powerpc/chrp: Use the same RTAS daemon as pSeries

The CHRP code has some fishy timer based code to scan the RTAS event
log, which uses a 1KB stack buffer and doesn't even use the results.

The pSeries code as a nicer daemon that allows userspace to read the
event log and basically uses the same RTAS interface

This patch moves rtasd.c out of platform/pseries and makes it usable
by CHRP, after removing the old crufty event log mechanism in there.

The nvram logging part of the daemon is still only available on 64-bit
since the underlying nvram management routines aren't currently shared.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 540 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 3faa39114219..c002b0410219 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -46,6 +46,7 @@ procfs-y			:= proc_powerpc.o
 obj-$(CONFIG_PROC_FS)		+= $(procfs-y)
 rtaspci-$(CONFIG_PPC64)-$(CONFIG_PCI)	:= rtas_pci.o
 obj-$(CONFIG_PPC_RTAS)		+= rtas.o rtas-rtc.o $(rtaspci-y-y)
+obj-$(CONFIG_PPC_RTAS_DAEMON)	+= rtasd.o
 obj-$(CONFIG_RTAS_FLASH)	+= rtas_flash.o
 obj-$(CONFIG_RTAS_PROC)		+= rtas-proc.o
 obj-$(CONFIG_LPARCFG)		+= lparcfg.o
diff --git a/arch/powerpc/kernel/rtasd.c b/arch/powerpc/kernel/rtasd.c
new file mode 100644
index 000000000000..2e4832ab2108
--- /dev/null
+++ b/arch/powerpc/kernel/rtasd.c
@@ -0,0 +1,539 @@
+/*
+ * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
+ *
+ * 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.
+ *
+ * Communication to userspace based on kernel/printk.c
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/vmalloc.h>
+#include <linux/spinlock.h>
+#include <linux/cpu.h>
+#include <linux/workqueue.h>
+
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/rtas.h>
+#include <asm/prom.h>
+#include <asm/nvram.h>
+#include <asm/atomic.h>
+#include <asm/machdep.h>
+
+
+static DEFINE_SPINLOCK(rtasd_log_lock);
+
+static DECLARE_WAIT_QUEUE_HEAD(rtas_log_wait);
+
+static char *rtas_log_buf;
+static unsigned long rtas_log_start;
+static unsigned long rtas_log_size;
+
+static int surveillance_timeout = -1;
+
+static unsigned int rtas_error_log_max;
+static unsigned int rtas_error_log_buffer_max;
+
+/* RTAS service tokens */
+static unsigned int event_scan;
+static unsigned int rtas_event_scan_rate;
+
+static int full_rtas_msgs = 0;
+
+/* Stop logging to nvram after first fatal error */
+static int logging_enabled; /* Until we initialize everything,
+                             * make sure we don't try logging
+                             * anything */
+static int error_log_cnt;
+
+/*
+ * Since we use 32 bit RTAS, the physical address of this must be below
+ * 4G or else bad things happen. Allocate this in the kernel data and
+ * make it big enough.
+ */
+static unsigned char logdata[RTAS_ERROR_LOG_MAX];
+
+static char *rtas_type[] = {
+	"Unknown", "Retry", "TCE Error", "Internal Device Failure",
+	"Timeout", "Data Parity", "Address Parity", "Cache Parity",
+	"Address Invalid", "ECC Uncorrected", "ECC Corrupted",
+};
+
+static char *rtas_event_type(int type)
+{
+	if ((type > 0) && (type < 11))
+		return rtas_type[type];
+
+	switch (type) {
+		case RTAS_TYPE_EPOW:
+			return "EPOW";
+		case RTAS_TYPE_PLATFORM:
+			return "Platform Error";
+		case RTAS_TYPE_IO:
+			return "I/O Event";
+		case RTAS_TYPE_INFO:
+			return "Platform Information Event";
+		case RTAS_TYPE_DEALLOC:
+			return "Resource Deallocation Event";
+		case RTAS_TYPE_DUMP:
+			return "Dump Notification Event";
+	}
+
+	return rtas_type[0];
+}
+
+/* To see this info, grep RTAS /var/log/messages and each entry
+ * will be collected together with obvious begin/end.
+ * There will be a unique identifier on the begin and end lines.
+ * This will persist across reboots.
