// SPDX-License-Identifier: GPL-2.0-only/* * CMOS/NV-RAM driver for Linux * * Copyright (C) 1997 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> * idea by and with help from Richard Jelinek <rj@suse.de> * Portions copyright (c) 2001,2002 Sun Microsystems (thockin@sun.com) * * This driver allows you to access the contents of the non-volatile memory in * the mc146818rtc.h real-time clock. This chip is built into all PCs and into * many Atari machines. In the former it's called "CMOS-RAM", in the latter * "NVRAM" (NV stands for non-volatile). * * The data are supplied as a (seekable) character device, /dev/nvram. The * size of this file is dependent on the controller. The usual size is 114, * the number of freely available bytes in the memory (i.e., not used by the * RTC itself). * * Checksums over the NVRAM contents are managed by this driver. In case of a * bad checksum, reads and writes return -EIO. The checksum can be initialized * to a sane state either by ioctl(NVRAM_INIT) (clear whole NVRAM) or * ioctl(NVRAM_SETCKS) (doesn't change contents, just makes checksum valid * again; use with care!) * * 1.1 Cesar Barros: SMP locking fixes * added changelog * 1.2 Erik Gilling: Cobalt Networks support * Tim Hockin: general cleanup, Cobalt support * 1.3 Wim Van Sebroeck: convert PRINT_PROC to seq_file */ #define NVRAM_VERSION "1.3" #include <linux/module.h>#include <linux/nvram.h>#include <linux/types.h>#include <linux/errno.h>#include <linux/miscdevice.h>#include <linux/ioport.h>#include <linux/fcntl.h>#include <linux/mc146818rtc.h>#include <linux/init.h>#include <linux/proc_fs.h>#include <linux/seq_file.h>#include <linux/slab.h>#include <linux/spinlock.h>#include <linux/io.h>#include <linux/uaccess.h>#include <linux/mutex.h>#include <linux/pagemap.h> #ifdef CONFIG_PPC#include <asm/nvram.h>#endif 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 * or after writing (needs to be done only once). * * It is worth noting that these functions all access bytes of general * purpose memory in the NVRAM - that is to say, they all add the * NVRAM_FIRST_BYTE offset. Pass them offsets into NVRAM as if you did not * know about the RTC cruft. */ #define NVRAM_BYTES (128 - NVRAM_FIRST_BYTE) /* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with * rtc_lock held. Due to the index-port/data-port design of the RTC, we * don't want two different things trying to get to it at once. (e.g. the * periodic 11 min sync from kernel/time/ntp.c vs. this driver.) */ static unsigned char __nvram_read_byte(int i){ return CMOS_READ(NVRAM_FIRST_BYTE + i);} static unsigned char pc_nvram_read_byte(int i){ unsigned long flags; unsigned char c; spin_lock_irqsave(&rtc_lock, flags); c = __nvram_read_byte(i); spin_unlock_irqrestore(&rtc_lock, flags); return c;} /* This races nicely with trying to read with checksum checking (nvram_read) */static void __nvram_write_byte(unsigned char c, int i){ CMOS_WRITE(c, NVRAM_FIRST_BYTE + i);} static void pc_nvram_write_byte(unsigned char c, int i){ unsigned long flags; spin_lock_irqsave(&rtc_lock, flags); __nvram_write_byte(c, i); spin_unlock_irqrestore(&rtc_lock, flags);} /* On PCs, the checksum is built only over bytes 2..31 */#define PC_CKS_RANGE_START 2#define PC_CKS_RANGE_END 31#define PC_CKS_LOC 32 static int __nvram_check_checksum(void){ int i; unsigned short sum = 0; unsigned short expect; for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i) sum += __nvram_read_byte(i); expect = __nvram_read_byte(PC_CKS_LOC)<<8 | __nvram_read_byte(PC_CKS_LOC+1); return (sum & 0xffff) == expect;} static void __nvram_set_checksum(void){ int i; unsigned short sum = 0; for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i) sum += __nvram_read_byte(i); __nvram_write_byte(sum >> 8, PC_CKS_LOC); __nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1);} static long pc_nvram_set_checksum(void){ spin_lock_irq(&rtc_lock); __nvram_set_checksum(); spin_unlock_irq(&rtc_lock); return 0;} static long pc_nvram_initialize(void){ ssize_t i; spin_lock_irq(&rtc_lock); for (i = 0; i < NVRAM_BYTES; ++i) __nvram_write_byte(0, i); __nvram_set_checksum(); spin_unlock_irq(&rtc_lock); return 0;} static ssize_t pc_nvram_get_size(void){ return NVRAM_BYTES;} static ssize_t pc_nvram_read(char *buf, size_t count, loff_t *ppos){ char *p = buf; loff_t i; spin_lock_irq(&rtc_lock); if (!__nvram_check_checksum()) { spin_unlock_irq(&rtc_lock); return -EIO; } for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p) *p = __nvram_read_byte(i); spin_unlock_irq(&rtc_lock); *ppos = i; return p - buf;} static ssize_t pc_nvram_write(char *buf, size_t count, loff_t *ppos){ char *p = buf; loff_t i; spin_lock_irq(&rtc_lock); if (!__nvram_check_checksum()) { spin_unlock_irq(&rtc_lock); return -EIO; } for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p) __nvram_write_byte(*p, i); __nvram_set_checksum(); spin_unlock_irq(&rtc_lock); *ppos = i; return p - buf;} const struct nvram_ops arch_nvram_ops = { .read = pc_nvram_read, .write = pc_nvram_write, .read_byte = pc_nvram_read_byte, .write_byte = pc_nvram_write_byte, .get_size = pc_nvram_get_size, .set_checksum = pc_nvram_set_checksum, .initialize = pc_nvram_initialize,};EXPORT_SYMBOL(arch_nvram_ops);#endif /* CONFIG_X86 */ /* * The are the file operation function for user access to /dev/nvram */ 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_size);} static ssize_t nvram_misc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos){ char *tmp; ssize_t ret; if (*ppos >= nvram_size) return 0; count = min_t(size_t, count, nvram_size - *ppos); count = min_t(size_t, count, PAGE_SIZE); tmp = kmalloc(count, GFP_KERNEL); if (!tmp) return -ENOMEM; ret = nvram_read(tmp, count, ppos); if (ret <= 0) goto out; if (copy_to_user(buf, tmp, ret)) { *ppos -= ret; ret = -EFAULT; } out: kfree(tmp); return ret;} static ssize_t nvram_misc_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos){ char *tmp; ssize_t ret; if (*ppos >= nvram_size) return 0; count = min_t(size_t, count, nvram_size - *ppos); count = min_t(size_t, count, PAGE_SIZE); tmp = memdup_user(buf, count); if (IS_ERR(tmp)) return PTR_ERR(tmp); ret = nvram_write(tmp, count, ppos); kfree(tmp); return ret;} static long nvram_misc_ioctl(struct file *file, unsigned int cmd, unsigned long arg){ long ret = -ENOTTY; switch (cmd) {#ifdef CONFIG_PPC case OBSOLETE_PMAC_NVRAM_GET_OFFSET: pr_warn("nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n"); fallthrough; case IOC_NVRAM_GET_OFFSET: ret = -EINVAL;#ifdef CONFIG_PPC_PMAC if (machine_is(powermac)) { int part, offset; 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 -EINVAL; if (copy_to_user((void __user *)arg, &offset, sizeof(offset)) != 0) return -EFAULT; ret = 0; }#endif break;#ifdef CONFIG_PPC32 case IOC_NVRAM_SYNC: if (ppc_md.nvram_sync) ppc_md.nvram_sync(); ret = 0; break;#endif#elif defined(CONFIG_X86) || defined(CONFIG_M68K) case NVRAM_INIT: /* initialize NVRAM contents and checksum */ if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (arch_nvram_ops.initialize) ret = arch_nvram_ops.initialize(); break; case NVRAM_SETCKS: /* just set checksum, contents unchanged (maybe useful after * checksum garbaged somehow...) */ if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (arch_nvram_ops.set_checksum) ret = arch_nvram_ops.set_checksum(); break;#endif /* CONFIG_X86 || CONFIG_M68K */ } return ret;} static int nvram_misc_open(struct inode *inode, struct file *file){ spin_lock(&nvram_state_lock); /* Prevent multiple readers/writers if desired. */ if ((nvram_open_cnt && (file->f_flags & O_EXCL)) || (nvram_open_mode & NVRAM_EXCL)) { spin_unlock(&nvram_state_lock); return -EBUSY; } #if defined(CONFIG_X86) || defined(CONFIG_M68K) /* Prevent multiple writers if the set_checksum ioctl is implemented. */ if ((arch_nvram_ops.set_checksum != NULL) && (file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE)) { spin_unlock(&nvram_state_lock); return -EBUSY; }#endif if (file->f_flags & O_EXCL) nvram_open_mode |= NVRAM_EXCL; if (file->f_mode & FMODE_WRITE) nvram_open_mode |= NVRAM_WRITE; nvram_open_cnt++; spin_unlock(&nvram_state_lock); return 0;} static int nvram_misc_release(struct inode *inode, struct file *file){ spin_lock(&nvram_state_lock); nvram_open_cnt--; /* if only one instance is open, clear the EXCL bit */ if (nvram_open_mode & NVRAM_EXCL) nvram_open_mode &= ~NVRAM_EXCL; if (file->f_mode & FMODE_WRITE) nvram_open_mode &= ~NVRAM_WRITE; spin_unlock(&nvram_state_lock); return 0;} #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"}; static const char * const gfx_types[] = { "EGA, VGA, ... (with BIOS)", "CGA (40 cols)", "CGA (80 cols)", "monochrome",}; static void pc_nvram_proc_read(unsigned char *nvram, struct seq_file *seq, void *offset){ int checksum; int type; spin_lock_irq(&rtc_lock); checksum = __nvram_check_checksum(); spin_unlock_irq(&rtc_lock); seq_printf(seq, "Checksum status: %svalid\n", checksum ? "" : "not "); seq_printf(seq, "# floppies : %d\n", (nvram[6] & 1) ? (nvram[6] >> 6) + 1 : 0); seq_printf(seq, "Floppy 0 type : "); type = nvram[2] >> 4; if (type < ARRAY_SIZE(floppy_types)) seq_printf(seq, "%s\n", floppy_types[type]); else seq_printf(seq, "%d (unknown)\n", type); seq_printf(seq, "Floppy 1 type : "); type = nvram[2] & 0x0f; if (type < ARRAY_SIZE(floppy_types)) seq_printf(seq, "%s\n", floppy_types[type]); else seq_printf(seq, "%d (unknown)\n", type); seq_printf(seq, "HD 0 type : "); type = nvram[4] >> 4; if (type) seq_printf(seq, "%02x\n", type == 0x0f ? nvram[11] : type); else seq_printf(seq, "none\n"); seq_printf(seq, "HD 1 type : "); type = nvram[4] & 0x0f; if (type) seq_printf(seq, "%02x\n", type == 0x0f ? nvram[12] : type); else seq_printf(seq, "none\n"); seq_printf(seq, "HD type 48 data: %d/%d/%d C/H/S, precomp %d, lz %d\n", nvram[18] | (nvram[19] << 8), nvram[20], nvram[25], nvram[21] | (nvram[22] << 8), nvram[23] | (nvram[24] << 8)); seq_printf(seq, "HD type 49 data: %d/%d/%d C/H/S, precomp %d, lz %d\n", nvram[39] | (nvram[40] << 8), nvram[41], nvram[46], nvram[42] | (nvram[43] << 8), nvram[44] | (nvram[45] << 8)); seq_printf(seq, "DOS base memory: %d kB\n", nvram[7] | (nvram[8] << 8)); seq_printf(seq, "Extended memory: %d kB (configured), %d kB (tested)\n", nvram[9] | (nvram[10] << 8), nvram[34] | (nvram[35] << 8)); seq_printf(seq, "Gfx adapter : %s\n", gfx_types[(nvram[6] >> 4) & 3]); seq_printf(seq, "FPU : %sinstalled\n", (nvram[6] & 2) ? "" : "not "); return;} static int nvram_proc_read(struct seq_file *seq, void *offset){ unsigned char contents[NVRAM_BYTES]; int i = 0; spin_lock_irq(&rtc_lock); for (i = 0; i < NVRAM_BYTES; ++i) contents[i] = __nvram_read_byte(i); spin_unlock_irq(&rtc_lock); pc_nvram_proc_read(contents, seq, offset); return 0;}#endif /* CONFIG_X86 && CONFIG_PROC_FS */ static const struct file_operations nvram_misc_fops = { .owner = THIS_MODULE, .llseek = nvram_misc_llseek, .read = nvram_misc_read, .write = nvram_misc_write, .unlocked_ioctl = nvram_misc_ioctl, .open = nvram_misc_open, .release = nvram_misc_release,}; static struct miscdevice nvram_misc = { NVRAM_MINOR, "nvram", &nvram_misc_fops,}; static int __init nvram_module_init(void){ int ret; nvram_size = nvram_get_size();Lines 1–500 of 536. Load more
