/* * ras.c * 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 *//* Change Activity: * 2001/09/21 : engebret : Created with minimal EPOW and HW exception support. * End Change Activity  */#include <linux/errno.h>#include <linux/threads.h>#include <linux/kernel_stat.h>#include <linux/signal.h>#include <linux/sched.h>#include <linux/ioport.h>#include <linux/interrupt.h>#include <linux/timex.h>#include <linux/init.h>#include <linux/slab.h>#include <linux/pci.h>#include <linux/delay.h>#include <linux/irq.h>#include <linux/random.h>#include <linux/sysrq.h>#include <linux/bitops.h>#include <asm/uaccess.h>#include <asm/system.h>#include <asm/io.h>#include <asm/pgtable.h>#include <asm/irq.h>#include <asm/cache.h>#include <asm/prom.h>#include <asm/ptrace.h>#include <asm/iSeries/LparData.h>#include <asm/machdep.h>#include <asm/rtas.h>#include <asm/ppcdebug.h>static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX];static DEFINE_SPINLOCK(ras_log_buf_lock);char mce_data_buf[RTAS_ERROR_LOG_MAX];/* This is true if we are using the firmware NMI handler (typically LPAR) */extern int fwnmi_active;extern void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr);static int ras_get_sensor_state_token;static int ras_check_exception_token;#define EPOW_SENSOR_TOKEN	9#define EPOW_SENSOR_INDEX	0#define RAS_VECTOR_OFFSET	0x500static irqreturn_t ras_epow_interrupt(int irq, void *dev_id,					struct pt_regs * regs);static irqreturn_t ras_error_interrupt(int irq, void *dev_id,					struct pt_regs * regs);/* #define DEBUG */static void request_ras_irqs(struct device_node *np, char *propname,			irqreturn_t (*handler)(int, void *, struct pt_regs *),			const char *name){	unsigned int *ireg, len, i;	int virq, n_intr;	ireg = (unsigned int *)get_property(np, propname, &len);	if (ireg == NULL)		return;	n_intr = prom_n_intr_cells(np);	len /= n_intr * sizeof(*ireg);	for (i = 0; i < len; i++) {		virq = virt_irq_create_mapping(*ireg);		if (virq == NO_IRQ) {			printk(KERN_ERR "Unable to allocate interrupt "			       "number for %s\n", np->full_name);			return;		}		if (request_irq(irq_offset_up(virq), handler, 0, name, NULL)) {			printk(KERN_ERR "Unable to request interrupt %d for "			       "%s\n", irq_offset_up(virq), np->full_name);			return;		}		ireg += n_intr;	}}/* * 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_get_sensor_state_token = rtas_token("get-sensor-state");	ras_check_exception_token = rtas_token("check-exception");	/* Internal Errors */	np = of_find_node_by_path("/event-sources/internal-errors");	if (np != NULL) {		request_ras_irqs(np, "open-pic-interrupt", ras_error_interrupt,				 "RAS_ERROR");		request_ras_irqs(np, "interrupts", 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_ras_irqs(np, "open-pic-interrupt", ras_epow_interrupt,				 "RAS_EPOW");		request_ras_irqs(np, "interrupts", ras_epow_interrupt,				 "RAS_EPOW");		of_node_put(np);	}	return 1;}__initcall(init_ras_IRQ);/* * Handle power subsystem events (EPOW). * * Presently we just log the event has occurred.  This should be fixed * to examine the type of power failure and take appropriate action where * the time horizon permits something useful to be done. */static irqreturn_tras_epow_interrupt(int irq, void *dev_id, struct pt_regs * regs){	int status = 0xdeadbeef;	int state = 0;	int critical;	status = rtas_call(ras_get_sensor_state_token, 2, 2, &state,			   EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX);	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,			   RAS_VECTOR_OFFSET,			   virt_irq_to_real(irq_offset_down(irq)),			   RTAS_EPOW_WARNING | RTAS_POWERMGM_EVENTS,			   critical, __pa(&ras_log_buf),				rtas_get_error_log_max());	udbg_printf("EPOW <0x%lx 0x%x 0x%x>\n",		    *((unsigned long *)&ras_log_buf), status, state);	printk(KERN_WARNING "EPOW <0x%lx 0x%x 0x%x>\n",	       *((unsigned long *)&ras_log_buf), status, state);	/* format and print the extended information */	log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);	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_tras_error_interrupt(int irq, void *dev_id, struct pt_regs * regs){	struct rtas_error_log *rtas_elog;	int status = 0xdeadbeef;	int fatal;	spin_lock(&ras_log_buf_lock);	status = rtas_call(ras_check_exception_token, 6, 1, NULL,			   RAS_VECTOR_OFFSET,			   virt_irq_to_real(irq_offset_down(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_elog->severity >= 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) {		udbg_printf("Fatal HW Error <0x%lx 0x%x>\n",			    *((unsigned long *)&ras_log_buf), status);		printk(KERN_EMERG "Error: Fatal hardware error <0x%lx 0x%x>\n",		       *((unsigned long *)&ras_log_buf), status);#ifndef DEBUG		/* Don't actually power off when debugging so we can test		 * without actually failing while injecting errors.		 * Error data will not be logged to syslog.		 */		ppc_md.power_off();#endif	} else {		udbg_printf("Recoverable HW Error <0x%lx 0x%x>\n",			    *((unsigned long *)&ras_log_buf), status);		printk(KERN_WARNING		       "Warning: Recoverable hardware error <0x%lx 0x%x>\n",		       *((unsigned long *)&ras_log_buf), status);	}	spin_unlock(&ras_log_buf_lock);	return IRQ_HANDLED;}/* 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. * * 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){	unsigned long errdata = regs->gpr[3];	struct rtas_error_log *errhdr = NULL;	unsigned long *savep;	if ((errdata >= 0x7000 && errdata < 0x7fff0) ||	    (errdata >= rtas.base && errdata < rtas.base + rtas.size - 16)) {		savep = __va(errdata);		regs->gpr[3] = savep[0];	/* restore original r3 */		memset(mce_data_buf, 0, RTAS_ERROR_LOG_MAX);		memcpy(mce_data_buf, (char *)(savep + 1), RTAS_ERROR_LOG_MAX);		errhdr = (struct rtas_error_log *)mce_data_buf;	} else {		printk("FWNMI: corrupt r3\n");	}	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("FWNMI: nmi-interlock failed: %d\n", ret);}void 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();	}}/* * 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 nonfatal = 0;	if (err->disposition == RTAS_DISP_FULLY_RECOVERED) {		/* Platform corrected itself */		nonfatal = 1;	} else if ((regs->msr & MSR_RI) &&		   user_mode(regs) &&		   err->severity == RTAS_SEVERITY_ERROR_SYNC &&		   err->disposition == RTAS_DISP_NOT_RECOVERED &&		   err->target == RTAS_TARGET_MEMORY &&		   err->type == RTAS_TYPE_ECC_UNCORR &&		   !(current->pid == 0 || current->pid == 1)) {		/* Kill off a user process with an ECC error */		printk(KERN_ERR "MCE: uncorrectable ecc error for pid %d\n",		       current->pid);		/* XXX something better for ECC error? */		_exception(SIGBUS, regs, BUS_ADRERR, regs->nip);		nonfatal = 1;	} 	log_error((char *)err, ERR_TYPE_RTAS_LOG, !nonfatal);	return nonfatal;}/* * 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;}