diff options
| -rw-r--r-- | drivers/char/nvram.c | 30 | ||||
| -rw-r--r-- | include/linux/nvram.h | 32 |
2 files changed, 56 insertions, 6 deletions
diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c index c98775bfd896..2df391f78986 100644 --- a/drivers/char/nvram.c +++ b/drivers/char/nvram.c @@ -52,9 +52,11 @@ static DEFINE_MUTEX(nvram_mutex); static DEFINE_SPINLOCK(nvram_state_lock); static int nvram_open_cnt; /* #times opened */ static int nvram_open_mode; /* special open modes */ +static ssize_t nvram_size; #define NVRAM_WRITE 1 /* opened for writing (exclusive) */ #define NVRAM_EXCL 2 /* opened with O_EXCL */ +#ifdef CONFIG_X86 /* * These functions are provided to be called internally or by other parts of * the kernel. It's up to the caller to ensure correct checksum before reading @@ -145,6 +147,19 @@ void nvram_set_checksum(void) } #endif /* 0 */ +static ssize_t pc_nvram_get_size(void) +{ + return NVRAM_BYTES; +} + +const struct nvram_ops arch_nvram_ops = { + .read_byte = pc_nvram_read_byte, + .write_byte = pc_nvram_write_byte, + .get_size = pc_nvram_get_size, +}; +EXPORT_SYMBOL(arch_nvram_ops); +#endif /* CONFIG_X86 */ + /* * The are the file operation function for user access to /dev/nvram */ @@ -152,7 +167,7 @@ void nvram_set_checksum(void) static loff_t nvram_misc_llseek(struct file *file, loff_t offset, int origin) { return generic_file_llseek_size(file, offset, origin, MAX_LFS_FILESIZE, - NVRAM_BYTES); + nvram_size); } static ssize_t nvram_misc_read(struct file *file, char __user *buf, @@ -303,8 +318,7 @@ static int nvram_misc_release(struct inode *inode, struct file *file) return 0; } -#ifdef CONFIG_PROC_FS - +#if defined(CONFIG_X86) && defined(CONFIG_PROC_FS) static const char * const floppy_types[] = { "none", "5.25'' 360k", "5.25'' 1.2M", "3.5'' 720k", "3.5'' 1.44M", "3.5'' 2.88M", "3.5'' 2.88M" @@ -394,7 +408,7 @@ static int nvram_proc_read(struct seq_file *seq, void *offset) return 0; } -#endif /* CONFIG_PROC_FS */ +#endif /* CONFIG_X86 && CONFIG_PROC_FS */ static const struct file_operations nvram_misc_fops = { .owner = THIS_MODULE, @@ -416,13 +430,17 @@ static int __init nvram_module_init(void) { int ret; + nvram_size = nvram_get_size(); + if (nvram_size < 0) + return nvram_size; + ret = misc_register(&nvram_misc); if (ret) { pr_err("nvram: can't misc_register on minor=%d\n", NVRAM_MINOR); return ret; } -#ifdef CONFIG_PROC_FS +#if defined(CONFIG_X86) && defined(CONFIG_PROC_FS) if (!proc_create_single("driver/nvram", 0, NULL, nvram_proc_read)) { pr_err("nvram: can't create /proc/driver/nvram\n"); misc_deregister(&nvram_misc); @@ -436,7 +454,7 @@ static int __init nvram_module_init(void) static void __exit nvram_module_exit(void) { -#ifdef CONFIG_PROC_FS +#if defined(CONFIG_X86) && defined(CONFIG_PROC_FS) remove_proc_entry("driver/nvram", NULL); #endif misc_deregister(&nvram_misc); diff --git a/include/linux/nvram.h b/include/linux/nvram.h index 79431dab87a1..bb4ea8cc6ea6 100644 --- a/include/linux/nvram.h +++ b/include/linux/nvram.h @@ -5,8 +5,30 @@ #include <linux/errno.h> #include <uapi/linux/nvram.h> +/** + * struct nvram_ops - NVRAM functionality made available to drivers + * @read: validate checksum (if any) then load a range of bytes from NVRAM + * @write: store a range of bytes to NVRAM then update checksum (if any) + * @read_byte: load a single byte from NVRAM + * @write_byte: store a single byte to NVRAM + * @get_size: return the fixed number of bytes in the NVRAM + * + * Architectures which provide an nvram ops struct need not implement all + * of these methods. If the NVRAM hardware can be accessed only one byte + * at a time then it may be sufficient to provide .read_byte and .write_byte. + * If the NVRAM has a checksum (and it is to be checked) the .read and + * .write methods can be used to implement that efficiently. + * + * Portable drivers may use the wrapper functions defined here. + * The nvram_read() and nvram_write() functions call the .read and .write + * methods when available and fall back on the .read_byte and .write_byte + * methods otherwise. + */ + struct nvram_ops { ssize_t (*get_size)(void); + unsigned char (*read_byte)(int); + void (*write_byte)(unsigned char, int); ssize_t (*read)(char *, size_t, loff_t *); ssize_t (*write)(char *, size_t, loff_t *); }; @@ -25,11 +47,21 @@ static inline ssize_t nvram_get_size(void) static inline unsigned char nvram_read_byte(int addr) { +#ifdef CONFIG_PPC +#else + if (arch_nvram_ops.read_byte) + return arch_nvram_ops.read_byte(addr); +#endif return 0xFF; } static inline void nvram_write_byte(unsigned char val, int addr) { +#ifdef CONFIG_PPC +#else + if (arch_nvram_ops.write_byte) + arch_nvram_ops.write_byte(val, addr); +#endif } static inline ssize_t nvram_read(char *buf, size_t count, loff_t *ppos) |