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authorNicholas Piggin <npiggin@gmail.com>2020-07-24 23:14:21 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2020-07-27 00:01:29 +1000
commit20c0e8269e9d515e677670902c7e1cc0209d6ad9 (patch)
tree1de7272a98830301f6d21a1b8cdab7d28d0e83c1 /arch/powerpc/include/asm/spinlock.h
parentaa65ff6b18e0366db1790609956a4ac7308c5668 (diff)
downloadlinux-20c0e8269e9d515e677670902c7e1cc0209d6ad9.tar.bz2
powerpc/pseries: Implement paravirt qspinlocks for SPLPAR
This implements the generic paravirt qspinlocks using H_PROD and H_CONFER to kick and wait. This uses an un-directed yield to any CPU rather than the directed yield to a pre-empted lock holder that paravirtualised simple spinlocks use, that requires no kick hcall. This is something that could be investigated and improved in future. Performance results can be found in the commit which added queued spinlocks. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131423.1362108-5-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/include/asm/spinlock.h')
-rw-r--r--arch/powerpc/include/asm/spinlock.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h
index 434615f1d761..6ec72282888d 100644
--- a/arch/powerpc/include/asm/spinlock.h
+++ b/arch/powerpc/include/asm/spinlock.h
@@ -10,5 +10,9 @@
#include <asm/simple_spinlock.h>
#endif
+#ifndef CONFIG_PARAVIRT_SPINLOCKS
+static inline void pv_spinlocks_init(void) { }
+#endif
+
#endif /* __KERNEL__ */
#endif /* __ASM_SPINLOCK_H */