Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 630 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..ecb375040
--- /dev/null
+++ b/arch/powerpc/kernel/mce_power.c
@@ -0,0 +1,630 @@
+/*
+ * 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>
+#include <asm/pgtable.h>
+#include <asm/pte-walk.h>
+#include <asm/sstep.h>
+#include <asm/exception-64s.h>
+
+/*
+ * Convert an address related to an mm to a PFN. NOTE: we are in real
+ * mode, we could potentially race with page table updates.
+ */
+static unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr)
+{
+	pte_t *ptep;
+	unsigned int shift;
+	unsigned long pfn, flags;
+	struct mm_struct *mm;
+
+	if (user_mode(regs))
+		mm = current->mm;
+	else
+		mm = &init_mm;
+
+	local_irq_save(flags);
+	ptep = __find_linux_pte(mm->pgd, addr, NULL, &shift);
+
+	if (!ptep || pte_special(*ptep)) {
+		pfn = ULONG_MAX;
+		goto out;
+	}
+
+	if (shift <= PAGE_SHIFT)
+		pfn = pte_pfn(*ptep);
+	else {
+		unsigned long rpnmask = (1ul << shift) - PAGE_SIZE;
+		pfn = pte_pfn(__pte(pte_val(*ptep) | (addr & rpnmask)));
+	}
+
+out:
+	local_irq_restore(flags);
+	return pfn;
+}
+
+/* flush SLBs and reload */
+#ifdef CONFIG_PPC_BOOK3S_64
+static void flush_and_reload_slb(void)
+{
+	/* Invalidate all SLBs */
+	slb_flush_all_realmode();
+
+#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
+	if (early_radix_enabled())
+		return;
+
+	/*
+	 * This probably shouldn't happen, but it may be possible it's
+	 * called in early boot before SLB shadows are allocated.
+	 */
+	if (!get_slb_shadow())
+		return;
+
+	slb_restore_bolted_realmode();
+}
+#endif
+
+static void flush_erat(void)
+{
+#ifdef CONFIG_PPC_BOOK3S_64
+	if (!early_cpu_has_feature(CPU_FTR_ARCH_300)) {
+		flush_and_reload_slb();
+		return;
+	}
+#endif
+	/* PPC_INVALIDATE_ERAT can only be used on ISA v3 and newer */
+	asm volatile(PPC_INVALIDATE_ERAT : : :"memory");
+}
+
+#define MCE_FLUSH_SLB 1
+#define MCE_FLUSH_TLB 2
+#define MCE_FLUSH_ERAT 3
+
+static int mce_flush(int what)
+{
+#ifdef CONFIG_PPC_BOOK3S_64
+	if (what == MCE_FLUSH_SLB) {
+		flush_and_reload_slb();
+		return 1;
+	}
+#endif
+	if (what == MCE_FLUSH_ERAT) {
+		flush_erat();
+		return 1;
+	}
+	if (what == MCE_FLUSH_TLB) {
+		tlbiel_all();
+		return 1;
+	}
+
+	return 0;
+}
+
+#define SRR1_MC_LOADSTORE(srr1)	((srr1) & PPC_BIT(42))
+
+struct mce_ierror_table {
+	unsigned long srr1_mask;
+	unsigned long srr1_value;
+	bool nip_valid; /* nip is a valid indicator of faulting address */
+	unsigned int error_type;
+	unsigned int error_subtype;
+	unsigned int initiator;
+	unsigned int severity;
+};
+
+static const struct mce_ierror_table mce_p7_ierror_table[] = {
+{ 0x00000000001c0000, 0x0000000000040000, true,
+  MCE_ERROR_TYPE_UE,  MCE_UE_ERROR_IFETCH,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000001c0000, 0x0000000000080000, true,
+  MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_PARITY,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000001c0000, 0x00000000000c0000, true,
+  MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000001c0000, 0x0000000000100000, true,
+  MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_INDETERMINATE, /* BOTH */
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000001c0000, 0x0000000000140000, true,
+  MCE_ERROR_TYPE_TLB, MCE_TLB_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000001c0000, 0x0000000000180000, true,
+  MCE_ERROR_TYPE_UE,  MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000001c0000, 0x00000000001c0000, true,
+  MCE_ERROR_TYPE_UE,  MCE_UE_ERROR_IFETCH,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0, 0, 0, 0, 0, 0 } };
