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Revert "parisc: Use ldcw instruction for SMP spinlock release barrier"

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This reverts commit 9e5c602186.
No need to use the ldcw instruction as SMP spinlock release barrier.
Revert it to gain back speed again.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v5.2+
This commit is contained in:
Helge Deller
2020-07-28 18:54:40 +02:00
parent 462fb756c7
commit 6e9f06ee6c
3 changed files with 24 additions and 39 deletions
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16
arch/parisc/kernel/syscall.S
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@@ -640,9 +640,7 @@ cas_action:
sub,<> %r28, %r25, %r0
2: stw %r24, 0(%r26)
/* Free lock */
#ifdef CONFIG_SMP
LDCW 0(%sr2,%r20), %r1 /* Barrier */
#endif
sync
stw %r20, 0(%sr2,%r20)
#if ENABLE_LWS_DEBUG
/* Clear thread register indicator */
@@ -657,9 +655,7 @@ cas_action:
3:
/* Error occurred on load or store */
/* Free lock */
#ifdef CONFIG_SMP
LDCW 0(%sr2,%r20), %r1 /* Barrier */
#endif
sync
stw %r20, 0(%sr2,%r20)
#if ENABLE_LWS_DEBUG
stw %r0, 4(%sr2,%r20)
@@ -861,9 +857,7 @@ cas2_action:
cas2_end:
/* Free lock */
#ifdef CONFIG_SMP
LDCW 0(%sr2,%r20), %r1 /* Barrier */
#endif
sync
stw %r20, 0(%sr2,%r20)
/* Enable interrupts */
ssm PSW_SM_I, %r0
@@ -874,9 +868,7 @@ cas2_end:
22:
/* Error occurred on load or store */
/* Free lock */
#ifdef CONFIG_SMP
LDCW 0(%sr2,%r20), %r1 /* Barrier */
#endif
sync
stw %r20, 0(%sr2,%r20)
ssm PSW_SM_I, %r0
ldo 1(%r0),%r28