path: root/lib/atomic64.c
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2011-07-26atomic: use <linux/atomic.h>Arun Sharma1-1/+1
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-01lib: Fix atomic64_add_unless return value conventionLuca Barbieri1-2/+2
atomic64_add_unless must return 1 if it perfomed the add and 0 otherwise. The generic implementation did the opposite thing. Reported-by: H. Peter Anvin <hpa@zytor.com> Confirmed-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Luca Barbieri <luca@luca-barbieri.com> LKML-Reference: <1267469749-11878-4-git-send-email-luca@luca-barbieri.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-07-29lib: export generic atomic64_t functionsRoland Dreier1-0/+11
The generic atomic64_t implementation in lib/ did not export the functions it defined, which means that modules that use atomic64_t would not link on platforms (such as 32-bit powerpc). For example, trying to build a kernel with CONFIG_NET_RDS on such a platform would fail with: ERROR: "atomic64_read" [net/rds/rds.ko] undefined! ERROR: "atomic64_set" [net/rds/rds.ko] undefined! Fix this by exporting the atomic64_t functions to modules. (I export the entire API even if it's not all currently used by in-tree modules to avoid having to continue fixing this in dribs and drabs) Signed-off-by: Roland Dreier <rolandd@cisco.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-15lib: Provide generic atomic64_t implementationPaul Mackerras1-0/+175
Many processor architectures have no 64-bit atomic instructions, but we need atomic64_t in order to support the perf_counter subsystem. This adds an implementation of 64-bit atomic operations using hashed spinlocks to provide atomicity. For each atomic operation, the address of the atomic64_t variable is hashed to an index into an array of 16 spinlocks. That spinlock is taken (with interrupts disabled) around the operation, which can then be coded non-atomically within the lock. On UP, all the spinlock manipulation goes away and we simply disable interrupts around each operation. In fact gcc eliminates the whole atomic64_lock variable as well. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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