[PATCH] dell_rbu: new Dell BIOS update driver

Remote BIOS Update driver for updating BIOS images on Dell servers and
desktops.  See dell_rbu.txt for details.

Signed-off-by: Abhay Salunke <Abhay_Salunke@dell.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 634 insertions, 0 deletions

diff --git a/drivers/firmware/dell_rbu.c b/drivers/firmware/dell_rbu.c
new file mode 100644
index 00000000000..3b865f34a09
--- /dev/null
+++ b/drivers/firmware/dell_rbu.c
@@ -0,0 +1,634 @@
+/*
+ * dell_rbu.c
+ * Bios Update driver for Dell systems
+ * Author: Dell Inc
+ *         Abhay Salunke <abhay_salunke@dell.com>
+ *
+ * Copyright (C) 2005 Dell Inc.
+ *
+ * Remote BIOS Update (rbu) driver is used for updating DELL BIOS by
+ * creating entries in the /sys file systems on Linux 2.6 and higher
+ * kernels. The driver supports two mechanism to update the BIOS namely
+ * contiguous and packetized. Both these methods still require having some
+ * application to set the CMOS bit indicating the BIOS to update itself
+ * after a reboot.
+ *
+ * Contiguous method:
+ * This driver writes the incoming data in a monolithic image by allocating
+ * contiguous physical pages large enough to accommodate the incoming BIOS
+ * image size.
+ *
+ * Packetized method:
+ * The driver writes the incoming packet image by allocating a new packet
+ * on every time the packet data is written. This driver requires an
+ * application to break the BIOS image in to fixed sized packet chunks.
+ *
+ * See Documentation/dell_rbu.txt for more info.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License v2.0 as published by
+ * the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <linux/version.h>
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/blkdev.h>
+#include <linux/device.h>
+#include <linux/spinlock.h>
+#include <linux/moduleparam.h>
+#include <linux/firmware.h>
+#include <linux/dma-mapping.h>
+
+MODULE_AUTHOR("Abhay Salunke <abhay_salunke@dell.com>");
+MODULE_DESCRIPTION("Driver for updating BIOS image on DELL systems");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.0");
+
+#define BIOS_SCAN_LIMIT 0xffffffff
+#define MAX_IMAGE_LENGTH 16
+static struct _rbu_data {
+	void *image_update_buffer;
+	unsigned long image_update_buffer_size;
+	unsigned long bios_image_size;
+	int image_update_ordernum;
+	int dma_alloc;
+	spinlock_t lock;
+	unsigned long packet_read_count;
+	unsigned long packet_write_count;
+	unsigned long num_packets;
+	unsigned long packetsize;
+} rbu_data;
+
+static char image_type[MAX_IMAGE_LENGTH] = "mono";
+module_param_string(image_type, image_type, sizeof(image_type), 0);
+MODULE_PARM_DESC(image_type, "BIOS image type. choose- mono or packet");
+
+struct packet_data {
+	struct list_head list;
+	size_t length;
+	void *data;
+	int ordernum;
+};
+
+static struct packet_data packet_data_head;
+
+static struct platform_device *rbu_device;
+static int context;
+static dma_addr_t dell_rbu_dmaaddr;
+
+static void init_packet_head(void)
+{
+	INIT_LIST_HEAD(&packet_data_head.list);
+	rbu_data.packet_write_count = 0;
+	rbu_data.packet_read_count = 0;
+	rbu_data.num_packets = 0;
+	rbu_data.packetsize = 0;
+}
+
+static int fill_last_packet(void *data, size_t length)
+{
+	struct list_head *ptemp_list;
+	struct packet_data *packet = NULL;
+	int packet_count = 0;
+
+	pr_debug("fill_last_packet: entry \n");
