text: /*
   * 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 <linux/slab.h>
  #include <linux/topology.h>
  
  #include <linux/uaccess.h>
  #include <asm/io.h>
  #include <asm/rtas.h>
  #include <asm/prom.h>
  #include <asm/nvram.h>
  #include <linux/atomic.h>
  #include <asm/machdep.h>
  #include <asm/topology.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 bool full_rtas_msgs;
  
  /* 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";
  		case RTAS_TYPE_PRRN:
  			return "Platform Resource Reassignment 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(rtas_error_type(errlog)),
  		       rtas_error_severity(errlog));
  	}
  }
  
  static int log_rtas_len(char * buf)
  {
  	int len;
  	struct rtas_error_log *err;
  	uint32_t extended_log_length;
  
  	/* rtas fixed header */
  	len = 8;
  	err = (struct rtas_error_log *)buf;
  	extended_log_length = rtas_error_extended_log_length(err);
  	if (rtas_error_extended(err) && extended_log_length) {
  
  		/* extended header */
  		len += 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;
  	}
  }
  
  #ifdef CONFIG_PPC_PSERIES
  static s32 prrn_update_scope;
  
  static void prrn_work_fn(struct work_struct *work)
  {
  	/*
  	 * For PRRN, we must pass the negative of the scope value in
  	 * the RTAS event.
  	 */
  	pseries_devicetree_update(-prrn_update_scope);
  	numa_update_cpu_topology(false);
  }
  
  static DECLARE_WORK(prrn_work, prrn_work_fn);
  
  static void prrn_schedule_update(u32 scope)
  {
  	flush_work(&prrn_work);
  	prrn_update_scope = scope;
  	schedule_work(&prrn_work);
  }
  
  static void handle_rtas_event(const struct rtas_error_log *log)
  {
  	if (rtas_error_type(log) != RTAS_TYPE_PRRN || !prrn_is_enabled())
  		return;
  
  	/* For PRRN Events the extended log length is used to denote
  	 * the scope for calling rtas update-nodes.
  	 */
  	prrn_schedule_update(rtas_error_extended_log_length(log));
  }
  
  #else
  
  static void handle_rtas_event(const struct rtas_error_log *log)
  {
  	return;
  }
  
  #endif
  
  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 __poll_t rtas_log_poll(struct file *file, poll_table * wait)
  {
  	poll_wait(file, &rtas_log_wait, wait);
  	if (rtas_log_size)
  		return EPOLLIN | EPOLLRDNORM;
  	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,
  	.llseek =	noop_llseek,
  };
  
  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) {
  			if (rtas_error_type((struct rtas_error_log *)logdata) !=
  			    RTAS_TYPE_PRRN)
  				pSeries_log_error(logdata, ERR_TYPE_RTAS_LOG,
  						  0);
  			handle_rtas_event((struct rtas_error_log *)logdata);
  		}
  
  	} while(error == 0);
  }
  
  static void rtas_event_scan(struct work_struct *w);
  static 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();
  
  	/* raw_ OK because just using CPU as starting point. */
  	cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
          if (cpu >= nr_cpu_ids) {
  		cpu = cpumask_first(cpu_online_mask);
  
  		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 retrieve_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 retrieve_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));
  
  	/* Retrieve errors from nvram if any */
  	retrieve_nvram_error_log();
  
  	schedule_delayed_work_on(cpumask_first(cpu_online_mask),
  				 &event_scan_work, event_scan_delay);
  }
  
  /* Cancel the rtas event scan work */
  void rtas_cancel_event_scan(void)
  {
  	cancel_delayed_work_sync(&event_scan_work);
  }
  EXPORT_SYMBOL_GPL(rtas_cancel_event_scan);
  
  static int __init rtas_event_scan_init(void)
  {
  	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;
  	}
  
  	if (!rtas_event_scan_rate) {
  		/* Broken firmware: take a rate of zero to mean don't scan */
  		printk(KERN_DEBUG "rtasd: scan rate is 0, not scanning\n");
  		return 0;
  	}
  
  	/* 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(array_size(LOG_NUMBER,
  					  rtas_error_log_buffer_max));
  	if (!rtas_log_buf) {
  		printk(KERN_ERR "rtasd: no memory\n");
  		return -ENOMEM;
  	}
  
  	start_event_scan();
  
  	return 0;
  }
  arch_initcall(rtas_event_scan_init);
  
  static int __init rtas_init(void)
  {
  	struct proc_dir_entry *entry;
  
  	if (!machine_is(pseries) && !machine_is(chrp))
  		return 0;
  
  	if (!rtas_log_buf)
  		return -ENODEV;
  
  	entry = proc_create("powerpc/rtas/error_log", 0400, NULL,
  			    &proc_rtas_log_operations);
  	if (!entry)
  		printk(KERN_ERR "Failed to create error_log proc entry\n");
  
  	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)
  {
  	return (kstrtobool(str, &full_rtas_msgs) == 0);
  }
  __setup("rtasmsgs=", rtasmsgs_setup);
  