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-rw-r--r--arch/powerpc/kernel/mce.c633
1 files changed, 633 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
new file mode 100644
index 000000000..93e06778b
--- /dev/null
+++ b/arch/powerpc/kernel/mce.c
@@ -0,0 +1,633 @@
+/*
+ * Machine check exception handling.
+ *
+ * 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: " fmt
+
+#include <linux/hardirq.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/percpu.h>
+#include <linux/export.h>
+#include <linux/irq_work.h>
+
+#include <asm/machdep.h>
+#include <asm/mce.h>
+
+static DEFINE_PER_CPU(int, mce_nest_count);
+static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event);
+
+/* Queue for delayed MCE events. */
+static DEFINE_PER_CPU(int, mce_queue_count);
+static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event_queue);
+
+/* Queue for delayed MCE UE events. */
+static DEFINE_PER_CPU(int, mce_ue_count);
+static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT],
+ mce_ue_event_queue);
+
+static void machine_check_process_queued_event(struct irq_work *work);
+static void machine_check_ue_irq_work(struct irq_work *work);
+void machine_check_ue_event(struct machine_check_event *evt);
+static void machine_process_ue_event(struct work_struct *work);
+
+static struct irq_work mce_event_process_work = {
+ .func = machine_check_process_queued_event,
+};
+
+static struct irq_work mce_ue_event_irq_work = {
+ .func = machine_check_ue_irq_work,
+};
+
+DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
+
+static void mce_set_error_info(struct machine_check_event *mce,
+ struct mce_error_info *mce_err)
+{
+ mce->error_type = mce_err->error_type;
+ switch (mce_err->error_type) {
+ case MCE_ERROR_TYPE_UE:
+ mce->u.ue_error.ue_error_type = mce_err->u.ue_error_type;
+ break;
+ case MCE_ERROR_TYPE_SLB:
+ mce->u.slb_error.slb_error_type = mce_err->u.slb_error_type;
+ break;
+ case MCE_ERROR_TYPE_ERAT:
+ mce->u.erat_error.erat_error_type = mce_err->u.erat_error_type;
+ break;
+ case MCE_ERROR_TYPE_TLB:
+ mce->u.tlb_error.tlb_error_type = mce_err->u.tlb_error_type;
+ break;
+ case MCE_ERROR_TYPE_USER:
+ mce->u.user_error.user_error_type = mce_err->u.user_error_type;
+ break;
+ case MCE_ERROR_TYPE_RA:
+ mce->u.ra_error.ra_error_type = mce_err->u.ra_error_type;
+ break;
+ case MCE_ERROR_TYPE_LINK:
+ mce->u.link_error.link_error_type = mce_err->u.link_error_type;
+ break;
+ case MCE_ERROR_TYPE_UNKNOWN:
+ default:
+ break;
+ }
+}
+
+/*
+ * Decode and save high level MCE information into per cpu buffer which
+ * is an array of machine_check_event structure.
+ */
+void save_mce_event(struct pt_regs *regs, long handled,
+ struct mce_error_info *mce_err,
+ uint64_t nip, uint64_t addr, uint64_t phys_addr)
+{
+ int index = __this_cpu_inc_return(mce_nest_count) - 1;
+ struct machine_check_event *mce = this_cpu_ptr(&mce_event[index]);
+
+ /*
+ * Return if we don't have enough space to log mce event.
+ * mce_nest_count may go beyond MAX_MC_EVT but that's ok,
+ * the check below will stop buffer overrun.
+ */
+ if (index >= MAX_MC_EVT)
+ return;
+
+ /* Populate generic machine check info */
+ mce->version = MCE_V1;
+ mce->srr0 = nip;
+ mce->srr1 = regs->msr;
+ mce->gpr3 = regs->gpr[3];
+ mce->in_use = 1;
+
+ /* Mark it recovered if we have handled it and MSR(RI=1). */
+ if (handled && (regs->msr & MSR_RI))
+ mce->disposition = MCE_DISPOSITION_RECOVERED;
+ else
+ mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;
+
+ mce->initiator = mce_err->initiator;
+ mce->severity = mce_err->severity;
+
+ /*
+ * Populate the mce error_type and type-specific error_type.
