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Commit b8dc93cbe91324b922395919cd5df4cca2fe55f6

Authored by Nick Piggin
Committed by Linus Torvalds
1 parent 66ffb04ca5
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

bit_spin_lock: use lock bitops 

Convert bit_spin_lock to new locking bitops.  Slub can use the non-atomic
store version to clear (Christoph?)

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 22 additions and 4 deletions Side-by-side Diff

include/linux/bit_spinlock.h
Diff comments   View file @ b8dc93c
... ... @@ -18,7 +18,7 @@
18 18 */
19 19 preempt_disable();
20 20 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
21   - while (test_and_set_bit(bitnum, addr)) {
  21 + while (unlikely(test_and_set_bit_lock(bitnum, addr))) {
22 22 while (test_bit(bitnum, addr)) {
23 23 preempt_enable();
24 24 cpu_relax();
... ... @@ -36,7 +36,7 @@
36 36 {
37 37 preempt_disable();
38 38 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
39   - if (test_and_set_bit(bitnum, addr)) {
  39 + if (unlikely(test_and_set_bit_lock(bitnum, addr))) {
40 40 preempt_enable();
41 41 return 0;
42 42 }
43 43  
44 44  
... ... @@ -50,10 +50,28 @@
50 50 */
51 51 static inline void bit_spin_unlock(int bitnum, unsigned long *addr)
52 52 {
  53 +#ifdef CONFIG_DEBUG_SPINLOCK
  54 + BUG_ON(!test_bit(bitnum, addr));
  55 +#endif
53 56 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
  57 + clear_bit_unlock(bitnum, addr);
  58 +#endif
  59 + preempt_enable();
  60 + __release(bitlock);
  61 +}
  62 +
  63 +/*
  64 + * bit-based spin_unlock()
  65 + * non-atomic version, which can be used eg. if the bit lock itself is
  66 + * protecting the rest of the flags in the word.
  67 + */
  68 +static inline void __bit_spin_unlock(int bitnum, unsigned long *addr)
  69 +{
  70 +#ifdef CONFIG_DEBUG_SPINLOCK
54 71 BUG_ON(!test_bit(bitnum, addr));
55   - smp_mb__before_clear_bit();
56   - clear_bit(bitnum, addr);
  72 +#endif
  73 +#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
  74 + __clear_bit_unlock(bitnum, addr);
57 75 #endif
58 76 preempt_enable();
59 77 __release(bitlock);