Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 545 insertions, 0 deletions

diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
new file mode 100644
index 000000000..e9f694b36
--- /dev/null
+++ b/drivers/char/nvram.c
@@ -0,0 +1,545 @@
+// 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_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
+ * 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 != NULL) {
+			mutex_lock(&nvram_mutex);
+			ppc_md.nvram_sync();
+			mutex_unlock(&nvram_mutex);
+		}
+		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 != NULL) {
+			mutex_lock(&nvram_mutex);
+			ret = arch_nvram_ops.initialize();
+			mutex_unlock(&nvram_mutex);
+		}
+		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 != NULL) {
+			mutex_lock(&nvram_mutex);
+			ret = arch_nvram_ops.set_checksum();
+			mutex_unlock(&nvram_mutex);
+		}
+		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();
+	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;
+	}
+
+#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);
+		return -ENOMEM;
+	}
+#endif
+
+	pr_info("Non-volatile memory driver v" NVRAM_VERSION "\n");
+	return 0;
+}
+
+static void __exit nvram_module_exit(void)
+{
+#if defined(CONFIG_X86) && defined(CONFIG_PROC_FS)
+	remove_proc_entry("driver/nvram", NULL);
+#endif
+	misc_deregister(&nvram_misc);
+}
+
+module_init(nvram_module_init);
+module_exit(nvram_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(NVRAM_MINOR);
+MODULE_ALIAS("devname:nvram");