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linux/arch/powerpc/kernel/mce_power.c
Mahesh Salgaonkar 75ecfb4951 powerpc/mce: Fix a bug where mce loops on memory UE. 
The current code extracts the physical address for UE errors and then
hooks it up into memory failure infrastructure. On successful
extraction of physical address it wrongly sets "handled = 1" which
means this UE error has been recovered. Since MCE handler gets return
value as handled = 1, it assumes that error has been recovered and
goes back to same NIP. This causes MCE interrupt again and again in a
loop leading to hard lockup.

Also, initialize phys_addr to ULONG_MAX so that we don't end up
queuing undesired page to hwpoison.

Without this patch we see:
  Severe Machine check interrupt [Recovered]
    NIP: [000000001002588c] PID: 7109 Comm: find
    Initiator: CPU
    Error type: UE [Load/Store]
      Effective address: 00007fffd2755940
      Physical address:  000020181a080000
  ...
  Severe Machine check interrupt [Recovered]
    NIP: [000000001002588c] PID: 7109 Comm: find
    Initiator: CPU
    Error type: UE [Load/Store]
      Effective address: 00007fffd2755940
      Physical address:  000020181a080000
  Severe Machine check interrupt [Recovered]
    NIP: [000000001002588c] PID: 7109 Comm: find
    Initiator: CPU
    Error type: UE [Load/Store]
      Effective address: 00007fffd2755940
      Physical address:  000020181a080000
  Memory failure: 0x20181a08: recovery action for dirty LRU page: Recovered
  Memory failure: 0x20181a08: already hardware poisoned
  Memory failure: 0x20181a08: already hardware poisoned
  Memory failure: 0x20181a08: already hardware poisoned
  Memory failure: 0x20181a08: already hardware poisoned
  Memory failure: 0x20181a08: already hardware poisoned
  Memory failure: 0x20181a08: already hardware poisoned
  ...
  Watchdog CPU:38 Hard LOCKUP

After this patch we see:

  Severe Machine check interrupt [Not recovered]
    NIP: [00007fffaae585f4] PID: 7168 Comm: find
    Initiator: CPU
    Error type: UE [Load/Store]
      Effective address: 00007fffaafe28ac
      Physical address:  00002017c0bd0000
  find[7168]: unhandled signal 7 at 00007fffaae585f4 nip 00007fffaae585f4 lr 00007fffaae585e0 code 4
  Memory failure: 0x2017c0bd: recovery action for dirty LRU page: Recovered

Fixes: 01eaac2b05 ("powerpc/mce: Hookup ierror (instruction) UE errors")
Fixes: ba41e1e1cc ("powerpc/mce: Hookup derror (load/store) UE errors")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-24 13:54:51 +10:00

621 lines
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/*
* 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 long flags;
struct mm_struct *mm;
if (user_mode(regs))
mm = current->mm;
else
mm = &init_mm;
local_irq_save(flags);
if (mm == current->mm)
ptep = find_current_mm_pte(mm->pgd, addr, NULL, NULL);
else
ptep = find_init_mm_pte(addr, NULL);
local_irq_restore(flags);
if (!ptep || pte_special(*ptep))
return ULONG_MAX;
return pte_pfn(*ptep);
}
/* flush SLBs and reload */
#ifdef CONFIG_PPC_BOOK3S_64
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));
}
}
#endif
static void flush_erat(void)
{
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, },
{ 0x00000100, true,
MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_PARITY,
MCE_INITIATOR_CPU, MCE_SEV_ERROR_SYNC, },
{ 0x00000080, true,
MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_MULTIHIT,
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, },
{ 0x00000100, true,
MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_PARITY,
MCE_INITIATOR_CPU, MCE_SEV_ERROR_SYNC, },
{ 0x00000080, true,
MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_MULTIHIT,
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, },
{ 0x00000100, true,
MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_PARITY,
MCE_INITIATOR_CPU, MCE_SEV_ERROR_SYNC, },
{ 0x00000080, true,
MCE_ERROR_TYPE_SLB, MCE_SLB_ERROR_MULTIHIT,
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_pfn(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_pfn(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);
}
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