Re: [PATCH 12/13] powerpc: Add a Kconfig and a functions to set new soft_enabled mask
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2016-09-16 10:34:21
On Thu, 15 Sep 2016 18:32:02 +0530 Madhavan Srinivasan [off-list ref] wrote:
New Kconfig is added "CONFIG_IRQ_DEBUG_SUPPORT" to add warn_on to alert the invalid transitions. Have also moved the code under the CONFIG_TRACE_IRQFLAGS in arch_local_irq_restore() to new Kconfig as suggested.
I can't tempt you to put the Kconfig changes into their own patch? :)
To support disabling and enabling of irq with PMI, set of new powerpc_local_irq_pmu_save() and powerpc_local_irq_restore() functions are added. And powerpc_local_irq_save() implemented, by adding a new soft_enabled manipulation function soft_enabled_or_return(). Local_irq_pmu_* macros are provided to access these powerpc_local_irq_pmu* functions which includes trace_hardirqs_on|off() to match what we have in include/linux/irqflags.h. Signed-off-by: Madhavan Srinivasan <redacted>
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@@ -81,6 +81,20 @@ static inline notrace unsigned long soft_enabled_set_return(unsigned long enable return flags; } +static inline notrace unsigned long soft_enabled_or_return(unsigned long enable) +{ + unsigned long flags, zero; + + asm volatile( + "mr %1,%3; lbz %0,%2(13); or %1,%0,%1; stb %1,%2(13)" + : "=r" (flags), "=&r"(zero) + : "i" (offsetof(struct paca_struct, soft_enabled)),\ + "r" (enable) + : "memory"); + + return flags; +}
Another candidate for builtin_constification using immediates. And do you actually need the initial mr instruction there?
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@@ -105,7 +119,7 @@ static inline unsigned long arch_local_irq_save(void) static inline bool arch_irqs_disabled_flags(unsigned long flags) { - return flags == IRQ_DISABLE_MASK_LINUX; + return (flags); } static inline bool arch_irqs_disabled(void)
This part logically belongs in patch 11, but it also needs to be changed,
I think? Keep in mind it's the generic kernel asking whether it has "Linux
interrupts" disabled.
return flags & IRQ_DISABLE_MASK_LINUX;
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@@ -113,6 +127,59 @@ static inline bool arch_irqs_disabled(void) return arch_irqs_disabled_flags(arch_local_save_flags()); } +static inline void powerpc_local_irq_pmu_restore(unsigned long flags) +{ + arch_local_irq_restore(flags); +} + +static inline unsigned long powerpc_local_irq_pmu_disable(void) +{ + return soft_enabled_or_return(IRQ_DISABLE_MASK_LINUX | IRQ_DISABLE_MASK_PMU); +} + +static inline unsigned long powerpc_local_irq_pmu_save(void) +{ + return powerpc_local_irq_pmu_disable(); +} + +#define raw_local_irq_pmu_save(flags) \ + do { \ + typecheck(unsigned long, flags); \ + flags = powerpc_local_irq_pmu_save(); \ + } while(0) + +#define raw_local_irq_pmu_restore(flags) \ + do { \ + typecheck(unsigned long, flags); \ + powerpc_local_irq_pmu_restore(flags); \ + } while(0) + +#ifdef CONFIG_TRACE_IRQFLAGS +#define local_irq_pmu_save(flags) \ + do { \ + raw_local_irq_pmu_save(flags); \ + trace_hardirqs_off(); \ + } while(0) +#define local_irq_pmu_restore(flags) \ + do { \ + if (raw_irqs_disabled_flags(flags)) { \ + raw_local_irq_pmu_restore(flags);\ + trace_hardirqs_off(); \ + } else { \ + trace_hardirqs_on(); \ + raw_local_irq_pmu_restore(flags);\ + } \ + } while(0) +#else +#define local_irq_pmu_save(flags) \ + do { \ + raw_local_irq_pmu_save(flags); \ + } while(0) +#define local_irq_pmu_restore(flags) \ + do { raw_local_irq_pmu_restore(flags); } while (0) +#endif /* CONFIG_TRACE_IRQFLAGS */ + +
This looks pretty good. When I suggested powerpc_ prefix, I intended in these functions here, so it wouldn't match with the local_irq_ namespace of generic kernel. But that was just an idea. If you prefer to do it this way, could you just drop the powerpc_ wrappers entirely? A comment above that says it comes from the generic Linux local_irq code might be an idea too. Provided at least the arch_irqs_disabled_flags comment gets addressed: Reviewed-by: Nicholas Piggin <npiggin@gmail.com>