+
+	if (!rbu_data.num_packets) {
+		pr_debug("fill_last_packet: num_packets=0\n");
+		return -ENOMEM;
+	}
+
+	packet_count = rbu_data.num_packets;
+
+	ptemp_list = (&packet_data_head.list)->prev;
+
+	packet = list_entry(ptemp_list, struct packet_data, list);
+
+	if ((rbu_data.packet_write_count + length) > rbu_data.packetsize) {
+		pr_debug("dell_rbu:%s: packet size data "
+			 "overrun\n", __FUNCTION__);
+		return -EINVAL;
+	}
+
+	pr_debug("fill_last_packet : buffer = %p\n", packet->data);
+
+	memcpy((packet->data + rbu_data.packet_write_count), data, length);
+
+	if ((rbu_data.packet_write_count + length) == rbu_data.packetsize) {
+		/*
+		 * this was the last data chunk in the packet
+		 * so reinitialize the packet data counter to zero
+		 */
+		rbu_data.packet_write_count = 0;
+	} else
+		rbu_data.packet_write_count += length;
+
+	pr_debug("fill_last_packet: exit \n");
+	return 0;
+}
+
+static int create_packet(size_t length)
+{
+	struct packet_data *newpacket;
+	int ordernum = 0;
+
+	pr_debug("create_packet: entry \n");
+
+	if (!rbu_data.packetsize) {
+		pr_debug("create_packet: packetsize not specified\n");
+		return -EINVAL;
+	}
+
+	newpacket = kmalloc(sizeof(struct packet_data), GFP_KERNEL);
+	if (!newpacket) {
+		printk(KERN_WARNING
+		       "dell_rbu:%s: failed to allocate new "
+		       "packet\n", __FUNCTION__);
+		return -ENOMEM;
+	}
+
+	ordernum = get_order(length);
+	/*
+	 * there is no upper limit on memory
+	 * address for packetized mechanism
+	 */
+	newpacket->data = (unsigned char *)__get_free_pages(GFP_KERNEL,
+							    ordernum);
+
+	pr_debug("create_packet: newpacket %p\n", newpacket->data);
+
+	if (!newpacket->data) {
+		printk(KERN_WARNING
+		       "dell_rbu:%s: failed to allocate new "
+		       "packet\n", __FUNCTION__);
+		kfree(newpacket);
+		return -ENOMEM;
+	}
+
+	newpacket->ordernum = ordernum;
+	++rbu_data.num_packets;
+	/*
+	 * initialize the newly created packet headers
+	 */
+	INIT_LIST_HEAD(&newpacket->list);
+	list_add_tail(&newpacket->list, &packet_data_head.list);
+	/*
+	 * packets have fixed size
+	 */
+	newpacket->length = rbu_data.packetsize;
+
+	pr_debug("create_packet: exit \n");
+
+	return 0;
+}
+
+static int packetize_data(void *data, size_t length)
+{
+	int rc = 0;
+
+	if (!rbu_data.packet_write_count) {
+		if ((rc = create_packet(length)))
+			return rc;
+	}
+	if ((rc = fill_last_packet(data, length)))
+		return rc;
+
+	return rc;
+}
+
+static int
+do_packet_read(char *data, struct list_head *ptemp_list,
+	       int length, int bytes_read, int *list_read_count)
+{
+	void *ptemp_buf;
+	struct packet_data *newpacket = NULL;
+	int bytes_copied = 0;
+	int j = 0;
+
+	newpacket = list_entry(ptemp_list, struct packet_data, list);
+	*list_read_count += newpacket->length;
+
+	if (*list_read_count > bytes_read) {
+		/* point to the start of unread data */
+		j = newpacket->length - (*list_read_count - bytes_read);
+		/* point to the offset in the packet buffer */
+		ptemp_buf = (u8 *) newpacket->data + j;
+		/*
+		 * check if there is enough room in
+		 * * the incoming buffer
+		 */
+		if (length > (*list_read_count - bytes_read))
+			/*
+			 * copy what ever is there in this
+			 * packet and move on
+			 */
+			bytes_copied = (*list_read_count - bytes_read);
+		else
+			/* copy the remaining */
+			bytes_copied = length;
+		memcpy(data, ptemp_buf, bytes_copied);
