diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/ras.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/ras.c | 875 |
1 files changed, 875 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c new file mode 100644 index 000000000..b2b245b25 --- /dev/null +++ b/arch/powerpc/platforms/pseries/ras.c @@ -0,0 +1,875 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2001 Dave Engebretsen IBM Corporation + */ + +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/of.h> +#include <linux/fs.h> +#include <linux/reboot.h> +#include <linux/irq_work.h> + +#include <asm/machdep.h> +#include <asm/rtas.h> +#include <asm/firmware.h> +#include <asm/mce.h> + +#include "pseries.h" + +static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX]; +static DEFINE_SPINLOCK(ras_log_buf_lock); + +static int ras_check_exception_token; + +static void mce_process_errlog_event(struct irq_work *work); +static struct irq_work mce_errlog_process_work = { + .func = mce_process_errlog_event, +}; + +#define EPOW_SENSOR_TOKEN 9 +#define EPOW_SENSOR_INDEX 0 + +/* EPOW events counter variable */ +static int num_epow_events; + +static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id); +static irqreturn_t ras_epow_interrupt(int irq, void *dev_id); +static irqreturn_t ras_error_interrupt(int irq, void *dev_id); + +/* RTAS pseries MCE errorlog section. */ +struct pseries_mc_errorlog { + __be32 fru_id; + __be32 proc_id; + u8 error_type; + /* + * sub_err_type (1 byte). Bit fields depends on error_type + * + * MSB0 + * | + * V + * 01234567 + * XXXXXXXX + * + * For error_type == MC_ERROR_TYPE_UE + * XXXXXXXX + * X 1: Permanent or Transient UE. + * X 1: Effective address provided. + * X 1: Logical address provided. + * XX 2: Reserved. + * XXX 3: Type of UE error. + * + * For error_type != MC_ERROR_TYPE_UE + * XXXXXXXX + * X 1: Effective address provided. + * XXXXX 5: Reserved. + * XX 2: Type of SLB/ERAT/TLB error. + */ + u8 sub_err_type; + u8 reserved_1[6]; + __be64 effective_address; + __be64 logical_address; +} __packed; + +/* RTAS pseries MCE error types */ +#define MC_ERROR_TYPE_UE 0x00 +#define MC_ERROR_TYPE_SLB 0x01 +#define MC_ERROR_TYPE_ERAT 0x02 +#define MC_ERROR_TYPE_UNKNOWN 0x03 +#define MC_ERROR_TYPE_TLB 0x04 +#define MC_ERROR_TYPE_D_CACHE 0x05 +#define MC_ERROR_TYPE_I_CACHE 0x07 + +/* RTAS pseries MCE error sub types */ +#define MC_ERROR_UE_INDETERMINATE 0 +#define MC_ERROR_UE_IFETCH 1 +#define MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH 2 +#define MC_ERROR_UE_LOAD_STORE 3 +#define MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE 4 + +#define UE_EFFECTIVE_ADDR_PROVIDED 0x40 +#define UE_LOGICAL_ADDR_PROVIDED 0x20 + +#define MC_ERROR_SLB_PARITY 0 +#define MC_ERROR_SLB_MULTIHIT 1 +#define MC_ERROR_SLB_INDETERMINATE 2 + +#define MC_ERROR_ERAT_PARITY 1 +#define MC_ERROR_ERAT_MULTIHIT 2 +#define MC_ERROR_ERAT_INDETERMINATE 3 + +#define MC_ERROR_TLB_PARITY 1 +#define MC_ERROR_TLB_MULTIHIT 2 +#define MC_ERROR_TLB_INDETERMINATE 3 + +static inline u8 rtas_mc_error_sub_type(const struct pseries_mc_errorlog *mlog) +{ + switch (mlog->error_type) { + case MC_ERROR_TYPE_UE: + return (mlog->sub_err_type & 0x07); + case MC_ERROR_TYPE_SLB: + case MC_ERROR_TYPE_ERAT: + case MC_ERROR_TYPE_TLB: + return (mlog->sub_err_type & 0x03); + default: + return 0; + } +} + +/* + * Enable the hotplug interrupt late because processing them may touch other + * devices or systems (e.g. hugepages) that have not been initialized at the + * subsys stage. + */ +int __init init_ras_hotplug_IRQ(void) +{ + struct device_node *np; + + /* Hotplug Events */ + np = of_find_node_by_path("/event-sources/hot-plug-events"); + if (np != NULL) { + if (dlpar_workqueue_init() == 0) + request_event_sources_irqs(np, ras_hotplug_interrupt, + "RAS_HOTPLUG"); + of_node_put(np); + } + + return 0; +} +machine_late_initcall(pseries, init_ras_hotplug_IRQ); + +/* + * Initialize handlers for the set of interrupts caused by hardware errors + * and power system events. + */ +static int __init init_ras_IRQ(void) +{ + struct device_node *np; + + ras_check_exception_token = rtas_token("check-exception"); + + /* Internal Errors */ + np = of_find_node_by_path("/event-sources/internal-errors"); + if (np != NULL) { + request_event_sources_irqs(np, ras_error_interrupt, + "RAS_ERROR"); + of_node_put(np); + } + + /* EPOW Events */ + np = of_find_node_by_path("/event-sources/epow-events"); + if (np != NULL) { + request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW"); + of_node_put(np); + } + + return 0; +} +machine_subsys_initcall(pseries, init_ras_IRQ); + +#define EPOW_SHUTDOWN_NORMAL 1 +#define EPOW_SHUTDOWN_ON_UPS 2 +#define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS 3 +#define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH 4 + +static void handle_system_shutdown(char event_modifier) +{ + switch (event_modifier) { + case EPOW_SHUTDOWN_NORMAL: + pr_emerg("Power off requested\n"); + orderly_poweroff(true); + break; + + case EPOW_SHUTDOWN_ON_UPS: + pr_emerg("Loss of system power detected. System is running on" + " UPS/battery. Check RTAS error log for details\n"); + break; + + case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS: + pr_emerg("Loss of system critical functions detected. Check" + " RTAS error log for details\n"); + orderly_poweroff(true); + break; + + case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH: + pr_emerg("High ambient temperature detected. Check RTAS" + " error log for details\n"); + orderly_poweroff(true); + break; + + default: + pr_err("Unknown power/cooling shutdown event (modifier = %d)\n", + event_modifier); + } +} + +struct epow_errorlog { + unsigned char sensor_value; + unsigned char event_modifier; + unsigned char extended_modifier; + unsigned char reserved; + unsigned char platform_reason; +}; + +#define EPOW_RESET 0 +#define EPOW_WARN_COOLING 1 +#define EPOW_WARN_POWER 2 +#define EPOW_SYSTEM_SHUTDOWN 3 +#define EPOW_SYSTEM_HALT 4 +#define EPOW_MAIN_ENCLOSURE 5 +#define EPOW_POWER_OFF 7 + +static void rtas_parse_epow_errlog(struct rtas_error_log *log) +{ + struct pseries_errorlog *pseries_log; + struct epow_errorlog *epow_log; + char action_code; + char modifier; + + pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW); + if (pseries_log == NULL) + return; + + epow_log = (struct epow_errorlog *)pseries_log->data; + action_code = epow_log->sensor_value & 0xF; /* bottom 4 bits */ + modifier = epow_log->event_modifier & 0xF; /* bottom 4 bits */ + + switch (action_code) { + case EPOW_RESET: + if (num_epow_events) { + pr_info("Non critical power/cooling issue cleared\n"); + num_epow_events--; + } + break; + + case EPOW_WARN_COOLING: + pr_info("Non-critical cooling issue detected. Check RTAS error" + " log for details\n"); + break; + + case EPOW_WARN_POWER: + pr_info("Non-critical power issue detected. Check RTAS error" + " log for details\n"); + break; + + case EPOW_SYSTEM_SHUTDOWN: + handle_system_shutdown(modifier); + break; + + case EPOW_SYSTEM_HALT: + pr_emerg("Critical power/cooling issue detected. Check RTAS" + " error log for details. Powering off.