diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/blackfin/mach-common/ints-priority.c | 41 |
1 files changed, 37 insertions, 4 deletions
diff --git a/arch/blackfin/mach-common/ints-priority.c b/arch/blackfin/mach-common/ints-priority.c index 8e9d3cc30885..6cd52395a999 100644 --- a/arch/blackfin/mach-common/ints-priority.c +++ b/arch/blackfin/mach-common/ints-priority.c @@ -15,6 +15,7 @@ #include <linux/kernel_stat.h> #include <linux/seq_file.h> #include <linux/irq.h> +#include <linux/sched.h> #ifdef CONFIG_IPIPE #include <linux/ipipe.h> #endif @@ -556,10 +557,9 @@ static void bfin_demux_mac_status_irq(unsigned int int_err_irq, static inline void bfin_set_irq_handler(unsigned irq, irq_flow_handler_t handle) { #ifdef CONFIG_IPIPE - _set_irq_handler(irq, handle_level_irq); -#else - __set_irq_handler_unlocked(irq, handle); + handle = handle_level_irq; #endif + __set_irq_handler_unlocked(irq, handle); } static DECLARE_BITMAP(gpio_enabled, MAX_BLACKFIN_GPIOS); @@ -1392,7 +1392,7 @@ asmlinkage int __ipipe_grab_irq(int vec, struct pt_regs *regs) struct ipipe_domain *this_domain = __ipipe_current_domain; struct ivgx *ivg_stop = ivg7_13[vec-IVG7].istop; struct ivgx *ivg = ivg7_13[vec-IVG7].ifirst; - int irq, s; + int irq, s = 0; if (likely(vec == EVT_IVTMR_P)) irq = IRQ_CORETMR; @@ -1442,6 +1442,21 @@ asmlinkage int __ipipe_grab_irq(int vec, struct pt_regs *regs) __raw_get_cpu_var(__ipipe_tick_regs).ipend |= 0x10; } + /* + * We don't want Linux interrupt handlers to run at the + * current core priority level (i.e. < EVT15), since this + * might delay other interrupts handled by a high priority + * domain. Here is what we do instead: + * + * - we raise the SYNCDEFER bit to prevent + * __ipipe_handle_irq() to sync the pipeline for the root + * stage for the incoming interrupt. Upon return, that IRQ is + * pending in the interrupt log. + * + * - we raise the TIF_IRQ_SYNC bit for the current thread, so + * that _schedule_and_signal_from_int will eventually sync the + * pipeline from EVT15. + */ if (this_domain == ipipe_root_domain) { s = __test_and_set_bit(IPIPE_SYNCDEFER_FLAG, &p->status); barrier(); @@ -1451,6 +1466,24 @@ asmlinkage int __ipipe_grab_irq(int vec, struct pt_regs *regs) __ipipe_handle_irq(irq, regs); ipipe_trace_irq_exit(irq); + if (user_mode(regs) && + !ipipe_test_foreign_stack() && + (current->ipipe_flags & PF_EVTRET) != 0) { + /* + * Testing for user_regs() does NOT fully eliminate + * foreign stack contexts, because of the forged + * interrupt returns we do through + * __ipipe_call_irqtail. In that case, we might have + * preempted a foreign stack context in a high + * priority domain, with a single interrupt level now + * pending after the irqtail unwinding is done. In + * which case user_mode() is now true, and the event + * gets dispatched spuriously. + */ + current->ipipe_flags &= ~PF_EVTRET; + __ipipe_dispatch_event(IPIPE_EVENT_RETURN, regs); + } + if (this_domain == ipipe_root_domain) { set_thread_flag(TIF_IRQ_SYNC); if (!s) { |