+	}
+	return bytes_copied;
+}
+
+static int packet_read_list(char *data, size_t * pread_length)
+{
+	struct list_head *ptemp_list;
+	int temp_count = 0;
+	int bytes_copied = 0;
+	int bytes_read = 0;
+	int remaining_bytes = 0;
+	char *pdest = data;
+
+	/* check if we have any packets */
+	if (0 == rbu_data.num_packets)
+		return -ENOMEM;
+
+	remaining_bytes = *pread_length;
+	bytes_read = rbu_data.packet_read_count;
+
+	ptemp_list = (&packet_data_head.list)->next;
+	while (!list_empty(ptemp_list)) {
+		bytes_copied = do_packet_read(pdest, ptemp_list,
+					      remaining_bytes, bytes_read,
+					      &temp_count);
+		remaining_bytes -= bytes_copied;
+		bytes_read += bytes_copied;
+		pdest += bytes_copied;
+		/*
+		 * check if we reached end of buffer before reaching the
+		 * last packet
+		 */
+		if (remaining_bytes == 0)
+			break;
+
+		ptemp_list = ptemp_list->next;
+	}
+	/*finally set the bytes read */
+	*pread_length = bytes_read - rbu_data.packet_read_count;
+	rbu_data.packet_read_count = bytes_read;
+	return 0;
+}
+
+static void packet_empty_list(void)
+{
+	struct list_head *ptemp_list;
+	struct list_head *pnext_list;
+	struct packet_data *newpacket;
+
+	ptemp_list = (&packet_data_head.list)->next;
+	while (!list_empty(ptemp_list)) {
+		newpacket =
+		    list_entry(ptemp_list, struct packet_data, list);
+		pnext_list = ptemp_list->next;
+		list_del(ptemp_list);
+		ptemp_list = pnext_list;
+		/*
+		 * zero out the RBU packet memory before freeing
+		 * to make sure there are no stale RBU packets left in memory
+		 */
+		memset(newpacket->data, 0, rbu_data.packetsize);
+		free_pages((unsigned long)newpacket->data,
+			   newpacket->ordernum);
+		kfree(newpacket);
+	}
+	rbu_data.packet_write_count = 0;
+	rbu_data.packet_read_count = 0;
+	rbu_data.num_packets = 0;
+	rbu_data.packetsize = 0;
+}
+
+/*
+ * img_update_free: Frees the buffer allocated for storing BIOS image
+ * Always called with lock held and returned with lock held
+ */
+static void img_update_free(void)
+{
+	if (!rbu_data.image_update_buffer)
+		return;
+	/*
+	 * zero out this buffer before freeing it to get rid of any stale
+	 * BIOS image copied in memory.
+	 */
+	memset(rbu_data.image_update_buffer, 0,
+	       rbu_data.image_update_buffer_size);
+	if (rbu_data.dma_alloc == 1)
+		dma_free_coherent(NULL, rbu_data.bios_image_size,
+				  rbu_data.image_update_buffer,
+				  dell_rbu_dmaaddr);
+	else
+		free_pages((unsigned long)rbu_data.image_update_buffer,
+			   rbu_data.image_update_ordernum);
+
+	/*
+	 * Re-initialize the rbu_data variables after a free
+	 */
+	rbu_data.image_update_ordernum = -1;
+	rbu_data.image_update_buffer = NULL;
+	rbu_data.image_update_buffer_size = 0;
+	rbu_data.bios_image_size = 0;
+	rbu_data.dma_alloc = 0;
+}
+
+/*
+ * img_update_realloc: This function allocates the contiguous pages to
+ * accommodate the requested size of data. The memory address and size
+ * values are stored globally and on every call to this function the new
+ * size is checked to see if more data is required than the existing size.
+ * If true the previous memory is freed and new allocation is done to
+ * accommodate the new size. If the incoming size is less then than the
+ * already allocated size, then that memory is reused. This function is
+ * called with lock held and returns with lock held.