+
+static const struct mce_ierror_table mce_p8_ierror_table[] = {
+{ 0x00000000081c0000, 0x0000000000040000, true,
+  MCE_ERROR_TYPE_UE,  MCE_UE_ERROR_IFETCH,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000000080000, true,
+  MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_PARITY,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x00000000000c0000, true,
+  MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000000100000, true,
+  MCE_ERROR_TYPE_ERAT,MCE_ERAT_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000000140000, true,
+  MCE_ERROR_TYPE_TLB, MCE_TLB_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000000180000, true,
+  MCE_ERROR_TYPE_UE,  MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x00000000001c0000, true,
+  MCE_ERROR_TYPE_UE,  MCE_UE_ERROR_IFETCH,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000008000000, true,
+  MCE_ERROR_TYPE_LINK,MCE_LINK_ERROR_IFETCH_TIMEOUT,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000008040000, true,
+  MCE_ERROR_TYPE_LINK,MCE_LINK_ERROR_PAGE_TABLE_WALK_IFETCH_TIMEOUT,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0, 0, 0, 0, 0, 0 } };
+
+static const struct mce_ierror_table mce_p9_ierror_table[] = {
+{ 0x00000000081c0000, 0x0000000000040000, true,
+  MCE_ERROR_TYPE_UE,  MCE_UE_ERROR_IFETCH,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000000080000, true,
+  MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_PARITY,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x00000000000c0000, true,
+  MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000000100000, true,
+  MCE_ERROR_TYPE_ERAT,MCE_ERAT_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000000140000, true,
+  MCE_ERROR_TYPE_TLB, MCE_TLB_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000000180000, true,
+  MCE_ERROR_TYPE_UE,  MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x00000000001c0000, true,
+  MCE_ERROR_TYPE_RA,  MCE_RA_ERROR_IFETCH_FOREIGN,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000008000000, true,
+  MCE_ERROR_TYPE_LINK,MCE_LINK_ERROR_IFETCH_TIMEOUT,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000008040000, true,
+  MCE_ERROR_TYPE_LINK,MCE_LINK_ERROR_PAGE_TABLE_WALK_IFETCH_TIMEOUT,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x00000000080c0000, true,
+  MCE_ERROR_TYPE_RA,  MCE_RA_ERROR_IFETCH,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000008100000, true,
+  MCE_ERROR_TYPE_RA,  MCE_RA_ERROR_PAGE_TABLE_WALK_IFETCH,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0x00000000081c0000, 0x0000000008140000, false,
+  MCE_ERROR_TYPE_RA,  MCE_RA_ERROR_STORE,
+  MCE_INITIATOR_CPU,  MCE_SEV_FATAL, }, /* ASYNC is fatal */
+{ 0x00000000081c0000, 0x0000000008180000, false,
+  MCE_ERROR_TYPE_LINK,MCE_LINK_ERROR_STORE_TIMEOUT,
+  MCE_INITIATOR_CPU,  MCE_SEV_FATAL, }, /* ASYNC is fatal */
+{ 0x00000000081c0000, 0x00000000081c0000, true,
+  MCE_ERROR_TYPE_RA,  MCE_RA_ERROR_PAGE_TABLE_WALK_IFETCH_FOREIGN,
+  MCE_INITIATOR_CPU,  MCE_SEV_ERROR_SYNC, },
+{ 0, 0, 0, 0, 0, 0 } };
+
+struct mce_derror_table {
+	unsigned long dsisr_value;
+	bool dar_valid; /* dar is a valid indicator of faulting address */
+	unsigned int error_type;
+	unsigned int error_subtype;
+	unsigned int initiator;
+	unsigned int severity;
+};
+
+static const struct mce_derror_table mce_p7_derror_table[] = {
+{ 0x00008000, false,
+  MCE_ERROR_TYPE_UE,   MCE_UE_ERROR_LOAD_STORE,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00004000, true,
+  MCE_ERROR_TYPE_UE,   MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000800, true,
