diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-18 08:25:29 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-18 08:25:29 -0700 |
commit | d7bb545d86825e635cab33a1dd81ca0ad7b92887 (patch) | |
tree | 34da4139ef06ceab6549aea3906639c7413978c8 /arch/sparc64/kernel/semaphore.c | |
parent | 75e98b34155264d943aa53edce465e87f3ccbadf (diff) | |
parent | 2342e51ba2b52a7f5b78227e6faa4603ed3632a0 (diff) |
Merge branch 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc
* 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc:
Remove DEBUG_SEMAPHORE from Kconfig
Improve semaphore documentation
Simplify semaphore implementation
Add down_timeout and change ACPI to use it
Introduce down_killable()
Generic semaphore implementation
Add semaphore.h to kernel_lock.c
Fix quota.h includes
Diffstat (limited to 'arch/sparc64/kernel/semaphore.c')
-rw-r--r-- | arch/sparc64/kernel/semaphore.c | 254 |
1 files changed, 0 insertions, 254 deletions
diff --git a/arch/sparc64/kernel/semaphore.c b/arch/sparc64/kernel/semaphore.c deleted file mode 100644 index 9974a689955..00000000000 --- a/arch/sparc64/kernel/semaphore.c +++ /dev/null @@ -1,254 +0,0 @@ -/* semaphore.c: Sparc64 semaphore implementation. - * - * This is basically the PPC semaphore scheme ported to use - * the sparc64 atomic instructions, so see the PPC code for - * credits. - */ - -#include <linux/sched.h> -#include <linux/errno.h> -#include <linux/init.h> - -/* - * Atomically update sem->count. - * This does the equivalent of the following: - * - * old_count = sem->count; - * tmp = MAX(old_count, 0) + incr; - * sem->count = tmp; - * return old_count; - */ -static inline int __sem_update_count(struct semaphore *sem, int incr) -{ - int old_count, tmp; - - __asm__ __volatile__("\n" -" ! __sem_update_count old_count(%0) tmp(%1) incr(%4) &sem->count(%3)\n" -"1: ldsw [%3], %0\n" -" mov %0, %1\n" -" cmp %0, 0\n" -" movl %%icc, 0, %1\n" -" add %1, %4, %1\n" -" cas [%3], %0, %1\n" -" cmp %0, %1\n" -" membar #StoreLoad | #StoreStore\n" -" bne,pn %%icc, 1b\n" -" nop\n" - : "=&r" (old_count), "=&r" (tmp), "=m" (sem->count) - : "r" (&sem->count), "r" (incr), "m" (sem->count) - : "cc"); - - return old_count; -} - -static void __up(struct semaphore *sem) -{ - __sem_update_count(sem, 1); - wake_up(&sem->wait); -} - -void up(struct semaphore *sem) -{ - /* This atomically does: - * old_val = sem->count; - * new_val = sem->count + 1; - * sem->count = new_val; - * if (old_val < 0) - * __up(sem); - * - * The (old_val < 0) test is equivalent to - * the more straightforward (new_val <= 0), - * but it is easier to test the former because - * of how the CAS instruction works. - */ - - __asm__ __volatile__("\n" -" ! up sem(%0)\n" -" membar #StoreLoad | #LoadLoad\n" -"1: lduw [%0], %%g1\n" -" add %%g1, 1, %%g7\n" -" cas [%0], %%g1, %%g7\n" -" cmp %%g1, %%g7\n" -" bne,pn %%icc, 1b\n" -" addcc %%g7, 1, %%g0\n" -" membar #StoreLoad | #StoreStore\n" -" ble,pn %%icc, 3f\n" -" nop\n" -"2:\n" -" .subsection 2\n" -"3: mov %0, %%g1\n" -" save %%sp, -160, %%sp\n" -" call %1\n" -" mov %%g1, %%o0\n" -" ba,pt %%xcc, 2b\n" -" restore\n" -" .previous\n" - : : "r" (sem), "i" (__up) - : "g1", "g2", "g3", "g7", "memory", "cc"); -} - -static void __sched __down(struct semaphore * sem) -{ - struct task_struct *tsk = current; - DECLARE_WAITQUEUE(wait, tsk); - - tsk->state = TASK_UNINTERRUPTIBLE; - add_wait_queue_exclusive(&sem->wait, &wait); - - while (__sem_update_count(sem, -1) <= 