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Commit 305b15c7 authored by Linux Build Service Account's avatar Linux Build Service Account Committed by Gerrit - the friendly Code Review server
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Merge "ARM64: spinlock: Add SEV and dsb(ishst) in unlock code"

parents 446a4c80 59cae187

arch/arm64/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -529,6 +529,15 @@ config CPU_BIG_ENDIAN 
       help

         Say Y if you plan on running a kernel in big-endian mode.



config ARM64_SEV_IN_LOCK_UNLOCK

	bool "Add explicit SEV in the spinlock unlock code path"

	help

	  In certain unexplained cases, the stlr alone might not wakeup

	  the processor waiting in WFE on a spinlock.

	  Add an explicity dsb and SEV in write_unlock, read_unlock

	  and spin_unlock to ensure that the core waiting on the lock

	  wakes up from WFE.



config SMP

	bool "Symmetric Multi-Processing"

	help

arch/arm64/include/asm/spinlock.h

+12 −0
Original line number Diff line number Diff line
@@ -86,6 +86,10 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock) 
{

	asm volatile(

"	stlrh	%w1, %0\n"

#ifdef CONFIG_ARM64_SEV_IN_LOCK_UNLOCK

"	dsb ishst\n"

"	sev\n"

#endif

	: "=Q" (lock->owner)

	: "r" (lock->owner + 1)

	: "memory");
@@ -154,6 +158,10 @@ static inline void arch_write_unlock(arch_rwlock_t *rw) 
{

	asm volatile(

	"	stlr	%w1, %0\n"

#ifdef CONFIG_ARM64_SEV_IN_LOCK_UNLOCK

	"	dsb ishst\n"

	"	sev\n"

#endif

	: "=Q" (rw->lock) : "r" (0) : "memory");

}
@@ -197,6 +205,10 @@ static inline void arch_read_unlock(arch_rwlock_t *rw) 
	"1:	ldxr	%w0, %2\n"

	"	sub	%w0, %w0, #1\n"

	"	stlxr	%w1, %w0, %2\n"

#ifdef CONFIG_ARM64_SEV_IN_LOCK_UNLOCK

	"	dsb ishst\n"

	"	sev\n"

#endif

	"	cbnz	%w1, 1b\n"

	: "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)

	: