Revert "parisc: Revert "Release spinlocks using ordered store""

This reverts commit 86d4d068df573a8c2105554624796c086d6bec3d.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v5.0+

diff --git a/arch/parisc/include/asm/spinlock.h b/arch/parisc/include/asm/spinlock.h
index 6f85ca7..51b6c47 100644 (file)
--- a/arch/parisc/include/asm/spinlock.h
+++ b/arch/parisc/include/asm/spinlock.h
@@ -37,8 +37,8 @@ static inline void arch_spin_unlock(arch_spinlock_t *x)
        volatile unsigned int *a;
 
        a = __ldcw_align(x);
-       mb();
-       *a = 1;
+       /* Release with ordered store. */
+       __asm__ __volatile__("stw,ma %0,0(%1)" : : "r"(1), "r"(a) : "memory");
 }
 
 static inline int arch_spin_trylock(arch_spinlock_t *x)

diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S
index 472ce99..3ad61a1 100644 (file)
--- a/arch/parisc/kernel/syscall.S
+++ b/arch/parisc/kernel/syscall.S
@@ -640,8 +640,7 @@ cas_action:
        sub,<>  %r28, %r25, %r0
 2:     stw     %r24, 0(%r26)
        /* Free lock */
-       sync
-       stw     %r20, 0(%sr2,%r20)
+       stw,ma  %r20, 0(%sr2,%r20)
 #if ENABLE_LWS_DEBUG
        /* Clear thread register indicator */
        stw     %r0, 4(%sr2,%r20)
@@ -655,8 +654,7 @@ cas_action:
 3:             
        /* Error occurred on load or store */
        /* Free lock */
-       sync
-       stw     %r20, 0(%sr2,%r20)
+       stw,ma  %r20, 0(%sr2,%r20)
 #if ENABLE_LWS_DEBUG
        stw     %r0, 4(%sr2,%r20)
 #endif
@@ -857,8 +855,7 @@ cas2_action:
 
 cas2_end:
        /* Free lock */
-       sync
-       stw     %r20, 0(%sr2,%r20)
+       stw,ma  %r20, 0(%sr2,%r20)
        /* Enable interrupts */
        ssm     PSW_SM_I, %r0
        /* Return to userspace, set no error */
@@ -868,8 +865,7 @@ cas2_end:
 22:
        /* Error occurred on load or store */
        /* Free lock */
-       sync
-       stw     %r20, 0(%sr2,%r20)
+       stw,ma  %r20, 0(%sr2,%r20)
        ssm     PSW_SM_I, %r0
        ldo     1(%r0),%r28
        b       lws_exit