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| author | Olof Johansson <olof@lixom.net> | 2013-10-27 21:42:44 -0700 |
|---|---|---|
| committer | Olof Johansson <olof@lixom.net> | 2013-10-27 21:42:44 -0700 |
| commit | 3316dee245ef297155fa45b8d14263dfd6a9164b (patch) | |
| tree | 7adbf9875893ce0405f771d92d266d70df1aedbb /lib/lockref.c | |
| parent | f2c4e82e350dab489ae0d8fcd84b780de508ab64 (diff) | |
| parent | 1fecf8958eb7f90791f2c7e99afac393b64fa976 (diff) | |
Merge tag 's3c24xx-dma' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into next/drivers
From Kukjin Kim, this branch adds device-tree support to the DMA controller
on the older Samsung SoCs. It also adds support for one of the missing SoCs
in the family (2410).
The driver has been Ack:ed by Vinod Koul, but is merged through here due
to dependencies with platform code.
* tag 's3c24xx-dma' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
ARM: S3C24XX: add dma pdata for s3c2410, s3c2440 and s3c2442
dmaengine: s3c24xx-dma: add support for the s3c2410 type of controller
ARM: S3C24XX: Fix possible dma selection warning
ARM: SAMSUNG: set s3c24xx_dma_filter for s3c64xx-spi0 device
ARM: S3C24XX: add platform-devices for new dma driver for s3c2412 and s3c2443
dmaengine: add driver for Samsung s3c24xx SoCs
ARM: S3C24XX: number the dma clocks
+ Linux 3.12-rc3
Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'lib/lockref.c')
| -rw-r--r-- | lib/lockref.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/lib/lockref.c b/lib/lockref.c index 677d036cf3c..6f9d434c152 100644 --- a/lib/lockref.c +++ b/lib/lockref.c @@ -4,6 +4,22 @@ #ifdef CONFIG_CMPXCHG_LOCKREF /* + * Allow weakly-ordered memory architectures to provide barrier-less + * cmpxchg semantics for lockref updates. + */ +#ifndef cmpxchg64_relaxed +# define cmpxchg64_relaxed cmpxchg64 +#endif + +/* + * Allow architectures to override the default cpu_relax() within CMPXCHG_LOOP. + * This is useful for architectures with an expensive cpu_relax(). + */ +#ifndef arch_mutex_cpu_relax +# define arch_mutex_cpu_relax() cpu_relax() +#endif + +/* * Note that the "cmpxchg()" reloads the "old" value for the * failure case. */ @@ -14,12 +30,13 @@ while (likely(arch_spin_value_unlocked(old.lock.rlock.raw_lock))) { \ struct lockref new = old, prev = old; \ CODE \ - old.lock_count = cmpxchg64(&lockref->lock_count, \ - old.lock_count, new.lock_count); \ + old.lock_count = cmpxchg64_relaxed(&lockref->lock_count, \ + old.lock_count, \ + new.lock_count); \ if (likely(old.lock_count == prev.lock_count)) { \ SUCCESS; \ } \ - cpu_relax(); \ + arch_mutex_cpu_relax(); \ } \ } while (0) |