--- /dev/null
+/*
+ * 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.
+ *
+ * /dev/nvram driver for PPC64
+ *
+ * This perhaps should live in drivers/char
+ *
+ * TODO: Split the /dev/nvram part (that one can use
+ * drivers/char/generic_nvram.c) from the arch & partition
+ * parsing code.
+ */
+
+#include <linux/module.h>
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/fcntl.h>
+#include <linux/nvram.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <asm/uaccess.h>
+#include <asm/nvram.h>
+#include <asm/rtas.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+
+#undef DEBUG_NVRAM
+
+static int nvram_scan_partitions(void);
+static int nvram_setup_partition(void);
+static int nvram_create_os_partition(void);
+static int nvram_remove_os_partition(void);
+
+static struct nvram_partition * nvram_part;
+static long nvram_error_log_index = -1;
+static long nvram_error_log_size = 0;
+
+int no_logging = 1; /* Until we initialize everything,
+ * make sure we don't try logging
+ * anything */
+
+extern volatile int error_log_cnt;
+
+struct err_log_info {
+ int error_type;
+ unsigned int seq_num;
+};
+
+static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
+{
+ int size;
+
+ if (ppc_md.nvram_size == NULL)
+ return -ENODEV;
+ size = ppc_md.nvram_size();
+
+ switch (origin) {
+ case 1:
+ offset += file->f_pos;
+ break;
+ case 2:
+ offset += size;
+ break;
+ }
+ if (offset < 0)
+ return -EINVAL;
+ file->f_pos = offset;
+ return file->f_pos;
+}
+
+
+static ssize_t dev_nvram_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ ssize_t ret;
+ char *tmp = NULL;
+ ssize_t size;
+
+ ret = -ENODEV;
+ if (!ppc_md.nvram_size)
+ goto out;
+
+ ret = 0;
+ size = ppc_md.nvram_size();
+ if (*ppos >= size || size < 0)
+ goto out;
+
+ count = min_t(size_t, count, size - *ppos);
+ count = min(count, PAGE_SIZE);
+
+ ret = -ENOMEM;
+ tmp = kmalloc(count, GFP_KERNEL);
+ if (!tmp)
+ goto out;
+
+ ret = ppc_md.nvram_read(tmp, count, ppos);
+ if (ret <= 0)
+ goto out;
+
+ if (copy_to_user(buf, tmp, ret))
+ ret = -EFAULT;
+
+out:
+ kfree(tmp);
+ return ret;
+
+}
+
+static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ ssize_t ret;
+ char *tmp = NULL;
+ ssize_t size;
+
+ ret = -ENODEV;
+ if (!ppc_md.nvram_size)
+ goto out;
+
+ ret = 0;
+ size = ppc_md.nvram_size();
+ if (*ppos >= size || size < 0)
+ goto out;
+
+ count = min_t(size_t, count, size - *ppos);
+ count = min(count, PAGE_SIZE);
+
+ ret = -ENOMEM;
+ tmp = kmalloc(count, GFP_KERNEL);
+ if (!tmp)
+ goto out;
+
+ ret = -EFAULT;
+ if (copy_from_user(tmp, buf, count))
+ goto out;
+
+ ret = ppc_md.nvram_write(tmp, count, ppos);
+
+out:
+ kfree(tmp);
+ return ret;
+
+}
+
+static int dev_nvram_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ switch(cmd) {
+#ifdef CONFIG_PPC_PMAC
+ case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
+ printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
+ case IOC_NVRAM_GET_OFFSET: {
+ int part, offset;
+
+ if (!machine_is(powermac))
+ return -EINVAL;
+ if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
+ return -EFAULT;
+ if (part < pmac_nvram_OF || part > pmac_nvram_NR)
+ return -EINVAL;
+ offset = pmac_get_partition(part);
+ if (offset < 0)
+ return offset;
+ if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
+ return -EFAULT;
+ return 0;
+ }
+#endif /* CONFIG_PPC_PMAC */
+ default:
+ return -EINVAL;
+ }
+}
+
+struct file_operations nvram_fops = {
+ .owner = THIS_MODULE,
+ .llseek = dev_nvram_llseek,
+ .read = dev_nvram_read,
+ .write = dev_nvram_write,
+ .ioctl = dev_nvram_ioctl,
+};
+
+static struct miscdevice nvram_dev = {
+ NVRAM_MINOR,
