diff options
Diffstat (limited to 'arch/powerpc/kernel/nvram_64.c')
-rw-r--r-- | arch/powerpc/kernel/nvram_64.c | 564 |
1 files changed, 564 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c new file mode 100644 index 00000000..bec1e930 --- /dev/null +++ b/arch/powerpc/kernel/nvram_64.c @@ -0,0 +1,564 @@ +/* + * 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 + +#define NVRAM_HEADER_LEN sizeof(struct nvram_header) +#define NVRAM_BLOCK_LEN NVRAM_HEADER_LEN + +/* If change this size, then change the size of NVNAME_LEN */ +struct nvram_header { + unsigned char signature; + unsigned char checksum; + unsigned short length; + /* Terminating null required only for names < 12 chars. */ + char name[12]; +}; + +struct nvram_partition { + struct list_head partition; + struct nvram_header header; + unsigned int index; +}; + +static LIST_HEAD(nvram_partitions); + +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 long dev_nvram_ioctl(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; + } +} + +const struct file_operations nvram_fops = { + .owner = THIS_MODULE, + .llseek = dev_nvram_llseek, + .read = dev_nvram_read, + .write = dev_nvram_write, + .unlocked_ioctl = dev_nvram_ioctl, +}; + +static struct miscdevice nvram_dev = { + NVRAM_MINOR, + "nvram", + &nvram_fops +}; + + +#ifdef DEBUG_NVRAM +static void __init nvram_print_partitions(char * label) +{ + struct nvram_partition * tmp_part; + + printk(KERN_WARNING "--------%s---------\n", label); + printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n"); + list_for_each_entry(tmp_part, &nvram_partitions, partition) { + printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%12s\n", + tmp_part->index, tmp_part->header.signature, + tmp_part->header.checksum, tmp_part->header.length, + tmp_part->header.name); + } +} +#endif + + +static int __init 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 __init 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; +} + +/* + * Per the criteria passed via nvram_remove_partition(), should this + * partition be removed? 1=remove, 0=keep + */ +static int nvram_can_remove_partition(struct nvram_partition *part, + const char *name, int sig, const char *exceptions[]) +{ + if (part->header.signature != sig) + return 0; + if (name) { + if (strncmp(name, part->header.name, 12)) + return 0; + } else if (exceptions) { + const char **except; + for (except = exceptions; *except; except++) { + if (!strncmp(*except, part->header.name, 12)) + return 0; + } + } + return 1; +} + +/** + * nvram_remove_partition - Remove one or more partitions in nvram + * @name: name of the partition to remove, or NULL for a + * signature only match + * @sig: signature of the partition(s) to remove + * @exceptions: When removing all partitions with a matching signature, + * leave these alone. + */ + +int __init nvram_remove_partition(const char *name, int sig, + const char *exceptions[]) +{ + struct nvram_partition *part, *prev, *tmp; + int rc; + + list_for_each_entry(part, &nvram_partitions, partition) { + if (!nvram_can_remove_partition(part, name, sig, exceptions)) + continue; + + /* Make partition a free partition */ + part->header.signature = NVRAM_SIG_FREE; + strncpy(part->header.name, "wwwwwwwwwwww", 12); + part->header.checksum = nvram_checksum(&part->header); + rc = nvram_write_header(part); + if (rc <= 0) { + printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc); + return rc; + } + } + + /* Merge contiguous ones */ + prev = NULL; + list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) { + if (part->header.signature != NVRAM_SIG_FREE) { + prev = NULL; + continue; + } + if (prev) { + prev->header.length += part->header.length; + prev->header.checksum = nvram_checksum(&part->header); + rc = nvram_write_header(part); + if (rc <= 0) { + printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc); + return rc; + } + list_del(&part->partition); + kfree(part); + } else + prev = part; + } + + return 0; +} + +/** + * nvram_create_partition - Create a partition in nvram + * @name: name of the partition to create + * @sig: signature of the partition to create + * @req_size: size of data to allocate in bytes + * @min_size: minimum acceptable size (0 means req_size) + * + * Returns a negative error code or a positive nvram index + * of the beginning of the data area of the newly created + * partition. If you provided a min_size smaller than req_size + * you need to query for the actual