\n"); + orderly_poweroff(true); + break; + + case EPOW_MAIN_ENCLOSURE: + case EPOW_POWER_OFF: + pr_emerg("System about to lose power. Check RTAS error log " + " for details. Powering off immediately.\n"); + emergency_sync(); + kernel_power_off(); + break; + + default: + pr_err("Unknown power/cooling event (action code = %d)\n", + action_code); + } + + /* Increment epow events counter variable */ + if (action_code != EPOW_RESET) + num_epow_events++; +} + +static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id) +{ + struct pseries_errorlog *pseries_log; + struct pseries_hp_errorlog *hp_elog; + + spin_lock(&ras_log_buf_lock); + + rtas_call(ras_check_exception_token, 6, 1, NULL, + RTAS_VECTOR_EXTERNAL_INTERRUPT, virq_to_hw(irq), + RTAS_HOTPLUG_EVENTS, 0, __pa(&ras_log_buf), + rtas_get_error_log_max()); + + pseries_log = get_pseries_errorlog((struct rtas_error_log *)ras_log_buf, + PSERIES_ELOG_SECT_ID_HOTPLUG); + hp_elog = (struct pseries_hp_errorlog *)pseries_log->data; + + /* + * Since PCI hotplug is not currently supported on pseries, put PCI + * hotplug events on the ras_log_buf to be handled by rtas_errd. + */ + if (hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_MEM || + hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_CPU || + hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_PMEM) + queue_hotplug_event(hp_elog); + else + log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); + + spin_unlock(&ras_log_buf_lock); + return IRQ_HANDLED; +} + +/* Handle environmental and power warning (EPOW) interrupts. */ +static irqreturn_t ras_epow_interrupt(int irq, void *dev_id) +{ + int status; + int state; + int critical; + + status = rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX, + &state); + + if (state > 3) + critical = 1; /* Time Critical */ + else + critical = 0; + + spin_lock(&ras_log_buf_lock); + + status = rtas_call(ras_check_exception_token, 6, 1, NULL, + RTAS_VECTOR_EXTERNAL_INTERRUPT, + virq_to_hw(irq), + RTAS_EPOW_WARNING, + critical, __pa(&ras_log_buf), + rtas_get_error_log_max()); + + log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); + + rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf); + + spin_unlock(&ras_log_buf_lock); + return IRQ_HANDLED; +} + +/* + * Handle hardware error interrupts. + * + * RTAS check-exception is called to collect data on the exception. If + * the error is deemed recoverable, we log a warning and return. + * For nonrecoverable errors, an error is logged and we stop all processing + * as quickly as possible in order to prevent propagation of the failure. + */ +static irqreturn_t ras_error_interrupt(int irq, void *dev_id) +{ + struct rtas_error_log *rtas_elog; + int status; + int fatal; + + spin_lock(&ras_log_buf_lock); + + status = rtas_call(ras_check_exception_token, 6, 1, NULL, + RTAS_VECTOR_EXTERNAL_INTERRUPT, + virq_to_hw(irq), + RTAS_INTERNAL_ERROR, 1 /* Time Critical */, + __pa(&ras_log_buf), + rtas_get_error_log_max()); + + rtas_elog = (struct rtas_error_log *)ras_log_buf; + + if (status == 0 && + rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC) + fatal = 1; + else + fatal = 0; + + /* format and print the extended information */ + log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal); + + if (fatal) { + pr_emerg("Fatal hardware error detected. Check RTAS error" + " log for details. Powering off immediately\n"); + emergency_sync(); + kernel_power_off(); + } else { + pr_err("Recoverable hardware error detected\n"); + } + + spin_unlock(&ras_log_buf_lock); + return IRQ_HANDLED; +} + +/* + * Some versions of FWNMI place the