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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-30 21:47:12 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-30 21:47:12 -0700 |
commit | 05a8256c586ab75bcd6b793737b2022a1a98cb1e (patch) | |
tree | 2f25fcae0d63a0bfbfa16d887eb518d8d5c226e2 /arch/tile/include/asm/spinlock_64.h | |
parent | 0161b6e0d88e04f54ada7112bb2dad1f3ae472af (diff) | |
parent | 5316a64ce518f850afb0fca322b85b6dff3cb59f (diff) | |
download | linux-05a8256c586ab75bcd6b793737b2022a1a98cb1e.tar.bz2 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
Pull arch/tile updates from Chris Metcalf:
"These are a grab bag of changes to improve debugging and respond to a
variety of issues raised on LKML over the last couple of months"
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
tile: avoid a "label not used" warning in do_page_fault()
tile: vdso: use raw_read_seqcount_begin() in vdso
tile: force CONFIG_TILEGX if ARCH != tilepro
tile: improve stack backtrace
tile: fix "odd fault" warning for stack backtraces
tile: set up initial stack top to honor STACK_TOP_DELTA
tile: support delivering NMIs for multicore backtrace
drivers/tty/hvc/hvc_tile.c: properly return -EAGAIN
tile: add <asm/word-at-a-time.h> and enable support functions
tile: use READ_ONCE() in arch_spin_is_locked()
tile: modify arch_spin_unlock_wait() semantics
Diffstat (limited to 'arch/tile/include/asm/spinlock_64.h')
-rw-r--r-- | arch/tile/include/asm/spinlock_64.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/tile/include/asm/spinlock_64.h b/arch/tile/include/asm/spinlock_64.h index 9a12b9c7e5d3..b9718fb4e74a 100644 --- a/arch/tile/include/asm/spinlock_64.h +++ b/arch/tile/include/asm/spinlock_64.h @@ -18,6 +18,8 @@ #ifndef _ASM_TILE_SPINLOCK_64_H #define _ASM_TILE_SPINLOCK_64_H +#include <linux/compiler.h> + /* Shifts and masks for the various fields in "lock". */ #define __ARCH_SPIN_CURRENT_SHIFT 17 #define __ARCH_SPIN_NEXT_MASK 0x7fff @@ -44,7 +46,8 @@ static inline u32 arch_spin_next(u32 val) /* The lock is locked if a task would have to wait to get it. */ static inline int arch_spin_is_locked(arch_spinlock_t *lock) { - u32 val = lock->lock; + /* Use READ_ONCE() to ensure that calling this in a loop is OK. */ + u32 val = READ_ONCE(lock->lock); return arch_spin_current(val) != arch_spin_next(val); } |