mirror of https://gitee.com/openkylin/linux.git
201 lines
5.1 KiB
C
201 lines
5.1 KiB
C
/*
|
|
* c 2001 PPC 64 Team, IBM Corp
|
|
*
|
|
* 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.
|
|
*
|
|
* scan-log-data driver for PPC64 Todd Inglett <tinglett@vnet.ibm.com>
|
|
*
|
|
* When ppc64 hardware fails the service processor dumps internal state
|
|
* of the system. After a reboot the operating system can access a dump
|
|
* of this data using this driver. A dump exists if the device-tree
|
|
* /chosen/ibm,scan-log-data property exists.
|
|
*
|
|
* This driver exports /proc/powerpc/scan-log-dump which can be read.
|
|
* The driver supports only sequential reads.
|
|
*
|
|
* The driver looks at a write to the driver for the single word "reset".
|
|
* If given, the driver will reset the scanlog so the platform can free it.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/types.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/init.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/uaccess.h>
|
|
#include <asm/rtas.h>
|
|
#include <asm/prom.h>
|
|
|
|
#define MODULE_VERS "1.0"
|
|
#define MODULE_NAME "scanlog"
|
|
|
|
/* Status returns from ibm,scan-log-dump */
|
|
#define SCANLOG_COMPLETE 0
|
|
#define SCANLOG_HWERROR -1
|
|
#define SCANLOG_CONTINUE 1
|
|
|
|
|
|
static unsigned int ibm_scan_log_dump; /* RTAS token */
|
|
static unsigned int *scanlog_buffer; /* The data buffer */
|
|
|
|
static ssize_t scanlog_read(struct file *file, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned int *data = scanlog_buffer;
|
|
int status;
|
|
unsigned long len, off;
|
|
unsigned int wait_time;
|
|
|
|
if (count > RTAS_DATA_BUF_SIZE)
|
|
count = RTAS_DATA_BUF_SIZE;
|
|
|
|
if (count < 1024) {
|
|
/* This is the min supported by this RTAS call. Rather
|
|
* than do all the buffering we insist the user code handle
|
|
* larger reads. As long as cp works... :)
|
|
*/
|
|
printk(KERN_ERR "scanlog: cannot perform a small read (%ld)\n", count);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!access_ok(VERIFY_WRITE, buf, count))
|
|
return -EFAULT;
|
|
|
|
for (;;) {
|
|
wait_time = 500; /* default wait if no data */
|
|
spin_lock(&rtas_data_buf_lock);
|
|
memcpy(rtas_data_buf, data, RTAS_DATA_BUF_SIZE);
|
|
status = rtas_call(ibm_scan_log_dump, 2, 1, NULL,
|
|
(u32) __pa(rtas_data_buf), (u32) count);
|
|
memcpy(data, rtas_data_buf, RTAS_DATA_BUF_SIZE);
|
|
spin_unlock(&rtas_data_buf_lock);
|
|
|
|
pr_debug("scanlog: status=%d, data[0]=%x, data[1]=%x, " \
|
|
"data[2]=%x\n", status, data[0], data[1], data[2]);
|
|
switch (status) {
|
|
case SCANLOG_COMPLETE:
|
|
pr_debug("scanlog: hit eof\n");
|
|
return 0;
|
|
case SCANLOG_HWERROR:
|
|
pr_debug("scanlog: hardware error reading data\n");
|
|
return -EIO;
|
|
case SCANLOG_CONTINUE:
|
|
/* We may or may not have data yet */
|
|
len = data[1];
|
|
off = data[2];
|
|
if (len > 0) {
|
|
if (copy_to_user(buf, ((char *)data)+off, len))
|
|
return -EFAULT;
|
|
return len;
|
|
}
|
|
/* Break to sleep default time */
|
|
break;
|
|
default:
|
|
/* Assume extended busy */
|
|
wait_time = rtas_busy_delay_time(status);
|
|
if (!wait_time) {
|
|
printk(KERN_ERR "scanlog: unknown error " \
|
|
"from rtas: %d\n", status);
|
|
return -EIO;
|
|
}
|
|
}
|
|
/* Apparently no data yet. Wait and try again. */
|
|
msleep_interruptible(wait_time);
|
|
}
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
static ssize_t scanlog_write(struct file * file, const char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
char stkbuf[20];
|
|
int status;
|
|
|
|
if (count > 19) count = 19;
|
|
if (copy_from_user (stkbuf, buf, count)) {
|
|
return -EFAULT;
|
|
}
|
|
stkbuf[count] = 0;
|
|
|
|
if (buf) {
|
|
if (strncmp(stkbuf, "reset", 5) == 0) {
|
|
pr_debug("scanlog: reset scanlog\n");
|
|
status = rtas_call(ibm_scan_log_dump, 2, 1, NULL, 0, 0);
|
|
pr_debug("scanlog: rtas returns %d\n", status);
|
|
}
|
|
}
|
|
return count;
|
|
}
|
|
|
|
static int scanlog_open(struct inode * inode, struct file * file)
|
|
{
|
|
unsigned int *data = scanlog_buffer;
|
|
|
|
if (data[0] != 0) {
|
|
/* This imperfect test stops a second copy of the
|
|
* data (or a reset while data is being copied)
|
|
*/
|
|
return -EBUSY;
|
|
}
|
|
|
|
data[0] = 0; /* re-init so we restart the scan */
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int scanlog_release(struct inode * inode, struct file * file)
|
|
{
|
|
unsigned int *data = scanlog_buffer;
|
|
|
|
data[0] = 0;
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations scanlog_fops = {
|
|
.owner = THIS_MODULE,
|
|
.read = scanlog_read,
|
|
.write = scanlog_write,
|
|
.open = scanlog_open,
|
|
.release = scanlog_release,
|
|
.llseek = noop_llseek,
|
|
};
|
|
|
|
static int __init scanlog_init(void)
|
|
{
|
|
struct proc_dir_entry *ent;
|
|
int err = -ENOMEM;
|
|
|
|
ibm_scan_log_dump = rtas_token("ibm,scan-log-dump");
|
|
if (ibm_scan_log_dump == RTAS_UNKNOWN_SERVICE)
|
|
return -ENODEV;
|
|
|
|
/* Ideally we could allocate a buffer < 4G */
|
|
scanlog_buffer = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
|
|
if (!scanlog_buffer)
|
|
goto err;
|
|
|
|
ent = proc_create("powerpc/rtas/scan-log-dump", S_IRUSR, NULL,
|
|
&scanlog_fops);
|
|
if (!ent)
|
|
goto err;
|
|
return 0;
|
|
err:
|
|
kfree(scanlog_buffer);
|
|
return err;
|
|
}
|
|
|
|
static void __exit scanlog_cleanup(void)
|
|
{
|
|
remove_proc_entry("powerpc/rtas/scan-log-dump", NULL);
|
|
kfree(scanlog_buffer);
|
|
}
|
|
|
|
module_init(scanlog_init);
|
|
module_exit(scanlog_cleanup);
|
|
MODULE_LICENSE("GPL");
|