1 files changed, 362 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c
new file mode 100644
index 000000000..2c647b1e6
--- /dev/null
+++ b/arch/powerpc/kernel/mce_power.c
@@ -0,0 +1,362 @@
+/*
+ * 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>
+
+static void flush_tlb_206(unsigned int num_sets, unsigned int action)
+{
+	unsigned long rb;
+	unsigned int i;
+
+	switch (action) {
+	case TLB_INVAL_SCOPE_GLOBAL:
+		rb = TLBIEL_INVAL_SET;
+		break;
+	case TLB_INVAL_SCOPE_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 => TLB_INVAL_SCOPE_GLOBAL:  Invalidate all TLBs.
+ *	     TLB_INVAL_SCOPE_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 => TLB_INVAL_SCOPE_GLOBAL:  Invalidate all TLBs.
+ *	     TLB_INVAL_SCOPE_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)
+{
+	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(TLB_INVAL_SCOPE_GLOBAL);
+		/* 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(TLB_INVAL_SCOPE_GLOBAL);
+			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;
+}