// SPDX-License-Identifier: GPL-2.0-only /* * CMOS/NV-RAM driver for Linux * * Copyright (C) 1997 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> * idea by and with help from Richard Jelinek <rj@suse.de> * Portions copyright (c) 2001,2002 Sun Microsystems (thockin@sun.com) * * This driver allows you to access the contents of the non-volatile memory in * the mc146818rtc.h real-time clock. This chip is built into all PCs and into * many Atari machines. In the former it's called "CMOS-RAM", in the latter * "NVRAM" (NV stands for non-volatile). * * The data are supplied as a (seekable) character device, /dev/nvram. The * size of this file is dependent on the controller. The usual size is 114, * the number of freely available bytes in the memory (i.e., not used by the * RTC itself). * * Checksums over the NVRAM contents are managed by this driver. In case of a * bad checksum, reads and writes return -EIO. The checksum can be initialized * to a sane state either by ioctl(NVRAM_INIT) (clear whole NVRAM) or * ioctl(NVRAM_SETCKS) (doesn't change contents, just makes checksum valid * again; use with care!) * * 1.1 Cesar Barros: SMP locking fixes * added changelog * 1.2 Erik Gilling: Cobalt Networks support * Tim Hockin: general cleanup, Cobalt support * 1.3 Wim Van Sebroeck: convert PRINT_PROC to seq_file */ #define NVRAM_VERSION "1.3" #include <linux/module.h> #include <linux/nvram.h> #include <linux/types.h> #include <linux/errno.h> #include <linux/miscdevice.h> #include <linux/ioport.h> #include <linux/fcntl.h> #include <linux/mc146818rtc.h> #include <linux/init.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/io.h> #include <linux/uaccess.h> #include <linux/mutex.h> #include <linux/pagemap.h> #ifdef CONFIG_PPC #include <asm/nvram.h> #endif 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 * or after writing (needs to be done only once). * * It is worth noting that these functions all access bytes of general * purpose memory in the NVRAM - that is to say, they all add the * NVRAM_FIRST_BYTE offset. Pass them offsets into NVRAM as if you did not * know about the RTC cruft. */ #define NVRAM_BYTES (128 - NVRAM_FIRST_BYTE) /* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with * rtc_lock held. Due to the index-port/data-port design of the RTC, we * don't want two different things trying to get to it at once. (e.g. the * periodic 11 min sync from kernel/time/ntp.c vs. this driver.) */ static unsigned char __nvram_read_byte(int i) { return CMOS_READ(NVRAM_FIRST_BYTE + i); } static unsigned char pc_nvram_read_byte(int i) { unsigned long flags; unsigned char c; spin_lock_irqsave(&rtc_lock, flags); c = __nvram_read_byte(i); spin_unlock_irqrestore(&rtc_lock, flags); return c; } /* This races nicely with trying to read with checksum checking (nvram_read) */ static void __nvram_write_byte(unsigned char c, int i) { CMOS_WRITE(c, NVRAM_FIRST_BYTE + i); } static void pc_nvram_write_byte(unsigned char c, int i) { unsigned long flags; spin_lock_irqsave(&rtc_lock, flags); __nvram_write_byte(c, i); spin_unlock_irqrestore(&rtc_lock, flags); } /* On PCs, the checksum is built only over bytes 2..31 */ #define PC_CKS_RANGE_START 2 #define PC_CKS_RANGE_END 31 #define PC_CKS_LOC 32 static int __nvram_check_checksum(void) { int i; unsigned short sum = 0; unsigned short expect; for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i) sum += __nvram_read_byte(i); expect = __nvram_read_byte(PC_CKS_LOC)<<8 | __nvram_read_byte(PC_CKS_LOC+1); return (sum & 0xffff) == expect; } static void __nvram_set_checksum(void) { int i; unsigned short sum = 0; for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i) sum += __nvram_read_byte(i); __nvram_write_byte(sum >> 8, PC_CKS_LOC); __nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1); } static long pc_nvram_set_checksum(void) { spin_lock_irq(&rtc_lock); __nvram_set_checksum(); spin_unlock_irq(&rtc_lock); return 0; } static long pc_nvram_initialize(void) { ssize_t i; spin_lock_irq(&rtc_lock); for (i = 0; i < NVRAM_BYTES; ++i) __nvram_write_byte(0, i); __nvram_set_checksum(); spin_unlock_irq(&rtc_lock); return 0; } static ssize_t pc_nvram_get_size(void) { return NVRAM_BYTES; } static ssize_t pc_nvram_read(char *buf, size_t count, loff_t *ppos) { char *p = buf; loff_t i; spin_lock_irq(&rtc_lock); if (!__nvram_check_checksum()) { spin_unlock_irq(&rtc_lock); return -EIO; } for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p) *p = __nvram_read_byte(i); spin_unlock_irq(&rtc_lock); *ppos = i; return p - buf; } static ssize_t pc_nvram_write(char *buf, size_t count, loff_t *ppos) { char *p = buf; loff_t i; spin_lock_irq(&rtc_lock); if (!__nvram_check_checksum()) { spin_unlock_irq(&rtc_lock); return -EIO; } for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p) __nvram_write_byte(*p, i); __nvram_set_checksum(); spin_unlock_irq(&rtc_lock); *ppos = i; return p - buf; } const struct nvram_ops arch_nvram_ops = { .read = pc_nvram_read, .write = pc_nvram_write, .read_byte = pc_nvram_read_byte, .write_byte = pc_nvram_write_byte, .get_size = pc_nvram_get_size, .set_checksum = pc_nvram_set_checksum, .initialize = pc_nvram_initialize, }; EXPORT_SYMBOL(arch_nvram_ops); #endif /* CONFIG_X86 */ /* * The are the file operation function for user access to /dev/nvram */ 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_size); } static ssize_t nvram_misc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { char *tmp; ssize_t ret; if (*ppos >= nvram_size) return 0; count = min_t(size_t, count, nvram_size - *ppos); count = min_t(size_t, count, PAGE_SIZE); tmp = kmalloc(count, GFP_KERNEL); if (!tmp) return -ENOMEM; ret = nvram_read(tmp, count, ppos); if (ret <= 0) goto out; if (copy_to_user(buf, tmp, ret)) { *ppos -= ret; ret = -EFAULT; } out: kfree(tmp); return ret; } static ssize_t nvram_misc_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { char *tmp; ssize_t ret; if (*ppos >= nvram_size) return 0; count = min_t(size_t, count, nvram_size - *ppos); count = min_t(size_t, count, PAGE_SIZE); tmp = memdup_user(buf, count); if (IS_ERR(tmp)) return PTR_ERR(tmp); ret = nvram_write(tmp, count, ppos); kfree(tmp); return ret; } static long nvram_misc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { long ret = -ENOTTY; switch (cmd) { #ifdef CONFIG_PPC case OBSOLETE_PMAC_NVRAM_GET_OFFSET: pr_warn("nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n"); fallthrough; case IOC_NVRAM_GET_OFFSET: ret = -EINVAL; #ifdef CONFIG_PPC_PMAC if (machine_is(powermac)) { int part, offset; 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 -EINVAL; if (copy_to_user((void __user *)arg, &offset, sizeof(offset)) != 0) return -EFAULT; ret = 0; } #endif break; #ifdef CONFIG_PPC32 case IOC_NVRAM_SYNC: if (ppc_md.nvram_sync) ppc_md.nvram_sync(); ret = 0; break; #endif #elif defined(CONFIG_X86) || defined(CONFIG_M68K) case NVRAM_INIT: /* initialize NVRAM contents and checksum */ if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (arch_nvram_ops.initialize) ret = arch_nvram_ops.initialize(); break; case NVRAM_SETCKS: /* just set checksum, contents unchanged (maybe useful after * checksum garbaged somehow...) */ if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (arch_nvram_ops.set_checksum) ret = arch_nvram_ops.set_checksum(); break; #endif /* CONFIG_X86 || CONFIG_M68K */ } return ret; } static int nvram_misc_open(struct inode *inode, struct file *file) { spin_lock(&nvram_state_lock); /* Prevent