[PATCH 2/2] ia64: implement interrupt-enabling rwlocks

[PATCH 2/2] ia64: implement interrupt-enabling rwlocks

[Petr Tesarik]

Implement __raw_read_lock_flags and __raw_write_lock_flags for the
ia64 architecture.
    
Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
---
 arch/ia64/include/asm/spinlock.h |   58 ++++++++++++++++++++++++++++++++-----
 1 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/arch/ia64/include/asm/spinlock.h b/arch/ia64/include/asm/spinlock.h
index 0a61961..58f6a0d 100644
--- a/arch/ia64/include/asm/spinlock.h
+++ b/arch/ia64/include/asm/spinlock.h
@@ -120,6 +120,36 @@ do {											\
 #define __raw_read_can_lock(rw)		(*(volatile int *)(rw) >= 0)
 #define __raw_write_can_lock(rw)	(*(volatile int *)(rw) = 0)
 
+#ifdef ASM_SUPPORTED
+#define __raw_read_lock_flags(rw, flags)					\
+do {										\
+	__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"(rw), "r"(flags), "i"(IA64_PSR_I_BIT)			\
+		: "p6", "p7", "r2", "memory");					\
+} while(0)
+
+#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 +161,8 @@ do {											\
 	}										\
 } while (0)
 
+#endif /* !ASM_SUPPORTED */
+
 #define __raw_read_unlock(rw)					\
 do {								\
 	raw_rwlock_t *__read_lock_ptr = (rw);			\
@@ -138,21 +170,32 @@ do {								\
 } while (0)
 
 #ifdef ASM_SUPPORTED
-#define __raw_write_lock(rw)							\
+#define __raw_write_lock_flags(rw, flags)					\
 do {										\
  	__asm__ __volatile__ (							\
+		"tbit.nz p6, p0 = %1, %2\n"					\
 		"mov ar.ccv = r0\n"						\
-		"dep r29 = -1, r0, 31, 1;;\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 1b \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"(rw) : "ar.ccv", "p7", "r2", "r29", "memory");		\
+		:: "r"(rw), "r"(flags), "i"(IA64_PSR_I_BIT)			\
+		: "ar.ccv", "p6", "p7", "r2", "r29", "memory");			\
 } while(0)
 
+#define __raw_write_lock(rw) __raw_write_lock_flags(rw, 0)
+
 #define __raw_write_trylock(rw)							\
 ({										\
 	register long result;							\
@@ -174,6 +217,8 @@ 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 +258,6 @@ 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()

Re: [PATCH 2/2] ia64: implement interrupt-enabling rwlocks

[Matthew Wilcox]

On Wed, Oct 22, 2008 at 10:35:34AM +0200, Petr Tesarik wrote:
> +#define __raw_read_lock_flags(rw, flags)					\

I appreciate that ia64 is full of overlength lines, but could you not
add more of them?  There's no reason not to delete one of the tabs on
these lines.

> +} while(0)

checkpatch.pl says you need a space between 'while' and '(0)'.

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."