[PATCH v2] powerpc/book3s: Fix flush_tlb cpu_spec hook to take a generic argument.
Mahesh J Salgaonkar
mahesh at linux.vnet.ibm.com
Wed Dec 3 15:26:35 AEDT 2014
From: Mahesh Salgaonkar <mahesh at linux.vnet.ibm.com>
The flush_tlb hook in cpu_spec was introduced as a generic function hook
to invalidate TLBs. But the current implementation of flush_tlb hook
takes IS (invalidation selector) as an argument which is architecture
dependent. Hence, It is not right to have a generic routine where caller
has to pass non-generic argument.
This patch fixes this and makes flush_tlb hook as high level API.
The existing MCE code calls flush_tlb hook with IS=0 (single page) resulting
partial invalidation of TLBs which is not right. This rework now makes
sure that whole TLB is invalidated to be able to successfully recover from
TLB and ERAT errors.
Reported-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Signed-off-by: Mahesh Salgaonkar <mahesh at linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
---
Changes in V2:
- Moved TLB flush action #defines to cputable.h
- Added missing ptesyncs to before and after TLB flush.
- Moved switch case to flush_tlb_206() function as suggested by
Michael Ellerman.
arch/powerpc/include/asm/cputable.h | 6 +++-
arch/powerpc/include/asm/mmu-hash64.h | 1 +
arch/powerpc/kernel/cpu_setup_power.S | 10 +-----
arch/powerpc/kernel/cputable.c | 4 +-
arch/powerpc/kernel/mce_power.c | 53 ++++++++++++++++++++++++++++++++-
arch/powerpc/kvm/book3s_hv_ras.c | 4 +-
6 files changed, 63 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
index daa5af9..d053301 100644
--- a/arch/powerpc/include/asm/cputable.h
+++ b/arch/powerpc/include/asm/cputable.h
@@ -100,7 +100,7 @@ struct cpu_spec {
/*
* Processor specific routine to flush tlbs.
*/
- void (*flush_tlb)(unsigned long inval_selector);
+ void (*flush_tlb)(unsigned int action);
};
@@ -114,6 +114,10 @@ extern void do_feature_fixups(unsigned long value, void *fixup_start,
extern const char *powerpc_base_platform;
+/* TLB flush actions. Used as argument to cpu_spec.flush_tlb() hook */
+#define FLUSH_TLB_ALL 0 /* invalidate all TLBs */
+#define FLUSH_TLB_LPID 1 /* invalidate TLBs for current LPID */
+
#endif /* __ASSEMBLY__ */
/* CPU kernel features */
diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h
index aeebc94..4f50db7 100644
--- a/arch/powerpc/include/asm/mmu-hash64.h
+++ b/arch/powerpc/include/asm/mmu-hash64.h
@@ -112,6 +112,7 @@
#define TLBIEL_INVAL_SET_SHIFT 12
#define POWER7_TLB_SETS 128 /* # sets in POWER7 TLB */
+#define POWER8_TLB_SETS 512 /* # sets in POWER8 TLB */
#ifndef __ASSEMBLY__
diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S
index 4673353..9c9b741 100644
--- a/arch/powerpc/kernel/cpu_setup_power.S
+++ b/arch/powerpc/kernel/cpu_setup_power.S
@@ -137,15 +137,11 @@ __init_HFSCR:
/*
* Clear the TLB using the specified IS form of tlbiel instruction
* (invalidate by congruence class). P7 has 128 CCs., P8 has 512.
