Initial import

1 files changed, 416 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..02e4a1745
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -0,0 +1,416 @@
+/*
+ * Copyright (C) 2001 Dave Engebretsen IBM Corporation
+ *
+ * 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
+ */
+
+#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 <asm/machdep.h>
+#include <asm/rtas.h>
+#include <asm/firmware.h>
+
+#include "pseries.h"
+
+static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX];
+static DEFINE_SPINLOCK(ras_log_buf_lock);
+
+static char global_mce_data_buf[RTAS_ERROR_LOG_MAX];
+static DEFINE_PER_CPU(__u64, mce_data_buf);
+
+static int ras_check_exception_token;
+
+#define EPOW_SENSOR_TOKEN	9
+#define EPOW_SENSOR_INDEX	0
+
+static irqreturn_t ras_epow_interrupt(int irq, void *dev_id);
+static irqreturn_t ras_error_interrupt(int irq, void *dev_id);
+
+
+/*
+ * 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("Firmware initiated power off");
+		orderly_poweroff(true);
+		break;
+
+	case EPOW_SHUTDOWN_ON_UPS:
+		pr_emerg("Loss of power reported by firmware, system is "
+			"running on UPS/battery");
+		pr_emerg("Check RTAS error log for details");
+		orderly_poweroff(true);
+		break;
+
+	case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
+		pr_emerg("Loss of system critical functions reported by "
+			"firmware");
+		pr_emerg("Check RTAS error log for details");
+		orderly_poweroff(true);
+		break;
+
+	case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH:
+		pr_emerg("Ambient temperature too high reported by firmware");
+		pr_emerg("Check RTAS error log for details");
+		orderly_poweroff(true);
+		break;
+
+	default:
+		pr_err("Unknown power/cooling shutdown event (modifier %d)",
+			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:
+		pr_err("Non critical power or cooling issue cleared");
+		break;
+
+	case EPOW_WARN_COOLING:
+		pr_err("Non critical cooling issue reported by firmware");
+		pr_err("Check RTAS error log for details");
+		break;
+
+	case EPOW_WARN_POWER:
+		pr_err("Non critical power issue reported by firmware");
+		pr_err("Check RTAS error log for details");
+		break;
+
+	case EPOW_SYSTEM_SHUTDOWN:
+		handle_system_shutdown(epow_log->event_modifier);
+		break;
+
+	case EPOW_SYSTEM_HALT:
+		pr_emerg("Firmware initiated power off");
+		orderly_poweroff(true);
+		break;
+
+	case EPOW_MAIN_ENCLOSURE:
+	case EPOW_POWER_OFF:
+		pr_emerg("Critical power/cooling issue reported by firmware");
+		pr_emerg("Check RTAS error log for details");
+		pr_emerg("Immediate power off");
+		emergency_sync();
+		kernel_power_off();
+		break;
+
+	default:
+		pr_err("Unknown power/cooling event (action code %d)",
+			action_code);
+	}
+}
+
+/* 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(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 reported by firmware");
+		pr_emerg("Check RTAS error log for details");
+		pr_emerg("Immediate power off");
+		emergency_sync();
+		kernel_power_off();
+	} else {
+		pr_err("Recoverable hardware error reported by firmware");
+	}
+
+	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.
+ */
+#define VALID_FWNMI_BUFFER(A) \
+	((((A) >= 0x7000) && ((A) < 0x7ff0)) || \
+	(((A) >= rtas.base) && ((A) < (rtas.base + rtas.size - 16))))
+
+/*
+ * 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.
+ *
+ * If the RTAS error is not of the extended type, then we put it in a per
+ * cpu 64bit buffer. If it is the extended type we use global_mce_data_buf.
+ *
+ * The global_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)
+{
+	unsigned long *savep;
+	struct rtas_error_log *h, *errhdr = NULL;
+
+	/* Mask top two bits */
+	regs->gpr[3] &= ~(0x3UL << 62);
+
+	if (!VALID_FWNMI_BUFFER(regs->gpr[3])) {
+		printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]);
+		return NULL;
+	}
+
+	savep = __va(regs->gpr[3]);
+	regs->gpr[3] = savep[0];	/* restore original r3 */
+
+	/* If it isn't an extended log we can use the per cpu 64bit buffer */
+	h = (struct rtas_error_log *)&savep[1];
+	if (!rtas_error_extended(h)) {
+		memcpy(this_cpu_ptr(&mce_data_buf), h, sizeof(__u64));
+		errhdr = (struct rtas_error_log *)this_cpu_ptr(&mce_data_buf);
+	} else {
+		int len, error_log_length;
+
+		error_log_length = 8 + rtas_error_extended_log_length(h);
+		len = max_t(int, error_log_length, RTAS_ERROR_LOG_MAX);
+		memset(global_mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
+		memcpy(global_mce_data_buf, h, len);
+		errhdr = (struct rtas_error_log *)global_mce_data_buf;
+	}
+
+	return errhdr;
+}
+
+/* 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)
+{
+	int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL);
+	if (ret != 0)
+		printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret);
+}
+
+int pSeries_system_reset_exception(struct pt_regs *regs)
+{
+	if (fwnmi_active) {
+		struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs);
+		if (errhdr) {
+			/* XXX Should look at FWNMI information */
+		}
+		fwnmi_release_errinfo();
+	}
+	return 0; /* need to perform reset */
+}
+
+/*
+ * 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 rtas_error_log *err)
+{
+	int recovered = 0;
+	int disposition = rtas_error_disposition(err);
+
+	if (!(regs->msr & MSR_RI)) {
+		/* If MSR_RI isn't set, we cannot recover */
+		recovered = 0;
+
+	} else if (disposition == RTAS_DISP_FULLY_RECOVERED) {
+		/* Platform corrected itself */
+		recovered = 1;
+
+	} else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
+		/* Platform corrected itself but could be degraded */
+		printk(KERN_ERR "MCE: limited recovery, system may "
+		       "be degraded\n");
+		recovered = 1;
+
+	} else if (user_mode(regs) && !is_global_init(current) &&
+		   rtas_error_severity(err) == RTAS_SEVERITY_ERROR_SYNC) {
+
+		/*
+		 * If we received a synchronous error when in userspace
+		 * kill the task. Firmware may report details of the fail
+		 * asynchronously, so we can't rely on the target and type
+		 * fields being valid here.
+		 */
+		printk(KERN_ERR "MCE: uncorrectable error, killing task "
+		       "%s:%d\n", current->comm, current->pid);
+
+		_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
+		recovered = 1;
+	}
+
+	log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);
+
+	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 rtas_error_log *errp;
+
+	if (fwnmi_active) {
+		errp = fwnmi_get_errinfo(regs);
+		fwnmi_release_errinfo();
+		if (errp && recover_mce(regs, errp))
+			return 1;
+	}
+
+	return 0;
+}