diff options
| author | John David Anglin | 2019-04-14 19:20:40 -0400 |
|---|---|---|
| committer | Helge Deller | 2019-05-03 23:47:40 +0200 |
| commit | 9e5c602186a692a7e848c0da17aed40f49d30519 (patch) | |
| tree | 845499e6cc5d1ee17c786233d9a427ab44c2bb6b /arch/parisc/kernel | |
| parent | 6c63ef80014b60ab13bee7e683d0a95521bb7fdd (diff) | |
parisc: Use ldcw instruction for SMP spinlock release barrier
There are only a couple of instructions that can function as a memory
barrier on parisc. Currently, we use the sync instruction as a memory
barrier when releasing a spinlock. However, the ldcw instruction is a
better barrier when we have a handy memory location since it operates in
the cache on coherent machines.
This patch updates the spinlock release code to use ldcw. I also
changed the "stw,ma" instructions to "stw" instructions as it is not an
adequate barrier.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch/parisc/kernel')
| -rw-r--r-- | arch/parisc/kernel/entry.S | 43 | ||||
| -rw-r--r-- | arch/parisc/kernel/syscall.S | 16 |
2 files changed, 35 insertions, 24 deletions
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index d5eb19efa65b..5796524a3137 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -471,8 +471,9 @@ nop LDREG 0(\ptp),\pte bb,<,n \pte,_PAGE_PRESENT_BIT,3f + LDCW 0(\tmp),\tmp1 b \fault - stw,ma \spc,0(\tmp) + stw \spc,0(\tmp) 99: ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP) #endif 2: LDREG 0(\ptp),\pte @@ -481,20 +482,22 @@ .endm /* Release pa_tlb_lock lock without reloading lock address. */ - .macro tlb_unlock0 spc,tmp + .macro tlb_unlock0 spc,tmp,tmp1 #ifdef CONFIG_SMP 98: or,COND(=) %r0,\spc,%r0 - stw,ma \spc,0(\tmp) + LDCW 0(\tmp),\tmp1 + or,COND(=) %r0,\spc,%r0 + stw \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 + .macro tlb_unlock1 spc,tmp,tmp1 #ifdef CONFIG_SMP 98: load_pa_tlb_lock \tmp 99: ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP) - tlb_unlock0 \spc,\tmp + tlb_unlock0 \spc,\tmp,\tmp1 #endif .endm @@ -1177,7 +1180,7 @@ dtlb_miss_20w: idtlbt pte,prot - tlb_unlock1 spc,t0 + tlb_unlock1 spc,t0,t1 rfir nop @@ -1203,7 +1206,7 @@ nadtlb_miss_20w: idtlbt pte,prot - tlb_unlock1 spc,t0 + tlb_unlock1 spc,t0,t1 rfir nop @@ -1237,7 +1240,7 @@ dtlb_miss_11: mtsp t1, %sr1 /* Restore sr1 */ - tlb_unlock1 spc,t0 + tlb_unlock1 spc,t0,t1 rfir nop @@ -1270,7 +1273,7 @@ nadtlb_miss_11: mtsp t1, %sr1 /* Restore sr1 */ - tlb_unlock1 spc,t0 + tlb_unlock1 spc,t0,t1 rfir nop @@ -1299,7 +1302,7 @@ dtlb_miss_20: idtlbt pte,prot - tlb_unlock1 spc,t0 + tlb_unlock1 spc,t0,t1 rfir nop @@ -1327,7 +1330,7 @@ nadtlb_miss_20: idtlbt pte,prot - tlb_unlock1 spc,t0 + tlb_unlock1 spc,t0,t1 rfir nop @@ -1434,7 +1437,7 @@ itlb_miss_20w: iitlbt pte,prot - tlb_unlock1 spc,t0 + tlb_unlock1 spc,t0,t1 rfir nop @@ -1458,7 +1461,7 @@ naitlb_miss_20w: iitlbt pte,prot - tlb_unlock1 spc,t0 + tlb_unlock1 spc,t0,t1 rfir nop @@ -1492,7 +1495,7 @@ itlb_miss_11: mtsp t1, %sr1 /* Restore sr1 */ - tlb_unlock1 spc,t0 + tlb_unlock1 spc,t0,t1 rfir nop @@ -1516,7 +1519,7 @@ naitlb_miss_11: mtsp t1, %sr1 /* Restore sr1 */ - tlb_unlock1 spc,t0 + tlb_unlock1 spc,t0,t1 rfir nop @@ -1546,7 +1549,7 @@ itlb_miss_20: iitlbt pte,prot - tlb_unlock1 spc,t0 + tlb_unlock1 spc,t0,t1 rfir nop @@ -1566,7 +1569,7 @@ naitlb_miss_20: iitlbt pte,prot - tlb_unlock1 spc,t0 + tlb_unlock1 spc,t0,t1 rfir nop @@ -1596,7 +1599,7 @@ dbit_trap_20w: idtlbt pte,prot - tlb_unlock0 spc,t0 + tlb_unlock0 spc,t0,t1 rfir nop #else @@ -1622,7 +1625,7 @@ dbit_trap_11: mtsp t1, %sr1 /* Restore sr1 */ - tlb_unlock0 spc,t0 + tlb_unlock0 spc,t0,t1 rfir nop @@ -1642,7 +1645,7 @@ dbit_trap_20: idtlbt pte,prot - tlb_unlock0 spc,t0 + tlb_unlock0 spc,t0,t1 rfir nop #endif diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S index 4f77bd9be66b..e2b4c8d81275 100644 --- a/arch/parisc/kernel/syscall.S +++ b/arch/parisc/kernel/syscall.S @@ -640,7 +640,9 @@ cas_action: sub,<> %r28, %r25, %r0 2: stw %r24, 0(%r26) /* Free lock */ - sync +#ifdef CONFIG_SMP + LDCW 0(%sr2,%r20), %r1 /* Barrier */ +#endif stw %r20, 0(%sr2,%r20) #if ENABLE_LWS_DEBUG /* Clear thread register indicator */ @@ -655,7 +657,9 @@ cas_action: 3: /* Error occurred on load or store */ /* Free lock */ - sync +#ifdef CONFIG_SMP + LDCW 0(%sr2,%r20), %r1 /* Barrier */ +#endif stw %r20, 0(%sr2,%r20) #if ENABLE_LWS_DEBUG stw %r0, 4(%sr2,%r20) @@ -857,7 +861,9 @@ cas2_action: cas2_end: /* Free lock */ - sync +#ifdef CONFIG_SMP + LDCW 0(%sr2,%r20), %r1 /* Barrier */ +#endif stw %r20, 0(%sr2,%r20) /* Enable interrupts */ ssm PSW_SM_I, %r0 @@ -868,7 +874,9 @@ cas2_end: 22: /* Error occurred on load or store */ /* Free lock */ - sync +#ifdef CONFIG_SMP + LDCW 0(%sr2,%r20), %r1 /* Barrier */ +#endif stw %r20, 0(%sr2,%r20) ssm PSW_SM_I, %r0 ldo 1(%r0),%r28 |