[PATCH] dell_rbu: enhancements and fixes

BUG fixes:

  The driver used to allocate memory with spinlock held which has been
  fixed in this patch.

  The driver was printing the entire buffer when it received a invalid
  entry in image_type.  The fix is to only print a warning message and not
  the buffer.

Usability enhancements:

  It is possible that due to user error the /sys/class/firmware/dell_rbu
  entries might be missing, this can happen if the user does the following

	echo 1 > /sys/class/firmware/dell_rbu/loading
	echo 0 > /sys/class/firmware/dell_rbu/loading

  This will make the entries in /sys/class/firmware/ to disappear and the
  only way get them back was bby unloading and loading the driver.

  This patch makes the user recreate these entries by echoing init in to
  image_type.

This patch has been tested with Libsmbios and Dell OpenManage.
Signed-off-by: Abhay Salunke <Abhay_Salunke@dell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Documentation/dell_rbu.txt

@@ -13,6 +13,8 @@ the BIOS on Dell servers (starting from servers sold since 1999), desktops
 and notebooks (starting from those sold in 2005).
 Please go to  http://support.dell.com register and you can find info on
 OpenManage and Dell Update packages (DUP).
+Libsmbios can also be used to update BIOS on Dell systems go to
+http://linux.dell.com/libsmbios/ for details.
 
 Dell_RBU driver supports BIOS update using the monilothic image and packetized
 image methods. In case of moniolithic the driver allocates a contiguous chunk
@@ -22,8 +24,8 @@ would place each packet in contiguous physical memory. The driver also
 maintains a link list of packets for reading them back.
 If the dell_rbu driver is unloaded all the allocated memory is freed.
 
-The rbu driver needs to have an application which will inform the BIOS to
-enable the update in the next system reboot.
+The rbu driver needs to have an application (as mentioned above)which will
+inform the BIOS to enable the update in the next system reboot.
 
 The user should not unload the rbu driver after downloading the BIOS image
 or updating.
@@ -42,9 +44,11 @@ In case of packet mechanism the single memory can be broken in smaller chuks
 of contiguous memory and the BIOS image is scattered in these packets.
 
 By default the driver uses monolithic memory for the update type. This can be
-changed to contiguous during the driver load time by specifying the load
+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.
 
 Do the steps below to download the BIOS image.
 1) echo 1 > /sys/class/firmware/dell_rbu/loading
@@ -53,9 +57,13 @@ 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
-
+echo -1 > /sys/class/firmware/dell_rbu/loading.
 Until this step is completed the drivr cannot be unloaded.
+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
+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

drivers/firmware/dell_rbu.c

@@ -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("1.0");
+MODULE_VERSION("2.0");
 
 #define BIOS_SCAN_LIMIT 0xffffffff
 #define MAX_IMAGE_LENGTH 16
@@ -65,10 +65,11 @@ static struct _rbu_data {
 	unsigned long packet_write_count;
 	unsigned long num_packets;
 	unsigned long packetsize;
+	int entry_created;
 } rbu_data;
 
-static char image_type[MAX_IMAGE_LENGTH] = "mono";
-module_param_string(image_type, image_type, sizeof(image_type), 0);
+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");
 
 struct packet_data {
@@ -84,7 +85,8 @@ static struct platform_device *rbu_device;
 static int context;
 static dma_addr_t dell_rbu_dmaaddr;
 
-static void init_packet_head(void)
+static void
+init_packet_head(void)
 {
 	INIT_LIST_HEAD(&packet_data_head.list);
 	rbu_data.packet_write_count = 0;
@@ -93,7 +95,8 @@ static void init_packet_head(void)
 	rbu_data.packetsize = 0;
 }
 
-static int fill_last_packet(void *data, size_t length)
+static int
+fill_last_packet(void *data, size_t length)
 {
 	struct list_head *ptemp_list;
 	struct packet_data *packet = NULL;
@@ -135,7 +138,8 @@ static int fill_last_packet(void *data, size_t length)
 	return 0;
 }
 
