[PATCH] dell_rbu: changes in packet update mechanism (ad6ce87e) · Commits · 戴 / test

Documentation/dell_rbu.txt

+28 −10

Original line number	Diff line number	Diff line
		@@ -35,6 +35,7 @@ The driver load creates the following directories under the /sys file system.
		/sys/class/firmware/dell_rbu/data
		/sys/devices/platform/dell_rbu/image_type
		/sys/devices/platform/dell_rbu/data
		/sys/devices/platform/dell_rbu/packet_size

		The driver supports two types of update mechanism; monolithic and packetized.
		These update mechanism depends upon the BIOS currently running on the system.
		@@ -47,8 +48,26 @@ By default the driver uses monolithic memory for the update type. This can be
		changed to packets during the driver load time by specifying the load
		parameter image_type=packet. This can also be changed later as below
		echo packet > /sys/devices/platform/dell_rbu/image_type
		Also echoing either mono ,packet or init in to image_type will free up the
		memory allocated by the driver.

		In packet update mode the packet size has to be given before any packets can
		be downloaded. It is done as below
		echo XXXX > /sys/devices/platform/dell_rbu/packet_size
		In the packet update mechanism, the user neesd to create a new file having
		packets of data arranged back to back. It can be done as follows
		The user creates packets header, gets the chunk of the BIOS image and
		placs it next to the packetheader; now, the packetheader + BIOS image chunk
		added to geather should match the specified packet_size. This makes one
		packet, the user needs to create more such packets out of the entire BIOS
		image file and then arrange all these packets back to back in to one single
		file.
		This file is then copied to /sys/class/firmware/dell_rbu/data.
		Once this file gets to the driver, the driver extracts packet_size data from
		the file and spreads it accross the physical memory in contiguous packet_sized
		space.
		This method makes sure that all the packets get to the driver in a single operation.

		In monolithic update the user simply get the BIOS image (.hdr file) and copies
		to the data file as is without any change to the BIOS image itself.

		Do the steps below to download the BIOS image.
		1) echo 1 > /sys/class/firmware/dell_rbu/loading
		@@ -58,7 +77,10 @@ Do the steps below to download the BIOS image.
		The /sys/class/firmware/dell_rbu/ entries will remain till the following is
		done.
		echo -1 > /sys/class/firmware/dell_rbu/loading.
		Until this step is completed the drivr cannot be unloaded.
		Until this step is completed the driver cannot be unloaded.
		Also echoing either mono ,packet or init in to image_type will free up the
		memory allocated by the driver.

		If an user by accident executes steps 1 and 3 above without executing step 2;
		it will make the /sys/class/firmware/dell_rbu/ entries to disappear.
		The entries can be recreated by doing the following
		@@ -66,15 +88,11 @@ echo init > /sys/devices/platform/dell_rbu/image_type
		NOTE: echoing init in image_type does not change it original value.

		Also the driver provides /sys/devices/platform/dell_rbu/data readonly file to
		read back the image downloaded. This is useful in case of packet update
		mechanism where the above steps 1,2,3 will repeated for every packet.
		By reading the /sys/devices/platform/dell_rbu/data file all packet data
		downloaded can be verified in a single file.
		The packets are arranged in this file one after the other in a FIFO order.
		read back the image downloaded.

		NOTE:
		This driver requires a patch for firmware_class.c which has the addition
		of request_firmware_nowait_nohotplug function to wortk
		This driver requires a patch for firmware_class.c which has the modified
		request_firmware_nowait function.
		Also after updating the BIOS image an user mdoe application neeeds to execute
		code which message the BIOS update request to the BIOS. So on the next reboot
		the BIOS knows about the new image downloaded and it updates it self.

drivers/firmware/dell_rbu.c

+93 −81

Original line number	Diff line number	Diff line
		@@ -50,7 +50,7 @@
		MODULE_AUTHOR("Abhay Salunke <abhay_salunke@dell.com>");
		MODULE_DESCRIPTION("Driver for updating BIOS image on DELL systems");
		MODULE_LICENSE("GPL");
		MODULE_VERSION("2.0");
		MODULE_VERSION("3.0");

		#define BIOS_SCAN_LIMIT 0xffffffff
		#define MAX_IMAGE_LENGTH 16
		@@ -62,15 +62,16 @@ static struct _rbu_data {
		int dma_alloc;
		spinlock_t lock;
		unsigned long packet_read_count;
		unsigned long packet_write_count;
		unsigned long num_packets;
		unsigned long packetsize;
		unsigned long imagesize;
		int entry_created;
		} rbu_data;

		static char image_type[MAX_IMAGE_LENGTH + 1] = "mono";
		module_param_string(image_type, image_type, sizeof (image_type), 0);
		MODULE_PARM_DESC(image_type, "BIOS image type. choose- mono or packet");
		MODULE_PARM_DESC(image_type,
		"BIOS image type. choose- mono or packet or init");

		struct packet_data {
		struct list_head list;
		@@ -88,55 +89,13 @@ 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;
		rbu_data.imagesize = 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)
		static int create_packet(void *data, size_t length)
		{
		struct packet_data *newpacket;
		int ordernum = 0;
		@@ -186,9 +145,11 @@ static int create_packet(size_t length)
		INIT_LIST_HEAD(&newpacket->list);
		list_add_tail(&newpacket->list, &packet_data_head.list);
		/*
		* packets have fixed size
		* packets may not have fixed size
		*/
		newpacket->length = rbu_data.packetsize;
		newpacket->length = length;

		memcpy(newpacket->data, data, length);

		pr_debug("create_packet: exit \n");