0) { - schedule(); - tsk->state = TASK_UNINTERRUPTIBLE; - } - remove_wait_queue(&sem->wait, &wait); - tsk->state = TASK_RUNNING; - - wake_up(&sem->wait); -} - -void __sched down(struct semaphore *sem) -{ - might_sleep(); - /* This atomically does: - * old_val = sem->count; - * new_val = sem->count - 1; - * sem->count = new_val; - * if (old_val < 1) - * __down(sem); - * - * The (old_val < 1) test is equivalent to - * the more straightforward (new_val < 0), - * but it is easier to test the former because - * of how the CAS instruction works. - */ - - __asm__ __volatile__("\n" -" ! down sem(%0)\n" -"1: lduw [%0], %%g1\n" -" sub %%g1, 1, %%g7\n" -" cas [%0], %%g1, %%g7\n" -" cmp %%g1, %%g7\n" -" bne,pn %%icc, 1b\n" -" cmp %%g7, 1\n" -" membar #StoreLoad | #StoreStore\n" -" bl,pn %%icc, 3f\n" -" nop\n" -"2:\n" -" .subsection 2\n" -"3: mov %0, %%g1\n" -" save %%sp, -160, %%sp\n" -" call %1\n" -" mov %%g1, %%o0\n" -" ba,pt %%xcc, 2b\n" -" restore\n" -" .previous\n" - : : "r" (sem), "i" (__down) - : "g1", "g2", "g3", "g7", "memory", "cc"); -} - -int down_trylock(struct semaphore *sem) -{ - int ret; - - /* This atomically does: - * old_val = sem->count; - * new_val = sem->count - 1; - * if (old_val < 1) { - * ret = 1; - * } else { - * sem->count = new_val; - * ret = 0; - * } - * - * The (old_val < 1) test is equivalent to - * the more straightforward (new_val < 0), - * but it is easier to test the former because - * of how the CAS instruction works. - */ - - __asm__ __volatile__("\n" -" ! down_trylock sem(%1) ret(%0)\n" -"1: lduw [%1], %%g1\n" -" sub %%g1, 1, %%g7\n" -" cmp %%g1, 1\n" -" bl,pn %%icc, 2f\n" -" mov 1, %0\n" -" cas [%1], %%g1, %%g7\n" -" cmp %%g1, %%g7\n" -" bne,pn %%icc, 1b\n" -" mov 0, %0\n" -" membar #StoreLoad | #StoreStore\n" -"2:\n" - : "=&r" (ret) - : "r" (sem) - : "g1", "g7", "memory", "cc"); - - return ret; -} - -static int __sched __down_interruptible(struct semaphore * sem) -{ - int retval = 0; - struct task_struct *tsk = current; - DECLARE_WAITQUEUE(wait, tsk); - - tsk->state = TASK_INTERRUPTIBLE; - add_wait_queue_exclusive(&sem->wait, &wait); - - while (__sem_update_count(sem, -1) <= 0) { - if (signal_pending(current)) { - __sem_update_count(sem, 0); - retval = -EINTR; - break; - } - schedule(); - tsk->state = TASK_INTERRUPTIBLE; - } - tsk->state = TASK_RUNNING; - remove_wait_queue(&sem->wait, &wait); - wake_up(&sem->wait); - return retval; -} - -int __sched down_interruptible(struct semaphore *sem) -{ - int ret = 0; - - might_sleep(); - /* This atomically does: - * old_val = sem->count; - * new_val = sem->count - 1; - * sem->count = new_val; - * if (old_val < 1) - * ret = __down_interruptible(sem); - * - * The (old_val < 1) test is equivalent to - * the more straightforward (new_val < 0), - * but it is easier to test the former because - * of how the CAS instruction works. - */ - - __asm__ __volatile__("\n" -" ! down_interruptible sem(%2) ret(%0)\n" -"1: lduw [%2], %%g1\n" -" sub %%g1, 1, %%g7\n" -" cas [%2], %%g1, %%g7\n" -" cmp %%g1, %%g7\n" -" bne,pn %%icc, 1b\n" -" cmp %%g7, 1\n" -" membar #StoreLoad | #StoreStore\n" -" bl,pn %%icc, 3f\n" -" nop\n" -"2:\n" -" .subsection 2\n" -"3: mov %2, %%g1\n" -" save %%sp, -160, %%sp\n" -" call %3\n" -" mov %%g1, %%o0\n" -" ba,pt %%xcc, 2b\n" -" restore\n" -" .previous\n" - : "=r" (ret) - : "0" (ret), "r" (sem), "i" (__down_interruptible) - : "g1", "g2", "g3", "g7", "memory", "cc"); - return ret; -} |