buffer inside the 4kB page starting at + * 0x7000. Other versions place it inside the rtas buffer. We check both. + * Minimum size of the buffer is 16 bytes. + */ +#define VALID_FWNMI_BUFFER(A) \ + ((((A) >= 0x7000) && ((A) <= 0x8000 - 16)) || \ + (((A) >= rtas.base) && ((A) <= (rtas.base + rtas.size - 16)))) + +static inline struct rtas_error_log *fwnmi_get_errlog(void) +{ + return (struct rtas_error_log *)local_paca->mce_data_buf; +} + +static __be64 *fwnmi_get_savep(struct pt_regs *regs) +{ + unsigned long savep_ra; + + /* Mask top two bits */ + savep_ra = regs->gpr[3] & ~(0x3UL << 62); + if (!VALID_FWNMI_BUFFER(savep_ra)) { + printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]); + return NULL; + } + + return __va(savep_ra); +} + +/* + * Get the error information for errors coming through the + * FWNMI vectors. The pt_regs' r3 will be updated to reflect + * the actual r3 if possible, and a ptr to the error log entry + * will be returned if found. + * + * Use one buffer mce_data_buf per cpu to store RTAS error. + * + * The mce_data_buf does not have any locks or protection around it, + * if a second machine check comes in, or a system reset is done + * before we have logged the error, then we will get corruption in the + * error log. This is preferable over holding off on calling + * ibm,nmi-interlock which would result in us checkstopping if a + * second machine check did come in. + */ +static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) +{ + struct rtas_error_log *h; + __be64 *savep; + + savep = fwnmi_get_savep(regs); + if (!savep) + return NULL; + + regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */ + + h = (struct rtas_error_log *)&savep[1]; + /* Use the per cpu buffer from paca to store rtas error log */ + memset(local_paca->mce_data_buf, 0, RTAS_ERROR_LOG_MAX); + if (!rtas_error_extended(h)) { + memcpy(local_paca->mce_data_buf, h, sizeof(__u64)); + } else { + int len, error_log_length; + + error_log_length = 8 + rtas_error_extended_log_length(h); + len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX); + memcpy(local_paca->mce_data_buf, h, len); + } + + return (struct rtas_error_log *)local_paca->mce_data_buf; +} + +/* Call this when done with the data returned by FWNMI_get_errinfo. + * It will release the saved data area for other CPUs in the + * partition to receive FWNMI errors. + */ +static void fwnmi_release_errinfo(void) +{ + struct rtas_args rtas_args; + int ret; + + /* + * On pseries, the machine check stack is limited to under 4GB, so + * args can be on-stack. + */ + rtas_call_unlocked(&rtas_args, ibm_nmi_interlock_token, 0, 1, NULL); + ret = be32_to_cpu(rtas_args.rets[0]); + if (ret != 0) + printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret); +} + +int pSeries_system_reset_exception(struct pt_regs *regs) +{ +#ifdef __LITTLE_ENDIAN__ + /* + * Some firmware byteswaps SRR registers and gives incorrect SRR1. Try + * to detect the bad SRR1 pattern here. Flip the NIP back to correct + * endian for reporting purposes. Unfortunately the MSR can't be fixed, + * so clear it. It will be missing MSR_RI so we won't try to recover. + */ + if ((be64_to_cpu(regs->msr) & + (MSR_LE|MSR_RI|MSR_DR|MSR_IR|MSR_ME|MSR_PR| + MSR_ILE|MSR_HV|MSR_SF)) == (MSR_DR|MSR_SF)) { + regs->nip = be64_to_cpu((__be64)regs->nip); + regs->msr = 0; + } +#endif + + if (fwnmi_active) { + __be64 *savep; + + /* + * Firmware (PowerVM and KVM) saves r3 to a save area like + * machine check, which is not exactly what PAPR (2.9) + * suggests but there is no way to detect otherwise, so