+ "nvram",
+ &nvram_fops
+};
+
+
+#ifdef DEBUG_NVRAM
+static void nvram_print_partitions(char * label)
+{
+ struct list_head * p;
+ struct nvram_partition * tmp_part;
+
+ printk(KERN_WARNING "--------%s---------\n", label);
+ printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
+ list_for_each(p, &nvram_part->partition) {
+ tmp_part = list_entry(p, struct nvram_partition, partition);
+ printk(KERN_WARNING "%d \t%02x\t%02x\t%d\t%s\n",
+ tmp_part->index, tmp_part->header.signature,
+ tmp_part->header.checksum, tmp_part->header.length,
+ tmp_part->header.name);
+ }
+}
+#endif
+
+
+static int nvram_write_header(struct nvram_partition * part)
+{
+ loff_t tmp_index;
+ int rc;
+
+ tmp_index = part->index;
+ rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index);
+
+ return rc;
+}
+
+
+static unsigned char nvram_checksum(struct nvram_header *p)
+{
+ unsigned int c_sum, c_sum2;
+ unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
+ c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
+
+ /* The sum may have spilled into the 3rd byte. Fold it back. */
+ c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
+ /* The sum cannot exceed 2 bytes. Fold it into a checksum */
+ c_sum2 = (c_sum >> 8) + (c_sum << 8);
+ c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
+ return c_sum;
+}
+
+
+/*
+ * Find an nvram partition, sig can be 0 for any
+ * partition or name can be NULL for any name, else
+ * tries to match both
+ */
+struct nvram_partition *nvram_find_partition(int sig, const char *name)
+{
+ struct nvram_partition * part;
+ struct list_head * p;
+
+ list_for_each(p, &nvram_part->partition) {
+ part = list_entry(p, struct nvram_partition, partition);
+
+ if (sig && part->header.signature != sig)
+ continue;
+ if (name && 0 != strncmp(name, part->header.name, 12))
+ continue;
+ return part;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(nvram_find_partition);
+
+
+static int nvram_remove_os_partition(void)
+{
+ struct list_head *i;
+ struct list_head *j;
+ struct nvram_partition * part;
+ struct nvram_partition * cur_part;
+ int rc;
+
+ list_for_each(i, &nvram_part->partition) {
+ part = list_entry(i, struct nvram_partition, partition);
+ if (part->header.signature != NVRAM_SIG_OS)
+ continue;
+
+ /* Make os partition a free partition */
+ part->header.signature = NVRAM_SIG_FREE;
+ sprintf(part->header.name, "wwwwwwwwwwww");
+ part->header.checksum = nvram_checksum(&part->header);
+
+ /* Merge contiguous free partitions backwards */
+ list_for_each_prev(j, &part->partition) {
+ cur_part = list_entry(j, struct nvram_partition, partition);
+ if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) {
+ break;
+ }
+
+ part->header.length += cur_part->header.length;
+ part->header.checksum = nvram_checksum(&part->header);
+ part->index = cur_part->index;
+
+ list_del(&cur_part->partition);
+ kfree(cur_part);
+ j = &part->partition; /* fixup our loop */
+ }
+
+ /* Merge contiguous free partitions forwards */
+ list_for_each(j, &part->partition) {
+ cur_part = list_entry(j, struct nvram_partition, partition);
+ if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) {
+ break;
+ }
+
+ part->header.length += cur_part->header.length;
+ part->header.checksum = nvram_checksum(&part->header);
+
+ list_del(&cur_part->partition);
+ kfree(cur_part);
+ j = &part->partition; /* fixup our loop */
+ }
+
+ rc = nvram_write_header(part);
+ if (rc <= 0) {
+ printk(KERN_ERR "nvram_remove_os_partition: nvram_write failed (%d)\n", rc);
+ return rc;
+ }
+
+ }
+
+ return 0;
+}
+
+/* nvram_create_os_partition
+ *
+ * Create a OS linux partition to buffer error logs.
