v4.19.13 snapshot.
diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
new file mode 100644
index 0000000..25264d6
--- /dev/null
+++ b/drivers/char/nvram.c
@@ -0,0 +1,699 @@
+/*
+ * 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!)
+ *
+ * This file also provides some functions for other parts of the kernel that
+ * want to access the NVRAM: nvram_{read,write,check_checksum,set_checksum}.
+ * Obviously this can be used only if this driver is always configured into
+ * the kernel and is not a module. Since the functions are used by some Atari
+ * drivers, this is the case on the Atari.
+ *
+ *
+ * 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>
+
+#define PC 1
+#define ATARI 2
+
+/* select machine configuration */
+#if defined(CONFIG_ATARI)
+# define MACH ATARI
+#elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) /* and ?? */
+# define MACH PC
+#else
+# error Cannot build nvram driver for this machine configuration.
+#endif
+
+#if MACH == PC
+
+/* RTC in a PC */
+#define CHECK_DRIVER_INIT() 1
+
+/* 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
+#define NVRAM_BYTES (128-NVRAM_FIRST_BYTE)
+
+#define mach_check_checksum pc_check_checksum
+#define mach_set_checksum pc_set_checksum
+#define mach_proc_infos pc_proc_infos
+
+#endif
+
+#if MACH == ATARI
+
+/* Special parameters for RTC in Atari machines */
+#include <asm/atarihw.h>
+#include <asm/atariints.h>
+#define RTC_PORT(x) (TT_RTC_BAS + 2*(x))
+#define CHECK_DRIVER_INIT() (MACH_IS_ATARI && ATARIHW_PRESENT(TT_CLK))
+
+#define NVRAM_BYTES 50
+
+/* On Ataris, the checksum is over all bytes except the checksum bytes
+ * themselves; these are at the very end */
+#define ATARI_CKS_RANGE_START 0
+#define ATARI_CKS_RANGE_END 47
+#define ATARI_CKS_LOC 48
+
+#define mach_check_checksum atari_check_checksum
+#define mach_set_checksum atari_set_checksum
+#define mach_proc_infos atari_proc_infos
+
+#endif
+
+/* 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.)
+ */
+
+#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/spinlock.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/mutex.h>
+#include <linux/pagemap.h>
+
+
+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 */
+#define NVRAM_WRITE 1 /* opened for writing (exclusive) */
+#define NVRAM_EXCL 2 /* opened with O_EXCL */
+
+static int mach_check_checksum(void);
+static void mach_set_checksum(void);
+
+#ifdef CONFIG_PROC_FS
+static void mach_proc_infos(unsigned char *contents, struct seq_file *seq,
+ void *offset);
+#endif
+
+/*
+ * 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.
+ */
+
+unsigned char __nvram_read_byte(int i)
+{
+ return CMOS_READ(NVRAM_FIRST_BYTE + i);
+}
+EXPORT_SYMBOL(__nvram_read_byte);
+
+unsigned char 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;
+}
+EXPORT_SYMBOL(nvram_read_byte);
+
+/* This races nicely with trying to read with checksum checking (nvram_read) */
+void __nvram_write_byte(unsigned char c, int i)
+{
+ CMOS_WRITE(c, NVRAM_FIRST_BYTE + i);
+}
+EXPORT_SYMBOL(__nvram_write_byte);
+
+void 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);
+}
+EXPORT_SYMBOL(nvram_write_byte);
+
+int __nvram_check_checksum(void)
+{
+ return mach_check_checksum();
+}
+EXPORT_SYMBOL(__nvram_check_checksum);
+
+int nvram_check_checksum(void)
+{
+ unsigned long flags;
+ int rv;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ rv = __nvram_check_checksum();
+ spin_unlock_irqrestore(&rtc_lock, flags);
+ return rv;
+}
+EXPORT_SYMBOL(nvram_check_checksum);
+
+static void __nvram_set_checksum(void)
+{
+ mach_set_checksum();
+}
+
+#if 0
+void nvram_set_checksum(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ __nvram_set_checksum();
+ spin_unlock_irqrestore(&rtc_lock, flags);
+}
+#endif /* 0 */
+
+/*
+ * The are the file operation function for user access to /dev/nvram
+ */
+
+static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
+{
