[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>

1 files changed, 154 insertions, 97 deletions

diff --git a/drivers/firmware/dell_rbu.c b/drivers/firmware/dell_rbu.c
index 3b865f34a095..9c2c2b199454 100644
--- a/drivers/firmware/dell_rbu.c
+++ b/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;
@@ -114,7 +117,7 @@ static int fill_last_packet(void *data, size_t length)
 
         if ((rbu_data.packet_write_count + length) > rbu_data.packetsize) {
                 pr_debug("dell_rbu:%s: packet size data "
-                         "overrun\n", __FUNCTION__);
+                        "overrun\n", __FUNCTION__);
                 return -EINVAL;
         }
 
@@ -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;
@@ -146,12 +150,14 @@ 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 "
-                       "packet\n", __FUNCTION__);
+                        "dell_rbu:%s: failed to allocate new "
+                        "packet\n", __FUNCTION__);
                 return -ENOMEM;
         }
 
@@ -160,15 +166,17 @@ 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,
-                                                            ordernum);
+        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);
 
         if (!newpacket->data) {
                 printk(KERN_WARNING
-                       "dell_rbu:%s: failed to allocate new "
-                       "packet\n", __FUNCTION__);
+                        "dell_rbu:%s: failed to allocate new "
+                        "packet\n", __FUNCTION__);
                 kfree(newpacket);
                 return -ENOMEM;
         }
@@ -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;
 
@@ -206,7 +215,7 @@ static int packetize_data(void *data, size_t length)
 
 static int
 do_packet_read(char *data, struct list_head *ptemp_list,
-               int length, int bytes_read, int *list_read_count)
+        int length, int bytes_read, int *list_read_count)
 {
         void *ptemp_buf;
         struct packet_data *newpacket = NULL;
@@ -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;
@@ -287,7 +297,7 @@ static void packet_empty_list(void)
         ptemp_list = (&packet_data_head.list)->next;
         while (!list_empty(ptemp_list)) {
                 newpacket =
-                    list_entry(ptemp_list, struct packet_data, list);
+                        list_entry(ptemp_list, struct packet_data, list);
                 pnext_list = ptemp_list->next;
                 list_del(ptemp_list);
                 ptemp_list = pnext_list;
@@ -296,8 +306,8 @@ 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,
-                           newpacket->ordernum);
+                free_pages((unsigned long) newpacket->data,
+                        newpacket->ordernum);
                 kfree(newpacket);
         }
         rbu_data.packet_write_count = 0;
@@ -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;
@@ -319,14 +330,13 @@ static void img_update_free(void)
          * BIOS image copied in memory.
          */
         memset(rbu_data.image_update_buffer, 0,
-               rbu_data.image_update_buffer_size);
+                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,
-                           rbu_data.image_update_ordernum);
+                free_pages((unsigned long) rbu_data.image_update_buffer,
+                        rbu_data.image_update_ordernum);
 
         /*
          * Re-initialize the rbu_data variables after a free
@@ -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;
@@ -366,7 +377,7 @@ static int img_update_realloc(unsigned long size)
                  */
                 if ((size != 0) && (rbu_data.image_update_buffer == NULL)) {
                         printk(KERN_ERR "dell_rbu:%s: corruption "
-                               "check failed\n", __FUNCTION__);
+                                "check failed\n", __FUNCTION__);
                         return -EINVAL;
                 }
                 /*
@@ -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;
         }
 
@@ -405,20 +415,21 @@ static int img_update_realloc(unsigned long size)
                 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_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);
+                        "size = %ld\n", size);
                 rc = -ENOMEM;
         }
 
         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;
@@ -438,7 +449,7 @@ static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count)
         if (pos > imagesize) {
                 retval = 0;
                 printk(KERN_WARNING "dell_rbu:read_packet_data: "
-                       "data underrun\n");
+                        "data underrun\n");
                 goto read_rbu_data_exit;
         }
 
@@ -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;
@@ -468,11 +480,11 @@ static ssize_t read_rbu_mono_data(char *buffer, loff_t pos, size_t count)
 
         /* check to see if we have something to return */
         if ((rbu_data.image_update_buffer == NULL) ||
-            (rbu_data.bios_image_size == 0)) {
+                (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);
+                        "bios_image_size %lu\n",
+                        rbu_data.image_update_buffer,
+                        rbu_data.bios_image_size);
                 ret_count = -ENOMEM;
                 goto read_rbu_data_exit;
         }
@@ -515,9 +527,46 @@ 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)
+        size_t count)
 {
         int size = 0;
         if (!pos)
@@ -527,25 +576,63 @@ read_rbu_image_type(struct kobject *kobj, char *buffer, loff_t pos,
 
 static ssize_t
 write_rbu_image_type(struct kobject *kobj, char *buffer, loff_t pos,
-                     size_t count)
+        size_t count)
 {
         int rc = count;
+        int req_firm_rc = 0;
+        int i;
         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);
+        /*
+         * 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;
+
+                        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 = {
@@ -559,51 +646,19 @@ 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);
 
         init_packet_head();
         rbu_device =
-            platform_device_register_simple("dell_rbu", -1, NULL, 0);
+                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__);
+                        "dell_rbu:%s:platform_device_register_simple "
+                        "failed\n", __FUNCTION__);
                 return -EIO;
         }
 
@@ -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);
+                        " 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();