this + * is the interface now. + * + * System resets do not save any error log or require an + * "ibm,nmi-interlock" rtas call to release. + */ + + savep = fwnmi_get_savep(regs); + if (savep) + regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */ + } + + if (smp_handle_nmi_ipi(regs)) + return 1; + + return 0; /* need to perform reset */ +} + +static int mce_handle_err_realmode(int disposition, u8 error_type) +{ +#ifdef CONFIG_PPC_BOOK3S_64 + if (disposition == RTAS_DISP_NOT_RECOVERED) { + switch (error_type) { + case MC_ERROR_TYPE_SLB: + case MC_ERROR_TYPE_ERAT: + /* + * Store the old slb content in paca before flushing. + * Print this when we go to virtual mode. + * There are chances that we may hit MCE again if there + * is a parity error on the SLB entry we trying to read + * for saving. Hence limit the slb saving to single + * level of recursion. + */ + if (local_paca->in_mce == 1) + slb_save_contents(local_paca->mce_faulty_slbs); + flush_and_reload_slb(); + disposition = RTAS_DISP_FULLY_RECOVERED; + break; + default: + break; + } + } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) { + /* Platform corrected itself but could be degraded */ + pr_err("MCE: limited recovery, system may be degraded\n"); + disposition = RTAS_DISP_FULLY_RECOVERED; + } +#endif + return disposition; +} + +static int mce_handle_err_virtmode(struct pt_regs *regs, + struct rtas_error_log *errp, + struct pseries_mc_errorlog *mce_log, + int disposition) +{ + struct mce_error_info mce_err = { 0 }; + int initiator = rtas_error_initiator(errp); + int severity = rtas_error_severity(errp); + unsigned long eaddr = 0, paddr = 0; + u8 error_type, err_sub_type; + + if (!mce_log) + goto out; + + error_type = mce_log->error_type; + err_sub_type = rtas_mc_error_sub_type(mce_log); + + if (initiator == RTAS_INITIATOR_UNKNOWN) + mce_err.initiator = MCE_INITIATOR_UNKNOWN; + else if (initiator == RTAS_INITIATOR_CPU) + mce_err.initiator = MCE_INITIATOR_CPU; + else if (initiator == RTAS_INITIATOR_PCI) + mce_err.initiator = MCE_INITIATOR_PCI; + else if (initiator == RTAS_INITIATOR_ISA) + mce_err.initiator = MCE_INITIATOR_ISA; + else if (initiator == RTAS_INITIATOR_MEMORY) + mce_err.initiator = MCE_INITIATOR_MEMORY; + else if (initiator == RTAS_INITIATOR_POWERMGM) + mce_err.initiator = MCE_INITIATOR_POWERMGM; + else + mce_err.initiator = MCE_INITIATOR_UNKNOWN; + + if (severity == RTAS_SEVERITY_NO_ERROR) + mce_err.severity = MCE_SEV_NO_ERROR; + else if (severity == RTAS_SEVERITY_EVENT) + mce_err.severity = MCE_SEV_WARNING; + else if (severity == RTAS_SEVERITY_WARNING) + mce_err.severity = MCE_SEV_WARNING; + else if (severity == RTAS_SEVERITY_ERROR_SYNC) + mce_err.severity = MCE_SEV_SEVERE; + else if (severity == RTAS_SEVERITY_ERROR) + mce_err.severity = MCE_SEV_SEVERE; + else if (severity == RTAS_SEVERITY_FATAL) + mce_err.severity = MCE_SEV_FATAL; + else + mce_err.severity = MCE_SEV_FATAL; + + if (severity <= RTAS_SEVERITY_ERROR_SYNC) + mce_err.sync_error = true; + else + mce_err.sync_error = false; + + mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN; + mce_err.error_class = MCE_ECLASS_UNKNOWN; + + switch (error_type) { + case MC_ERROR_TYPE_UE: + mce_err.error_type = MCE_ERROR_TYPE_UE; + mce_common_process_ue(regs, &mce_err); + if (mce_err.ignore_event) + disposition = RTAS_DISP_FULLY_RECOVERED; + switch (err_sub_type) { + case MC_ERROR_UE_IFETCH: + mce_err.u.ue_error_type = MCE_UE_ERROR_IFETCH; + break; + case MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH: + mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH; + break; + case