From 27782f2752aca65a241f10fb2d4508c71bb2656b Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 23 Apr 2014 19:51:36 +0200 Subject: mips: Provide atomic_{or,xor,and} Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Acked-by: Ralf Baechle Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner --- arch/mips/include/asm/atomic.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'arch/mips/include/asm') diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h index 26d436336f2e..0430ba6ab762 100644 --- a/arch/mips/include/asm/atomic.h +++ b/arch/mips/include/asm/atomic.h @@ -137,6 +137,12 @@ static __inline__ int atomic_##op##_return(int i, atomic_t * v) \ ATOMIC_OPS(add, +=, addu) ATOMIC_OPS(sub, -=, subu) +#define CONFIG_ARCH_HAS_ATOMIC_OR + +ATOMIC_OP(and, &=, and) +ATOMIC_OP(or, |=, or) +ATOMIC_OP(xor, ^=, xor) + #undef ATOMIC_OPS #undef ATOMIC_OP_RETURN #undef ATOMIC_OP @@ -416,6 +422,9 @@ static __inline__ long atomic64_##op##_return(long i, atomic64_t * v) \ ATOMIC64_OPS(add, +=, daddu) ATOMIC64_OPS(sub, -=, dsubu) +ATOMIC64_OP(and, &=, and) +ATOMIC64_OP(or, |=, or) +ATOMIC64_OP(xor, ^=, xor) #undef ATOMIC64_OPS #undef ATOMIC64_OP_RETURN -- cgit v1.2.3 From e6942b7de2dfe44ebde9bae57dadece5abca9de8 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 23 Apr 2014 19:32:50 +0200 Subject: atomic: Provide atomic_{or,xor,and} Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner --- arch/alpha/include/asm/atomic.h | 1 - arch/arc/include/asm/atomic.h | 1 - arch/arm/include/asm/atomic.h | 1 - arch/arm64/include/asm/atomic.h | 1 - arch/avr32/include/asm/atomic.h | 2 -- arch/blackfin/include/asm/atomic.h | 2 -- arch/frv/include/asm/atomic.h | 2 -- arch/h8300/include/asm/atomic.h | 2 -- arch/hexagon/include/asm/atomic.h | 2 -- arch/ia64/include/asm/atomic.h | 2 -- arch/m32r/include/asm/atomic.h | 2 -- arch/m68k/include/asm/atomic.h | 2 -- arch/metag/include/asm/atomic_lnkget.h | 2 -- arch/mips/include/asm/atomic.h | 2 -- arch/mn10300/include/asm/atomic.h | 2 -- arch/parisc/include/asm/atomic.h | 2 -- arch/powerpc/include/asm/atomic.h | 2 -- arch/s390/include/asm/atomic.h | 2 -- arch/sh/include/asm/atomic-grb.h | 2 -- arch/sparc/include/asm/atomic_32.h | 2 -- arch/sparc/include/asm/atomic_64.h | 2 -- arch/tile/include/asm/atomic_32.h | 2 -- arch/tile/include/asm/atomic_64.h | 2 -- arch/x86/include/asm/atomic.h | 2 -- arch/xtensa/include/asm/atomic.h | 2 -- include/asm-generic/atomic.h | 21 ++++++++++++--------- include/asm-generic/atomic64.h | 4 ++++ include/linux/atomic.h | 13 ------------- lib/atomic64.c | 3 +++ 29 files changed, 19 insertions(+), 68 deletions(-) (limited to 'arch/mips/include/asm') diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h index 0eff853398d2..e8c956098424 100644 --- a/arch/alpha/include/asm/atomic.h +++ b/arch/alpha/include/asm/atomic.h @@ -110,7 +110,6 @@ static __inline__ long atomic64_##op##_return(long i, atomic64_t * v) \ ATOMIC_OPS(add) ATOMIC_OPS(sub) -#define CONFIG_ARCH_HAS_ATOMIC_OR #define atomic_andnot atomic_andnot #define atomic64_andnot atomic64_andnot diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h index e90b701fc6a8..2a847821dee1 100644 --- a/arch/arc/include/asm/atomic.h +++ b/arch/arc/include/asm/atomic.h @@ -144,7 +144,6 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ ATOMIC_OPS(add, +=, add) ATOMIC_OPS(sub, -=, sub) -#define CONFIG_ARCH_HAS_ATOMIC_OR #define atomic_andnot atomic_andnot ATOMIC_OP(and, &=, and) diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h index ff214bac9cb4..82b75a7cb762 100644 --- a/arch/arm/include/asm/atomic.h +++ b/arch/arm/include/asm/atomic.h @@ -194,7 +194,6 @@ static inline int __atomic_add_unless(atomic_t *v, int a, int u) ATOMIC_OPS(add, +=, add) ATOMIC_OPS(sub, -=, sub) -#define CONFIG_ARCH_HAS_ATOMIC_OR #define atomic_andnot atomic_andnot ATOMIC_OP(and, &=, and) diff --git a/arch/arm64/include/asm/atomic.h b/arch/arm64/include/asm/atomic.h index 2876173397b2..866a71fca9a3 100644 --- a/arch/arm64/include/asm/atomic.h +++ b/arch/arm64/include/asm/atomic.h @@ -85,7 +85,6 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ ATOMIC_OPS(add, add) ATOMIC_OPS(sub, sub) -#define CONFIG_ARCH_HAS_ATOMIC_OR #define atomic_andnot atomic_andnot ATOMIC_OP(and, and) diff --git a/arch/avr32/include/asm/atomic.h b/arch/avr32/include/asm/atomic.h index 115d3005e4bc..97c9bdf83409 100644 --- a/arch/avr32/include/asm/atomic.h +++ b/arch/avr32/include/asm/atomic.h @@ -51,8 +51,6 @@ static inline void atomic_##op(int i, atomic_t *v) \ (void)__atomic_##op##_return(i, v); \ } -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and, and) ATOMIC_OP(or, or) ATOMIC_OP(xor, eor) diff --git a/arch/blackfin/include/asm/atomic.h b/arch/blackfin/include/asm/atomic.h index eafa55b81a7b..2d6a7a3823c3 100644 --- a/arch/blackfin/include/asm/atomic.h +++ b/arch/blackfin/include/asm/atomic.h @@ -28,8 +28,6 @@ asmlinkage int __raw_atomic_test_asm(const volatile int *ptr, int value); #define atomic_add_return(i, v) __raw_atomic_add_asm(&(v)->counter, i) #define atomic_sub_return(i, v) __raw_atomic_add_asm(&(v)->counter, -(i)) -#define CONFIG_ARCH_HAS_ATOMIC_OR - #define atomic_or(i, v) (void)__raw_atomic_or_asm(&(v)->counter, i) #define atomic_and(i, v) (void)__raw_atomic_and_asm(&(v)->counter, i) #define atomic_xor(i, v) (void)__raw_atomic_xor_asm(&(v)->counter, i) diff --git a/arch/frv/include/asm/atomic.h b/arch/frv/include/asm/atomic.h index 74d22454d7c6..fc48bea26b40 100644 --- a/arch/frv/include/asm/atomic.h +++ b/arch/frv/include/asm/atomic.h @@ -192,8 +192,6 @@ static inline void atomic64_##op(long long i, atomic64_t *v) \ (void)__atomic64_fetch_##op(i, &v->counter); \ } -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(or) ATOMIC_OP(and) ATOMIC_OP(xor) diff --git a/arch/h8300/include/asm/atomic.h b/arch/h8300/include/asm/atomic.h index f181f820be33..c4d061f09c44 100644 --- a/arch/h8300/include/asm/atomic.h +++ b/arch/h8300/include/asm/atomic.h @@ -41,8 +41,6 @@ static inline void atomic_##op(int i, atomic_t *v) \ ATOMIC_OP_RETURN(add, +=) ATOMIC_OP_RETURN(sub, -=) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and, &=) ATOMIC_OP(or, |=) ATOMIC_OP(xor, ^=) diff --git a/arch/hexagon/include/asm/atomic.h b/arch/hexagon/include/asm/atomic.h index 4efe2c7c0dd8..811d61f6422d 100644 --- a/arch/hexagon/include/asm/atomic.h +++ b/arch/hexagon/include/asm/atomic.h @@ -132,8 +132,6 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ ATOMIC_OPS(add) ATOMIC_OPS(sub) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and) ATOMIC_OP(or) ATOMIC_OP(xor) diff --git a/arch/ia64/include/asm/atomic.h b/arch/ia64/include/asm/atomic.h index 0809ef5d6b9a..be4beeb77d57 100644 --- a/arch/ia64/include/asm/atomic.h +++ b/arch/ia64/include/asm/atomic.h @@ -69,8 +69,6 @@ ATOMIC_OP(sub, -) : ia64_atomic_sub(__ia64_asr_i, v); \ }) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and, &) ATOMIC_OP(or, |) ATOMIC_OP(xor, ^) diff --git a/arch/m32r/include/asm/atomic.h b/arch/m32r/include/asm/atomic.h index 7245463c1e98..b2a13fbd5be0 100644 --- a/arch/m32r/include/asm/atomic.h +++ b/arch/m32r/include/asm/atomic.h @@ -94,8 +94,6 @@ static __inline__ int atomic_##op##_return(int i, atomic_t *v) \ ATOMIC_OPS(add) ATOMIC_OPS(sub) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and) ATOMIC_OP(or) ATOMIC_OP(xor) diff --git a/arch/m68k/include/asm/atomic.h b/arch/m68k/include/asm/atomic.h index c30e43ea49a3..93ebd96aa494 100644 --- a/arch/m68k/include/asm/atomic.h +++ b/arch/m68k/include/asm/atomic.h @@ -77,8 +77,6 @@ static inline int atomic_##op##_return(int i, atomic_t * v) \ ATOMIC_OPS(add, +=, add) ATOMIC_OPS(sub, -=, sub) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and, &=, and) ATOMIC_OP(or, |=, or) ATOMIC_OP(xor, ^=, eor) diff --git a/arch/metag/include/asm/atomic_lnkget.h b/arch/metag/include/asm/atomic_lnkget.h index 930c12cb8d37..0642606de901 100644 --- a/arch/metag/include/asm/atomic_lnkget.h +++ b/arch/metag/include/asm/atomic_lnkget.h @@ -74,8 +74,6 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ ATOMIC_OPS(add) ATOMIC_OPS(sub) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and) ATOMIC_OP(or) ATOMIC_OP(xor) diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h index 0430ba6ab762..4c42fd9af777 100644 --- a/arch/mips/include/asm/atomic.h +++ b/arch/mips/include/asm/atomic.h @@ -137,8 +137,6 @@ static __inline__ int atomic_##op##_return(int i, atomic_t * v) \ ATOMIC_OPS(add, +=, addu) ATOMIC_OPS(sub, -=, subu) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and, &=, and) ATOMIC_OP(or, |=, or) ATOMIC_OP(xor, ^=, xor) diff --git a/arch/mn10300/include/asm/atomic.h b/arch/mn10300/include/asm/atomic.h index 03eea8158cf9..f5a63f0bda46 100644 --- a/arch/mn10300/include/asm/atomic.h +++ b/arch/mn10300/include/asm/atomic.h @@ -89,8 +89,6 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ ATOMIC_OPS(add) ATOMIC_OPS(sub) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and) ATOMIC_OP(or) ATOMIC_OP(xor) diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h index be2c50ddebd6..2536965d00ea 100644 --- a/arch/parisc/include/asm/atomic.h +++ b/arch/parisc/include/asm/atomic.h @@ -126,8 +126,6 @@ static __inline__ int atomic_##op##_return(int i, atomic_t *v) \ ATOMIC_OPS(add, +=) ATOMIC_OPS(sub, -=) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and, &=) ATOMIC_OP(or, |=) ATOMIC_OP(xor, ^=) diff --git a/arch/powerpc/include/asm/atomic.h b/arch/powerpc/include/asm/atomic.h index 6ca89e2aca15..55f106ed12bf 100644 --- a/arch/powerpc/include/asm/atomic.h +++ b/arch/powerpc/include/asm/atomic.h @@ -67,8 +67,6 @@ static __inline__ int atomic_##op##_return(int a, atomic_t *v) \ ATOMIC_OPS(add, add) ATOMIC_OPS(sub, subf) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and, and) ATOMIC_OP(or, or) ATOMIC_OP(xor, xor) diff --git a/arch/s390/include/asm/atomic.h b/arch/s390/include/asm/atomic.h index b3859d8e001f..d761aeff72da 100644 --- a/arch/s390/include/asm/atomic.h +++ b/arch/s390/include/asm/atomic.h @@ -282,8 +282,6 @@ static inline void atomic64_##op(long i, atomic64_t *v) \ __ATOMIC64_LOOP(v, i, __ATOMIC64_##OP, __ATOMIC64_NO_BARRIER); \ } -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC64_OP(and, AND) ATOMIC64_OP(or, OR) ATOMIC64_OP(xor, XOR) diff --git a/arch/sh/include/asm/atomic-grb.h b/arch/sh/include/asm/atomic-grb.h index 4b03830d48c7..b94df40e5f2d 100644 --- a/arch/sh/include/asm/atomic-grb.h +++ b/arch/sh/include/asm/atomic-grb.h @@ -48,8 +48,6 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ ATOMIC_OPS(add) ATOMIC_OPS(sub) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and) ATOMIC_OP(or) ATOMIC_OP(xor) diff --git a/arch/sparc/include/asm/atomic_32.h b/arch/sparc/include/asm/atomic_32.h index e19d8880b146..7dcbebbcaec6 100644 --- a/arch/sparc/include/asm/atomic_32.h +++ b/arch/sparc/include/asm/atomic_32.h @@ -17,8 +17,6 @@ #include #include -#define CONFIG_ARCH_HAS_ATOMIC_OR - #define ATOMIC_INIT(i) { (i) } int atomic_add_return(int, atomic_t *); diff --git a/arch/sparc/include/asm/atomic_64.h b/arch/sparc/include/asm/atomic_64.h index d6af27c93450..917084ace49d 100644 --- a/arch/sparc/include/asm/atomic_64.h +++ b/arch/sparc/include/asm/atomic_64.h @@ -33,8 +33,6 @@ long atomic64_##op##_return(long, atomic64_t *); ATOMIC_OPS(add) ATOMIC_OPS(sub) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and) ATOMIC_OP(or) ATOMIC_OP(xor) diff --git a/arch/tile/include/asm/atomic_32.h b/arch/tile/include/asm/atomic_32.h index 94237922f0dd..d320ce253d86 100644 --- a/arch/tile/include/asm/atomic_32.h +++ b/arch/tile/include/asm/atomic_32.h @@ -41,8 +41,6 @@ static inline void atomic_##op(int i, atomic_t *v) \ _atomic_##op((unsigned long *)&v->counter, i); \ } -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and) ATOMIC_OP(or) ATOMIC_OP(xor) diff --git a/arch/tile/include/asm/atomic_64.h b/arch/tile/include/asm/atomic_64.h index d07d9fc6e2a1..096a56d6ead4 100644 --- a/arch/tile/include/asm/atomic_64.h +++ b/arch/tile/include/asm/atomic_64.h @@ -58,8 +58,6 @@ static inline int __atomic_add_unless(atomic_t *v, int a, int u) return oldval; } -#define CONFIG_ARCH_HAS_ATOMIC_OR - static inline void atomic_and(int i, atomic_t *v) { __insn_fetchand4((void *)&v->counter, i); diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h index f3a3ec040694..b3493023efda 100644 --- a/arch/x86/include/asm/atomic.h +++ b/arch/x86/include/asm/atomic.h @@ -191,8 +191,6 @@ static inline void atomic_##op(int i, atomic_t *v) \ : "memory"); \ } -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and) ATOMIC_OP(or) ATOMIC_OP(xor) diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h index 4dd2450300a6..31371f43c23b 100644 --- a/arch/xtensa/include/asm/atomic.h +++ b/arch/xtensa/include/asm/atomic.h @@ -145,8 +145,6 @@ static inline int atomic_##op##_return(int i, atomic_t * v) \ ATOMIC_OPS(add) ATOMIC_OPS(sub) -#define CONFIG_ARCH_HAS_ATOMIC_OR - ATOMIC_OP(and) ATOMIC_OP(or) ATOMIC_OP(xor) diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h index 92947e0a532a..a41b0b8f7404 100644 --- a/include/asm-generic/atomic.h +++ b/include/asm-generic/atomic.h @@ -102,24 +102,27 @@ ATOMIC_OP_RETURN(sub, -) ATOMIC_OP(and, &) #endif -#ifndef atomic_clear_mask -#define atomic_clear_mask(i, v) atomic_and(~(i), (v)) -#endif - #ifndef atomic_or -#ifndef CONFIG_ARCH_HAS_ATOMIC_OR -#define CONFIG_ARCH_HAS_ATOMIC_OR -#endif ATOMIC_OP(or, |) #endif -#ifndef atomic_set_mask -#define atomic_set_mask(i, v) atomic_or((i), (v)) +#ifndef atomic_xor +ATOMIC_OP(xor, ^) #endif #undef ATOMIC_OP_RETURN #undef ATOMIC_OP +static inline __deprecated void atomic_clear_mask(unsigned int mask, atomic_t *v) +{ + atomic_and(~mask, v); +} + +static inline __deprecated void atomic_set_mask(unsigned int mask, atomic_t *v) +{ + atomic_or(mask, v); +} + /* * Atomic operations that C can't guarantee us. Useful for * resource counting etc.. diff --git a/include/asm-generic/atomic64.h b/include/asm-generic/atomic64.h index 30ad9c86cebb..d48e78ccad3d 100644 --- a/include/asm-generic/atomic64.h +++ b/include/asm-generic/atomic64.h @@ -32,6 +32,10 @@ extern long long atomic64_##op##_return(long long a, atomic64_t *v); ATOMIC64_OPS(add) ATOMIC64_OPS(sub) +ATOMIC64_OP(and) +ATOMIC64_OP(or) +ATOMIC64_OP(xor) + #undef ATOMIC64_OPS #undef ATOMIC64_OP_RETURN #undef ATOMIC64_OP diff --git a/include/linux/atomic.h b/include/linux/atomic.h index 5b08a8540ecf..7d6279012a1f 100644 --- a/include/linux/atomic.h +++ b/include/linux/atomic.h @@ -111,19 +111,6 @@ static inline int atomic_dec_if_positive(atomic_t *v) } #endif -#ifndef CONFIG_ARCH_HAS_ATOMIC_OR -static inline void atomic_or(int i, atomic_t *v) -{ - int old; - int new; - - do { - old = atomic_read(v); - new = old | i; - } while (atomic_cmpxchg(v, old, new) != old); -} -#endif /* #ifndef CONFIG_ARCH_HAS_ATOMIC_OR */ - #include #ifdef CONFIG_GENERIC_ATOMIC64 #include diff --git a/lib/atomic64.c b/lib/atomic64.c index 1298c05ef528..2886ebac6567 100644 --- a/lib/atomic64.c +++ b/lib/atomic64.c @@ -102,6 +102,9 @@ EXPORT_SYMBOL(atomic64_##op##_return); ATOMIC64_OPS(add, +=) ATOMIC64_OPS(sub, -=) +ATOMIC64_OP(and, &=) +ATOMIC64_OP(or, |=) +ATOMIC64_OP(xor, ^=) #undef ATOMIC64_OPS #undef ATOMIC64_OP_RETURN -- cgit v1.2.3 From 76695af20c015206cffb84b15912be6797d0cca2 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Sun, 2 Aug 2015 17:11:04 +0200 Subject: locking, arch: use WRITE_ONCE()/READ_ONCE() in smp_store_release()/smp_load_acquire() Replace ACCESS_ONCE() macro in smp_store_release() and smp_load_acquire() with WRITE_ONCE() and READ_ONCE() on x86, arm, arm64, ia64, metag, mips, powerpc, s390, sparc and asm-generic since ACCESS_ONCE() does not work reliably on non-scalar types. WRITE_ONCE() and READ_ONCE() were introduced in the following commits: 230fa253df63 ("kernel: Provide READ_ONCE and ASSIGN_ONCE") 43239cbe79fc ("kernel: Change ASSIGN_ONCE(val, x) to WRITE_ONCE(x, val)") Signed-off-by: Andrey Konovalov Signed-off-by: Peter Zijlstra (Intel) Acked-by: Davidlohr Bueso Acked-by: Michael Ellerman (powerpc) Acked-by: Ralf Baechle Cc: Alexander Duyck Cc: Andre Przywara Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Catalin Marinas Cc: Christian Borntraeger Cc: David S. Miller Cc: Davidlohr Bueso Cc: Dmitry Vyukov Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Heiko Carstens Cc: James Hogan Cc: Linus Torvalds Cc: Martin Schwidefsky Cc: Paul E. McKenney Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Russell King Cc: Thomas Gleixner Cc: Tony Luck Cc: Will Deacon Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/1438528264-714-1-git-send-email-andreyknvl@google.com Signed-off-by: Ingo Molnar --- arch/arm/include/asm/barrier.h | 4 ++-- arch/arm64/include/asm/barrier.h | 4 ++-- arch/ia64/include/asm/barrier.h | 4 ++-- arch/metag/include/asm/barrier.h | 4 ++-- arch/mips/include/asm/barrier.h | 4 ++-- arch/powerpc/include/asm/barrier.h | 4 ++-- arch/s390/include/asm/barrier.h | 4 ++-- arch/sparc/include/asm/barrier_64.h | 4 ++-- arch/x86/include/asm/barrier.h | 8 ++++---- include/asm-generic/barrier.h | 4 ++-- 10 files changed, 22 insertions(+), 22 deletions(-) (limited to 'arch/mips/include/asm') diff --git a/arch/arm/include/asm/barrier.h b/arch/arm/include/asm/barrier.h index 6c2327e1c732..70393574e0fa 100644 --- a/arch/arm/include/asm/barrier.h +++ b/arch/arm/include/asm/barrier.h @@ -67,12 +67,12 @@ do { \ compiletime_assert_atomic_type(*p); \ smp_mb(); \ - ACCESS_ONCE(*p) = (v); \ + WRITE_ONCE(*p, v); \ } while (0) #define smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ smp_mb(); \ ___p1; \ diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h index 0fa47c4275cb..ef93b20bc964 100644 --- a/arch/arm64/include/asm/barrier.h +++ b/arch/arm64/include/asm/barrier.h @@ -44,12 +44,12 @@ do { \ compiletime_assert_atomic_type(*p); \ barrier(); \ - ACCESS_ONCE(*p) = (v); \ + WRITE_ONCE(*p, v); \ } while (0) #define smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ barrier(); \ ___p1; \ diff --git a/arch/ia64/include/asm/barrier.h b/arch/ia64/include/asm/barrier.h index 843ba435e43b..df896a1c41d3 100644 --- a/arch/ia64/include/asm/barrier.h +++ b/arch/ia64/include/asm/barrier.h @@ -66,12 +66,12 @@ do { \ compiletime_assert_atomic_type(*p); \ barrier(); \ - ACCESS_ONCE(*p) = (v); \ + WRITE_ONCE(*p, v); \ } while (0) #define smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ barrier(); \ ___p1; \ diff --git a/arch/metag/include/asm/barrier.h b/arch/metag/include/asm/barrier.h index 5a696e507930..172b7e5efc53 100644 --- a/arch/metag/include/asm/barrier.h +++ b/arch/metag/include/asm/barrier.h @@ -90,12 +90,12 @@ static inline void fence(void) do { \ compiletime_assert_atomic_type(*p); \ smp_mb(); \ - ACCESS_ONCE(*p) = (v); \ + WRITE_ONCE(*p, v); \ } while (0) #define smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ smp_mb(); \ ___p1; \ diff --git a/arch/mips/include/asm/barrier.h b/arch/mips/include/asm/barrier.h index 7ecba84656d4..752e0b86c171 100644 --- a/arch/mips/include/asm/barrier.h +++ b/arch/mips/include/asm/barrier.h @@ -133,12 +133,12 @@ do { \ compiletime_assert_atomic_type(*p); \ smp_mb(); \ - ACCESS_ONCE(*p) = (v); \ + WRITE_ONCE(*p, v); \ } while (0) #define smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ smp_mb(); \ ___p1; \ diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h index 51ccc7232042..0eca6efc0631 100644 --- a/arch/powerpc/include/asm/barrier.h +++ b/arch/powerpc/include/asm/barrier.h @@ -76,12 +76,12 @@ do { \ compiletime_assert_atomic_type(*p); \ smp_lwsync(); \ - ACCESS_ONCE(*p) = (v); \ + WRITE_ONCE(*p, v); \ } while (0) #define smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ smp_lwsync(); \ ___p1; \ diff --git a/arch/s390/include/asm/barrier.h b/arch/s390/include/asm/barrier.h index e6f8615a11eb..d48fe0162331 100644 --- a/arch/s390/include/asm/barrier.h +++ b/arch/s390/include/asm/barrier.h @@ -42,12 +42,12 @@ do { \ compiletime_assert_atomic_type(*p); \ barrier(); \ - ACCESS_ONCE(*p) = (v); \ + WRITE_ONCE(*p, v); \ } while (0) #define smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ barrier(); \ ___p1; \ diff --git a/arch/sparc/include/asm/barrier_64.h b/arch/sparc/include/asm/barrier_64.h index 809941e33e12..14a928601657 100644 --- a/arch/sparc/include/asm/barrier_64.h +++ b/arch/sparc/include/asm/barrier_64.h @@ -60,12 +60,12 @@ do { __asm__ __volatile__("ba,pt %%xcc, 1f\n\t" \ do { \ compiletime_assert_atomic_type(*p); \ barrier(); \ - ACCESS_ONCE(*p) = (v); \ + WRITE_ONCE(*p, v); \ } while (0) #define smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ barrier(); \ ___p1; \ diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h index e51a8f803f55..d2bcfbed11c3 100644 --- a/arch/x86/include/asm/barrier.h +++ b/arch/x86/include/asm/barrier.h @@ -57,12 +57,12 @@ do { \ compiletime_assert_atomic_type(*p); \ smp_mb(); \ - ACCESS_ONCE(*p) = (v); \ + WRITE_ONCE(*p, v); \ } while (0) #define smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ smp_mb(); \ ___p1; \ @@ -74,12 +74,12 @@ do { \ do { \ compiletime_assert_atomic_type(*p); \ barrier(); \ - ACCESS_ONCE(*p) = (v); \ + WRITE_ONCE(*p, v); \ } while (0) #define smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ barrier(); \ ___p1; \ diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h index 55e3abc2d027..b42afada1280 100644 --- a/include/asm-generic/barrier.h +++ b/include/asm-generic/barrier.h @@ -108,12 +108,12 @@ do { \ compiletime_assert_atomic_type(*p); \ smp_mb(); \ - ACCESS_ONCE(*p) = (v); \ + WRITE_ONCE(*p, v); \ } while (0) #define smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ smp_mb(); \ ___p1; \ -- cgit v1.2.3 From 11276d5306b8e5b438a36bbff855fe792d7eaa61 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 24 Jul 2015 15:09:55 +0200 Subject: locking/static_keys: Add a new static_key interface There are various problems and short-comings with the current static_key interface: - static_key_{true,false}() read like a branch depending on the key value, instead of the actual likely/unlikely branch depending on init value. - static_key_{true,false}() are, as stated above, tied to the static_key init values STATIC_KEY_INIT_{TRUE,FALSE}. - we're limited to the 2 (out of 4) possible options that compile to a default NOP because that's what our arch_static_branch() assembly emits. So provide a new static_key interface: DEFINE_STATIC_KEY_TRUE(name); DEFINE_STATIC_KEY_FALSE(name); Which define a key of different types with an initial true/false value. Then allow: static_branch_likely() static_branch_unlikely() to take a key of either type and emit the right instruction for the case. This means adding a second arch_static_branch_jump() assembly helper which emits a JMP per default. In order to determine the right instruction for the right state, encode the branch type in the LSB of jump_entry::key. This is the final step in removing the naming confusion that has led to a stream of avoidable bugs such as: a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()") ... but it also allows new static key combinations that will give us performance enhancements in the subsequent patches. Tested-by: Rabin Vincent # arm Signed-off-by: Peter Zijlstra (Intel) Acked-by: Michael Ellerman # ppc Acked-by: Heiko Carstens # s390 Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- arch/arm/include/asm/jump_label.h | 25 ++++-- arch/arm64/include/asm/jump_label.h | 18 +++- arch/mips/include/asm/jump_label.h | 19 ++++- arch/powerpc/include/asm/jump_label.h | 19 ++++- arch/s390/include/asm/jump_label.h | 19 ++++- arch/sparc/include/asm/jump_label.h | 35 ++++++-- arch/x86/include/asm/jump_label.h | 21 ++++- include/linux/jump_label.h | 149 +++++++++++++++++++++++++++++++--- kernel/jump_label.c | 37 +++++++-- 9 files changed, 298 insertions(+), 44 deletions(-) (limited to 'arch/mips/include/asm') diff --git a/arch/arm/include/asm/jump_label.h b/arch/arm/include/asm/jump_label.h index 5f337dc5c108..34f7b6980d21 100644 --- a/arch/arm/include/asm/jump_label.h +++ b/arch/arm/include/asm/jump_label.h @@ -4,23 +4,32 @@ #ifndef __ASSEMBLY__ #include +#include #define JUMP_LABEL_NOP_SIZE 4 -#ifdef CONFIG_THUMB2_KERNEL -#define JUMP_LABEL_NOP "nop.w" -#else -#define JUMP_LABEL_NOP "nop" -#endif +static __always_inline bool arch_static_branch(struct static_key *key, bool branch) +{ + asm_volatile_goto("1:\n\t" + WASM(nop) "\n\t" + ".pushsection __jump_table, \"aw\"\n\t" + ".word 1b, %l[l_yes], %c0\n\t" + ".popsection\n\t" + : : "i" (&((char *)key)[branch]) : : l_yes); + + return false; +l_yes: + return true; +} -static __always_inline bool arch_static_branch(struct static_key *key) +static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) { asm_volatile_goto("1:\n\t" - JUMP_LABEL_NOP "\n\t" + WASM(b) " %l[l_yes]\n\t" ".pushsection __jump_table, \"aw\"\n\t" ".word 1b, %l[l_yes], %c0\n\t" ".popsection\n\t" - : : "i" (key) : : l_yes); + : : "i" (&((char *)key)[branch]) : : l_yes); return false; l_yes: diff --git a/arch/arm64/include/asm/jump_label.h b/arch/arm64/include/asm/jump_label.h index c0e5165c2f76..1b5e0e843c3a 100644 --- a/arch/arm64/include/asm/jump_label.h +++ b/arch/arm64/include/asm/jump_label.h @@ -26,14 +26,28 @@ #define JUMP_LABEL_NOP_SIZE AARCH64_INSN_SIZE -static __always_inline bool arch_static_branch(struct static_key *key) +static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { asm goto("1: nop\n\t" ".pushsection __jump_table, \"aw\"\n\t" ".align 3\n\t" ".quad 1b, %l[l_yes], %c0\n\t" ".popsection\n\t" - : : "i"(key) : : l_yes); + : : "i"(&((char *)key)[branch]) : : l_yes); + + return false; +l_yes: + return true; +} + +static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) +{ + asm goto("1: b %l[l_yes]\n\t" + ".pushsection __jump_table, \"aw\"\n\t" + ".align 3\n\t" + ".quad 1b, %l[l_yes], %c0\n\t" + ".popsection\n\t" + : : "i"(&((char *)key)[branch]) : : l_yes); return false; l_yes: diff --git a/arch/mips/include/asm/jump_label.h b/arch/mips/include/asm/jump_label.h index 608aa57799c8..e77672539e8e 100644 --- a/arch/mips/include/asm/jump_label.h +++ b/arch/mips/include/asm/jump_label.h @@ -26,14 +26,29 @@ #define NOP_INSN "nop" #endif -static __always_inline bool arch_static_branch(struct static_key *key) +static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { asm_volatile_goto("1:\t" NOP_INSN "\n\t" "nop\n\t" ".pushsection __jump_table, \"aw\"\n\t" WORD_INSN " 1b, %l[l_yes], %0\n\t" ".popsection\n\t" - : : "i" (key) : : l_yes); + : : "i" (&((char *)key)[branch]) : : l_yes); + + return false; +l_yes: + return true; +} + +static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) +{ + asm_volatile_goto("1:\tj %l[l_yes]\n\t" + "nop\n\t" + ".pushsection __jump_table, \"aw\"\n\t" + WORD_INSN " 1b, %l[l_yes], %0\n\t" + ".popsection\n\t" + : : "i" (&((char *)key)[branch]) : : l_yes); + return false; l_yes: return true; diff --git a/arch/powerpc/include/asm/jump_label.h b/arch/powerpc/include/asm/jump_label.h index efbf9a322a23..47e155f15433 100644 --- a/arch/powerpc/include/asm/jump_label.h +++ b/arch/powerpc/include/asm/jump_label.h @@ -18,14 +18,29 @@ #define JUMP_ENTRY_TYPE stringify_in_c(FTR_ENTRY_LONG) #define JUMP_LABEL_NOP_SIZE 4 -static __always_inline bool arch_static_branch(struct static_key *key) +static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { asm_volatile_goto("1:\n\t" "nop\n\t" ".pushsection __jump_table, \"aw\"\n\t" JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t" ".popsection \n\t" - : : "i" (key) : : l_yes); + : : "i" (&((char *)key)[branch]) : : l_yes); + + return false; +l_yes: + return true; +} + +static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) +{ + asm_volatile_goto("1:\n\t" + "b %l[l_yes]\n\t" + ".pushsection __jump_table, \"aw\"\n\t" + JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t" + ".popsection \n\t" + : : "i" (&((char *)key)[branch]) : : l_yes); + return false; l_yes: return true; diff --git a/arch/s390/include/asm/jump_label.h b/arch/s390/include/asm/jump_label.h index 69972b7957ee..7f9fd5e3f1bf 100644 --- a/arch/s390/include/asm/jump_label.h +++ b/arch/s390/include/asm/jump_label.h @@ -12,14 +12,29 @@ * We use a brcl 0,2 instruction for jump labels at compile time so it * can be easily distinguished from a hotpatch generated instruction. */ -static __always_inline bool arch_static_branch(struct static_key *key) +static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n" ".pushsection __jump_table, \"aw\"\n" ".balign 8\n" ".quad 0b, %l[label], %0\n" ".popsection\n" - : : "X" (key) : : label); + : : "X" (&((char *)key)[branch]) : : label); + + return false; +label: + return true; +} + +static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) +{ + asm_volatile_goto("0: brcl 15, %l[label]\n" + ".pushsection __jump_table, \"aw\"\n" + ".balign 8\n" + ".quad 0b, %l[label], %0\n" + ".popsection\n" + : : "X" (&((char *)key)[branch]) : : label); + return false; label: return true; diff --git a/arch/sparc/include/asm/jump_label.h b/arch/sparc/include/asm/jump_label.h index cc9b04a2b11b..62d0354d1727 100644 --- a/arch/sparc/include/asm/jump_label.h +++ b/arch/sparc/include/asm/jump_label.h @@ -7,16 +7,33 @@ #define JUMP_LABEL_NOP_SIZE 4 -static __always_inline bool arch_static_branch(struct static_key *key) +static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { - asm_volatile_goto("1:\n\t" - "nop\n\t" - "nop\n\t" - ".pushsection __jump_table, \"aw\"\n\t" - ".align 4\n\t" - ".word 1b, %l[l_yes], %c0\n\t" - ".popsection \n\t" - : : "i" (key) : : l_yes); + asm_volatile_goto("1:\n\t" + "nop\n\t" + "nop\n\t" + ".pushsection __jump_table, \"aw\"\n\t" + ".align 4\n\t" + ".word 1b, %l[l_yes], %c0\n\t" + ".popsection \n\t" + : : "i" (&((char *)key)[branch]) : : l_yes); + + return false; +l_yes: + return true; +} + +static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) +{ + asm_volatile_goto("1:\n\t" + "b %l[l_yes]\n\t" + "nop\n\t" + ".pushsection __jump_table, \"aw\"\n\t" + ".align 4\n\t" + ".word 1b, %l[l_yes], %c0\n\t" + ".popsection \n\t" + : : "i" (&((char *)key)[branch]) : : l_yes); + return false; l_yes: return true; diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index a4c1cf7e93f8..28d7a857f9d1 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -16,7 +16,7 @@ # define STATIC_KEY_INIT_NOP GENERIC_NOP5_ATOMIC #endif -static __always_inline bool arch_static_branch(struct static_key *key) +static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { asm_volatile_goto("1:" ".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t" @@ -24,7 +24,24 @@ static __always_inline bool arch_static_branch(struct static_key *key) _ASM_ALIGN "\n\t" _ASM_PTR "1b, %l[l_yes], %c0 \n\t" ".popsection \n\t" - : : "i" (key) : : l_yes); + : : "i" (&((char *)key)[branch]) : : l_yes); + + return false; +l_yes: + return true; +} + +static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) +{ + asm_volatile_goto("1:" + ".byte 0xe9\n\t .long %l[l_yes] - 2f\n\t" + "2:\n\t" + ".pushsection __jump_table, \"aw\" \n\t" + _ASM_ALIGN "\n\t" + _ASM_PTR "1b, %l[l_yes], %c0 \n\t" + ".popsection \n\t" + : : "i" (&((char *)key)[branch]) : : l_yes); + return false; l_yes: return true; diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 65f0ebac63cf..e337a1961933 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -107,12 +107,12 @@ static inline int static_key_count(struct static_key *key) static __always_inline bool static_key_false(struct static_key *key) { - return arch_static_branch(key); + return arch_static_branch(key, false); } static __always_inline bool static_key_true(struct static_key *key) { - return !static_key_false(key); + return !arch_static_branch(key, true); } extern struct jump_entry __start___jump_table[]; @@ -130,12 +130,12 @@ extern void static_key_slow_inc(struct static_key *key); extern void static_key_slow_dec(struct static_key *key); extern void jump_label_apply_nops(struct module *mod); -#define STATIC_KEY_INIT_TRUE ((struct static_key) \ +#define STATIC_KEY_INIT_TRUE \ { .enabled = ATOMIC_INIT(1), \ - .entries = (void *)JUMP_TYPE_TRUE }) -#define STATIC_KEY_INIT_FALSE ((struct static_key) \ + .entries = (void *)JUMP_TYPE_TRUE } +#define STATIC_KEY_INIT_FALSE \ { .enabled = ATOMIC_INIT(0), \ - .entries = (void *)JUMP_TYPE_FALSE }) + .entries = (void *)JUMP_TYPE_FALSE } #else /* !HAVE_JUMP_LABEL */ @@ -183,10 +183,8 @@ static inline int jump_label_apply_nops(struct module *mod) return 0; } -#define STATIC_KEY_INIT_TRUE ((struct static_key) \ - { .enabled = ATOMIC_INIT(1) }) -#define STATIC_KEY_INIT_FALSE ((struct static_key) \ - { .enabled = ATOMIC_INIT(0) }) +#define STATIC_KEY_INIT_TRUE { .enabled = ATOMIC_INIT(1) } +#define STATIC_KEY_INIT_FALSE { .enabled = ATOMIC_INIT(0) } #endif /* HAVE_JUMP_LABEL */ @@ -218,6 +216,137 @@ static inline void static_key_disable(struct static_key *key) static_key_slow_dec(key); } +/* -------------------------------------------------------------------------- */ + +/* + * Two type wrappers around static_key, such that we can use compile time + * type differentiation to emit the right code. + * + * All the below code is macros in order to play type games. + */ + +struct static_key_true { + struct static_key key; +}; + +struct static_key_false { + struct static_key key; +}; + +#define STATIC_KEY_TRUE_INIT (struct static_key_true) { .key = STATIC_KEY_INIT_TRUE, } +#define STATIC_KEY_FALSE_INIT (struct static_key_false){ .key = STATIC_KEY_INIT_FALSE, } + +#define DEFINE_STATIC_KEY_TRUE(name) \ + struct static_key_true name = STATIC_KEY_TRUE_INIT + +#define DEFINE_STATIC_KEY_FALSE(name) \ + struct static_key_false name = STATIC_KEY_FALSE_INIT + +#ifdef HAVE_JUMP_LABEL + +/* + * Combine the right initial value (type) with the right branch order + * to generate the desired result. + * + * + * type\branch| likely (1) | unlikely (0) + * -----------+-----------------------+------------------ + * | | + * true (1) | ... | ... + * | NOP | JMP L + * | | 1: ... + * | L: ... | + * | | + * | | L: + * | | jmp 1b + * | | + * -----------+-----------------------+------------------ + * | | + * false (0) | ... | ... + * | JMP L | NOP + * | | 1: ... + * | L: ... | + * | | + * | | L: + * | | jmp 1b + * | | + * -----------+-----------------------+------------------ + * + * The initial value is encoded in the LSB of static_key::entries, + * type: 0 = false, 1 = true. + * + * The branch type is encoded in the LSB of jump_entry::key, + * branch: 0 = unlikely, 1 = likely. + * + * This gives the following logic table: + * + * enabled type branch instuction + * -----------------------------+----------- + * 0 0 0 | NOP + * 0 0 1 | JMP + * 0 1 0 | NOP + * 0 1 1 | JMP + * + * 1 0 0 | JMP + * 1 0 1 | NOP + * 1 1 0 | JMP + * 1 1 1 | NOP + * + * Which gives the following functions: + * + * dynamic: instruction = enabled ^ branch + * static: instruction = type ^ branch + * + * See jump_label_type() / jump_label_init_type(). + */ + +extern bool ____wrong_branch_error(void); + +#define static_branch_likely(x) \ +({ \ + bool branch; \ + if (__builtin_types_compatible_p(typeof(*x), struct static_key_true)) \ + branch = !arch_static_branch(&(x)->key, true); \ + else if (__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \ + branch = !arch_static_branch_jump(&(x)->key, true); \ + else \ + branch = ____wrong_branch_error(); \ + branch; \ +}) + +#define static_branch_unlikely(x) \ +({ \ + bool branch; \ + if (__builtin_types_compatible_p(typeof(*x), struct static_key_true)) \ + branch = arch_static_branch_jump(&(x)->key, false); \ + else if (__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \ + branch = arch_static_branch(&(x)->key, false); \ + else \ + branch = ____wrong_branch_error(); \ + branch; \ +}) + +#else /* !HAVE_JUMP_LABEL */ + +#define static_branch_likely(x) likely(static_key_enabled(&(x)->key)) +#define static_branch_unlikely(x) unlikely(static_key_enabled(&(x)->key)) + +#endif /* HAVE_JUMP_LABEL */ + +/* + * Advanced usage; refcount, branch is enabled when: count != 0 + */ + +#define static_branch_inc(x) static_key_slow_inc(&(x)->key) +#define static_branch_dec(x) static_key_slow_dec(&(x)->key) + +/* + * Normal usage; boolean enable/disable. + */ + +#define static_branch_enable(x) static_key_enable(&(x)->key) +#define static_branch_disable(x) static_key_disable(&(x)->key) + #endif /* _LINUX_JUMP_LABEL_H */ #endif /* __ASSEMBLY__ */ diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 2e7cc1e4b4b5..8fd00d892286 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -165,16 +165,22 @@ static inline bool static_key_type(struct static_key *key) static inline struct static_key *jump_entry_key(struct jump_entry *entry) { - return (struct static_key *)((unsigned long)entry->key); + return (struct static_key *)((unsigned long)entry->key & ~1UL); +} + +static bool jump_entry_branch(struct jump_entry *entry) +{ + return (unsigned long)entry->key & 1UL; } static enum jump_label_type jump_label_type(struct jump_entry *entry) { struct static_key *key = jump_entry_key(entry); bool enabled = static_key_enabled(key); - bool type = static_key_type(key); + bool branch = jump_entry_branch(entry); - return enabled ^ type; + /* See the comment in linux/jump_label.h */ + return enabled ^ branch; } static void __jump_label_update(struct static_key *key, @@ -205,7 +211,10 @@ void __init jump_label_init(void) for (iter = iter_start; iter < iter_stop; iter++) { struct static_key *iterk; - arch_jump_label_transform_static(iter, jump_label_type(iter)); + /* rewrite NOPs */ + if (jump_label_type(iter) == JUMP_LABEL_NOP) + arch_jump_label_transform_static(iter, JUMP_LABEL_NOP); + iterk = jump_entry_key(iter); if (iterk == key) continue; @@ -225,6 +234,16 @@ void __init jump_label_init(void) #ifdef CONFIG_MODULES +static enum jump_label_type jump_label_init_type(struct jump_entry *entry) +{ + struct static_key *key = jump_entry_key(entry); + bool type = static_key_type(key); + bool branch = jump_entry_branch(entry); + + /* See the comment in linux/jump_label.h */ + return type ^ branch; +} + struct static_key_mod { struct static_key_mod *next; struct jump_entry *entries; @@ -276,8 +295,11 @@ void jump_label_apply_nops(struct module *mod) if (iter_start == iter_stop) return; - for (iter = iter_start; iter < iter_stop; iter++) - arch_jump_label_transform_static(iter, JUMP_LABEL_NOP); + for (iter = iter_start; iter < iter_stop; iter++) { + /* Only write NOPs for arch_branch_static(). */ + if (jump_label_init_type(iter) == JUMP_LABEL_NOP) + arch_jump_label_transform_static(iter, JUMP_LABEL_NOP); + } } static int jump_label_add_module(struct module *mod) @@ -318,7 +340,8 @@ static int jump_label_add_module(struct module *mod) jlm->next = key->next; key->next = jlm; - if (jump_label_type(iter) == JUMP_LABEL_JMP) + /* Only update if we've changed from our initial state */ + if (jump_label_type(iter) != jump_label_init_type(iter)) __jump_label_update(key, iter, iter_stop); } -- cgit v1.2.3