+ */
+ mce_set_error_info(mce, mce_err);
+
+ if (!addr)
+ return;
+
+ if (mce->error_type == MCE_ERROR_TYPE_TLB) {
+ mce->u.tlb_error.effective_address_provided = true;
+ mce->u.tlb_error.effective_address = addr;
+ } else if (mce->error_type == MCE_ERROR_TYPE_SLB) {
+ mce->u.slb_error.effective_address_provided = true;
+ mce->u.slb_error.effective_address = addr;
+ } else if (mce->error_type == MCE_ERROR_TYPE_ERAT) {
+ mce->u.erat_error.effective_address_provided = true;
+ mce->u.erat_error.effective_address = addr;
+ } else if (mce->error_type == MCE_ERROR_TYPE_USER) {
+ mce->u.user_error.effective_address_provided = true;
+ mce->u.user_error.effective_address = addr;
+ } else if (mce->error_type == MCE_ERROR_TYPE_RA) {
+ mce->u.ra_error.effective_address_provided = true;
+ mce->u.ra_error.effective_address = addr;
+ } else if (mce->error_type == MCE_ERROR_TYPE_LINK) {
+ mce->u.link_error.effective_address_provided = true;
+ mce->u.link_error.effective_address = addr;
+ } else if (mce->error_type == MCE_ERROR_TYPE_UE) {
+ mce->u.ue_error.effective_address_provided = true;
+ mce->u.ue_error.effective_address = addr;
+ if (phys_addr != ULONG_MAX) {
+ mce->u.ue_error.physical_address_provided = true;
+ mce->u.ue_error.physical_address = phys_addr;
+ machine_check_ue_event(mce);
+ }
+ }
+ return;
+}
+
+/*
+ * get_mce_event:
+ * mce Pointer to machine_check_event structure to be filled.
+ * release Flag to indicate whether to free the event slot or not.
+ * 0 <= do not release the mce event. Caller will invoke
+ * release_mce_event() once event has been consumed.
+ * 1 <= release the slot.
+ *
+ * return 1 = success
+ * 0 = failure
+ *
+ * get_mce_event() will be called by platform specific machine check
+ * handle routine and in KVM.
+ * When we call get_mce_event(), we are still in interrupt context and
+ * preemption will not be scheduled until ret_from_expect() routine
+ * is called.
+ */
+int get_mce_event(struct machine_check_event *mce, bool release)
+{
+ int index = __this_cpu_read(mce_nest_count) - 1;
+ struct machine_check_event *mc_evt;
+ int ret = 0;
+
+ /* Sanity check */
+ if (index < 0)
+ return ret;
+
+ /* Check if we have MCE info to process. */
+ if (index < MAX_MC_EVT) {
+ mc_evt = this_cpu_ptr(&mce_event[index]);
+ /* Copy the event structure and release the original */
+ if (mce)
+ *mce = *mc_evt;
+ if (release)
+ mc_evt->in_use = 0;
+ ret = 1;
+ }
+ /* Decrement the count to free the slot. */
+ if (release)
+ __this_cpu_dec(mce_nest_count);
+
+ return ret;
+}
+
+void release_mce_event(void)
+{
+ get_mce_event(NULL, true);
+}
+
+static void machine_check_ue_irq_work(struct irq_work *work)
+{
+ schedule_work(&mce_ue_event_work);
+}
+
+/*
+ * Queue up the MCE event which then can be handled later.
+ */
+void machine_check_ue_event(struct machine_check_event *evt)
+{
+ int index;
+
+ index = __this_cpu_inc_return(mce_ue_count) - 1;
+ /* If queue is full, just return for now. */
+ if (index >= MAX_MC_EVT) {
+ __this_cpu_dec(mce_ue_count);
+ return;
+ }
+ memcpy(this_cpu_ptr(&mce_ue_event_queue[index]), evt, sizeof(*evt));
+
+ /* Queue work to process this event later. */
+ irq_work_queue(&mce_ue_event_irq_work);
+}
+
+/*
+ * Queue up the MCE event which then can be handled later.
+ */
+void machine_check_queue_event(void)
+{
+ int index;
+ struct machine_check_event evt;
+
+ if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
+ return;
+
+ index = __this_cpu_inc_return(mce_queue_count) - 1;
+ /* If queue is full, just return for now. */
+ if (index >= MAX_MC_EVT) {
+ __this_cpu_dec(mce_queue_count);
+ return;
+ }
+ memcpy(this_cpu_ptr(&mce_event_queue[index]), &evt, sizeof(evt));
+
+ /* Queue irq work to process this event later. */
+ irq_work_queue(&mce_event_process_work);
+}
+/*
+ * process pending MCE event from the mce event queue. This function will be
+ * called during syscall exit.