MC_ERROR_UE_LOAD_STORE: + mce_err.u.ue_error_type = MCE_UE_ERROR_LOAD_STORE; + break; + case MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE: + mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE; + break; + case MC_ERROR_UE_INDETERMINATE: + default: + mce_err.u.ue_error_type = MCE_UE_ERROR_INDETERMINATE; + break; + } + if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) + eaddr = be64_to_cpu(mce_log->effective_address); + + if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) { + paddr = be64_to_cpu(mce_log->logical_address); + } else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) { + unsigned long pfn; + + pfn = addr_to_pfn(regs, eaddr); + if (pfn != ULONG_MAX) + paddr = pfn << PAGE_SHIFT; + } + + break; + case MC_ERROR_TYPE_SLB: + mce_err.error_type = MCE_ERROR_TYPE_SLB; + switch (err_sub_type) { + case MC_ERROR_SLB_PARITY: + mce_err.u.slb_error_type = MCE_SLB_ERROR_PARITY; + break; + case MC_ERROR_SLB_MULTIHIT: + mce_err.u.slb_error_type = MCE_SLB_ERROR_MULTIHIT; + break; + case MC_ERROR_SLB_INDETERMINATE: + default: + mce_err.u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE; + break; + } + if (mce_log->sub_err_type & 0x80) + eaddr = be64_to_cpu(mce_log->effective_address); + break; + case MC_ERROR_TYPE_ERAT: + mce_err.error_type = MCE_ERROR_TYPE_ERAT; + switch (err_sub_type) { + case MC_ERROR_ERAT_PARITY: + mce_err.u.erat_error_type = MCE_ERAT_ERROR_PARITY; + break; + case MC_ERROR_ERAT_MULTIHIT: + mce_err.u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT; + break; + case MC_ERROR_ERAT_INDETERMINATE: + default: + mce_err.u.erat_error_type = MCE_ERAT_ERROR_INDETERMINATE; + break; + } + if (mce_log->sub_err_type & 0x80) + eaddr = be64_to_cpu(mce_log->effective_address); + break; + case MC_ERROR_TYPE_TLB: + mce_err.error_type = MCE_ERROR_TYPE_TLB; + switch (err_sub_type) { + case MC_ERROR_TLB_PARITY: + mce_err.u.tlb_error_type = MCE_TLB_ERROR_PARITY; + break; + case MC_ERROR_TLB_MULTIHIT: + mce_err.u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT; + break; + case MC_ERROR_TLB_INDETERMINATE: + default: + mce_err.u.tlb_error_type = MCE_TLB_ERROR_INDETERMINATE; + break; + } + if (mce_log->sub_err_type & 0x80) + eaddr = be64_to_cpu(mce_log->effective_address); + break; + case MC_ERROR_TYPE_D_CACHE: + mce_err.error_type = MCE_ERROR_TYPE_DCACHE; + break; + case MC_ERROR_TYPE_I_CACHE: + mce_err.error_type = MCE_ERROR_TYPE_DCACHE; + break; + case MC_ERROR_TYPE_UNKNOWN: + default: + mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN; + break; + } +out: + save_mce_event(regs, disposition == RTAS_DISP_FULLY_RECOVERED, + &mce_err, regs->nip, eaddr, paddr); + return disposition; +} + +static int mce_handle_error(struct pt_regs *regs, struct rtas_error_log *errp) +{ + struct pseries_errorlog *pseries_log; + struct pseries_mc_errorlog *mce_log = NULL; + int disposition = rtas_error_disposition(errp); + u8 error_type; + + if (!rtas_error_extended(errp)) + goto out; + + pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE); + if (!pseries_log) + goto out; + + mce_log = (struct pseries_mc_errorlog *)pseries_log->data; + error_type = mce_log->error_type; + + disposition = mce_handle_err_realmode(disposition, error_type); + + /* + * Enable translation as we will be accessing per-cpu variables + * in save_mce_event() which may fall outside RMO region, also + * leave it enabled because subsequently we will be queuing work + * to workqueues where again per-cpu variables accessed, besides + * fwnmi_release_errinfo() crashes when called