metag: move irq enable out of irqflags.h on SMP (fa771d02) · Commits · 戴 / test

The SMP version of arch_local_irq_enable() uses preempt_disable(), but <asm/irqflags.h> doesn't include <linux/preempt.h> causing the following errors on SMP when pstore/ftrace is enabled (caught by buildbot smp allyesconfig): In file included from include/linux/irqflags.h:15, from fs/pstore/ftrace.c:16: arch/metag/include/asm/irqflags.h: In function 'arch_local_irq_enable': arch/metag/include/asm/irqflags.h:84: error: implicit declaration of function 'preempt_disable' arch/metag/include/asm/irqflags.h:86: error: implicit declaration of function 'preempt_enable_no_resched' However <linux/preempt.h> cannot be easily included from <asm/irqflags.h> as it can cause circular include dependencies in the !SMP case, and potentially in the SMP case in the future. Therefore move the SMP implementation of arch_local_irq_enable() into traps.c and use an inline version of get_trigger_mask() which is also defined in traps.c for SMP. This adds an extra layer of function call / stack push when preempt_disable needs to call other functions, however in the non-preemptive SMP case it should be about as fast, as it was already calling the get_trigger_mask() function which is now used inline. Signed-off-by:

James Hogan <james.hogan@imgtec.com>

arch/metag/include/asm/irqflags.h

+5 −6

Original line number	Diff line number	Diff line
		@@ -78,16 +78,15 @@ static inline void arch_local_irq_disable(void)
		asm volatile("MOV TXMASKI,%0\n" : : "r" (flags) : "memory");
		}

		static inline void arch_local_irq_enable(void)
		{
		#ifdef CONFIG_SMP
		preempt_disable();
		arch_local_irq_restore(get_trigger_mask());
		preempt_enable_no_resched();
		/* Avoid circular include dependencies through <linux/preempt.h> */
		void arch_local_irq_enable(void);
		#else
		static inline void arch_local_irq_enable(void)
		{
		arch_local_irq_restore(get_trigger_mask());
		#endif
		}
		#endif

		#endif /* (__ASSEMBLY__) */

arch/metag/kernel/traps.c

+15 −1

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		#include <linux/types.h>
		#include <linux/init.h>
		#include <linux/interrupt.h>
		#include <linux/preempt.h>
		#include <linux/ptrace.h>
		#include <linux/module.h>
		#include <linux/kallsyms.h>
		@@ -776,17 +777,30 @@ int traps_restore_context(void)
		#endif

		#ifdef CONFIG_SMP
		unsigned int get_trigger_mask(void)
		static inline unsigned int _get_trigger_mask(void)
		{
		unsigned long cpu = smp_processor_id();
		return per_cpu(trigger_mask, cpu);
		}

		unsigned int get_trigger_mask(void)
		{
		return _get_trigger_mask();
		}

		static void set_trigger_mask(unsigned int mask)
		{
		unsigned long cpu = smp_processor_id();
		per_cpu(trigger_mask, cpu) = mask;
		}

		void arch_local_irq_enable(void)
		{
		preempt_disable();
		arch_local_irq_restore(_get_trigger_mask());
		preempt_enable_no_resched();
		}
		EXPORT_SYMBOL(arch_local_irq_enable);
		#else
		static void set_trigger_mask(unsigned int mask)
		{

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