| /* |
| * 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; |
| } |