+ */
+static void machine_process_ue_event(struct work_struct *work)
+{
+ int index;
+ struct machine_check_event *evt;
+
+ while (__this_cpu_read(mce_ue_count) > 0) {
+ index = __this_cpu_read(mce_ue_count) - 1;
+ evt = this_cpu_ptr(&mce_ue_event_queue[index]);
+#ifdef CONFIG_MEMORY_FAILURE
+ /*
+ * This should probably queued elsewhere, but
+ * oh! well
+ */
+ if (evt->error_type == MCE_ERROR_TYPE_UE) {
+ if (evt->u.ue_error.physical_address_provided) {
+ unsigned long pfn;
+
+ pfn = evt->u.ue_error.physical_address >>
+ PAGE_SHIFT;
+ memory_failure(pfn, 0);
+ } else
+ pr_warn("Failed to identify bad address from "
+ "where the uncorrectable error (UE) "
+ "was generated\n");
+ }
+#endif
+ __this_cpu_dec(mce_ue_count);
+ }
+}
+/*
+ * process pending MCE event from the mce event queue. This function will be
+ * called during syscall exit.
+ */
+static void machine_check_process_queued_event(struct irq_work *work)
+{
+ int index;
+ struct machine_check_event *evt;
+
+ add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
+
+ /*
+ * For now just print it to console.
+ * TODO: log this error event to FSP or nvram.
+ */
+ while (__this_cpu_read(mce_queue_count) > 0) {
+ index = __this_cpu_read(mce_queue_count) - 1;
+ evt = this_cpu_ptr(&mce_event_queue[index]);
+ machine_check_print_event_info(evt, false);
+ __this_cpu_dec(mce_queue_count);
+ }
+}
+
+void machine_check_print_event_info(struct machine_check_event *evt,
+ bool user_mode)
+{
+ const char *level, *sevstr, *subtype;
+ static const char *mc_ue_types[] = {
+ "Indeterminate",
+ "Instruction fetch",
+ "Page table walk ifetch",
+ "Load/Store",
+ "Page table walk Load/Store",
+ };
+ static const char *mc_slb_types[] = {
+ "Indeterminate",
+ "Parity",
+ "Multihit",
+ };
+ static const char *mc_erat_types[] = {
+ "Indeterminate",
+ "Parity",
+ "Multihit",
+ };
+ static const char *mc_tlb_types[] = {
+ "Indeterminate",
+ "Parity",
+ "Multihit",
+ };
+ static const char *mc_user_types[] = {
+ "Indeterminate",
+ "tlbie(l) invalid",
+ };
+ static const char *mc_ra_types[] = {
+ "Indeterminate",
+ "Instruction fetch (bad)",
+ "Instruction fetch (foreign)",
+ "Page table walk ifetch (bad)",
+ "Page table walk ifetch (foreign)",
+ "Load (bad)",
+ "Store (bad)",
+ "Page table walk Load/Store (bad)",
+ "Page table walk Load/Store (foreign)",
+ "Load/Store (foreign)",
+ };
+ static const char *mc_link_types[] = {
+ "Indeterminate",
+ "Instruction fetch (timeout)",
+ "Page table walk ifetch (timeout)",
+ "Load (timeout)",
+ "Store (timeout)",
+ "Page table walk Load/Store (timeout)",
+ };
+
+ /* Print things out */
+ if (evt->version != MCE_V1) {
+ pr_err("Machine Check Exception, Unknown event version %d !\n",
+ evt->version);
+ return;
+ }
+ switch (evt->severity) {
+ case MCE_SEV_NO_ERROR:
+ level = KERN_INFO;
+ sevstr = "Harmless";
+ break;
+ case MCE_SEV_WARNING:
+ level = KERN_WARNING;
+ sevstr = "";
+ break;
+ case MCE_SEV_ERROR_SYNC:
+ level = KERN_ERR;
+ sevstr = "Severe";
+ break;
+ case MCE_SEV_FATAL:
+ default:
+ level = KERN_ERR;
+ sevstr = "Fatal";
+ break;
+ }
+
+ printk("%s%s Machine check interrupt [%s]\n", level, sevstr,
+ evt->disposition == MCE_DISPOSITION_RECOVERED ?
