patch-2.4.20 linux-2.4.20/arch/ppc64/kernel/rtas_flash.c

• Lines: 241
• Date: Thu Nov 28 15:53:11 2002
• Orig file: linux-2.4.19/arch/ppc64/kernel/rtas_flash.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/arch/ppc64/kernel/rtas_flash.c linux-2.4.20/arch/ppc64/kernel/rtas_flash.c
@@ -0,0 +1,240 @@
+/*
+ *  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.
+ *
+ * /proc/ppc64/rtas/firmware_flash interface
+ *
+ * This file implements a firmware_flash interface to pump a firmware
+ * image into the kernel.  At reboot time rtas_restart() will see the
+ * firmware image and flash it as it reboots (see rtas.c).
+ */
+
+#include <linux/module.h>
+
+#include <linux/config.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include <asm/rtas.h>
+
+#define MODULE_VERSION "1.0"
+#define MODULE_NAME "rtas_flash"
+
+#define FIRMWARE_FLASH_NAME "firmware_flash"
+
+/* Local copy of the flash block list.
+ * We only allow one open of the flash proc file and create this
+ * list as we go.  This list will be put in the kernel's
+ * rtas_firmware_flash_list global var once it is fully read.
+ *
+ * For convenience as we build the list we use virtual addrs,
+ * we do not fill in the version number, and the length field
+ * is treated as the number of entries currently in the block
+ * (i.e. not a byte count).  This is all fixed on release.
+ */
+static struct flash_block_list *flist;
+static char *flash_msg;
+static int flash_possible;
+
+static int rtas_flash_open(struct inode *inode, struct file *file)
+{
+	if ((file->f_mode & FMODE_WRITE) && flash_possible) {
+		if (flist)
+			return -EBUSY;
+		flist = (struct flash_block_list *)get_free_page(GFP_KERNEL);
+		if (!flist)
+			return -ENOMEM;
+	}
+	return 0;
+}
+
+/* Do simple sanity checks on the flash image. */
+static int flash_list_valid(struct flash_block_list *flist)
+{
+	struct flash_block_list *f;
+	int i;
+	unsigned long block_size, image_size;
+
+	flash_msg = NULL;
+	/* Paranoid self test here.  We also collect the image size. */
+	image_size = 0;
+	for (f = flist; f; f = f->next) {
+		for (i = 0; i < f->num_blocks; i++) {
+			if (f->blocks[i].data == NULL) {
+				flash_msg = "error: internal error null data\n";
+				return 0;
+			}
+			block_size = f->blocks[i].length;
+			if (block_size <= 0 || block_size > PAGE_SIZE) {
+				flash_msg = "error: internal error bad length\n";
+				return 0;
+			}
+			image_size += block_size;
+		}
+	}
+	if (image_size < (256 << 10)) {
+		if (image_size < 2)
+			flash_msg = NULL;	/* allow "clear" of image */
+		else
+			flash_msg = "error: flash image short\n";
+		return 0;
+	}
+	printk(KERN_INFO "FLASH: flash image with %ld bytes stored for hardware flash on reboot\n", image_size);
+	return 1;
+}
+
+static void free_flash_list(struct flash_block_list *f)
+{
+	struct flash_block_list *next;
+	int i;
+
+	while (f) {
+		for (i = 0; i < f->num_blocks; i++)
+			free_page((unsigned long)(f->blocks[i].data));
+		next = f->next;
+		free_page((unsigned long)f);
+		f = next;
+	}
+}
+
+static int rtas_flash_release(struct inode *inode, struct file *file)
+{
+	if (flist) {
+		/* Always clear saved list on a new attempt. */
+		if (rtas_firmware_flash_list.next) {
+			free_flash_list(rtas_firmware_flash_list.next);
