Commit 857c34cd authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'parisc-4.20-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 

Pull parisc fix from Helge Deller:
 "Revert one patch which changed how spinlocks get released. It breaks
  the rwlock implementation in glibc"

* 'parisc-4.20-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Revert "Release spinlocks using ordered store"
parents e2f8b472 86d4d068

arch/parisc/include/asm/spinlock.h

+2 −2
Original line number Diff line number Diff line
@@ -37,8 +37,8 @@ static inline void arch_spin_unlock(arch_spinlock_t *x) 
	volatile unsigned int *a;



	a = __ldcw_align(x);

	/* Release with ordered store. */

	__asm__ __volatile__("stw,ma %0,0(%1)" : : "r"(1), "r"(a) : "memory");

	mb();

	*a = 1;

}



static inline int arch_spin_trylock(arch_spinlock_t *x)

arch/parisc/kernel/syscall.S

+8 −4
Original line number Diff line number Diff line
@@ -640,7 +640,8 @@ cas_action: 
	sub,<>	%r28, %r25, %r0

2:	stw	%r24, 0(%r26)

	/* Free lock */

	stw,ma	%r20, 0(%sr2,%r20)

	sync

	stw	%r20, 0(%sr2,%r20)

#if ENABLE_LWS_DEBUG

	/* Clear thread register indicator */

	stw	%r0, 4(%sr2,%r20)
@@ -654,7 +655,8 @@ cas_action: 
3:		

	/* Error occurred on load or store */

	/* Free lock */

	stw,ma	%r20, 0(%sr2,%r20)

	sync

	stw	%r20, 0(%sr2,%r20)

#if ENABLE_LWS_DEBUG

	stw	%r0, 4(%sr2,%r20)

#endif
@@ -855,7 +857,8 @@ cas2_action: 


cas2_end:

	/* Free lock */

	stw,ma	%r20, 0(%sr2,%r20)

	sync

	stw	%r20, 0(%sr2,%r20)

	/* Enable interrupts */

	ssm	PSW_SM_I, %r0

	/* Return to userspace, set no error */
@@ -865,7 +868,8 @@ cas2_end: 
22:

	/* Error occurred on load or store */

	/* Free lock */

	stw,ma	%r20, 0(%sr2,%r20)

	sync

	stw	%r20, 0(%sr2,%r20)

	ssm	PSW_SM_I, %r0

	ldo	1(%r0),%r28

	b	lws_exit

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