ia64: implement interrupt-enabling rwlocks
Robin Holt [Thu, 2 Apr 2009 23:59:47 +0000 (16:59 -0700)]
Implement __raw_read_lock_flags and __raw_write_lock_flags for the ia64
architecture.

[kosaki.motohiro@jp.fujitsu.com: typo fix]
Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/ia64/include/asm/spinlock.h

index 0a61961..13ab715 100644 (file)
@@ -120,6 +120,38 @@ do {                                                                                       \
 #define __raw_read_can_lock(rw)                (*(volatile int *)(rw) >= 0)
 #define __raw_write_can_lock(rw)       (*(volatile int *)(rw) == 0)
 
+#ifdef ASM_SUPPORTED
+
+static __always_inline void
+__raw_read_lock_flags(raw_rwlock_t *lock, unsigned long flags)
+{
+       __asm__ __volatile__ (
+               "tbit.nz p6, p0 = %1,%2\n"
+               "br.few 3f\n"
+               "1:\n"
+               "fetchadd4.rel r2 = [%0], -1;;\n"
+               "(p6) ssm psr.i\n"
+               "2:\n"
+               "hint @pause\n"
+               "ld4 r2 = [%0];;\n"
+               "cmp4.lt p7,p0 = r2, r0\n"
+               "(p7) br.cond.spnt.few 2b\n"
+               "(p6) rsm psr.i\n"
+               ";;\n"
+               "3:\n"
+               "fetchadd4.acq r2 = [%0], 1;;\n"
+               "cmp4.lt p7,p0 = r2, r0\n"
+               "(p7) br.cond.spnt.few 1b\n"
+               : : "r"(lock), "r"(flags), "i"(IA64_PSR_I_BIT)
+               : "p6", "p7", "r2", "memory");
+}
+
+#define __raw_read_lock(lock) __raw_read_lock_flags(lock, 0)
+
+#else /* !ASM_SUPPORTED */
+
+#define __raw_read_lock_flags(rw, flags) __raw_read_lock(rw)
+
 #define __raw_read_lock(rw)                                                            \
 do {                                                                                   \
        raw_rwlock_t *__read_lock_ptr = (rw);                                           \
@@ -131,6 +163,8 @@ do {                                                                                        \
        }                                                                               \
 } while (0)
 
+#endif /* !ASM_SUPPORTED */
+
 #define __raw_read_unlock(rw)                                  \
 do {                                                           \
        raw_rwlock_t *__read_lock_ptr = (rw);                   \
@@ -138,20 +172,33 @@ do {                                                              \
 } while (0)
 
 #ifdef ASM_SUPPORTED
-#define __raw_write_lock(rw)                                                   \
-do {                                                                           \
-       __asm__ __volatile__ (                                                  \
-               "mov ar.ccv = r0\n"                                             \
-               "dep r29 = -1, r0, 31, 1;;\n"                                   \
-               "1:\n"                                                          \
-               "ld4 r2 = [%0];;\n"                                             \
-               "cmp4.eq p0,p7 = r0,r2\n"                                       \
-               "(p7) br.cond.spnt.few 1b \n"                                   \
-               "cmpxchg4.acq r2 = [%0], r29, ar.ccv;;\n"                       \
-               "cmp4.eq p0,p7 = r0, r2\n"                                      \
-               "(p7) br.cond.spnt.few 1b;;\n"                                  \
-               :: "r"(rw) : "ar.ccv", "p7", "r2", "r29", "memory");            \
-} while(0)
+
+static __always_inline void
+__raw_write_lock_flags(raw_rwlock_t *lock, unsigned long flags)
+{
+       __asm__ __volatile__ (
+               "tbit.nz p6, p0 = %1, %2\n"
+               "mov ar.ccv = r0\n"
+               "dep r29 = -1, r0, 31, 1\n"
+               "br.few 3f;;\n"
+               "1:\n"
+               "(p6) ssm psr.i\n"
+               "2:\n"
+               "hint @pause\n"
+               "ld4 r2 = [%0];;\n"
+               "cmp4.eq p0,p7 = r0, r2\n"
+               "(p7) br.cond.spnt.few 2b\n"
+               "(p6) rsm psr.i\n"
+               ";;\n"
+               "3:\n"
+               "cmpxchg4.acq r2 = [%0], r29, ar.ccv;;\n"
+               "cmp4.eq p0,p7 = r0, r2\n"
+               "(p7) br.cond.spnt.few 1b;;\n"
+               : : "r"(lock), "r"(flags), "i"(IA64_PSR_I_BIT)
+               : "ar.ccv", "p6", "p7", "r2", "r29", "memory");
+}
+
+#define __raw_write_lock(rw) __raw_write_lock_flags(rw, 0)
 
 #define __raw_write_trylock(rw)                                                        \
 ({                                                                             \
@@ -174,6 +221,8 @@ static inline void __raw_write_unlock(raw_rwlock_t *x)
 
 #else /* !ASM_SUPPORTED */
 
+#define __raw_write_lock_flags(l, flags) __raw_write_lock(l)
+
 #define __raw_write_lock(l)                                                            \
 ({                                                                                     \
        __u64 ia64_val, ia64_set_val = ia64_dep_mi(-1, 0, 31, 1);                       \
@@ -213,9 +262,6 @@ static inline int __raw_read_trylock(raw_rwlock_t *x)
        return (u32)ia64_cmpxchg4_acq((__u32 *)(x), new.word, old.word) == old.word;
 }
 
-#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)
-#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)
-
 #define _raw_spin_relax(lock)  cpu_relax()
 #define _raw_read_relax(lock)  cpu_relax()
 #define _raw_write_relax(lock) cpu_relax()