+ *
+ * format of error logs returned from RTAS:
+ * bytes	(size)	: contents
+ * --------------------------------------------------------
+ * 0-7		(8)	: rtas_error_log
+ * 8-47		(40)	: extended info
+ * 48-51	(4)	: vendor id
+ * 52-1023 (vendor specific) : location code and debug data
+ */
+static void printk_log_rtas(char *buf, int len)
+{
+
+	int i,j,n = 0;
+	int perline = 16;
+	char buffer[64];
+	char * str = "RTAS event";
+
+	if (full_rtas_msgs) {
+		printk(RTAS_DEBUG "%d -------- %s begin --------\n",
+		       error_log_cnt, str);
+
+		/*
+		 * Print perline bytes on each line, each line will start
+		 * with RTAS and a changing number, so syslogd will
+		 * print lines that are otherwise the same.  Separate every
+		 * 4 bytes with a space.
+		 */
+		for (i = 0; i < len; i++) {
+			j = i % perline;
+			if (j == 0) {
+				memset(buffer, 0, sizeof(buffer));
+				n = sprintf(buffer, "RTAS %d:", i/perline);
+			}
+
+			if ((i % 4) == 0)
+				n += sprintf(buffer+n, " ");
+
+			n += sprintf(buffer+n, "%02x", (unsigned char)buf[i]);
+
+			if (j == (perline-1))
+				printk(KERN_DEBUG "%s\n", buffer);
+		}
+		if ((i % perline) != 0)
+			printk(KERN_DEBUG "%s\n", buffer);
+
+		printk(RTAS_DEBUG "%d -------- %s end ----------\n",
+		       error_log_cnt, str);
+	} else {
+		struct rtas_error_log *errlog = (struct rtas_error_log *)buf;
+
+		printk(RTAS_DEBUG "event: %d, Type: %s, Severity: %d\n",
+		       error_log_cnt, rtas_event_type(errlog->type),
+		       errlog->severity);
+	}
+}
+
+static int log_rtas_len(char * buf)
+{
+	int len;
+	struct rtas_error_log *err;
+
+	/* rtas fixed header */
+	len = 8;
+	err = (struct rtas_error_log *)buf;
+	if (err->extended_log_length) {
+
+		/* extended header */
+		len += err->extended_log_length;
+	}
+
+	if (rtas_error_log_max == 0)
+		rtas_error_log_max = rtas_get_error_log_max();
+
+	if (len > rtas_error_log_max)
+		len = rtas_error_log_max;
+
+	return len;
+}
+
+/*
+ * First write to nvram, if fatal error, that is the only
+ * place we log the info.  The error will be picked up
+ * on the next reboot by rtasd.  If not fatal, run the
+ * method for the type of error.  Currently, only RTAS
+ * errors have methods implemented, but in the future
+ * there might be a need to store data in nvram before a
+ * call to panic().
+ *
+ * XXX We write to nvram periodically, to indicate error has
+ * been written and sync'd, but there is a possibility
+ * that if we don't shutdown correctly, a duplicate error
+ * record will be created on next reboot.
+ */
+void pSeries_log_error(char *buf, unsigned int err_type, int fatal)
+{
+	unsigned long offset;
+	unsigned long s;
+	int len = 0;
+
+	pr_debug("rtasd: logging event\n");
+	if (buf == NULL)
+		return;
+
+	spin_lock_irqsave(&rtasd_log_lock, s);
+
+	/* get length and increase count */
+	switch (err_type & ERR_TYPE_MASK) {
+	case ERR_TYPE_RTAS_LOG:
+		len = log_rtas_len(buf);
+		if (!(err_type & ERR_FLAG_BOOT))
+			error_log_cnt++;
+		break;
+	case ERR_TYPE_KERNEL_PANIC:
+	default:
+		WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
+		spin_unlock_irqrestore(&rtasd_log_lock, s);
+		return;
+	}
+
+#ifdef CONFIG_PPC64
+	/* Write error to NVRAM */
+	if (logging_enabled && !(err_type & ERR_FLAG_BOOT))
+		nvram_write_error_log(buf, len, err_type, error_log_cnt);
+#endif /* CONFIG_PPC64 */
+
+	/*
+	 * rtas errors can occur during boot, and we do want to capture
+	 * those somewhere, even if nvram isn't ready (why not?), and even
+	 * if rtasd isn't ready. Put them into the boot log, at least.