+ * Will create a partition starting at the first free
+ * space found if space has enough room.
+ */
+static int nvram_create_os_partition(void)
+{
+ struct nvram_partition *part;
+ struct nvram_partition *new_part;
+ struct nvram_partition *free_part = NULL;
+ int seq_init[2] = { 0, 0 };
+ loff_t tmp_index;
+ long size = 0;
+ int rc;
+
+ /* Find a free partition that will give us the maximum needed size
+ If can't find one that will give us the minimum size needed */
+ list_for_each_entry(part, &nvram_part->partition, partition) {
+ if (part->header.signature != NVRAM_SIG_FREE)
+ continue;
+
+ if (part->header.length >= NVRAM_MAX_REQ) {
+ size = NVRAM_MAX_REQ;
+ free_part = part;
+ break;
+ }
+ if (!size && part->header.length >= NVRAM_MIN_REQ) {
+ size = NVRAM_MIN_REQ;
+ free_part = part;
+ }
+ }
+ if (!size)
+ return -ENOSPC;
+
+ /* Create our OS partition */
+ new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
+ if (!new_part) {
+ printk(KERN_ERR "nvram_create_os_partition: kmalloc failed\n");
+ return -ENOMEM;
+ }
+
+ new_part->index = free_part->index;
+ new_part->header.signature = NVRAM_SIG_OS;
+ new_part->header.length = size;
+ strcpy(new_part->header.name, "ppc64,linux");
+ new_part->header.checksum = nvram_checksum(&new_part->header);
+
+ rc = nvram_write_header(new_part);
+ if (rc <= 0) {
+ printk(KERN_ERR "nvram_create_os_partition: nvram_write_header \
+ failed (%d)\n", rc);
+ return rc;
+ }
+
+ /* make sure and initialize to zero the sequence number and the error
+ type logged */
+ tmp_index = new_part->index + NVRAM_HEADER_LEN;
+ rc = ppc_md.nvram_write((char *)&seq_init, sizeof(seq_init), &tmp_index);
+ if (rc <= 0) {
+ printk(KERN_ERR "nvram_create_os_partition: nvram_write "
+ "failed (%d)\n", rc);
+ return rc;
+ }
+
+ nvram_error_log_index = new_part->index + NVRAM_HEADER_LEN;
+ nvram_error_log_size = ((part->header.length - 1) *
+ NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
+
+ list_add_tail(&new_part->partition, &free_part->partition);
+
+ if (free_part->header.length <= size) {
+ list_del(&free_part->partition);
+ kfree(free_part);
+ return 0;
+ }
+
+ /* Adjust the partition we stole the space from */
+ free_part->index += size * NVRAM_BLOCK_LEN;
+ free_part->header.length -= size;
+ free_part->header.checksum = nvram_checksum(&free_part->header);
+
+ rc = nvram_write_header(free_part);
+ if (rc <= 0) {
+ printk(KERN_ERR "nvram_create_os_partition: nvram_write_header "
+ "failed (%d)\n", rc);
+ return rc;
+ }
+
+ return 0;
+}
+
+
+/* nvram_setup_partition
+ *
+ * This will setup the partition we need for buffering the
+ * error logs and cleanup partitions if needed.
+ *
+ * The general strategy is the following:
+ * 1.) If there is ppc64,linux partition large enough then use it.
+ * 2.) If there is not a ppc64,linux partition large enough, search
+ * for a free partition that is large enough.
+ * 3.) If there is not a free partition large enough remove
+ * _all_ OS partitions and consolidate the space.
+ * 4.) Will first try getting a chunk that will satisfy the maximum
+ * error log size (NVRAM_MAX_REQ).
+ * 5.) If the max chunk cannot be allocated then try finding a chunk
+ * that will satisfy the minum needed (NVRAM_MIN_REQ).
+ */
+static int nvram_setup_partition(void)
+{
+ struct list_head * p;
+ struct nvram_partition * part;
+ int rc;
+
+ /* For now, we don't do any of this on pmac, until I
+ * have figured out if it's worth killing some unused stuffs
+ * in our nvram, as Apple defined partitions use pretty much
+ * all of the space
+ */
+ if (machine_is(powermac))
+ return -ENOSPC;
+
+ /* see if we have an OS partition that meets our needs.
