm/disasm.h>
@@ -253,6 +254,7 @@ int misaligned_fixup(unsigned long address, struct pt_regs *regs,
}
}
+ perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, address);
return 0;
fault: