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Diffstat (limited to 'arch/powerpc/kernel/mce_power.c')
-rw-r--r--arch/powerpc/kernel/mce_power.c313
1 files changed, 313 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c
new file mode 100644
index 00000000000..aa9aff3d6ad
--- /dev/null
+++ b/arch/powerpc/kernel/mce_power.c
@@ -0,0 +1,313 @@
+/*
+ * Machine check exception handling CPU-side for power7 and power8
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright 2013 IBM Corporation
+ * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
+ */
+
+#undef DEBUG
+#define pr_fmt(fmt) "mce_power: " fmt
+
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <asm/mmu.h>
+#include <asm/mce.h>
+#include <asm/machdep.h>
+
+/* flush SLBs and reload */
+static void flush_and_reload_slb(void)
+{
+ struct slb_shadow *slb;
+ unsigned long i, n;
+
+ /* Invalidate all SLBs */
+ asm volatile("slbmte %0,%0; slbia" : : "r" (0));
+
+#ifdef CONFIG_KVM_BOOK3S_HANDLER
+ /*
+ * If machine check is hit when in guest or in transition, we will
+ * only flush the SLBs and continue.
+ */
+ if (get_paca()->kvm_hstate.in_guest)
+ return;
+#endif
+
+ /* For host kernel, reload the SLBs from shadow SLB buffer. */
+ slb = get_slb_shadow();
+ if (!slb)
+ return;
+
+ n = min_t(u32, be32_to_cpu(slb->persistent), SLB_MIN_SIZE);
+
+ /* Load up the SLB entries from shadow SLB */
+ for (i = 0; i < n; i++) {
+ unsigned long rb = be64_to_cpu(slb->save_area[i].esid);
+ unsigned long rs = be64_to_cpu(slb->save_area[i].vsid);
+
+ rb = (rb & ~0xFFFul) | i;
+ asm volatile("slbmte %0,%1" : : "r" (rs), "r" (rb));
+ }
+}
+
+static long mce_handle_derror(uint64_t dsisr, uint64_t slb_error_bits)
+{
+ long handled = 1;
+
+ /*
+ * flush and reload SLBs for SLB errors and flush TLBs for TLB errors.
+ * reset the error bits whenever we handle them so that at the end
+ * we can check whether we handled all of them or not.
+ * */
+ if (dsisr & slb_error_bits) {
+ flush_and_reload_slb();
+ /* reset error bits */
+ dsisr &= ~(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);
+ /* reset error bits */
+ dsisr &= ~P7_DSISR_MC_TLB_MULTIHIT_MFTLB;
+ }
+ /* Any other errors we don't understand? */
+ if (dsisr & 0xffffffffUL)
+ handled = 0;
+
+ return handled;
+}
+
+static long mce_handle_derror_p7(uint64_t dsisr)
+{
+ return mce_handle_derror(dsisr, P7_DSISR_MC_SLB_ERRORS);
+}
+
+static long mce_handle_common_ierror(uint64_t srr1)
+{
+ long handled = 0;
+
+ switch (P7_SRR1_MC_IFETCH(srr1)) {
+ case 0:
+ break;
+ case P7_SRR1_MC_IFETCH_SLB_PARITY:
+ case P7_SRR1_MC_IFETCH_SLB_MULTIHIT:
+ /* flush and reload SLBs for SLB errors. */
+ flush_and_reload_slb();
+ handled = 1;
+ 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);
+ handled = 1;
+ }
+ break;
+ default:
+ break;
+ }
+
+ return handled;
+}
+
+static long mce_handle_ierror_p7(uint64_t srr1)
+{
+ long handled = 0;
+
+ handled = mce_handle_common_ierror(srr1);
+
+ if (P7_SRR1_MC_IFETCH(srr1) == P7_SRR1_MC_IFETCH_SLB_BOTH) {
+ flush_and_reload_slb();
+ handled = 1;
+ }
+ return handled;
+}
+
+static void mce_get_common_ierror(struct mce_error_info *mce_err, uint64_t srr1)
+{
+ switch (P7_SRR1_MC_IFETCH(srr1)) {
+ case P7_SRR1_MC_IFETCH_SLB_PARITY:
+ mce_err->error_type = MCE_ERROR_TYPE_SLB;
+ mce_err->u.slb_error_type = MCE_SLB_ERROR_PARITY;
+ break;
+ case P7_SRR1_MC_IFETCH_SLB_MULTIHIT:
+ mce_err->error_type = MCE_ERROR_TYPE_SLB;
+ mce_err->u.slb_error_type = MCE_SLB_ERROR_MULTIHIT;
+ break;
+ case P7_SRR1_MC_IFETCH_TLB_MULTIHIT:
+ mce_err->error_type = MCE_ERROR_TYPE_TLB;
+ mce_err->u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT;
+ break;
+ case P7_SRR1_MC_IFETCH_UE:
+ case P7_SRR1_MC_IFETCH_UE_IFU_INTERNAL:
+ mce_err->error_type = MCE_ERROR_TYPE_UE;
+ mce_err->u.ue_error_type = MCE_UE_ERROR_IFETCH;
+ break;
+ case P7_SRR1_MC_IFETCH_UE_TLB_RELOAD:
+ mce_err->error_type = MCE_ERROR_TYPE_UE;
+ mce_err->u.ue_error_type =
+ MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH;
+ break;
+ }
+}
+
+static void mce_get_ierror_p7(struct mce_error_info *mce_err, uint64_t srr1)
+{
+ mce_get_common_ierror(mce_err, srr1);
+ if (P7_SRR1_MC_IFETCH(srr1) == P7_SRR1_MC_IFETCH_SLB_BOTH) {
+ mce_err->error_type = MCE_ERROR_TYPE_SLB;
+ mce_err->u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE;
+ }
+}
+
+static void mce_get_derror_p7(struct mce_error_info *mce_err, uint64_t dsisr)
+{
+ if (dsisr & P7_DSISR_MC_UE) {
+ mce_err->error_type = MCE_ERROR_TYPE_UE;
+ mce_err->u.ue_error_type = MCE_UE_ERROR_LOAD_STORE;
+ } else if (dsisr & P7_DSISR_MC_UE_TABLEWALK) {
+ mce_err->error_type = MCE_ERROR_TYPE_UE;
+ mce_err->u.ue_error_type =
+ MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE;
+ } else if (dsisr & P7_DSISR_MC_ERAT_MULTIHIT) {
+ mce_err->error_type = MCE_ERROR_TYPE_ERAT;
+ mce_err->u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
+ } else if (dsisr & P7_DSISR_MC_SLB_MULTIHIT) {
+ mce_err->error_type = MCE_ERROR_TYPE_SLB;
+ mce_err->u.slb_error_type = MCE_SLB_ERROR_MULTIHIT;
+ } else if (dsisr & P7_DSISR_MC_SLB_PARITY_MFSLB) {
+ mce_err->error_type = MCE_ERROR_TYPE_SLB;
+ mce_err->u.slb_error_type = MCE_SLB_ERROR_PARITY;
+ } else if (dsisr & P7_DSISR_MC_TLB_MULTIHIT_MFTLB) {
+ mce_err->error_type = MCE_ERROR_TYPE_TLB;
+ mce_err->u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT;
+ } else if (dsisr & P7_DSISR_MC_SLB_MULTIHIT_PARITY) {
+ mce_err->error_type = MCE_ERROR_TYPE_SLB;
+ mce_err->u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE;
+ }
+}
+
+static long mce_handle_ue_error(struct pt_regs *regs)
+{
+ long handled = 0;
+
+ /*
+ * On specific SCOM read via MMIO we may get a machine check
+ * exception with SRR0 pointing inside opal. If that is the
+ * case OPAL may have recovery address to re-read SCOM data in
+ * different way and hence we can recover from this MC.
