From: Helge Deller <deller@xxxxxx> 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@xxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # v5.2+ Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/parisc/include/asm/spinlock.h | 4 --- arch/parisc/kernel/entry.S | 43 +++++++++++++++++-------------------- arch/parisc/kernel/syscall.S | 16 +++---------- 3 files changed, 24 insertions(+), 39 deletions(-) --- a/arch/parisc/include/asm/spinlock.h +++ b/arch/parisc/include/asm/spinlock.h @@ -37,11 +37,7 @@ static inline void arch_spin_unlock(arch volatile unsigned int *a; a = __ldcw_align(x); -#ifdef CONFIG_SMP - (void) __ldcw(a); -#else mb(); -#endif *a = 1; } --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -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 --- 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
