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

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commit 6e9f06ee6c9566f3606d93182ac8f803a148504b upstream.

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+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Helge Deller 2020-07-28 18:54:40 +02:00 committed by Greg Kroah-Hartman
parent 7612ce180e
commit 431d999bd0
3 changed files with 24 additions and 39 deletions
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4
arch/parisc/include/asm/spinlock.h
View File

@ -37,11 +37,7 @@ static inline void arch_spin_unlock(arch_spinlock_t *x)
volatile unsigned int *a;
a = __ldcw_align(x);
#ifdef CONFIG_SMP
(void) __ldcw(a);
#else
mb();
#endif
*a = 1;
}

43
arch/parisc/kernel/entry.S
View File

@ -454,9 +454,8 @@
nop
LDREG 0(\ptp),\pte
bb,<,n \pte,_PAGE_PRESENT_BIT,3f
LDCW 0(\tmp),\tmp1
b \fault
stw \spc,0(\tmp)
stw,ma \spc,0(\tmp)
99: ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
#endif
2: LDREG 0(\ptp),\pte
@ -465,22 +464,20 @@
.endm
/* Release pa_tlb_lock lock without reloading lock address. */
.macro tlb_unlock0 spc,tmp,tmp1
.macro tlb_unlock0 spc,tmp
#ifdef CONFIG_SMP
98: or,COND(=) %r0,\spc,%r0
LDCW 0(\tmp),\tmp1
or,COND(=) %r0,\spc,%r0
stw \spc,0(\tmp)
stw,ma \spc,0(\tmp)
99: ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
#endif
.endm
/* Release pa_tlb_lock lock. */
.macro tlb_unlock1 spc,tmp,tmp1
.macro tlb_unlock1 spc,tmp
#ifdef CONFIG_SMP
98: load_pa_tlb_lock \tmp
99: ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
tlb_unlock0 \spc,\tmp,\tmp1
tlb_unlock0 \spc,\tmp
#endif
.endm
@ -1163,7 +1160,7 @@ dtlb_miss_20w:
idtlbt pte,prot
tlb_unlock1 spc,t0,t1
tlb_unlock1 spc,t0
rfir
nop
@ -1189,7 +1186,7 @@ nadtlb_miss_20w:
idtlbt pte,prot
tlb_unlock1 spc,t0,t1
tlb_unlock1 spc,t0
rfir
nop
@ -1223,7 +1220,7 @@ dtlb_miss_11:
mtsp t1, %sr1 /* Restore sr1 */
tlb_unlock1 spc,t0,t1
tlb_unlock1 spc,t0
rfir
nop
@ -1256,7 +1253,7 @@ nadtlb_miss_11:
mtsp t1, %sr1 /* Restore sr1 */
tlb_unlock1 spc,t0,t1
tlb_unlock1 spc,t0
rfir
nop
@ -1285,7 +1282,7 @@ dtlb_miss_20:
idtlbt pte,prot
tlb_unlock1 spc,t0,t1
tlb_unlock1 spc,t0
rfir
nop
@ -1313,7 +1310,7 @@ nadtlb_miss_20:
idtlbt pte,prot
tlb_unlock1 spc,t0,t1
tlb_unlock1 spc,t0
rfir
nop
@ -1420,7 +1417,7 @@ itlb_miss_20w:
iitlbt pte,prot
tlb_unlock1 spc,t0,t1
tlb_unlock1 spc,t0
rfir
nop
@ -1444,7 +1441,7 @@ naitlb_miss_20w:
iitlbt pte,prot
tlb_unlock1 spc,t0,t1
tlb_unlock1 spc,t0
rfir
nop
@ -1478,7 +1475,7 @@ itlb_miss_11:
mtsp t1, %sr1 /* Restore sr1 */
tlb_unlock1 spc,t0,t1
tlb_unlock1 spc,t0
rfir
nop
@ -1502,7 +1499,7 @@ naitlb_miss_11:
mtsp t1, %sr1 /* Restore sr1 */
tlb_unlock1 spc,t0,t1
tlb_unlock1 spc,t0
rfir
nop
@ -1532,7 +1529,7 @@ itlb_miss_20:
iitlbt pte,prot
tlb_unlock1 spc,t0,t1
tlb_unlock1 spc,t0
rfir
nop
@ -1552,7 +1549,7 @@ naitlb_miss_20:
iitlbt pte,prot
tlb_unlock1 spc,t0,t1
tlb_unlock1 spc,t0
rfir
nop
@ -1582,7 +1579,7 @@ dbit_trap_20w:
idtlbt pte,prot
tlb_unlock0 spc,t0,t1
tlb_unlock0 spc,t0
rfir
nop
#else
@ -1608,7 +1605,7 @@ dbit_trap_11:
mtsp t1, %sr1 /* Restore sr1 */
tlb_unlock0 spc,t0,t1
tlb_unlock0 spc,t0
rfir
nop
@ -1628,7 +1625,7 @@ dbit_trap_20:
idtlbt pte,prot
tlb_unlock0 spc,t0,t1
tlb_unlock0 spc,t0
rfir
nop
#endif

16
arch/parisc/kernel/syscall.S
View File

@ -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