-static int create_packet(size_t length)
+static int
+create_packet(size_t length)
 {
 	struct packet_data *newpacket;
 	int ordernum = 0;
@@ -146,8 +150,10 @@ static int create_packet(size_t length)
 		pr_debug("create_packet: packetsize not specified\n");
 		return -EINVAL;
 	}
+	spin_unlock(&rbu_data.lock);
+	newpacket = kmalloc(sizeof (struct packet_data), GFP_KERNEL);
+	spin_lock(&rbu_data.lock);
 
-	newpacket = kmalloc(sizeof(struct packet_data), GFP_KERNEL);
 	if (!newpacket) {
 		printk(KERN_WARNING
 			"dell_rbu:%s: failed to allocate new "
@@ -160,8 +166,10 @@ static int create_packet(size_t length)
 	 * there is no upper limit on memory
 	 * address for packetized mechanism
 	 */
-	newpacket->data = (unsigned char *)__get_free_pages(GFP_KERNEL,
+	spin_unlock(&rbu_data.lock);
+	newpacket->data = (unsigned char *) __get_free_pages(GFP_KERNEL,
 		ordernum);
+	spin_lock(&rbu_data.lock);
 
 	pr_debug("create_packet: newpacket %p\n", newpacket->data);
 
@@ -190,7 +198,8 @@ static int create_packet(size_t length)
 	return 0;
 }
 
-static int packetize_data(void *data, size_t length)
+static int
+packetize_data(void *data, size_t length)
 {
 	int rc = 0;
 
@@ -239,7 +248,8 @@ do_packet_read(char *data, struct list_head *ptemp_list,
 	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;
@@ -258,8 +268,7 @@ static int packet_read_list(char *data, size_t * pread_length)
 	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_read, &temp_count);
 		remaining_bytes -= bytes_copied;
 		bytes_read += bytes_copied;
 		pdest += bytes_copied;
@@ -278,7 +287,8 @@ static int packet_read_list(char *data, size_t * pread_length)
 	return 0;
 }
 
-static void packet_empty_list(void)
+static void
+packet_empty_list(void)
 {
 	struct list_head *ptemp_list;
 	struct list_head *pnext_list;
@@ -296,7 +306,7 @@ static void packet_empty_list(void)
 		 * 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,
+		free_pages((unsigned long) newpacket->data,
 			newpacket->ordernum);
 		kfree(newpacket);
 	}
@@ -310,7 +320,8 @@ static void packet_empty_list(void)
  * 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)
+static void
+img_update_free(void)
 {
 	if (!rbu_data.image_update_buffer)
 		return;
@@ -322,10 +333,9 @@ static void img_update_free(void)
 		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);
+			rbu_data.image_update_buffer, dell_rbu_dmaaddr);
 	else
-		free_pages((unsigned long)rbu_data.image_update_buffer,
+		free_pages((unsigned long) rbu_data.image_update_buffer,
 			rbu_data.image_update_ordernum);
 
 	/*
@@ -348,7 +358,8 @@ static void img_update_free(void)
  * 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)
+static int
+img_update_realloc(unsigned long size)
 {
 	unsigned char *image_update_buffer = NULL;
 	unsigned long rc;
@@ -385,17 +396,16 @@ static int img_update_realloc(unsigned long size)
 
 	ordernum = get_order(size);
 	image_update_buffer =
-	    (unsigned char *)__get_free_pages(GFP_KERNEL, ordernum);
+		(unsigned char *) __get_free_pages(GFP_KERNEL, ordernum);
 
 	img_buf_phys_addr =
-	    (unsigned long)virt_to_phys(image_update_buffer);
+		(unsigned long) virt_to_phys(image_update_buffer);
 
 	if (img_buf_phys_addr > BIOS_SCAN_LIMIT) {
-		free_pages((unsigned long)image_update_buffer, ordernum);
+		free_pages((unsigned long) image_update_buffer, ordernum);
 		ordernum = -1;
 		image_update_buffer = dma_alloc_coherent(NULL, size,
-							 &dell_rbu_dmaaddr,
-							 GFP_KERNEL);
+			&dell_rbu_dmaaddr, GFP_KERNEL);
 		dma_alloc = 1;
 	}
 