+  MCE_ERROR_TYPE_ERAT, MCE_ERAT_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000400, true,
+  MCE_ERROR_TYPE_TLB,  MCE_TLB_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000080, true,
+  MCE_ERROR_TYPE_SLB,  MCE_SLB_ERROR_MULTIHIT,	/* Before PARITY */
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000100, true,
+  MCE_ERROR_TYPE_SLB,  MCE_SLB_ERROR_PARITY,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000040, true,
+  MCE_ERROR_TYPE_SLB,  MCE_SLB_ERROR_INDETERMINATE, /* BOTH */
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0, false, 0, 0, 0, 0 } };
+
+static const struct mce_derror_table mce_p8_derror_table[] = {
+{ 0x00008000, false,
+  MCE_ERROR_TYPE_UE,   MCE_UE_ERROR_LOAD_STORE,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00004000, true,
+  MCE_ERROR_TYPE_UE,   MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00002000, true,
+  MCE_ERROR_TYPE_LINK, MCE_LINK_ERROR_LOAD_TIMEOUT,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00001000, true,
+  MCE_ERROR_TYPE_LINK, MCE_LINK_ERROR_PAGE_TABLE_WALK_LOAD_STORE_TIMEOUT,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000800, true,
+  MCE_ERROR_TYPE_ERAT, MCE_ERAT_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000400, true,
+  MCE_ERROR_TYPE_TLB,  MCE_TLB_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000200, true,
+  MCE_ERROR_TYPE_ERAT, MCE_ERAT_ERROR_MULTIHIT, /* SECONDARY ERAT */
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000080, true,
+  MCE_ERROR_TYPE_SLB,  MCE_SLB_ERROR_MULTIHIT,	/* Before PARITY */
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000100, true,
+  MCE_ERROR_TYPE_SLB,  MCE_SLB_ERROR_PARITY,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0, false, 0, 0, 0, 0 } };
+
+static const struct mce_derror_table mce_p9_derror_table[] = {
+{ 0x00008000, false,
+  MCE_ERROR_TYPE_UE,   MCE_UE_ERROR_LOAD_STORE,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00004000, true,
+  MCE_ERROR_TYPE_UE,   MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00002000, true,
+  MCE_ERROR_TYPE_LINK, MCE_LINK_ERROR_LOAD_TIMEOUT,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00001000, true,
+  MCE_ERROR_TYPE_LINK, MCE_LINK_ERROR_PAGE_TABLE_WALK_LOAD_STORE_TIMEOUT,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000800, true,
+  MCE_ERROR_TYPE_ERAT, MCE_ERAT_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000400, true,
+  MCE_ERROR_TYPE_TLB,  MCE_TLB_ERROR_MULTIHIT,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000200, false,
+  MCE_ERROR_TYPE_USER, MCE_USER_ERROR_TLBIE,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000080, true,
+  MCE_ERROR_TYPE_SLB,  MCE_SLB_ERROR_MULTIHIT,	/* Before PARITY */
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000100, true,
+  MCE_ERROR_TYPE_SLB,  MCE_SLB_ERROR_PARITY,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000040, true,
+  MCE_ERROR_TYPE_RA,   MCE_RA_ERROR_LOAD,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000020, false,
+  MCE_ERROR_TYPE_RA,   MCE_RA_ERROR_PAGE_TABLE_WALK_LOAD_STORE,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000010, false,
+  MCE_ERROR_TYPE_RA,   MCE_RA_ERROR_PAGE_TABLE_WALK_LOAD_STORE_FOREIGN,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0x00000008, false,
+  MCE_ERROR_TYPE_RA,   MCE_RA_ERROR_LOAD_STORE_FOREIGN,
+  MCE_INITIATOR_CPU,   MCE_SEV_ERROR_SYNC, },
+{ 0, false, 0, 0, 0, 0 } };
+
+static int mce_find_instr_ea_and_phys(struct pt_regs *regs, uint64_t *addr,
+					uint64_t *phys_addr)
+{
+	/*
+	 * Carefully look at the NIP to determine
+	 * the instruction to analyse. Reading the NIP
+	 * in real-mode is tricky and can lead to recursive
+	 * faults
