diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/Kconfig | 2 | ||||
| -rw-r--r-- | arch/x86/entry/syscalls/syscall_32.tbl | 3 | ||||
| -rw-r--r-- | arch/x86/entry/syscalls/syscall_64.tbl | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/cmpxchg.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/local.h | 33 |
5 files changed, 29 insertions, 18 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index aab5e3205602..9b2a598cce8d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -28,7 +28,6 @@ config X86_64 select ARCH_HAS_GIGANTIC_PAGE select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 select ARCH_SUPPORTS_PER_VMA_LOCK - select ARCH_USE_CMPXCHG_LOCKREF select HAVE_ARCH_SOFT_DIRTY select MODULES_USE_ELF_RELA select NEED_DMA_MAP_STATE @@ -118,6 +117,7 @@ config X86 select ARCH_SUPPORTS_LTO_CLANG select ARCH_SUPPORTS_LTO_CLANG_THIN select ARCH_USE_BUILTIN_BSWAP + select ARCH_USE_CMPXCHG_LOCKREF if X86_CMPXCHG64 select ARCH_USE_MEMTEST select ARCH_USE_QUEUED_RWLOCKS select ARCH_USE_QUEUED_SPINLOCKS diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 2d0b1bd866ea..31c48bc2c3d8 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -457,3 +457,6 @@ 450 i386 set_mempolicy_home_node sys_set_mempolicy_home_node 451 i386 cachestat sys_cachestat 452 i386 fchmodat2 sys_fchmodat2 +454 i386 futex_wake sys_futex_wake +455 i386 futex_wait sys_futex_wait +456 i386 futex_requeue sys_futex_requeue diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 1d6eee30eceb..a577bb27c16d 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -375,6 +375,9 @@ 451 common cachestat sys_cachestat 452 common fchmodat2 sys_fchmodat2 453 64 map_shadow_stack sys_map_shadow_stack +454 common futex_wake sys_futex_wake +455 common futex_wait sys_futex_wait +456 common futex_requeue sys_futex_requeue # # Due to a historical design error, certain syscalls are numbered differently diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h index d53636506134..5612648b0202 100644 --- a/arch/x86/include/asm/cmpxchg.h +++ b/arch/x86/include/asm/cmpxchg.h @@ -221,12 +221,18 @@ extern void __add_wrong_size(void) #define __try_cmpxchg(ptr, pold, new, size) \ __raw_try_cmpxchg((ptr), (pold), (new), (size), LOCK_PREFIX) +#define __sync_try_cmpxchg(ptr, pold, new, size) \ + __raw_try_cmpxchg((ptr), (pold), (new), (size), "lock; ") + #define __try_cmpxchg_local(ptr, pold, new, size) \ __raw_try_cmpxchg((ptr), (pold), (new), (size), "") #define arch_try_cmpxchg(ptr, pold, new) \ __try_cmpxchg((ptr), (pold), (new), sizeof(*(ptr))) +#define arch_sync_try_cmpxchg(ptr, pold, new) \ + __sync_try_cmpxchg((ptr), (pold), (new), sizeof(*(ptr))) + #define arch_try_cmpxchg_local(ptr, pold, new) \ __try_cmpxchg_local((ptr), (pold), (new), sizeof(*(ptr))) diff --git a/arch/x86/include/asm/local.h b/arch/x86/include/asm/local.h index 635132a12778..73dba8b94443 100644 --- a/arch/x86/include/asm/local.h +++ b/arch/x86/include/asm/local.h @@ -135,28 +135,27 @@ static inline bool local_try_cmpxchg(local_t *l, long *old, long new) #define local_xchg(l, n) (xchg(&((l)->a.counter), (n))) /** - * local_add_unless - add unless the number is a given value + * local_add_unless - add unless the number is already a given value * @l: pointer of type local_t * @a: the amount to add to l... * @u: ...unless l is equal to u. * - * Atomically adds @a to @l, so long as it was not @u. - * Returns non-zero if @l was not @u, and zero otherwise. + * Atomically adds @a to @l, if @v was not already @u. + * Returns true if the addition was done. */ -#define local_add_unless(l, a, u) \ -({ \ - long c, old; \ - c = local_read((l)); \ - for (;;) { \ - if (unlikely(c == (u))) \ - break; \ - old = local_cmpxchg((l), c, c + (a)); \ - if (likely(old == c)) \ - break; \ - c = old; \ - } \ - c != (u); \ -}) +static __always_inline bool +local_add_unless(local_t *l, long a, long u) +{ + long c = local_read(l); + + do { + if (unlikely(c == u)) + return false; + } while (!local_try_cmpxchg(l, &c, c + a)); + + return true; +} + #define local_inc_not_zero(l) local_add_unless((l), 1, 0) /* On x86_32, these are no better than the atomic variants. |