		@@ -198,14 +159,38 @@ static int create_packet(size_t length)
		static int packetize_data(void *data, size_t length)
		{
		int rc = 0;
		int done = 0;
		int packet_length;
		u8 *temp;
		u8 end = (u8 ) data + length;
		pr_debug("packetize_data: data length %d\n", length);
		if (!rbu_data.packetsize) {
		printk(KERN_WARNING
		"dell_rbu: packetsize not specified\n");
		return -EIO;
		}

		if (!rbu_data.packet_write_count) {
		if ((rc = create_packet(length)))
		return rc;
		temp = (u8 *) data;

		/* packetize the hunk */
		while (!done) {
		if ((temp + rbu_data.packetsize) < end)
		packet_length = rbu_data.packetsize;
		else {
		/* this is the last packet */
		packet_length = end - temp;
		done = 1;
		}
		if ((rc = fill_last_packet(data, length)))

		if ((rc = create_packet(temp, packet_length)))
		return rc;

		pr_debug("%lu:%lu\n", temp, (end - temp));
		temp += packet_length;
		}

		rbu_data.imagesize = length;

		return rc;
		}

		@@ -303,10 +288,9 @@ static void packet_empty_list(void)
		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;
		rbu_data.imagesize = 0;
		}

		/*
		@@ -425,7 +409,6 @@ static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count)
		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) {
		@@ -434,22 +417,20 @@ static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count)
		goto read_rbu_data_exit;
		}

		imagesize = rbu_data.num_packets * rbu_data.packetsize;

		if (pos > imagesize) {
		if (pos > rbu_data.imagesize) {
		retval = 0;
		printk(KERN_WARNING "dell_rbu:read_packet_data: "
		"data underrun\n");
		goto read_rbu_data_exit;
		}

		bytes_left = imagesize - pos;
		bytes_left = rbu_data.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) {
		if ((pos + count) > rbu_data.imagesize) {
		rbu_data.packet_read_count = 0;
		/* this was the last copy */
		retval = bytes_left;
		@@ -531,13 +512,18 @@ static void callbackfn_rbu(const struct firmware fw, void context)
		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) {
		/*
		* we need to free previous packets if a
		* new hunk of packets needs to be downloaded
		*/
		packet_empty_list();
		if (packetize_data(fw->data, fw->size))
		/* Incase something goes wrong when we are
		* in middle of packetizing the data, we
		* need to free up whatever packets might
		* have been created before we quit.
		*/
		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);
		@@ -621,25 +607,49 @@ static ssize_t write_rbu_image_type(struct kobject kobj, char buffer,
		return rc;
		}

		static ssize_t read_rbu_packet_size(struct kobject kobj, char buffer,
		loff_t pos, size_t count)
		{
		int size = 0;
		if (!pos) {
		spin_lock(&rbu_data.lock);
		size = sprintf(buffer, "%lu\n", rbu_data.packetsize);
		spin_unlock(&rbu_data.lock);
		}
		return size;
		}

		static ssize_t write_rbu_packet_size(struct kobject kobj, char buffer,
		loff_t pos, size_t count)
		{
		unsigned long temp;
		spin_lock(&rbu_data.lock);
		packet_empty_list();
		sscanf(buffer, "%lu", &temp);
		if (temp < 0xffffffff)
		rbu_data.packetsize = temp;

		spin_unlock(&rbu_data.lock);
		return count;
		}

		static struct bin_attribute rbu_data_attr = {
		.attr = {
		.name = "data",
		.owner = THIS_MODULE,
		.mode = 0444,
		},
		.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,
		},
		.attr = {.name = "image_type",.owner = THIS_MODULE,.mode = 0644},
		.read = read_rbu_image_type,
		.write = write_rbu_image_type,
		};

		static struct bin_attribute rbu_packet_size_attr = {
		.attr = {.name = "packet_size",.owner = THIS_MODULE,.mode = 0644},
		.read = read_rbu_packet_size,
		.write = write_rbu_packet_size,
		};

		static int __init dcdrbu_init(void)
		{
		int rc = 0;
		@@ -657,6 +667,8 @@ static int __init dcdrbu_init(void)

		sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_data_attr);
		sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_image_type_attr);
		sysfs_create_bin_file(&rbu_device->dev.kobj,
		&rbu_packet_size_attr);

		rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG,
		"dell_rbu", &rbu_device->dev, &context, callbackfn_rbu);

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