+ "Recovered" : "Not recovered");
+
+ if (user_mode) {
+ printk("%s NIP: [%016llx] PID: %d Comm: %s\n", level,
+ evt->srr0, current->pid, current->comm);
+ } else {
+ printk("%s NIP [%016llx]: %pS\n", level, evt->srr0,
+ (void *)evt->srr0);
+ }
+
+ printk("%s Initiator: %s\n", level,
+ evt->initiator == MCE_INITIATOR_CPU ? "CPU" : "Unknown");
+ switch (evt->error_type) {
+ case MCE_ERROR_TYPE_UE:
+ subtype = evt->u.ue_error.ue_error_type <
+ ARRAY_SIZE(mc_ue_types) ?
+ mc_ue_types[evt->u.ue_error.ue_error_type]
+ : "Unknown";
+ printk("%s Error type: UE [%s]\n", level, subtype);
+ if (evt->u.ue_error.effective_address_provided)
+ printk("%s Effective address: %016llx\n",
+ level, evt->u.ue_error.effective_address);
+ if (evt->u.ue_error.physical_address_provided)
+ printk("%s Physical address: %016llx\n",
+ level, evt->u.ue_error.physical_address);
+ break;
+ case MCE_ERROR_TYPE_SLB:
+ subtype = evt->u.slb_error.slb_error_type <
+ ARRAY_SIZE(mc_slb_types) ?
+ mc_slb_types[evt->u.slb_error.slb_error_type]
+ : "Unknown";
+ printk("%s Error type: SLB [%s]\n", level, subtype);
+ if (evt->u.slb_error.effective_address_provided)
+ printk("%s Effective address: %016llx\n",
+ level, evt->u.slb_error.effective_address);
+ break;
+ case MCE_ERROR_TYPE_ERAT:
+ subtype = evt->u.erat_error.erat_error_type <
+ ARRAY_SIZE(mc_erat_types) ?
+ mc_erat_types[evt->u.erat_error.erat_error_type]
+ : "Unknown";
+ printk("%s Error type: ERAT [%s]\n", level, subtype);
+ if (evt->u.erat_error.effective_address_provided)
+ printk("%s Effective address: %016llx\n",
+ level, evt->u.erat_error.effective_address);
+ break;
+ case MCE_ERROR_TYPE_TLB:
+ subtype = evt->u.tlb_error.tlb_error_type <
+ ARRAY_SIZE(mc_tlb_types) ?
+ mc_tlb_types[evt->u.tlb_error.tlb_error_type]
+ : "Unknown";
+ printk("%s Error type: TLB [%s]\n", level, subtype);
+ if (evt->u.tlb_error.effective_address_provided)
+ printk("%s Effective address: %016llx\n",
+ level, evt->u.tlb_error.effective_address);
+ break;
+ case MCE_ERROR_TYPE_USER:
+ subtype = evt->u.user_error.user_error_type <
+ ARRAY_SIZE(mc_user_types) ?
+ mc_user_types[evt->u.user_error.user_error_type]
+ : "Unknown";
+ printk("%s Error type: User [%s]\n", level, subtype);
+ if (evt->u.user_error.effective_address_provided)
+ printk("%s Effective address: %016llx\n",
+ level, evt->u.user_error.effective_address);
+ break;
+ case MCE_ERROR_TYPE_RA:
+ subtype = evt->u.ra_error.ra_error_type <
+ ARRAY_SIZE(mc_ra_types) ?
+ mc_ra_types[evt->u.ra_error.ra_error_type]
+ : "Unknown";
+ printk("%s Error type: Real address [%s]\n", level, subtype);
+ if (evt->u.ra_error.effective_address_provided)
+ printk("%s Effective address: %016llx\n",
+ level, evt->u.ra_error.effective_address);
+ break;
+ case MCE_ERROR_TYPE_LINK:
+ subtype = evt->u.link_error.link_error_type <
+ ARRAY_SIZE(mc_link_types) ?
+ mc_link_types[evt->u.link_error.link_error_type]
+ : "Unknown";
+ printk("%s Error type: Link [%s]\n", level, subtype);
+ if (evt->u.link_error.effective_address_provided)
+ printk("%s Effective address: %016llx\n",
+ level, evt->u.link_error.effective_address);
+ break;
+ default:
+ case MCE_ERROR_TYPE_UNKNOWN:
+ printk("%s Error type: Unknown\n", level);
+ break;
+ }
+}
+EXPORT_SYMBOL_GPL(machine_check_print_event_info);
+
+/*
+ * This function is called in real mode. Strictly no printk's please.
+ *
+ * regs->nip and regs->msr contains srr0 and ssr1.
