Commit 462fb756 authored by Helge Deller's avatar Helge Deller
Browse files

Revert "parisc: Drop LDCW barrier in CAS code when running UP" 



This reverts commit e6eb5fe9.
We need to optimize it differently. A follow up patch will correct it.

Signed-off-by: default avatarHelge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v5.2+
parent 3d05b8ae

arch/parisc/kernel/syscall.S

+4 −8
Original line number Diff line number Diff line
@@ -641,8 +641,7 @@ cas_action: 
2:	stw	%r24, 0(%r26)

	/* Free lock */

#ifdef CONFIG_SMP

98:	LDCW	0(%sr2,%r20), %r1			/* Barrier */

99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)

	LDCW	0(%sr2,%r20), %r1			/* Barrier */

#endif

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

#if ENABLE_LWS_DEBUG
@@ -659,8 +658,7 @@ cas_action: 
	/* Error occurred on load or store */

	/* Free lock */

#ifdef CONFIG_SMP

98:	LDCW	0(%sr2,%r20), %r1			/* Barrier */

99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)

	LDCW	0(%sr2,%r20), %r1			/* Barrier */

#endif

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

#if ENABLE_LWS_DEBUG
@@ -864,8 +862,7 @@ cas2_action: 
cas2_end:

	/* Free lock */

#ifdef CONFIG_SMP

98:	LDCW	0(%sr2,%r20), %r1			/* Barrier */

99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)

	LDCW	0(%sr2,%r20), %r1			/* Barrier */

#endif

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

	/* Enable interrupts */
@@ -878,8 +875,7 @@ cas2_end: 
	/* Error occurred on load or store */

	/* Free lock */

#ifdef CONFIG_SMP

98:	LDCW	0(%sr2,%r20), %r1			/* Barrier */

99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)

	LDCW	0(%sr2,%r20), %r1			/* Barrier */

#endif

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

	ssm	PSW_SM_I, %r0

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