in realmode on + * pseries. + * Note: All the realmode handling like flushing SLB entries for + * SLB multihit is done by now. + */ +out: + mtmsr(mfmsr() | MSR_IR | MSR_DR); + disposition = mce_handle_err_virtmode(regs, errp, mce_log, + disposition); + return disposition; +} + +/* + * Process MCE rtas errlog event. + */ +static void mce_process_errlog_event(struct irq_work *work) +{ + struct rtas_error_log *err; + + err = fwnmi_get_errlog(); + log_error((char *)err, ERR_TYPE_RTAS_LOG, 0); +} + +/* + * See if we can recover from a machine check exception. + * This is only called on power4 (or above) and only via + * the Firmware Non-Maskable Interrupts (fwnmi) handler + * which provides the error analysis for us. + * + * Return 1 if corrected (or delivered a signal). + * Return 0 if there is nothing we can do. + */ +static int recover_mce(struct pt_regs *regs, struct machine_check_event *evt) +{ + int recovered = 0; + + if (!(regs->msr & MSR_RI)) { + /* If MSR_RI isn't set, we cannot recover */ + pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n"); + recovered = 0; + } else if (evt->disposition == MCE_DISPOSITION_RECOVERED) { + /* Platform corrected itself */ + recovered = 1; + } else if (evt->severity == MCE_SEV_FATAL) { + /* Fatal machine check */ + pr_err("Machine check interrupt is fatal\n"); + recovered = 0; + } + + if (!recovered && evt->sync_error) { + /* + * Try to kill processes if we get a synchronous machine check + * (e.g., one caused by execution of this instruction). This + * will devolve into a panic if we try to kill init or are in + * an interrupt etc. + * + * TODO: Queue up this address for hwpoisioning later. + * TODO: This is not quite right for d-side machine + * checks ->nip is not necessarily the important + * address. + */ + if ((user_mode(regs))) { + _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip); + recovered = 1; + } else if (die_will_crash()) { + /* + * die() would kill the kernel, so better to go via + * the platform reboot code that will log the + * machine check. + */ + recovered = 0; + } else { + die("Machine check", regs, SIGBUS); + recovered = 1; + } + } + + return recovered; +} + +/* + * Handle a machine check. + * + * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi) + * should be present. If so the handler which called us tells us if the + * error was recovered (never true if RI=0). + * + * On hardware prior to Power 4 these exceptions were asynchronous which + * means we can't tell exactly where it occurred and so we can't recover. + */ +int pSeries_machine_check_exception(struct pt_regs *regs) +{ + struct machine_check_event evt; + + if (!get_mce_event(&evt, MCE_EVENT_RELEASE)) + return 0; + + /* Print things out */ + if (evt.version != MCE_V1) { + pr_err("Machine Check Exception, Unknown event version %d !\n", + evt.version); + return 0; + } + machine_check_print_event_info(&evt, user_mode(regs), false); + + if (recover_mce(regs, &evt)) + return 1; + + return 0; +} + +long pseries_machine_check_realmode(struct pt_regs *regs) +{ + struct rtas_error_log *errp; + int disposition; + + if (fwnmi_active) { + errp = fwnmi_get_errinfo(regs); + /* + * Call to fwnmi_release_errinfo() in real mode causes kernel + * to panic. Hence we will call it as soon as we go into + * virtual mode. + */ + disposition = mce_handle_error(regs, errp); + fwnmi_release_errinfo(); + + /* Queue irq work to log this rtas event later. */ + irq_work_queue(&mce_errlog_process_work); + + if (disposition == RTAS_DISP_FULLY_RECOVERED) + return 1; + } + + return 0; +} |