+ will try getting the max we need. If not we'll delete
+ partitions and try again. */
+ list_for_each(p, &nvram_part->partition) {
+ part = list_entry(p, struct nvram_partition, partition);
+ if (part->header.signature != NVRAM_SIG_OS)
+ continue;
+
+ if (strcmp(part->header.name, "ppc64,linux"))
+ continue;
+
+ if (part->header.length >= NVRAM_MIN_REQ) {
+ /* found our partition */
+ nvram_error_log_index = part->index + NVRAM_HEADER_LEN;
+ nvram_error_log_size = ((part->header.length - 1) *
+ NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
+ return 0;
+ }
+ }
+
+ /* try creating a partition with the free space we have */
+ rc = nvram_create_os_partition();
+ if (!rc) {
+ return 0;
+ }
+
+ /* need to free up some space */
+ rc = nvram_remove_os_partition();
+ if (rc) {
+ return rc;
+ }
+
+ /* create a partition in this new space */
+ rc = nvram_create_os_partition();
+ if (rc) {
+ printk(KERN_ERR "nvram_create_os_partition: Could not find a "
+ "NVRAM partition large enough\n");
+ return rc;
+ }
+
+ return 0;
+}
+
+
+static int nvram_scan_partitions(void)
+{
+ loff_t cur_index = 0;
+ struct nvram_header phead;
+ struct nvram_partition * tmp_part;
+ unsigned char c_sum;
+ char * header;
+ int total_size;
+ int err;
+
+ if (ppc_md.nvram_size == NULL)
+ return -ENODEV;
+ total_size = ppc_md.nvram_size();
+
+ header = (char *) kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
+ if (!header) {
+ printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
+ return -ENOMEM;
+ }
+
+ while (cur_index < total_size) {
+
+ err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
+ if (err != NVRAM_HEADER_LEN) {
+ printk(KERN_ERR "nvram_scan_partitions: Error parsing "
+ "nvram partitions\n");
+ goto out;
+ }
+
+ cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
+
+ memcpy(&phead, header, NVRAM_HEADER_LEN);
+
+ err = 0;
+ c_sum = nvram_checksum(&phead);
+ if (c_sum != phead.checksum) {
+ printk(KERN_WARNING "WARNING: nvram partition checksum"
+ " was %02x, should be %02x!\n",
+ phead.checksum, c_sum);
+ printk(KERN_WARNING "Terminating nvram partition scan\n");
+ goto out;
+ }
+ if (!phead.length) {
+ printk(KERN_WARNING "WARNING: nvram corruption "
+ "detected: 0-length partition\n");
+ goto out;
+ }
+ tmp_part = (struct nvram_partition *)
+ kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
+ err = -ENOMEM;
+ if (!tmp_part) {
+ printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
+ goto out;
+ }
+
+ memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
+ tmp_part->index = cur_index;
+ list_add_tail(&tmp_part->partition, &nvram_part->partition);
+
+ cur_index += phead.length * NVRAM_BLOCK_LEN;
+ }
+ err = 0;
+
+ out:
+ kfree(header);
+ return err;
+}
+
+static int __init nvram_init(void)
+{
+ int error;
+ int rc;
+
+ if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
+ return -ENODEV;
+
+ rc = misc_register(&nvram_dev);
+ if (rc != 0) {
+ printk(KERN_ERR "nvram_init: failed to register device\n");
+ return rc;
+ }
+
+ /* initialize our anchor for the nvram partition list */
+ nvram_part = (struct nvram_partition *) kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
+ if (!nvram_part) {
+ printk(KERN_ERR "nvram_init: Failed kmalloc\n");
+ return -ENOMEM;
+ }
+ INIT_LIST_HEAD(&nvram_part->partition);
+
+ /* Get all the NVRAM partitions */
+ error = nvram_scan_partitions();
+ if (error) {
+ printk(KERN_ERR "nvram_init: Failed nvram_scan_partitions\n");
+ return error;
+ }
+
+ if(nvram_setup_partition())
+ printk(KERN_WARNING "nvram_init: Could not find nvram partition"
+ " for nvram buffered error logging.\n");
+
+#ifdef DEBUG_NVRAM
+ nvram_print_partitions("NVRAM Partitions");
+#endif
+
+ return rc;
+}
+
+void __exit nvram_cleanup(void)
+{
+ misc_deregister( &nvram_dev );
+}
+
+
+#ifdef CONFIG_PPC_PSERIES
+
+/* nvram_write_error_log
+ *
+ * We need to buffer the error logs into nvram to ensure that we have
+ * the failure information to decode. If we have a severe error there
+ * is no way to guarantee that the OS or the machine is in a state to
+ * get back to user land and write the error to disk. For example if
+ * the SCSI device driver causes a Machine Check by writing to a bad
+ * IO address, there is no way of guaranteeing that the device driver
+ * is in any state that is would also be able to write the error data
+ * captured to disk, thus we buffer it in NVRAM for analysis on the
+ * next boot.
