arch/sparc: Enable queued spinlock support for SPARC

This patch makes the necessary changes in SPARC architecture to enable
queued spinlock support. Here are some of the earlier discussions about
this feature.
https://lwn.net/Articles/561775/
https://lwn.net/Articles/590243/

Cleaned-up the spinlock_64.h. The definitions of arch_spin_xxx are
replaced by the function in <asm-generic/qspinlock.h>

Signed-off-by: Babu Moger <babu.moger@oracle.com>
Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com>
Reviewed-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 83 deletions

diff --git a/arch/sparc/include/asm/spinlock_64.h b/arch/sparc/include/asm/spinlock_64.h
index 8901c2d4ada9..f7028f5e1a5a 100644
--- a/arch/sparc/include/asm/spinlock_64.h
+++ b/arch/sparc/include/asm/spinlock_64.h
@@ -11,89 +11,7 @@
 #include <asm/processor.h>
 #include <asm/barrier.h>
 #include <asm/qrwlock.h>
-
-/* To get debugging spinlocks which detect and catch
- * deadlock situations, set CONFIG_DEBUG_SPINLOCK
- * and rebuild your kernel.
- */
-
-/* Because we play games to save cycles in the non-contention case, we
- * need to be extra careful about branch targets into the "spinning"
- * code.  They live in their own section, but the newer V9 branches
- * have a shorter range than the traditional 32-bit sparc branch
- * variants.  The rule is that the branches that go into and out of
- * the spinner sections must be pre-V9 branches.
- */
-
-#define arch_spin_is_locked(lp)	((lp)->lock != 0)
-
-static inline void arch_spin_unlock_wait(arch_spinlock_t *lock)
-{
-	smp_cond_load_acquire(&lock->lock, !VAL);
-}
-
-static inline void arch_spin_lock(arch_spinlock_t *lock)
-{
-	unsigned long tmp;
-
-	__asm__ __volatile__(
-"1:	ldstub		[%1], %0\n"
-"	brnz,pn		%0, 2f\n"
-"	 nop\n"
-"	.subsection	2\n"
-"2:	ldub		[%1], %0\n"
-"	brnz,pt		%0, 2b\n"
-"	 nop\n"
-"	ba,a,pt		%%xcc, 1b\n"
-"	.previous"
-	: "=&r" (tmp)
-	: "r" (lock)
-	: "memory");
-}
-
-static inline int arch_spin_trylock(arch_spinlock_t *lock)
-{
-	unsigned long result;
-
-	__asm__ __volatile__(
-"	ldstub		[%1], %0\n"
-	: "=r" (result)
-	: "r" (lock)
-	: "memory");
-
-	return (result == 0UL);
-}
-
-static inline void arch_spin_unlock(arch_spinlock_t *lock)
-{
-	__asm__ __volatile__(
-"	stb		%%g0, [%0]"
-	: /* No outputs */
-	: "r" (lock)
-	: "memory");
-}
-
-static inline void arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
-{
-	unsigned long tmp1, tmp2;
-
-	__asm__ __volatile__(
-"1:	ldstub		[%2], %0\n"
-"	brnz,pn		%0, 2f\n"
-"	 nop\n"
-"	.subsection	2\n"
-"2:	rdpr		%%pil, %1\n"
-"	wrpr		%3, %%pil\n"
-"3:	ldub		[%2], %0\n"
-"	brnz,pt		%0, 3b\n"
-"	 nop\n"
-"	ba,pt		%%xcc, 1b\n"
-"	 wrpr		%1, %%pil\n"
-"	.previous"
-	: "=&r" (tmp1), "=&r" (tmp2)
-	: "r"(lock), "r"(flags)
-	: "memory");
-}
+#include <asm/qspinlock.h>
 
 #define arch_read_lock_flags(p, f) arch_read_lock(p)
 #define arch_write_lock_flags(p, f) arch_write_lock(p)