+	 */
+	if ((err_type & ERR_TYPE_MASK) == ERR_TYPE_RTAS_LOG)
+		printk_log_rtas(buf, len);
+
+	/* Check to see if we need to or have stopped logging */
+	if (fatal || !logging_enabled) {
+		logging_enabled = 0;
+		WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
+		spin_unlock_irqrestore(&rtasd_log_lock, s);
+		return;
+	}
+
+	/* call type specific method for error */
+	switch (err_type & ERR_TYPE_MASK) {
+	case ERR_TYPE_RTAS_LOG:
+		offset = rtas_error_log_buffer_max *
+			((rtas_log_start+rtas_log_size) & LOG_NUMBER_MASK);
+
+		/* First copy over sequence number */
+		memcpy(&rtas_log_buf[offset], (void *) &error_log_cnt, sizeof(int));
+
+		/* Second copy over error log data */
+		offset += sizeof(int);
+		memcpy(&rtas_log_buf[offset], buf, len);
+
+		if (rtas_log_size < LOG_NUMBER)
+			rtas_log_size += 1;
+		else
+			rtas_log_start += 1;
+
+		WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
+		spin_unlock_irqrestore(&rtasd_log_lock, s);
+		wake_up_interruptible(&rtas_log_wait);
+		break;
+	case ERR_TYPE_KERNEL_PANIC:
+	default:
+		WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
+		spin_unlock_irqrestore(&rtasd_log_lock, s);
+		return;
+	}
+
+}
+
+static int rtas_log_open(struct inode * inode, struct file * file)
+{
+	return 0;
+}
+
+static int rtas_log_release(struct inode * inode, struct file * file)
+{
+	return 0;
+}
+
+/* This will check if all events are logged, if they are then, we
+ * know that we can safely clear the events in NVRAM.
+ * Next we'll sit and wait for something else to log.
+ */
+static ssize_t rtas_log_read(struct file * file, char __user * buf,
+			 size_t count, loff_t *ppos)
+{
+	int error;
+	char *tmp;
+	unsigned long s;
+	unsigned long offset;
+
+	if (!buf || count < rtas_error_log_buffer_max)
+		return -EINVAL;
+
+	count = rtas_error_log_buffer_max;
+
+	if (!access_ok(VERIFY_WRITE, buf, count))
+		return -EFAULT;
+
+	tmp = kmalloc(count, GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&rtasd_log_lock, s);
+
+	/* if it's 0, then we know we got the last one (the one in NVRAM) */
+	while (rtas_log_size == 0) {
+		if (file->f_flags & O_NONBLOCK) {
+			spin_unlock_irqrestore(&rtasd_log_lock, s);
+			error = -EAGAIN;
+			goto out;
+		}
+
+		if (!logging_enabled) {
+			spin_unlock_irqrestore(&rtasd_log_lock, s);
+			error = -ENODATA;
+			goto out;
+		}
+#ifdef CONFIG_PPC64
+		nvram_clear_error_log();
+#endif /* CONFIG_PPC64 */
+
+		spin_unlock_irqrestore(&rtasd_log_lock, s);
+		error = wait_event_interruptible(rtas_log_wait, rtas_log_size);
+		if (error)
+			goto out;
+		spin_lock_irqsave(&rtasd_log_lock, s);
+	}
+
+	offset = rtas_error_log_buffer_max * (rtas_log_start & LOG_NUMBER_MASK);
+	memcpy(tmp, &rtas_log_buf[offset], count);
+
+	rtas_log_start += 1;
+	rtas_log_size -= 1;
+	spin_unlock_irqrestore(&rtasd_log_lock, s);
+
+	error = copy_to_user(buf, tmp, count) ? -EFAULT : count;
+out:
+	kfree(tmp);
+	return error;
+}
+
+static unsigned int rtas_log_poll(struct file *file, poll_table * wait)
+{
+	poll_wait(file, &rtas_log_wait, wait);
+	if (rtas_log_size)
+		return POLLIN | POLLRDNORM;
+	return 0;
+}
+
+static const struct file_operations proc_rtas_log_operations = {
+	.read =		rtas_log_read,
+	.poll =		rtas_log_poll,
+	.open =		rtas_log_open,
+	.release =	rtas_log_release,
+};
+
+static int enable_surveillance(int timeout)
+{
+	int error;
+
+	error = rtas_set_indicator(SURVEILLANCE_TOKEN, 0, timeout);
+
+	if (error == 0)
+		return 0;
+
+	if (error == -EINVAL) {
+		printk(KERN_DEBUG "rtasd: surveillance not supported\n");
+		return 0;
+	}
+
+	printk(KERN_ERR "rtasd: could not update surveillance\n");
+	return -1;
+}
+
+static void do_event_scan(void)
+{
+	int error;
+	do {
+		memset(logdata, 0, rtas_error_log_max);
+		error = rtas_call(event_scan, 4, 1, NULL,
+				  RTAS_EVENT_SCAN_ALL_EVENTS, 0,
+				  __pa(logdata), rtas_error_log_max);
+		if (error == -1) {
+			printk(KERN_ERR "event-scan failed\n");
+			break;
+		}
+
+		if (error == 0)
+			pSeries_log_error(logdata, ERR_TYPE_RTAS_LOG, 0);
+
+	} while(error == 0);
+}
+
+static void rtas_event_scan(struct work_struct *w);
+DECLARE_DELAYED_WORK(event_scan_work, rtas_event_scan);
+
+/*
+ * Delay should be at least one second since some machines have problems if
+ * we call event-scan too quickly.