+ *
+ * In NVRAM the partition containing the error log buffer will looks like:
+ * Header (in bytes):
+ * +-----------+----------+--------+------------+------------------+
+ * | signature | checksum | length | name | data |
+ * |0 |1 |2 3|4 15|16 length-1|
+ * +-----------+----------+--------+------------+------------------+
+ *
+ * The 'data' section would look like (in bytes):
+ * +--------------+------------+-----------------------------------+
+ * | event_logged | sequence # | error log |
+ * |0 3|4 7|8 nvram_error_log_size-1|
+ * +--------------+------------+-----------------------------------+
+ *
+ * event_logged: 0 if event has not been logged to syslog, 1 if it has
+ * sequence #: The unique sequence # for each event. (until it wraps)
+ * error log: The error log from event_scan
+ */
+int nvram_write_error_log(char * buff, int length, unsigned int err_type)
+{
+ int rc;
+ loff_t tmp_index;
+ struct err_log_info info;
+
+ if (no_logging) {
+ return -EPERM;
+ }
+
+ if (nvram_error_log_index == -1) {
+ return -ESPIPE;
+ }
+
+ if (length > nvram_error_log_size) {
+ length = nvram_error_log_size;
+ }
+
+ info.error_type = err_type;
+ info.seq_num = error_log_cnt;
+
+ tmp_index = nvram_error_log_index;
+
+ rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index);
+ if (rc <= 0) {
+ printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
+ return rc;
+ }
+
+ rc = ppc_md.nvram_write(buff, length, &tmp_index);
+ if (rc <= 0) {
+ printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
+ return rc;
+ }
+
+ return 0;
+}
+
+/* nvram_read_error_log
+ *
+ * Reads nvram for error log for at most 'length'
+ */
+int nvram_read_error_log(char * buff, int length, unsigned int * err_type)
+{
+ int rc;
+ loff_t tmp_index;
+ struct err_log_info info;
+
+ if (nvram_error_log_index == -1)
+ return -1;
+
+ if (length > nvram_error_log_size)
+ length = nvram_error_log_size;
+
+ tmp_index = nvram_error_log_index;
+
+ rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index);
+ if (rc <= 0) {
+ printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
+ return rc;
+ }
+
+ rc = ppc_md.nvram_read(buff, length, &tmp_index);
+ if (rc <= 0) {
+ printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
+ return rc;
+ }
+
+ error_log_cnt = info.seq_num;
+ *err_type = info.error_type;
+
+ return 0;
+}
+
+/* This doesn't actually zero anything, but it sets the event_logged
+ * word to tell that this event is safely in syslog.
+ */
+int nvram_clear_error_log(void)
+{
+ loff_t tmp_index;
+ int clear_word = ERR_FLAG_ALREADY_LOGGED;
+ int rc;
+
+ tmp_index = nvram_error_log_index;
+
+ rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index);
+ if (rc <= 0) {
+ printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc);
+ return rc;
+ }
+
+ return 0;
+}
+
+#endif /* CONFIG_PPC_PSERIES */
+
+module_init(nvram_init);
+module_exit(nvram_cleanup);
+MODULE_LICENSE("GPL");
git://git.onelab.eu / linux-2.6.git / blobdiff