Re: FW: [patch 2.6.14-rc2] dell_rbu: changes in packet update mechanism

[Abhay Salunke <Abhay_Salunke@dell.com>]

On Fri, Sep 23, 2005 at 12:44:51PM -0700, Andrew Morton wrote:
> <Abhay_Salunke@Dell.com> wrote:
> >
> > -static ssize_t write_rbu_image_type(struct kobject *kobj, char *buffer,
> >  -			loff_t pos, size_t count)
> >  +static ssize_t
> >  +write_rbu_image_type(struct kobject *kobj, char *buffer, loff_t pos,
> 
> This is contrary to the conventional kernel coding style.  I suggest you
> not include all these layout changes.

This patch uses the correct codind style. 

Signed-off-by: Abhay Salunke <abhay_salunke@dell.com>

Thanks,
Abhay Salunke

diff -uprN linux-2.6.14-rc2.orig/Documentation/dell_rbu.txt linux-2.6.14-rc2.new/Documentation/dell_rbu.txt
--- linux-2.6.14-rc2.orig/Documentation/dell_rbu.txt	2005-09-22 13:41:38.000000000 -0500
+++ linux-2.6.14-rc2.new/Documentation/dell_rbu.txt	2005-09-22 14:19:41.000000000 -0500
@@ -35,6 +35,7 @@ The driver load creates the following di
 /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.
@@ -46,10 +47,28 @@ of contiguous memory and the BIOS image 
 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.
+echo packet > /sys/devices/platform/dell_rbu/image_type 
 
+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
 2) cp bios_image.hdr /sys/class/firmware/dell_rbu/data
@@ -58,7 +77,10 @@ Do the steps below to download the BIOS 
 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_r
 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.
diff -uprN linux-2.6.14-rc2.orig/drivers/firmware/dell_rbu.c linux-2.6.14-rc2.new/drivers/firmware/dell_rbu.c
--- linux-2.6.14-rc2.orig/drivers/firmware/dell_rbu.c	2005-09-22 13:42:09.000000000 -0500
+++ linux-2.6.14-rc2.new/drivers/firmware/dell_rbu.c	2005-09-23 15:54:52.000000000 -0500
@@ -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");
 
@@ -198,13 +159,37 @@ 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)))
+	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 = create_packet(temp, packet_length)))
 			return rc;
+
+		pr_debug("%lu:%lu\n", temp, (end - temp));
+		temp += packet_length;
 	}
-	if ((rc = fill_last_packet(data, length)))
-		return rc;
+
+	rbu_data.imagesize = length;
 
 	return rc;
 }
@@ -243,7 +228,7 @@ static int do_packet_read(char *data, st
 	return bytes_copied;
 }
 
-static int packet_read_list(char *data, size_t *pread_length)
+static int packet_read_list(char *data, size_t * pread_length)
 {
 	struct list_head *ptemp_list;
 	int temp_count = 0;
@@ -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 *bu
 	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 *bu
 		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;
@@ -499,7 +480,7 @@ static ssize_t read_rbu_mono_data(char *
 }
 
 static ssize_t read_rbu_data(struct kobject *kobj, char *buffer,
-			loff_t pos, size_t count)
+	loff_t pos, size_t count)
 {
 	ssize_t ret_count = 0;
 
@@ -531,13 +512,18 @@ static void callbackfn_rbu(const struct 
 			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);
@@ -553,7 +539,7 @@ static void callbackfn_rbu(const struct 
 }
 
 static ssize_t read_rbu_image_type(struct kobject *kobj, char *buffer,
-			loff_t pos, size_t count)
+	loff_t pos, size_t count)
 {
 	int size = 0;
 	if (!pos)
@@ -562,14 +548,14 @@ static ssize_t read_rbu_image_type(struc
 }
 
 static ssize_t write_rbu_image_type(struct kobject *kobj, char *buffer,
-			loff_t pos, size_t count)
+	loff_t pos, size_t count)
 {
 	int rc = count;
 	int req_firm_rc = 0;
 	int i;
 	spin_lock(&rbu_data.lock);
 	/*
-	 * Find the first newline or space
+	 * Find the first newline or space 
 	 */
 	for (i = 0; i < count; ++i)
 		if (buffer[i] == '\n' || buffer[i] == ' ') {
@@ -621,25 +607,49 @@ static ssize_t write_rbu_image_type(stru
 	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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