+ */
+
+ if (ppc_md.mce_check_early_recovery) {
+ if (ppc_md.mce_check_early_recovery(regs))
+ handled = 1;
+ }
+ return handled;
+}
+
+long __machine_check_early_realmode_p7(struct pt_regs *regs)
+{
+ uint64_t srr1, nip, addr;
+ long handled = 1;
+ struct mce_error_info mce_error_info = { 0 };
+
+ srr1 = regs->msr;
+ nip = regs->nip;
+
+ /*
+ * Handle memory errors depending whether this was a load/store or
+ * ifetch exception. Also, populate the mce error_type and
+ * type-specific error_type from either SRR1 or DSISR, depending
+ * whether this was a load/store or ifetch exception
+ */
+ if (P7_SRR1_MC_LOADSTORE(srr1)) {
+ handled = mce_handle_derror_p7(regs->dsisr);
+ mce_get_derror_p7(&mce_error_info, regs->dsisr);
+ addr = regs->dar;
+ } else {
+ handled = mce_handle_ierror_p7(srr1);
+ mce_get_ierror_p7(&mce_error_info, srr1);
+ addr = regs->nip;
+ }
+
+ /* Handle UE error. */
+ if (mce_error_info.error_type == MCE_ERROR_TYPE_UE)
+ handled = mce_handle_ue_error(regs);
+
+ save_mce_event(regs, handled, &mce_error_info, nip, addr);
+ return handled;
+}
+
+static void mce_get_ierror_p8(struct mce_error_info *mce_err, uint64_t srr1)
+{
+ mce_get_common_ierror(mce_err, srr1);
+ if (P7_SRR1_MC_IFETCH(srr1) == P8_SRR1_MC_IFETCH_ERAT_MULTIHIT) {
+ mce_err->error_type = MCE_ERROR_TYPE_ERAT;
+ mce_err->u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
+ }
+}
+
+static void mce_get_derror_p8(struct mce_error_info *mce_err, uint64_t dsisr)
+{
+ mce_get_derror_p7(mce_err, dsisr);
+ if (dsisr & P8_DSISR_MC_ERAT_MULTIHIT_SEC) {
+ mce_err->error_type = MCE_ERROR_TYPE_ERAT;
+ mce_err->u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
+ }
+}
+
+static long mce_handle_ierror_p8(uint64_t srr1)
+{
+ long handled = 0;
+
+ handled = mce_handle_common_ierror(srr1);
+
+ if (P7_SRR1_MC_IFETCH(srr1) == P8_SRR1_MC_IFETCH_ERAT_MULTIHIT) {
+ flush_and_reload_slb();
+ handled = 1;
+ }
+ return handled;
+}
+
+static long mce_handle_derror_p8(uint64_t dsisr)
+{
+ return mce_handle_derror(dsisr, P8_DSISR_MC_SLB_ERRORS);
+}
+
+long __machine_check_early_realmode_p8(struct pt_regs *regs)
+{
+ uint64_t srr1, nip, addr;
+ long handled = 1;
+ struct mce_error_info mce_error_info = { 0 };
+
+ srr1 = regs->msr;
+ nip = regs->nip;
+
+ if (P7_SRR1_MC_LOADSTORE(srr1)) {
+ handled = mce_handle_derror_p8(regs->dsisr);
+ mce_get_derror_p8(&mce_error_info, regs->dsisr);
+ addr = regs->dar;
+ } else {
+ handled = mce_handle_ierror_p8(srr1);
+ mce_get_ierror_p8(&mce_error_info, srr1);
+ addr = regs->nip;
+ }
+
+ /* Handle UE error. */
+ if (mce_error_info.error_type == MCE_ERROR_TYPE_UE)
+ handled = mce_handle_ue_error(regs);
+
+ save_mce_event(regs, handled, &mce_error_info, nip, addr);
+ return handled;
+}
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