+			rtas_firmware_flash_list.next = NULL;
+		}
+
+		if (flash_list_valid(flist))
+			rtas_firmware_flash_list.next = flist;
+		else
+			free_flash_list(flist);
+		flist = NULL;
+	}
+	return 0;
+}
+
+/* Reading the proc file will show status (not the firmware contents) */
+static ssize_t rtas_flash_read(struct file *file, char *buf,
+			       size_t count, loff_t *ppos)
+{
+	int error;
+	char *msg;
+	int msglen;
+
+	if (!flash_possible) {
+		msg = "error: this partition does not have service authority\n";
+	} else if (flist) {
+		msg = "info: this file is busy for write by some process\n";
+	} else if (flash_msg) {
+		msg = flash_msg;	/* message from last flash attempt */
+	} else if (rtas_firmware_flash_list.next) {
+		msg = "ready: firmware image ready for flash on reboot\n";
+	} else {
+		msg = "info: no firmware image for flash\n";
+	}
+	msglen = strlen(msg);
+	if (msglen > count)
+		msglen = count;
+
+	if (ppos && *ppos != 0)
+		return 0;	/* be cheap */
+
+	error = verify_area(VERIFY_WRITE, buf, msglen);
+	if (error)
+		return -EINVAL;
+
+	copy_to_user(buf, msg, msglen);
+
+	if (ppos)
+		*ppos = msglen;
+	return msglen;
+}
+
+/* We could be much more efficient here.  But to keep this function
+ * simple we allocate a page to the block list no matter how small the
+ * count is.  If the system is low on memory it will be just as well
+ * that we fail....
+ */
+static ssize_t rtas_flash_write(struct file *file, const char *buffer,
+				size_t count, loff_t *off)
+{
+	size_t len = count;
+	char *p;
+	int next_free;
+	struct flash_block_list *fl = flist;
+
+	if (!flash_possible || len == 0)
+		return len;	/* discard data */
+
+	while (fl->next)
+		fl = fl->next; /* seek to last block_list for append */
+	next_free = fl->num_blocks;
+	if (next_free == FLASH_BLOCKS_PER_NODE) {
+		/* Need to allocate another block_list */
+		fl->next = (struct flash_block_list *)get_free_page(GFP_KERNEL);
+		if (!fl->next)
+			return -ENOMEM;
+		fl = fl->next;
+		next_free = 0;
+	}
+
+	if (len > PAGE_SIZE)
+		len = PAGE_SIZE;
+	p = (char *)get_free_page(GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+	if(copy_from_user(p, buffer, len)) {
+		free_page((unsigned long)p);
+		return -EFAULT;
+	}
+	fl->blocks[next_free].data = p;
+	fl->blocks[next_free].length = len;
+	fl->num_blocks++;
+
+	return len;
+}
+
+static struct file_operations rtas_flash_operations = {
+	read:		rtas_flash_read,
+	write:		rtas_flash_write,
+	open:		rtas_flash_open,
+	release:	rtas_flash_release,
+};
+
+
+int __init rtas_flash_init(void)
+{
+	struct proc_dir_entry *ent = NULL;
+
+	if (!rtas_proc_dir) {
+		printk(KERN_WARNING "rtas proc dir does not already exist");
+		return -ENOENT;
+	}
+
+	if (rtas_token("ibm,update-flash-64-and-reboot") != RTAS_UNKNOWN_SERVICE)
+		flash_possible = 1;
+
+	if ((ent = create_proc_entry(FIRMWARE_FLASH_NAME, S_IRUSR | S_IWUSR, rtas_proc_dir)) != NULL) {
+		ent->nlink = 1;
+		ent->proc_fops = &rtas_flash_operations;
+		ent->owner = THIS_MODULE;
+	}
+	return 0;
+}
+
+void __exit rtas_flash_cleanup(void)
+{
+	if (!rtas_proc_dir)
+		return;
+	remove_proc_entry(FIRMWARE_FLASH_NAME, rtas_proc_dir);
+}
+
+module_init(rtas_flash_init);
+module_exit(rtas_flash_cleanup);
+MODULE_LICENSE("GPL");