+ return generic_file_llseek_size(file, offset, origin, MAX_LFS_FILESIZE,
+ NVRAM_BYTES);
+}
+
+static ssize_t nvram_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned char contents[NVRAM_BYTES];
+ unsigned i = *ppos;
+ unsigned char *tmp;
+
+ spin_lock_irq(&rtc_lock);
+
+ if (!__nvram_check_checksum())
+ goto checksum_err;
+
+ for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
+ *tmp = __nvram_read_byte(i);
+
+ spin_unlock_irq(&rtc_lock);
+
+ if (copy_to_user(buf, contents, tmp - contents))
+ return -EFAULT;
+
+ *ppos = i;
+
+ return tmp - contents;
+
+checksum_err:
+ spin_unlock_irq(&rtc_lock);
+ return -EIO;
+}
+
+static ssize_t nvram_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned char contents[NVRAM_BYTES];
+ unsigned i = *ppos;
+ unsigned char *tmp;
+
+ if (i >= NVRAM_BYTES)
+ return 0; /* Past EOF */
+
+ if (count > NVRAM_BYTES - i)
+ count = NVRAM_BYTES - i;
+ if (count > NVRAM_BYTES)
+ return -EFAULT; /* Can't happen, but prove it to gcc */
+
+ if (copy_from_user(contents, buf, count))
+ return -EFAULT;
+
+ spin_lock_irq(&rtc_lock);
+
+ if (!__nvram_check_checksum())
+ goto checksum_err;
+
+ for (tmp = contents; count--; ++i, ++tmp)
+ __nvram_write_byte(*tmp, i);
+
+ __nvram_set_checksum();
+
+ spin_unlock_irq(&rtc_lock);
+
+ *ppos = i;
+
+ return tmp - contents;
+
+checksum_err:
+ spin_unlock_irq(&rtc_lock);
+ return -EIO;
+}
+
+static long nvram_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int i;
+
+ switch (cmd) {
+
+ case NVRAM_INIT:
+ /* initialize NVRAM contents and checksum */
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ mutex_lock(&nvram_mutex);
+ 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);
+ mutex_unlock(&nvram_mutex);
+ return 0;
+
+ case NVRAM_SETCKS:
+ /* just set checksum, contents unchanged (maybe useful after
+ * checksum garbaged somehow...) */
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ mutex_lock(&nvram_mutex);
+ spin_lock_irq(&rtc_lock);
+ __nvram_set_checksum();
+ spin_unlock_irq(&rtc_lock);
+ mutex_unlock(&nvram_mutex);
+ return 0;
+
+ default:
+ return -ENOTTY;
+ }
+}
+
+static int nvram_open(struct inode *inode, struct file *file)
+{
+ spin_lock(&nvram_state_lock);
+
+ if ((nvram_open_cnt && (file->f_flags & O_EXCL)) ||
+ (nvram_open_mode & NVRAM_EXCL) ||
+ ((file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE))) {
+ spin_unlock(&nvram_state_lock);
+ return -EBUSY;
+ }
+
+ 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_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;
+}
+
+#ifndef CONFIG_PROC_FS
+static int nvram_add_proc_fs(void)
+{
+ return 0;
+}
+
+#else
+
+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);
+
+ mach_proc_infos(contents, seq, offset);
+
+ return 0;
+}
+
+static int nvram_add_proc_fs(void)
+{
+ if (!proc_create_single("driver/nvram", 0, NULL, nvram_proc_read))
+ return -ENOMEM;
+ return 0;
+}
+
+#endif /* CONFIG_PROC_FS */
+
+static const struct file_operations nvram_fops = {
+ .owner = THIS_MODULE,
+ .llseek = nvram_llseek,
+ .read = nvram_read,
+ .write = nvram_write,
+ .unlocked_ioctl = nvram_ioctl,
+ .open = nvram_open,
+ .release = nvram_release,
+};
+
+static struct miscdevice nvram_dev = {
+ NVRAM_MINOR,
+ "nvram",
+ &nvram_fops
+};
+
+static int __init nvram_init(void)
+{
+ int ret;
+
+ /* First test whether the driver should init at all */
+ if (!CHECK_DRIVER_INIT())
+ return -ENODEV;
+
+ ret = misc_register(&nvram_dev);
+ if (ret) {
+ printk(KERN_ERR "nvram: can't misc_register on minor=%d\n",
+ NVRAM_MINOR);
+ goto out;
+ }
+ ret = nvram_add_proc_fs();
+ if (ret) {
+ printk(KERN_ERR "nvram: can't create /proc/driver/nvram\n");
+ goto outmisc;
+ }
+ ret = 0;
+ printk(KERN_INFO "Non-volatile memory driver v" NVRAM_VERSION "\n");
+out:
+ return ret;
+outmisc:
+ misc_deregister(&nvram_dev);
+ goto out;
+}
+
+static void __exit nvram_cleanup_module(void)
+{
+ remove_proc_entry("driver/nvram", NULL);