size yourself after the + * call using nvram_partition_get_size(). + */ +loff_t __init nvram_create_partition(const char *name, int sig, + int req_size, int min_size) +{ + struct nvram_partition *part; + struct nvram_partition *new_part; + struct nvram_partition *free_part = NULL; + static char nv_init_vals[16]; + loff_t tmp_index; + long size = 0; + int rc; + + /* Convert sizes from bytes to blocks */ + req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN; + min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN; + + /* If no minimum size specified, make it the same as the + * requested size + */ + if (min_size == 0) + min_size = req_size; + if (min_size > req_size) + return -EINVAL; + + /* Now add one block to each for the header */ + req_size += 1; + min_size += 1; + + /* 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_partitions, partition) { + if (part->header.signature != NVRAM_SIG_FREE) + continue; + + if (part->header.length >= req_size) { + size = req_size; + free_part = part; + break; + } + if (part->header.length > size && + part->header.length >= min_size) { + size = part->header.length; + free_part = part; + } + } + if (!size) + return -ENOSPC; + + /* Create our OS partition */ + new_part = kmalloc(sizeof(*new_part), GFP_KERNEL); + if (!new_part) { + pr_err("nvram_create_os_partition: kmalloc failed\n"); + return -ENOMEM; + } + + new_part->index = free_part->index; + new_part->header.signature = sig; + new_part->header.length = size; + strncpy(new_part->header.name, name, 12); + new_part->header.checksum = nvram_checksum(&new_part->header); + + rc = nvram_write_header(new_part); + if (rc <= 0) { + pr_err("nvram_create_os_partition: nvram_write_header " + "failed (%d)\n", rc); + return rc; + } + list_add_tail(&new_part->partition, &free_part->partition); + + /* Adjust or remove the partition we stole the space from */ + if (free_part->header.length > size) { + 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) { + pr_err("nvram_create_os_partition: nvram_write_header " + "failed (%d)\n", rc); + return rc; + } + } else { + list_del(&free_part->partition); + kfree(free_part); + } + + /* Clear the new partition */ + for (tmp_index = new_part->index + NVRAM_HEADER_LEN; + tmp_index < ((size - 1) * NVRAM_BLOCK_LEN); + tmp_index += NVRAM_BLOCK_LEN) { + rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index); + if (rc <= 0) { + pr_err("nvram_create_partition: nvram_write failed (%d)\n", rc); + return rc; + } + } + + return new_part->index + NVRAM_HEADER_LEN; +} + +/** + * nvram_get_partition_size - Get the data size of an nvram partition + * @data_index: This is the offset of the start of the data of + * the partition. The same value that is returned by + * nvram_create_partition(). + */ +int nvram_get_partition_size(loff_t data_index) +{ + struct nvram_partition *part; + + list_for_each_entry(part, &nvram_partitions, partition) { + if (part->index + NVRAM_HEADER_LEN == data_index) + return (part->header.length - 1) * NVRAM_BLOCK_LEN; + } + return -1; +} + + +/** + * nvram_find_partition - Find an nvram partition by signature and name + * @name: Name of the partition or NULL for any name + * @sig: Signature to test against + * @out_size: if non-NULL, returns the size of the data part of the partition + */ +loff_t nvram_find_partition(const char *name, int sig, int *out_size) +{ + struct nvram_partition *p; + + list_for_each_entry(p, &nvram_partitions, partition) { + if (p->header.signature == sig && + (!name || !strncmp(p->header.name, name, 12))) { + if (out_size) + *out_size = (p->header.length - 1) * + NVRAM_BLOCK_LEN; + return p->index + NVRAM_HEADER_LEN; + } + } + return 0; +} + +int __init 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 || ppc_md.nvram_size() <= 0) + return -ENODEV; + total_size = ppc_md.nvram_size(); + + header = 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_partitions); + + cur_index += phead.length * NVRAM_BLOCK_LEN; + } + err = 0; + +#ifdef DEBUG_NVRAM + nvram_print_partitions("NVRAM Partitions"); +#endif + + out: + kfree(header); + return err; +} + +static int __init nvram_init(void) +{ + int rc; + + BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16); + + 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; + } + + return rc; +} + +void __exit nvram_cleanup(void) +{ + misc_deregister( &nvram_dev ); +} + +module_init(nvram_init); +module_exit(nvram_cleanup); +MODULE_LICENSE("GPL"); |