@@ -418,7 +428,8 @@ static int img_update_realloc(unsigned long size)
 	return rc;
 }
 
-static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count)
+static ssize_t
+read_packet_data(char *buffer, loff_t pos, size_t count)
 {
 	int retval;
 	size_t bytes_left;
@@ -459,7 +470,8 @@ static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count)
 	return retval;
 }
 
-static ssize_t read_rbu_mono_data(char *buffer, loff_t pos, size_t count)
+static ssize_t
+read_rbu_mono_data(char *buffer, loff_t pos, size_t count)
 {
 	unsigned char *ptemp = NULL;
 	size_t bytes_left = 0;
@@ -515,6 +527,43 @@ read_rbu_data(struct kobject *kobj, char *buffer, loff_t pos, size_t count)
 	return ret_count;
 }
 
+static void
+callbackfn_rbu(const struct firmware *fw, void *context)
+{
+	int rc = 0;
+
+	if (!fw || !fw->size) {
+		rbu_data.entry_created = 0;
+		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);
+	else
+		rbu_data.entry_created = 1;
+}
+
 static ssize_t
 read_rbu_image_type(struct kobject *kobj, char *buffer, loff_t pos,
 	size_t count)
@@ -530,22 +579,60 @@ write_rbu_image_type(struct kobject *kobj, char *buffer, 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
+	 */
+	for (i = 0; i < count; ++i)
+		if (buffer[i] == '\n' || buffer[i] == ' ') {
+			buffer[i] = '\0';
+			break;
+		}
+	if (i == count)
+		buffer[count] = '\0';
+
+	if (strstr(buffer, "mono"))
+		strcpy(image_type, "mono");
+	else if (strstr(buffer, "packet"))
+		strcpy(image_type, "packet");
+	else if (strstr(buffer, "init")) {
+		/*
+		 * If due to the user error the driver gets in a bad
+		 * state where even though it is loaded , the
+		 * /sys/class/firmware/dell_rbu entries are missing.
+		 * to cover this situation the user can recreate entries
+		 * by writing init to image_type.
+		 */
+		if (!rbu_data.entry_created) {
+			spin_unlock(&rbu_data.lock);
+			req_firm_rc = request_firmware_nowait(THIS_MODULE,
+				FW_ACTION_NOHOTPLUG, "dell_rbu",
+				&rbu_device->dev, &context,
+				callbackfn_rbu);
+			if (req_firm_rc) {
+				printk(KERN_ERR
+					"dell_rbu:%s request_firmware_nowait"
+					" failed %d\n", __FUNCTION__, rc);
+				rc = -EIO;
+			} else
+				rbu_data.entry_created = 1;
 
-	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);
+			spin_lock(&rbu_data.lock);
+		}
+	} else {
+		printk(KERN_WARNING "dell_rbu: image_type is invalid\n");
+		spin_unlock(&rbu_data.lock);
+		return -EINVAL;
+	}
 
 	/* we must free all previous allocations */
 	packet_empty_list();
 	img_update_free();
-
 	spin_unlock(&rbu_data.lock);
-	return rc;
 
+	return rc;
 }
 
 static struct bin_attribute rbu_data_attr = {
@@ -559,40 +646,8 @@ static struct bin_attribute rbu_image_type_attr = {
 	.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)
+static int __init
+dcdrbu_init(void)
 {
 	int rc = 0;
 	spin_lock_init(&rbu_data.lock);
@@ -611,17 +666,19 @@ static int __init dcdrbu_init(void)
 	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);
+		"dell_rbu", &rbu_device->dev, &context, callbackfn_rbu);
 	if (rc)
 		printk(KERN_ERR "dell_rbu:%s:request_firmware_nowait"
 			" failed %d\n", __FUNCTION__, rc);
+	else
+		rbu_data.entry_created = 1;
 
 	return rc;
 
 }
 
-static __exit void dcdrbu_exit(void)
+static __exit void
+dcdrbu_exit(void)
 {
 	spin_lock(&rbu_data.lock);
 	packet_empty_list();