+ misc_deregister(&nvram_dev);
+}
+
+module_init(nvram_init);
+module_exit(nvram_cleanup_module);
+
+/*
+ * Machine specific functions
+ */
+
+#if MACH == PC
+
+static int pc_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 pc_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);
+}
+
+#ifdef 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_proc_infos(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;
+}
+#endif
+
+#endif /* MACH == PC */
+
+#if MACH == ATARI
+
+static int atari_check_checksum(void)
+{
+ int i;
+ unsigned char sum = 0;
+
+ for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
+ sum += __nvram_read_byte(i);
+ return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) &&
+ (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff));
+}
+
+static void atari_set_checksum(void)
+{
+ int i;
+ unsigned char sum = 0;
+
+ for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
+ sum += __nvram_read_byte(i);
+ __nvram_write_byte(~sum, ATARI_CKS_LOC);
+ __nvram_write_byte(sum, ATARI_CKS_LOC + 1);
+}
+
+#ifdef CONFIG_PROC_FS
+
+static struct {
+ unsigned char val;
+ const char *name;
+} boot_prefs[] = {
+ { 0x80, "TOS" },
+ { 0x40, "ASV" },
+ { 0x20, "NetBSD (?)" },
+ { 0x10, "Linux" },
+ { 0x00, "unspecified" }
+};
+
+static const char * const languages[] = {
+ "English (US)",
+ "German",
+ "French",
+ "English (UK)",
+ "Spanish",
+ "Italian",
+ "6 (undefined)",
+ "Swiss (French)",
+ "Swiss (German)"
+};
+
+static const char * const dateformat[] = {
+ "MM%cDD%cYY",
+ "DD%cMM%cYY",
+ "YY%cMM%cDD",
+ "YY%cDD%cMM",
+ "4 (undefined)",
+ "5 (undefined)",
+ "6 (undefined)",
+ "7 (undefined)"
+};
+
+static const char * const colors[] = {
+ "2", "4", "16", "256", "65536", "??", "??", "??"
+};
+
+static void atari_proc_infos(unsigned char *nvram, struct seq_file *seq,
+ void *offset)
+{
+ int checksum = nvram_check_checksum();
+ int i;
+ unsigned vmode;
+
+ seq_printf(seq, "Checksum status : %svalid\n", checksum ? "" : "not ");
+
+ seq_printf(seq, "Boot preference : ");
+ for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i) {
+ if (nvram[1] == boot_prefs[i].val) {
+ seq_printf(seq, "%s\n", boot_prefs[i].name);
+ break;
+ }
+ }
+ if (i < 0)
+ seq_printf(seq, "0x%02x (undefined)\n", nvram[1]);
+
+ seq_printf(seq, "SCSI arbitration : %s\n",
+ (nvram[16] & 0x80) ? "on" : "off");
+ seq_printf(seq, "SCSI host ID : ");
+ if (nvram[16] & 0x80)
+ seq_printf(seq, "%d\n", nvram[16] & 7);
+ else
+ seq_printf(seq, "n/a\n");
+
+ /* the following entries are defined only for the Falcon */
+ if ((atari_mch_cookie >> 16) != ATARI_MCH_FALCON)
+ return;
+
+ seq_printf(seq, "OS language : ");
+ if (nvram[6] < ARRAY_SIZE(languages))
+ seq_printf(seq, "%s\n", languages[nvram[6]]);
+ else
+ seq_printf(seq, "%u (undefined)\n", nvram[6]);
+ seq_printf(seq, "Keyboard language: ");
+ if (nvram[7] < ARRAY_SIZE(languages))
+ seq_printf(seq, "%s\n", languages[nvram[7]]);
+ else
+ seq_printf(seq, "%u (undefined)\n", nvram[7]);
+ seq_printf(seq, "Date format : ");
+ seq_printf(seq, dateformat[nvram[8] & 7],
+ nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/');
+ seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12);
+ seq_printf(seq, "Boot delay : ");
+ if (nvram[10] == 0)
+ seq_printf(seq, "default");
+ else
+ seq_printf(seq, "%ds%s\n", nvram[10],
+ nvram[10] < 8 ? ", no memory test" : "");
+
+ vmode = (nvram[14] << 8) | nvram[15];
+ seq_printf(seq,
+ "Video mode : %s colors, %d columns, %s %s monitor\n",
+ colors[vmode & 7],
+ vmode & 8 ? 80 : 40,
+ vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC");
+ seq_printf(seq, " %soverscan, compat. mode %s%s\n",
+ vmode & 64 ? "" : "no ",
+ vmode & 128 ? "on" : "off",
+ vmode & 256 ?
+ (vmode & 16 ? ", line doubling" : ", half screen") : "");
+
+ return;
+}
+#endif
+
+#endif /* MACH == ATARI */
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(NVRAM_MINOR);