+ */
+long machine_check_early(struct pt_regs *regs)
+{
+ long handled = 0;
+
+ __this_cpu_inc(irq_stat.mce_exceptions);
+
+ if (cur_cpu_spec && cur_cpu_spec->machine_check_early)
+ handled = cur_cpu_spec->machine_check_early(regs);
+ return handled;
+}
+
+/* Possible meanings for HMER_DEBUG_TRIG bit being set on POWER9 */
+static enum {
+ DTRIG_UNKNOWN,
+ DTRIG_VECTOR_CI, /* need to emulate vector CI load instr */
+ DTRIG_SUSPEND_ESCAPE, /* need to escape from TM suspend mode */
+} hmer_debug_trig_function;
+
+static int init_debug_trig_function(void)
+{
+ int pvr;
+ struct device_node *cpun;
+ struct property *prop = NULL;
+ const char *str;
+
+ /* First look in the device tree */
+ preempt_disable();
+ cpun = of_get_cpu_node(smp_processor_id(), NULL);
+ if (cpun) {
+ of_property_for_each_string(cpun, "ibm,hmi-special-triggers",
+ prop, str) {
+ if (strcmp(str, "bit17-vector-ci-load") == 0)
+ hmer_debug_trig_function = DTRIG_VECTOR_CI;
+ else if (strcmp(str, "bit17-tm-suspend-escape") == 0)
+ hmer_debug_trig_function = DTRIG_SUSPEND_ESCAPE;
+ }
+ of_node_put(cpun);
+ }
+ preempt_enable();
+
+ /* If we found the property, don't look at PVR */
+ if (prop)
+ goto out;
+
+ pvr = mfspr(SPRN_PVR);
+ /* Check for POWER9 Nimbus (scale-out) */
+ if ((PVR_VER(pvr) == PVR_POWER9) && (pvr & 0xe000) == 0) {
+ /* DD2.2 and later */
+ if ((pvr & 0xfff) >= 0x202)
+ hmer_debug_trig_function = DTRIG_SUSPEND_ESCAPE;
+ /* DD2.0 and DD2.1 - used for vector CI load emulation */
+ else if ((pvr & 0xfff) >= 0x200)
+ hmer_debug_trig_function = DTRIG_VECTOR_CI;
+ }
+
+ out:
+ switch (hmer_debug_trig_function) {
+ case DTRIG_VECTOR_CI:
+ pr_debug("HMI debug trigger used for vector CI load\n");
+ break;
+ case DTRIG_SUSPEND_ESCAPE:
+ pr_debug("HMI debug trigger used for TM suspend escape\n");
+ break;
+ default:
+ break;
+ }
+ return 0;
+}
+__initcall(init_debug_trig_function);
+
+/*
+ * Handle HMIs that occur as a result of a debug trigger.
+ * Return values:
+ * -1 means this is not a HMI cause that we know about
+ * 0 means no further handling is required
+ * 1 means further handling is required
+ */
+long hmi_handle_debugtrig(struct pt_regs *regs)
+{
+ unsigned long hmer = mfspr(SPRN_HMER);
+ long ret = 0;
+
+ /* HMER_DEBUG_TRIG bit is used for various workarounds on P9 */
+ if (!((hmer & HMER_DEBUG_TRIG)
+ && hmer_debug_trig_function != DTRIG_UNKNOWN))
+ return -1;
+
+ hmer &= ~HMER_DEBUG_TRIG;
+ /* HMER is a write-AND register */
+ mtspr(SPRN_HMER, ~HMER_DEBUG_TRIG);
+
+ switch (hmer_debug_trig_function) {
+ case DTRIG_VECTOR_CI:
+ /*
+ * Now to avoid problems with soft-disable we
+ * only do the emulation if we are coming from
+ * host user space
+ */
+ if (regs && user_mode(regs))
+ ret = local_paca->hmi_p9_special_emu = 1;
+
+ break;
+
+ default:
+ break;
+ }
+
+ /*
+ * See if any other HMI causes remain to be handled
+ */
+ if (hmer & mfspr(SPRN_HMEER))
+ return -1;
+
+ return ret;
+}
+
+/*
+ * Return values:
+ */
+long hmi_exception_realmode(struct pt_regs *regs)
+{
+ int ret;
+
+ __this_cpu_inc(irq_stat.hmi_exceptions);
+
+ ret = hmi_handle_debugtrig(regs);
+ if (ret >= 0)
+ return ret;
+
+ wait_for_subcore_guest_exit();
+
+ if (ppc_md.hmi_exception_early)
+ ppc_md.hmi_exception_early(regs);
+
+ wait_for_tb_resync();
+
+ return 1;
+}
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