+	 */
+	int instr;
+	unsigned long pfn, instr_addr;
+	struct instruction_op op;
+	struct pt_regs tmp = *regs;
+
+	pfn = addr_to_pfn(regs, regs->nip);
+	if (pfn != ULONG_MAX) {
+		instr_addr = (pfn << PAGE_SHIFT) + (regs->nip & ~PAGE_MASK);
+		instr = *(unsigned int *)(instr_addr);
+		if (!analyse_instr(&op, &tmp, instr)) {
+			pfn = addr_to_pfn(regs, op.ea);
+			*addr = op.ea;
+			*phys_addr = (pfn << PAGE_SHIFT);
+			return 0;
+		}
+		/*
+		 * analyse_instr() might fail if the instruction
+		 * is not a load/store, although this is unexpected
+		 * for load/store errors or if we got the NIP
+		 * wrong
+		 */
+	}
+	*addr = 0;
+	return -1;
+}
+
+static int mce_handle_ierror(struct pt_regs *regs,
+		const struct mce_ierror_table table[],
+		struct mce_error_info *mce_err, uint64_t *addr,
+		uint64_t *phys_addr)
+{
+	uint64_t srr1 = regs->msr;
+	int handled = 0;
+	int i;
+
+	*addr = 0;
+
+	for (i = 0; table[i].srr1_mask; i++) {
+		if ((srr1 & table[i].srr1_mask) != table[i].srr1_value)
+			continue;
+
+		/* attempt to correct the error */
+		switch (table[i].error_type) {
+		case MCE_ERROR_TYPE_SLB:
+			handled = mce_flush(MCE_FLUSH_SLB);
+			break;
+		case MCE_ERROR_TYPE_ERAT:
+			handled = mce_flush(MCE_FLUSH_ERAT);
+			break;
+		case MCE_ERROR_TYPE_TLB:
+			handled = mce_flush(MCE_FLUSH_TLB);
+			break;
+		}
+
+		/* now fill in mce_error_info */
+		mce_err->error_type = table[i].error_type;
+		switch (table[i].error_type) {
+		case MCE_ERROR_TYPE_UE:
+			mce_err->u.ue_error_type = table[i].error_subtype;
+			break;
+		case MCE_ERROR_TYPE_SLB:
+			mce_err->u.slb_error_type = table[i].error_subtype;
+			break;
+		case MCE_ERROR_TYPE_ERAT:
+			mce_err->u.erat_error_type = table[i].error_subtype;
+			break;
+		case MCE_ERROR_TYPE_TLB:
+			mce_err->u.tlb_error_type = table[i].error_subtype;
+			break;
+		case MCE_ERROR_TYPE_USER:
+			mce_err->u.user_error_type = table[i].error_subtype;
+			break;
+		case MCE_ERROR_TYPE_RA:
+			mce_err->u.ra_error_type = table[i].error_subtype;
+			break;
+		case MCE_ERROR_TYPE_LINK:
+			mce_err->u.link_error_type = table[i].error_subtype;
+			break;
+		}
+		mce_err->severity = table[i].severity;
+		mce_err->initiator = table[i].initiator;
+		if (table[i].nip_valid) {
+			*addr = regs->nip;
+			if (mce_err->severity == MCE_SEV_ERROR_SYNC &&
+				table[i].error_type == MCE_ERROR_TYPE_UE) {
+				unsigned long pfn;
+
+				if (get_paca()->in_mce < MAX_MCE_DEPTH) {
+					pfn = addr_to_pfn(regs, regs->nip);
+					if (pfn != ULONG_MAX) {
+						*phys_addr =
+							(pfn << PAGE_SHIFT);
+					}
+				}
+			}
+		}
+		return handled;
+	}
+
+	mce_err->error_type = MCE_ERROR_TYPE_UNKNOWN;
+	mce_err->severity = MCE_SEV_ERROR_SYNC;
+	mce_err->initiator = MCE_INITIATOR_CPU;
+
+	return 0;
+}
+
+static int mce_handle_derror(struct pt_regs *regs,
+		const struct mce_derror_table table[],
+		struct mce_error_info *mce_err, uint64_t *addr,
+		uint64_t *phys_addr)
+{
+	uint64_t dsisr = regs->dsisr;
+	int handled = 0;
+	int found = 0;
+	int i;
+
+	*addr = 0;
+
+	for (i = 0; table[i].dsisr_value; i++) {
+		if (!(dsisr & table[i].dsisr_value))
+			continue;
+
+		/* attempt to correct the error */
+		switch (table[i].error_type) {
+		case MCE_ERROR_TYPE_SLB:
+			if (mce_flush(MCE_FLUSH_SLB))
+				handled = 1;
+			break;
+		case MCE_ERROR_TYPE_ERAT:
+			if (mce_flush(MCE_FLUSH_ERAT))
+				handled = 1;
+			break;
+		case MCE_ERROR_TYPE_TLB:
+			if (mce_flush(MCE_FLUSH_TLB))
+				handled = 1;
+			break;
+		}
+
+		/*
+		 * Attempt to handle multiple conditions, but only return
+		 * one. Ensure uncorrectable errors are first in the table
+		 * to match.
