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Diffstat (limited to 'arch/arm64/include/asm/spinlock.h')
-rw-r--r--arch/arm64/include/asm/spinlock.h173
1 files changed, 1 insertions, 172 deletions
diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h
index 95ad7102b63c..fdb827c7832f 100644
--- a/arch/arm64/include/asm/spinlock.h
+++ b/arch/arm64/include/asm/spinlock.h
@@ -27,8 +27,6 @@
* instructions.
*/
-#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock)
-
static inline void arch_spin_lock(arch_spinlock_t *lock)
{
unsigned int tmp;
@@ -139,176 +137,7 @@ static inline int arch_spin_is_contended(arch_spinlock_t *lock)
}
#define arch_spin_is_contended arch_spin_is_contended
-/*
- * Write lock implementation.
- *
- * Write locks set bit 31. Unlocking, is done by writing 0 since the lock is
- * exclusively held.
- *
- * The memory barriers are implicit with the load-acquire and store-release
- * instructions.
- */
-
-static inline void arch_write_lock(arch_rwlock_t *rw)
-{
- unsigned int tmp;
-
- asm volatile(ARM64_LSE_ATOMIC_INSN(
- /* LL/SC */
- " sevl\n"
- "1: wfe\n"
- "2: ldaxr %w0, %1\n"
- " cbnz %w0, 1b\n"
- " stxr %w0, %w2, %1\n"
- " cbnz %w0, 2b\n"
- __nops(1),
- /* LSE atomics */
- "1: mov %w0, wzr\n"
- "2: casa %w0, %w2, %1\n"
- " cbz %w0, 3f\n"
- " ldxr %w0, %1\n"
- " cbz %w0, 2b\n"
- " wfe\n"
- " b 1b\n"
- "3:")
- : "=&r" (tmp), "+Q" (rw->lock)
- : "r" (0x80000000)
- : "memory");
-}
-
-static inline int arch_write_trylock(arch_rwlock_t *rw)
-{
- unsigned int tmp;
-
- asm volatile(ARM64_LSE_ATOMIC_INSN(
- /* LL/SC */
- "1: ldaxr %w0, %1\n"
- " cbnz %w0, 2f\n"
- " stxr %w0, %w2, %1\n"
- " cbnz %w0, 1b\n"
- "2:",
- /* LSE atomics */
- " mov %w0, wzr\n"
- " casa %w0, %w2, %1\n"
- __nops(2))
- : "=&r" (tmp), "+Q" (rw->lock)
- : "r" (0x80000000)
- : "memory");
-
- return !tmp;
-}
-
-static inline void arch_write_unlock(arch_rwlock_t *rw)
-{
- asm volatile(ARM64_LSE_ATOMIC_INSN(
- " stlr wzr, %0",
- " swpl wzr, wzr, %0")
- : "=Q" (rw->lock) :: "memory");
-}
-
-/* write_can_lock - would write_trylock() succeed? */
-#define arch_write_can_lock(x) ((x)->lock == 0)
-
-/*
- * Read lock implementation.
- *
- * It exclusively loads the lock value, increments it and stores the new value
- * back if positive and the CPU still exclusively owns the location. If the
- * value is negative, the lock is already held.
- *
- * During unlocking there may be multiple active read locks but no write lock.
- *
- * The memory barriers are implicit with the load-acquire and store-release
- * instructions.
- *
- * Note that in UNDEFINED cases, such as unlocking a lock twice, the LL/SC
- * and LSE implementations may exhibit different behaviour (although this
- * will have no effect on lockdep).
- */
-static inline void arch_read_lock(arch_rwlock_t *rw)
-{
- unsigned int tmp, tmp2;
-
- asm volatile(
- " sevl\n"
- ARM64_LSE_ATOMIC_INSN(
- /* LL/SC */
- "1: wfe\n"
- "2: ldaxr %w0, %2\n"
- " add %w0, %w0, #1\n"
- " tbnz %w0, #31, 1b\n"
- " stxr %w1, %w0, %2\n"
- " cbnz %w1, 2b\n"
- __nops(1),
- /* LSE atomics */
- "1: wfe\n"
- "2: ldxr %w0, %2\n"
- " adds %w1, %w0, #1\n"
- " tbnz %w1, #31, 1b\n"
- " casa %w0, %w1, %2\n"
- " sbc %w0, %w1, %w0\n"
- " cbnz %w0, 2b")
- : "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)
- :
- : "cc", "memory");
-}
-
-static inline void arch_read_unlock(arch_rwlock_t *rw)
-{
- unsigned int tmp, tmp2;
-
- asm volatile(ARM64_LSE_ATOMIC_INSN(
- /* LL/SC */
- "1: ldxr %w0, %2\n"
- " sub %w0, %w0, #1\n"
- " stlxr %w1, %w0, %2\n"
- " cbnz %w1, 1b",
- /* LSE atomics */
- " movn %w0, #0\n"
- " staddl %w0, %2\n"
- __nops(2))
- : "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)
- :
- : "memory");
-}
-
-static inline int arch_read_trylock(arch_rwlock_t *rw)
-{
- unsigned int tmp, tmp2;
-
- asm volatile(ARM64_LSE_ATOMIC_INSN(
- /* LL/SC */
- " mov %w1, #1\n"
- "1: ldaxr %w0, %2\n"
- " add %w0, %w0, #1\n"
- " tbnz %w0, #31, 2f\n"
- " stxr %w1, %w0, %2\n"
- " cbnz %w1, 1b\n"
- "2:",
- /* LSE atomics */
- " ldr %w0, %2\n"
- " adds %w1, %w0, #1\n"
- " tbnz %w1, #31, 1f\n"
- " casa %w0, %w1, %2\n"
- " sbc %w1, %w1, %w0\n"
- __nops(1)
- "1:")
- : "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)
- :
- : "cc", "memory");
-
- return !tmp2;
-}
-
-/* read_can_lock - would read_trylock() succeed? */
-#define arch_read_can_lock(x) ((x)->lock < 0x80000000)
-
-#define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
-#define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
-
-#define arch_spin_relax(lock) cpu_relax()
-#define arch_read_relax(lock) cpu_relax()
-#define arch_write_relax(lock) cpu_relax()
+#include <asm/qrwlock.h>
/* See include/linux/spinlock.h */
#define smp_mb__after_spinlock() smp_mb()