+ */
+static unsigned long event_scan_delay = 1*HZ;
+static int first_pass = 1;
+
+static void rtas_event_scan(struct work_struct *w)
+{
+	unsigned int cpu;
+
+	do_event_scan();
+
+	get_online_cpus();
+
+	cpu = next_cpu(smp_processor_id(), cpu_online_map);
+	if (cpu == NR_CPUS) {
+		cpu = first_cpu(cpu_online_map);
+
+		if (first_pass) {
+			first_pass = 0;
+			event_scan_delay = 30*HZ/rtas_event_scan_rate;
+
+			if (surveillance_timeout != -1) {
+				pr_debug("rtasd: enabling surveillance\n");
+				enable_surveillance(surveillance_timeout);
+				pr_debug("rtasd: surveillance enabled\n");
+			}
+		}
+	}
+
+	schedule_delayed_work_on(cpu, &event_scan_work,
+		__round_jiffies_relative(event_scan_delay, cpu));
+
+	put_online_cpus();
+}
+
+#ifdef CONFIG_PPC64
+static void retreive_nvram_error_log(void)
+{
+	unsigned int err_type ;
+	int rc ;
+
+	/* See if we have any error stored in NVRAM */
+	memset(logdata, 0, rtas_error_log_max);
+	rc = nvram_read_error_log(logdata, rtas_error_log_max,
+	                          &err_type, &error_log_cnt);
+	/* We can use rtas_log_buf now */
+	logging_enabled = 1;
+	if (!rc) {
+		if (err_type != ERR_FLAG_ALREADY_LOGGED) {
+			pSeries_log_error(logdata, err_type | ERR_FLAG_BOOT, 0);
+		}
+	}
+}
+#else /* CONFIG_PPC64 */
+static void retreive_nvram_error_log(void)
+{
+}
+#endif /* CONFIG_PPC64 */
+
+static void start_event_scan(void)
+{
+	printk(KERN_DEBUG "RTAS daemon started\n");
+	pr_debug("rtasd: will sleep for %d milliseconds\n",
+		 (30000 / rtas_event_scan_rate));
+
+	/* Retreive errors from nvram if any */
+	retreive_nvram_error_log();
+
+	schedule_delayed_work_on(first_cpu(cpu_online_map), &event_scan_work,
+				 event_scan_delay);
+}
+
+static int __init rtas_init(void)
+{
+	struct proc_dir_entry *entry;
+
+	if (!machine_is(pseries) && !machine_is(chrp))
+		return 0;
+
+	/* No RTAS */
+	event_scan = rtas_token("event-scan");
+	if (event_scan == RTAS_UNKNOWN_SERVICE) {
+		printk(KERN_INFO "rtasd: No event-scan on system\n");
+		return -ENODEV;
+	}
+
+	rtas_event_scan_rate = rtas_token("rtas-event-scan-rate");
+	if (rtas_event_scan_rate == RTAS_UNKNOWN_SERVICE) {
+		printk(KERN_ERR "rtasd: no rtas-event-scan-rate on system\n");
+		return -ENODEV;
+	}
+
+	/* Make room for the sequence number */
+	rtas_error_log_max = rtas_get_error_log_max();
+	rtas_error_log_buffer_max = rtas_error_log_max + sizeof(int);
+
+	rtas_log_buf = vmalloc(rtas_error_log_buffer_max*LOG_NUMBER);
+	if (!rtas_log_buf) {
+		printk(KERN_ERR "rtasd: no memory\n");
+		return -ENOMEM;
+	}
+
+	entry = proc_create("powerpc/rtas/error_log", S_IRUSR, NULL,
+			    &proc_rtas_log_operations);
+	if (!entry)
+		printk(KERN_ERR "Failed to create error_log proc entry\n");
+
+	start_event_scan();
+
+	return 0;
+}
+__initcall(rtas_init);
+
+static int __init surveillance_setup(char *str)
+{
+	int i;
+
+	/* We only do surveillance on pseries */
+	if (!machine_is(pseries))
+		return 0;
+
+	if (get_option(&str,&i)) {
+		if (i >= 0 && i <= 255)
+			surveillance_timeout = i;
+	}
+
+	return 1;
+}
+__setup("surveillance=", surveillance_setup);
+
+static int __init rtasmsgs_setup(char *str)
+{
+	if (strcmp(str, "on") == 0)
+		full_rtas_msgs = 1;
+	else if (strcmp(str, "off") == 0)
+		full_rtas_msgs = 0;
+
+	return 1;
+}
+__setup("rtasmsgs=", rtasmsgs_setup);