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| author | Helge Deller <deller@gmx.de> | 2020-07-28 18:54:40 +0200 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2020-07-28 18:54:40 +0200 |
| commit | 6e9f06ee6c9566f3606d93182ac8f803a148504b (patch) | |
| tree | d3a249ba445cdac167c333dc04a143b4069488de /arch/parisc/kernel/syscall.S | |
| parent | Revert "parisc: Drop LDCW barrier in CAS code when running UP" (diff) | |
| download | linux-6e9f06ee6c9566f3606d93182ac8f803a148504b.tar.xz linux-6e9f06ee6c9566f3606d93182ac8f803a148504b.zip | |
Revert "parisc: Use ldcw instruction for SMP spinlock release barrier"
This reverts commit 9e5c602186a692a7e848c0da17aed40f49d30519.
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+
Diffstat (limited to 'arch/parisc/kernel/syscall.S')
| -rw-r--r-- | arch/parisc/kernel/syscall.S | 16 |
1 files changed, 4 insertions, 12 deletions
diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S index ea505a81f821..472ce9921b30 100644 --- a/arch/parisc/kernel/syscall.S +++ b/arch/parisc/kernel/syscall.S @@ -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 |