Removing explicit calls to mmiowb() from driver code means that we must now call into the generic mmiowb_spin_{lock,unlock}() functions from the core spinlock code. In order to elide barriers following critical sections without any I/O writes, we also hook into the asm-generic I/O routines.
Showing the changes to kernel/locking (1 of 3 files). Show all
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| @@ -111,6 +111,7 @@ void do_raw_spin_lock(raw_spinlock_t *lock) · 110 unmodified lines | |||
| 111 | { | 111 | { |
| 112 | debug_spin_lock_before(lock); | 112 | debug_spin_lock_before(lock); |
| 113 | arch_spin_lock(&lock->raw_lock); | 113 | arch_spin_lock(&lock->raw_lock); |
| 114 | mmiowb_spin_lock(); | ||
| 114 | debug_spin_lock_after(lock); | 115 | debug_spin_lock_after(lock); |
| 115 | } | 116 | } |
| 116 | 117 | ||
| @@ -118,8 +119,10 @@ int do_raw_spin_trylock(raw_spinlock_t *lock) · 1 unmodified line | |||
| 118 | { | 119 | { |
| 119 | int ret = arch_spin_trylock(&lock->raw_lock); | 120 | int ret = arch_spin_trylock(&lock->raw_lock); |
| 120 | 121 | ||
| 121 | if (ret) | 122 | if (ret) { |
| 123 | mmiowb_spin_lock(); | ||
| 122 | debug_spin_lock_after(lock); | 124 | debug_spin_lock_after(lock); |
| 125 | } | ||
| 123 | #ifndef CONFIG_SMP | 126 | #ifndef CONFIG_SMP |
| 124 | /* | 127 | /* |
| 125 | * Must not happen on UP: | 128 | * Must not happen on UP: |
| @@ -131,6 +134,7 @@ int do_raw_spin_trylock(raw_spinlock_t *lock) · 5 unmodified lines | |||
| 131 | 134 | ||
| 132 | void do_raw_spin_unlock(raw_spinlock_t *lock) | 135 | void do_raw_spin_unlock(raw_spinlock_t *lock) |
| 133 | { | 136 | { |
| 137 | mmiowb_spin_unlock(); | ||
| 134 | debug_spin_unlock(lock); | 138 | debug_spin_unlock(lock); |
| 135 | arch_spin_unlock(&lock->raw_lock); | 139 | arch_spin_unlock(&lock->raw_lock); |
| 136 | } | 140 | } |