+ */
+static int img_update_realloc(unsigned long size)
+{
+	unsigned char *image_update_buffer = NULL;
+	unsigned long rc;
+	unsigned long img_buf_phys_addr;
+	int ordernum;
+	int dma_alloc = 0;
+
+	/*
+	 * check if the buffer of sufficient size has been
+	 * already allocated
+	 */
+	if (rbu_data.image_update_buffer_size >= size) {
+		/*
+		 * check for corruption
+		 */
+		if ((size != 0) && (rbu_data.image_update_buffer == NULL)) {
+			printk(KERN_ERR "dell_rbu:%s: corruption "
+			       "check failed\n", __FUNCTION__);
+			return -EINVAL;
+		}
+		/*
+		 * we have a valid pre-allocated buffer with
+		 * sufficient size
+		 */
+		return 0;
+	}
+
+	/*
+	 * free any previously allocated buffer
+	 */
+	img_update_free();
+
+	spin_unlock(&rbu_data.lock);
+
+	ordernum = get_order(size);
+	image_update_buffer =
+	    (unsigned char *)__get_free_pages(GFP_KERNEL, ordernum);
+
+	img_buf_phys_addr =
+	    (unsigned long)virt_to_phys(image_update_buffer);
+
+	if (img_buf_phys_addr > BIOS_SCAN_LIMIT) {
+		free_pages((unsigned long)image_update_buffer, ordernum);
+		ordernum = -1;
+		image_update_buffer = dma_alloc_coherent(NULL, size,
+							 &dell_rbu_dmaaddr,
+							 GFP_KERNEL);
+		dma_alloc = 1;
+	}
+
+	spin_lock(&rbu_data.lock);
+
+	if (image_update_buffer != NULL) {
+		rbu_data.image_update_buffer = image_update_buffer;
+		rbu_data.image_update_buffer_size = size;
+		rbu_data.bios_image_size =
+		    rbu_data.image_update_buffer_size;
+		rbu_data.image_update_ordernum = ordernum;
+		rbu_data.dma_alloc = dma_alloc;
+		rc = 0;
+	} else {
+		pr_debug("Not enough memory for image update:"
+			 "size = %ld\n", size);
+		rc = -ENOMEM;
+	}
+
+	return rc;
+}
+
+static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count)
+{
+	int retval;
+	size_t bytes_left;
+	size_t data_length;
+	char *ptempBuf = buffer;
+	unsigned long imagesize;
+
+	/* check to see if we have something to return */
+	if (rbu_data.num_packets == 0) {
+		pr_debug("read_packet_data: no packets written\n");
+		retval = -ENOMEM;
+		goto read_rbu_data_exit;
+	}
+
+	imagesize = rbu_data.num_packets * rbu_data.packetsize;
+
+	if (pos > imagesize) {
+		retval = 0;
+		printk(KERN_WARNING "dell_rbu:read_packet_data: "
+		       "data underrun\n");
+		goto read_rbu_data_exit;
+	}
+
+	bytes_left = imagesize - pos;
+	data_length = min(bytes_left, count);
+
+	if ((retval = packet_read_list(ptempBuf, &data_length)) < 0)
+		goto read_rbu_data_exit;
+
+	if ((pos + count) > imagesize) {
+		rbu_data.packet_read_count = 0;
+		/* this was the last copy */
+		retval = bytes_left;
+	} else
+		retval = count;
+
+      read_rbu_data_exit:
+	return retval;
+}
+
+static ssize_t read_rbu_mono_data(char *buffer, loff_t pos, size_t count)
+{
+	unsigned char *ptemp = NULL;
+	size_t bytes_left = 0;
+	size_t data_length = 0;
+	ssize_t ret_count = 0;
+
+	/* check to see if we have something to return */
+	if ((rbu_data.image_update_buffer == NULL) ||
+	    (rbu_data.bios_image_size == 0)) {
+		pr_debug("read_rbu_data_mono: image_update_buffer %p ,"
+			 "bios_image_size %lu\n",
+			 rbu_data.image_update_buffer,
+			 rbu_data.bios_image_size);
+		ret_count = -ENOMEM;
+		goto read_rbu_data_exit;
+	}
+
+	if (pos > rbu_data.bios_image_size) {
+		ret_count = 0;
+		goto read_rbu_data_exit;
+	}
+
+	bytes_left = rbu_data.bios_image_size - pos;
+	data_length = min(bytes_left, count);
+
+	ptemp = rbu_data.image_update_buffer;
+	memcpy(buffer, (ptemp + pos), data_length);
+
+	if ((pos + count) > rbu_data.bios_image_size)
+		/* this was the last copy */
+		ret_count = bytes_left;