multiple readers/writers if desired. */ if ((nvram_open_cnt && (file->f_flags & O_EXCL)) || (nvram_open_mode & NVRAM_EXCL)) { spin_unlock(&nvram_state_lock); return -EBUSY; } #if defined(CONFIG_X86) || defined(CONFIG_M68K) /* Prevent multiple writers if the set_checksum ioctl is implemented. */ if ((arch_nvram_ops.set_checksum != NULL) && (file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE)) { spin_unlock(&nvram_state_lock); return -EBUSY; } #endif if (file->f_flags & O_EXCL) nvram_open_mode |= NVRAM_EXCL; if (file->f_mode & FMODE_WRITE) nvram_open_mode |= NVRAM_WRITE; nvram_open_cnt++; spin_unlock(&nvram_state_lock); return 0; } static int nvram_misc_release(struct inode *inode, struct file *file) { spin_lock(&nvram_state_lock); nvram_open_cnt--; /* if only one instance is open, clear the EXCL bit */ if (nvram_open_mode & NVRAM_EXCL) nvram_open_mode &= ~NVRAM_EXCL; if (file->f_mode & FMODE_WRITE) nvram_open_mode &= ~NVRAM_WRITE; spin_unlock(&nvram_state_lock); return 0; } #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" }; static const char * const gfx_types[] = { "EGA, VGA, ... (with BIOS)", "CGA (40 cols)", "CGA (80 cols)", "monochrome", }; static void pc_nvram_proc_read(unsigned char *nvram, struct seq_file *seq, void *offset) { int checksum; int type; spin_lock_irq(&rtc_lock); checksum = __nvram_check_checksum(); spin_unlock_irq(&rtc_lock); seq_printf(seq, "Checksum status: %svalid\n", checksum ? "" : "not "); seq_printf(seq, "# floppies : %d\n", (nvram[6] & 1) ? (nvram[6] >> 6) + 1 : 0); seq_printf(seq, "Floppy 0 type : "); type = nvram[2] >> 4; if (type < ARRAY_SIZE(floppy_types)) seq_printf(seq, "%s\n", floppy_types[type]); else seq_printf(seq, "%d (unknown)\n", type); seq_printf(seq, "Floppy 1 type : "); type = nvram[2] & 0x0f; if (type < ARRAY_SIZE(floppy_types)) seq_printf(seq, "%s\n", floppy_types[type]); else seq_printf(seq, "%d (unknown)\n", type); seq_printf(seq, "HD 0 type : "); type = nvram[4] >> 4; if (type) seq_printf(seq, "%02x\n", type == 0x0f ? nvram[11] : type); else seq_printf(seq, "none\n"); seq_printf(seq, "HD 1 type : "); type = nvram[4] & 0x0f; if (type) seq_printf(seq, "%02x\n", type == 0x0f ? nvram[12] : type); else seq_printf(seq, "none\n"); seq_printf(seq, "HD type 48 data: %d/%d/%d C/H/S, precomp %d, lz %d\n", nvram[18] | (nvram[19] << 8), nvram[20], nvram[25], nvram[21] | (nvram[22] << 8), nvram[23] | (nvram[24] << 8)); seq_printf(seq, "HD type 49 data: %d/%d/%d C/H/S, precomp %d, lz %d\n", nvram[39] | (nvram[40] << 8), nvram[41], nvram[46], nvram[42] | (nvram[43] << 8), nvram[44] | (nvram[45] << 8)); seq_printf(seq, "DOS base memory: %d kB\n", nvram[7] | (nvram[8] << 8)); seq_printf(seq, "Extended memory: %d kB (configured), %d kB (tested)\n", nvram[9] | (nvram[10] << 8), nvram[34] | (nvram[35] << 8)); seq_printf(seq, "Gfx adapter : %s\n", gfx_types[(nvram[6] >> 4) & 3]); seq_printf(seq, "FPU : %sinstalled\n", (nvram[6] & 2) ? "" : "not "); return; } static int nvram_proc_read(struct seq_file *seq, void *offset) { unsigned char contents[NVRAM_BYTES]; int i = 0; spin_lock_irq(&rtc_lock); for (i = 0; i < NVRAM_BYTES; ++i) contents[i] = __nvram_read_byte(i); spin_unlock_irq(&rtc_lock); pc_nvram_proc_read(contents, seq, offset); return 0; } #endif /* CONFIG_X86 && CONFIG_PROC_FS */ static const struct file_operations nvram_misc_fops = { .owner = THIS_MODULE, .llseek = nvram_misc_llseek, .read = nvram_misc_read, .write = nvram_misc_write, .unlocked_ioctl = nvram_misc_ioctl, .open = nvram_misc_open, .release = nvram_misc_release, }; static struct miscdevice nvram_misc = { NVRAM_MINOR, "nvram", &nvram_misc_fops, }; static int __init nvram_module_init(void) { int ret; nvram_size = nvram_get_size();