+		 */
+		if (found)
+			continue;
+
+		/* now fill in mce_error_info */
+		mce_err->error_type = table[i].error_type;
+		switch (table[i].error_type) {
+		case MCE_ERROR_TYPE_UE:
+			mce_err->u.ue_error_type = table[i].error_subtype;
+			break;
+		case MCE_ERROR_TYPE_SLB:
+			mce_err->u.slb_error_type = table[i].error_subtype;
+			break;
+		case MCE_ERROR_TYPE_ERAT:
+			mce_err->u.erat_error_type = table[i].error_subtype;
+			break;
+		case MCE_ERROR_TYPE_TLB:
+			mce_err->u.tlb_error_type = table[i].error_subtype;
+			break;
+		case MCE_ERROR_TYPE_USER:
+			mce_err->u.user_error_type = table[i].error_subtype;
+			break;
+		case MCE_ERROR_TYPE_RA:
+			mce_err->u.ra_error_type = table[i].error_subtype;
+			break;
+		case MCE_ERROR_TYPE_LINK:
+			mce_err->u.link_error_type = table[i].error_subtype;
+			break;
+		}
+		mce_err->severity = table[i].severity;
+		mce_err->initiator = table[i].initiator;
+		if (table[i].dar_valid)
+			*addr = regs->dar;
+		else if (mce_err->severity == MCE_SEV_ERROR_SYNC &&
+				table[i].error_type == MCE_ERROR_TYPE_UE) {
+			/*
+			 * We do a maximum of 4 nested MCE calls, see
+			 * kernel/exception-64s.h
+			 */
+			if (get_paca()->in_mce < MAX_MCE_DEPTH)
+				mce_find_instr_ea_and_phys(regs, addr,
+							   phys_addr);
+		}
+		found = 1;
+	}
+
+	if (found)
+		return handled;
+
+	mce_err->error_type = MCE_ERROR_TYPE_UNKNOWN;
+	mce_err->severity = MCE_SEV_ERROR_SYNC;
+	mce_err->initiator = MCE_INITIATOR_CPU;
+
+	return 0;
+}
+
+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;
+}
+
+static long mce_handle_error(struct pt_regs *regs,
+		const struct mce_derror_table dtable[],
+		const struct mce_ierror_table itable[])
+{
+	struct mce_error_info mce_err = { 0 };
+	uint64_t addr, phys_addr = ULONG_MAX;
+	uint64_t srr1 = regs->msr;
+	long handled;
+
+	if (SRR1_MC_LOADSTORE(srr1))
+		handled = mce_handle_derror(regs, dtable, &mce_err, &addr,
+				&phys_addr);
+	else
+		handled = mce_handle_ierror(regs, itable, &mce_err, &addr,
+				&phys_addr);
+
+	if (!handled && mce_err.error_type == MCE_ERROR_TYPE_UE)
+		handled = mce_handle_ue_error(regs);
+
+	save_mce_event(regs, handled, &mce_err, regs->nip, addr, phys_addr);
+
+	return handled;
+}
+
+long __machine_check_early_realmode_p7(struct pt_regs *regs)
+{
+	/* P7 DD1 leaves top bits of DSISR undefined */
+	regs->dsisr &= 0x0000ffff;
+
+	return mce_handle_error(regs, mce_p7_derror_table, mce_p7_ierror_table);
+}
+
+long __machine_check_early_realmode_p8(struct pt_regs *regs)
+{
+	return mce_handle_error(regs, mce_p8_derror_table, mce_p8_ierror_table);
+}
+
+long __machine_check_early_realmode_p9(struct pt_regs *regs)
+{
+	/*
+	 * On POWER9 DD2.1 and below, it's possible to get a machine check
+	 * caused by a paste instruction where only DSISR bit 25 is set. This
+	 * will result in the MCE handler seeing an unknown event and the kernel
+	 * crashing. An MCE that occurs like this is spurious, so we don't need
+	 * to do anything in terms of servicing it. If there is something that
+	 * needs to be serviced, the CPU will raise the MCE again with the
+	 * correct DSISR so that it can be serviced properly. So detect this
+	 * case and mark it as handled.
+	 */
+	if (SRR1_MC_LOADSTORE(regs->msr) && regs->dsisr == 0x02000000)
+		return 1;
+
+	return mce_handle_error(regs, mce_p9_derror_table, mce_p9_ierror_table);
+}