+	else
+		ret_count = count;
+      read_rbu_data_exit:
+	return ret_count;
+}
+
+static ssize_t
+read_rbu_data(struct kobject *kobj, char *buffer, loff_t pos, size_t count)
+{
+	ssize_t ret_count = 0;
+
+	spin_lock(&rbu_data.lock);
+
+	if (!strcmp(image_type, "mono"))
+		ret_count = read_rbu_mono_data(buffer, pos, count);
+	else if (!strcmp(image_type, "packet"))
+		ret_count = read_packet_data(buffer, pos, count);
+	else
+		pr_debug("read_rbu_data: invalid image type specified\n");
+
+	spin_unlock(&rbu_data.lock);
+	return ret_count;
+}
+
+static ssize_t
+read_rbu_image_type(struct kobject *kobj, char *buffer, loff_t pos,
+		    size_t count)
+{
+	int size = 0;
+	if (!pos)
+		size = sprintf(buffer, "%s\n", image_type);
+	return size;
+}
+
+static ssize_t
+write_rbu_image_type(struct kobject *kobj, char *buffer, loff_t pos,
+		     size_t count)
+{
+	int rc = count;
+	spin_lock(&rbu_data.lock);
+
+	if (strlen(buffer) < MAX_IMAGE_LENGTH)
+		sscanf(buffer, "%s", image_type);
+	else
+		printk(KERN_WARNING "dell_rbu: image_type is invalid"
+		       "max chars = %d, \n incoming str--%s-- \n",
+		       MAX_IMAGE_LENGTH, buffer);
+
+	/* we must free all previous allocations */
+	packet_empty_list();
+	img_update_free();
+
+	spin_unlock(&rbu_data.lock);
+	return rc;
+
+}
+
+static struct bin_attribute rbu_data_attr = {
+	.attr = {.name = "data",.owner = THIS_MODULE,.mode = 0444},
+	.read = read_rbu_data,
+};
+
+static struct bin_attribute rbu_image_type_attr = {
+	.attr = {.name = "image_type",.owner = THIS_MODULE,.mode = 0644},
+	.read = read_rbu_image_type,
+	.write = write_rbu_image_type,
+};
+
+static void callbackfn_rbu(const struct firmware *fw, void *context)
+{
+	int rc = 0;
+
+	if (!fw || !fw->size)
+		return;
+
+	spin_lock(&rbu_data.lock);
+	if (!strcmp(image_type, "mono")) {
+		if (!img_update_realloc(fw->size))
+			memcpy(rbu_data.image_update_buffer,
+			       fw->data, fw->size);
+	} else if (!strcmp(image_type, "packet")) {
+		if (!rbu_data.packetsize)
+			rbu_data.packetsize = fw->size;
+		else if (rbu_data.packetsize != fw->size) {
+			packet_empty_list();
+			rbu_data.packetsize = fw->size;
+		}
+		packetize_data(fw->data, fw->size);
+	} else
+		pr_debug("invalid image type specified.\n");
+	spin_unlock(&rbu_data.lock);
+
+	rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG,
+				     "dell_rbu", &rbu_device->dev,
+				     &context, callbackfn_rbu);
+	if (rc)
+		printk(KERN_ERR
+		       "dell_rbu:%s request_firmware_nowait failed"
+		       " %d\n", __FUNCTION__, rc);
+}
+
+static int __init dcdrbu_init(void)
+{
+	int rc = 0;
+	spin_lock_init(&rbu_data.lock);
+
+	init_packet_head();
+	rbu_device =
+	    platform_device_register_simple("dell_rbu", -1, NULL, 0);
+	if (!rbu_device) {
+		printk(KERN_ERR
+		       "dell_rbu:%s:platform_device_register_simple "
+		       "failed\n", __FUNCTION__);
+		return -EIO;
+	}
+
+	sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_data_attr);
+	sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_image_type_attr);
+
+	rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG,
+				     "dell_rbu", &rbu_device->dev,
+				     &context, callbackfn_rbu);
+	if (rc)
+		printk(KERN_ERR "dell_rbu:%s:request_firmware_nowait"
+		       " failed %d\n", __FUNCTION__, rc);
+
+	return rc;
+
+}
+
+static __exit void dcdrbu_exit(void)
+{
+	spin_lock(&rbu_data.lock);
+	packet_empty_list();
+	img_update_free();
+	spin_unlock(&rbu_data.lock);
+	platform_device_unregister(rbu_device);
+}
+
+module_exit(dcdrbu_exit);
+module_init(dcdrbu_init);