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authorKevin Hilman <khilman@linaro.org>2013-10-14 18:46:26 -0400
committerKevin Hilman <khilman@linaro.org>2013-10-14 18:46:42 -0400
commit5b5bbc20fdddd7dd5a2c5b9fa85dfb3b5695616d (patch)
tree5ddd89d323e1dfe6a5ad204c34882e961ee57b9c /lib/lockref.c
parent4fd0376356ed2e1f6c2a4e8628782aedf903292e (diff)
parent9e490f486ea9ce7644be913e03ee5ccdf1be20f7 (diff)
Merge tag 'omap-for-v3.13/board-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into next/boards
From Tony Lindgren: Platform data changes for omaps for the display subsystem and n900 secure mode changes. Note that the n900 secure mode changes will still be needed for device tree based booting also. * tag 'omap-for-v3.13/board-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: (508 commits) ARM: OMAP2+: display: Create omap_vout device inside omap_display_init ARM: OMAP2+: display: Create omapvrfb and omapfb devices inside omap_display_init ARM: OMAP2+: display: Create omapdrm device inside omap_display_init ARM: OMAP2+: drm: Don't build device for DMM RX-51: Add support for OMAP3 ROM Random Number Generator ARM: OMAP3: RX-51: ARM errata 430973 workaround ARM: OMAP3: Add secure function omap_smc3() which calling instruction smc #1 +Linux 3.12-rc4 Signed-off-by: Kevin Hilman <khilman@linaro.org>
Diffstat (limited to 'lib/lockref.c')
-rw-r--r--lib/lockref.c23
1 files changed, 20 insertions, 3 deletions
diff --git a/lib/lockref.c b/lib/lockref.c
index 677d036cf3c7..6f9d434c1521 100644
--- a/lib/lockref.c
+++ b/lib/lockref.c
@@ -4,6 +4,22 @@
4#ifdef CONFIG_CMPXCHG_LOCKREF 4#ifdef CONFIG_CMPXCHG_LOCKREF
5 5
6/* 6/*
7 * Allow weakly-ordered memory architectures to provide barrier-less
8 * cmpxchg semantics for lockref updates.
9 */
10#ifndef cmpxchg64_relaxed
11# define cmpxchg64_relaxed cmpxchg64
12#endif
13
14/*
15 * Allow architectures to override the default cpu_relax() within CMPXCHG_LOOP.
16 * This is useful for architectures with an expensive cpu_relax().
17 */
18#ifndef arch_mutex_cpu_relax
19# define arch_mutex_cpu_relax() cpu_relax()
20#endif
21
22/*
7 * Note that the "cmpxchg()" reloads the "old" value for the 23 * Note that the "cmpxchg()" reloads the "old" value for the
8 * failure case. 24 * failure case.
9 */ 25 */
@@ -14,12 +30,13 @@
14 while (likely(arch_spin_value_unlocked(old.lock.rlock.raw_lock))) { \ 30 while (likely(arch_spin_value_unlocked(old.lock.rlock.raw_lock))) { \
15 struct lockref new = old, prev = old; \ 31 struct lockref new = old, prev = old; \
16 CODE \ 32 CODE \
17 old.lock_count = cmpxchg64(&lockref->lock_count, \ 33 old.lock_count = cmpxchg64_relaxed(&lockref->lock_count, \
18 old.lock_count, new.lock_count); \ 34 old.lock_count, \
35 new.lock_count); \
19 if (likely(old.lock_count == prev.lock_count)) { \ 36 if (likely(old.lock_count == prev.lock_count)) { \
20 SUCCESS; \ 37 SUCCESS; \
21 } \ 38 } \
22 cpu_relax(); \ 39 arch_mutex_cpu_relax(); \
23 } \ 40 } \
24} while (0) 41} while (0)
25 42