From: Helge Deller Date: Tue, 28 Jul 2020 16:52:58 +0000 (+0200) Subject: Revert "parisc: Drop LDCW barrier in CAS code when running UP" X-Git-Tag: v5.7.16~24 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1da1661a1a268aa57a5d33ce473052db1fce84f0;p=thirdparty%2Fkernel%2Fstable.git Revert "parisc: Drop LDCW barrier in CAS code when running UP" commit 462fb756c7de1ffe5bc6099149136031c2d9c02a upstream. This reverts commit e6eb5fe9123f05dcbf339ae5c0b6d32fcc0685d5. We need to optimize it differently. A follow up patch will correct it. Signed-off-by: Helge Deller Cc: # v5.2+ Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S index f05c9d5b6b9e7..ea505a81f8217 100644 --- a/arch/parisc/kernel/syscall.S +++ b/arch/parisc/kernel/syscall.S @@ -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