diff options
| author | Olof Johansson <olof@lixom.net> | 2013-10-28 14:39:03 -0700 |
|---|---|---|
| committer | Olof Johansson <olof@lixom.net> | 2013-10-28 14:39:03 -0700 |
| commit | 43d93947a54cf9323198a3a37eaf3ec14adb23e1 (patch) | |
| tree | 0c290a7fcbc644b94527f399e4f9509a8d379a5d /lib/lockref.c | |
| parent | 02673f94d04e629e4cdc41e2bf2dc980743cf3df (diff) | |
| parent | 54b89756a14aa1043507ce0811b4b6c02c5dddcc (diff) | |
Merge tag 'omap-for-v3.13/cm-scm-cleanup-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into next/cleanup
From Paul Walmsley <paul@pwsan.com> via Tony Lindgren:
Move some of the OMAP2+ CM and System Control Module direct
register accesses into CM- and System Control
Module-specific "drivers" underneath arch/arm/mach-omap2/. This
is a prerequisite for moving this code out of arch/arm/mach-omap2/ into
drivers/.
Basic test logs are available here:
http://www.pwsan.com/omap/testlogs/cm_scm_cleanup_a_v3.13/20131019101809/
* tag 'omap-for-v3.13/cm-scm-cleanup-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
ARM: OMAP3: control: add API for setting IVA bootmode
ARM: OMAP3: CM/control: move CM scratchpad save to CM driver
ARM: OMAP3: McBSP: do not access CM register directly
ARM: OMAP3: clock: add API to enable/disable autoidle for a single clock
ARM: OMAP2: CM/PM: remove direct register accesses outside CM code
+ Linux 3.12-rc4
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) |