- *
- * r3 = IS field
*/
__init_tlb_power7:
- li r3,0xc00 /* IS field = 0b11 */
-_GLOBAL(__flush_tlb_power7)
li r6,128
mtctr r6
- mr r7,r3 /* IS field */
+ li r7,0xc00 /* IS field = 0b11 */
ptesync
2: tlbiel r7
addi r7,r7,0x1000
@@ -154,11 +150,9 @@ _GLOBAL(__flush_tlb_power7)
1: blr
__init_tlb_power8:
- li r3,0xc00 /* IS field = 0b11 */
-_GLOBAL(__flush_tlb_power8)
li r6,512
mtctr r6
- mr r7,r3 /* IS field */
+ li r7,0xc00 /* IS field = 0b11 */
ptesync
2: tlbiel r7
addi r7,r7,0x1000
diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
index 8084059..81c1ba5 100644
--- a/arch/powerpc/kernel/cputable.c
+++ b/arch/powerpc/kernel/cputable.c
@@ -71,8 +71,8 @@ extern void __restore_cpu_power7(void);
extern void __setup_cpu_power8(unsigned long offset, struct cpu_spec* spec);
extern void __restore_cpu_power8(void);
extern void __restore_cpu_a2(void);
-extern void __flush_tlb_power7(unsigned long inval_selector);
-extern void __flush_tlb_power8(unsigned long inval_selector);
+extern void __flush_tlb_power7(unsigned int action);
+extern void __flush_tlb_power8(unsigned int action);
extern long __machine_check_early_realmode_p7(struct pt_regs *regs);
extern long __machine_check_early_realmode_p8(struct pt_regs *regs);
#endif /* CONFIG_PPC64 */
diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c
index aa9aff3..65f6043 100644
--- a/arch/powerpc/kernel/mce_power.c
+++ b/arch/powerpc/kernel/mce_power.c
@@ -28,6 +28,55 @@
#include <asm/mce.h>
#include <asm/machdep.h>
+static void flush_tlb_206(unsigned int num_sets, unsigned int action)
+{
+ unsigned long rb;
+ unsigned int i;
+
+ switch (action) {
+ case FLUSH_TLB_ALL:
+ rb = TLBIEL_INVAL_SET;
+ break;
+ case FLUSH_TLB_LPID:
+ rb = TLBIEL_INVAL_SET_LPID;
+ break;
+ default:
+ BUG();
+ break;
+ }
+
+ asm volatile("ptesync" : : : "memory");
+ for (i = 0; i < num_sets; i++) {
+ asm volatile("tlbiel %0" : : "r" (rb));
+ rb += 1 << TLBIEL_INVAL_SET_SHIFT;
+ }
+ asm volatile("ptesync" : : : "memory");
+}
+
+/*
+ * Generic routine to flush TLB on power7. This routine is used as
+ * flush_tlb hook in cpu_spec for Power7 processor.
+ *
+ * action => FLUSH_TLB_ALL: Invalidate all TLBs.
+ * FLUSH_TLB_LPID: Invalidate TLB for current LPID.
+ */
+void __flush_tlb_power7(unsigned int action)
+{
+ flush_tlb_206(POWER7_TLB_SETS, action);
+}
+
+/*
+ * Generic routine to flush TLB on power8. This routine is used as
+ * flush_tlb hook in cpu_spec for power8 processor.
+ *
+ * action => FLUSH_TLB_ALL: Invalidate all TLBs.
+ * FLUSH_TLB_LPID: Invalidate TLB for current LPID.
+ */
+void __flush_tlb_power8(unsigned int action)
+{
+ flush_tlb_206(POWER8_TLB_SETS, action);
+}
+
/* flush SLBs and reload */
static void flush_and_reload_slb(void)
{
@@ -79,7 +128,7 @@ static long mce_handle_derror(uint64_t dsisr, uint64_t slb_error_bits)
}
if (dsisr & P7_DSISR_MC_TLB_MULTIHIT_MFTLB) {
if (cur_cpu_spec && cur_cpu_spec->flush_tlb)
- cur_cpu_spec->flush_tlb(TLBIEL_INVAL_PAGE);
+ cur_cpu_spec->flush_tlb(FLUSH_TLB_ALL);
/* reset error bits */
dsisr &= ~P7_DSISR_MC_TLB_MULTIHIT_MFTLB;
}
@@ -110,7 +159,7 @@ static long mce_handle_common_ierror(uint64_t srr1)
break;
case P7_SRR1_MC_IFETCH_TLB_MULTIHIT:
if (cur_cpu_spec && cur_cpu_spec->flush_tlb) {
- cur_cpu_spec->flush_tlb(TLBIEL_INVAL_PAGE);
+ cur_cpu_spec->flush_tlb(FLUSH_TLB_ALL);
handled = 1;
}
break;
diff --git a/arch/powerpc/kvm/book3s_hv_ras.c b/arch/powerpc/kvm/book3s_hv_ras.c
index d562c8e..8246090 100644
--- a/arch/powerpc/kvm/book3s_hv_ras.c
+++ b/arch/powerpc/kvm/book3s_hv_ras.c
@@ -84,7 +84,7 @@ static long kvmppc_realmode_mc_power7(struct kvm_vcpu *vcpu)
}
if (dsisr & DSISR_MC_TLB_MULTI) {
if (cur_cpu_spec && cur_cpu_spec->flush_tlb)
- cur_cpu_spec->flush_tlb(TLBIEL_INVAL_SET_LPID);
+ cur_cpu_spec->flush_tlb(FLUSH_TLB_LPID);
dsisr &= ~DSISR_MC_TLB_MULTI;
}
/* Any other errors we don't understand? */
@@ -102,7 +102,7 @@ static long kvmppc_realmode_mc_power7(struct kvm_vcpu *vcpu)
break;
case SRR1_MC_IFETCH_TLBMULTI:
if (cur_cpu_spec && cur_cpu_spec->flush_tlb)
- cur_cpu_spec->flush_tlb(TLBIEL_INVAL_SET_LPID);
+ cur_cpu_spec->flush_tlb(FLUSH_TLB_LPID);
break;
default:
handled = 0;
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