1 files changed, 21 insertions, 18 deletions

diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c
index bfc2abafac44..67a84d8f118d 100644
--- a/arch/powerpc/kernel/rtas_flash.c
+++ b/arch/powerpc/kernel/rtas_flash.c
@@ -94,12 +94,8 @@ struct flash_block_list {
         struct flash_block_list *next;
         struct flash_block blocks[FLASH_BLOCKS_PER_NODE];
 };
-struct flash_block_list_header { /* just the header of flash_block_list */
-        unsigned long num_blocks;
-        struct flash_block_list *next;
-};
 
-static struct flash_block_list_header rtas_firmware_flash_list = {0, NULL};
+static struct flash_block_list *rtas_firmware_flash_list;
 
 /* Use slab cache to guarantee 4k alignment */
 static struct kmem_cache *flash_block_cache = NULL;
@@ -108,13 +104,14 @@ static struct kmem_cache *flash_block_cache = NULL;
 
 /* Local copy of the flash block list.
  * We only allow one open of the flash proc file and create this
- * list as we go.  This list will be put in the
- * rtas_firmware_flash_list var once it is fully read.
+ * list as we go.  The rtas_firmware_flash_list varable will be
+ * set once the data is fully read.
  *
  * For convenience as we build the list we use virtual addrs,
  * we do not fill in the version number, and the length field
  * is treated as the number of entries currently in the block
- * (i.e. not a byte count).  This is all fixed on release.
+ * (i.e. not a byte count).  This is all fixed when calling 
+ * the flash routine.
  */
 
 /* Status int must be first member of struct */
@@ -201,16 +198,16 @@ static int rtas_flash_release(struct inode *inode, struct file *file)
         if (uf->flist) {    
                 /* File was opened in write mode for a new flash attempt */
                 /* Clear saved list */
-                if (rtas_firmware_flash_list.next) {
-                        free_flash_list(rtas_firmware_flash_list.next);
-                        rtas_firmware_flash_list.next = NULL;
+                if (rtas_firmware_flash_list) {
+                        free_flash_list(rtas_firmware_flash_list);
+                        rtas_firmware_flash_list = NULL;
                 }
 
                 if (uf->status != FLASH_AUTH)  
                         uf->status = flash_list_valid(uf->flist);
 
                 if (uf->status == FLASH_IMG_READY) 
-                        rtas_firmware_flash_list.next = uf->flist;
+                        rtas_firmware_flash_list = uf->flist;
                 else
                         free_flash_list(uf->flist);
 
@@ -593,7 +590,7 @@ static void rtas_flash_firmware(int reboot_type)
         unsigned long rtas_block_list;
         int i, status, update_token;
 
-        if (rtas_firmware_flash_list.next == NULL)
+        if (rtas_firmware_flash_list == NULL)
                 return;         /* nothing to do */
 
         if (reboot_type != SYS_RESTART) {
@@ -610,20 +607,25 @@ static void rtas_flash_firmware(int reboot_type)
                 return;
         }
 
-        /* NOTE: the "first" block list is a global var with no data
-         * blocks in the kernel data segment.  We do this because
-         * we want to ensure this block_list addr is under 4GB.
+        /*
+         * NOTE: the "first" block must be under 4GB, so we create
+         * an entry with no data blocks in the reserved buffer in
+         * the kernel data segment.
          */
-        rtas_firmware_flash_list.num_blocks = 0;
-        flist = (struct flash_block_list *)&rtas_firmware_flash_list;
+        spin_lock(&rtas_data_buf_lock);
+        flist = (struct flash_block_list *)&rtas_data_buf[0];
+        flist->num_blocks = 0;
+        flist->next = rtas_firmware_flash_list;
         rtas_block_list = virt_to_abs(flist);
         if (rtas_block_list >= 4UL*1024*1024*1024) {
                 printk(KERN_ALERT "FLASH: kernel bug...flash list header addr above 4GB\n");
+                spin_unlock(&rtas_data_buf_lock);
                 return;
         }
 
         printk(KERN_ALERT "FLASH: preparing saved firmware image for flash\n");
         /* Update the block_list in place. */
+        rtas_firmware_flash_list = NULL; /* too hard to backout on error */
         image_size = 0;
         for (f = flist; f; f = next) {
                 /* Translate data addrs to absolute */
@@ -664,6 +666,7 @@ static void rtas_flash_firmware(int reboot_type)
                 printk(KERN_ALERT "FLASH: unknown flash return code %d\n", status);
                 break;
         }
+        spin_unlock(&rtas_data_buf_lock);
 }
 
 static void remove_flash_pde(struct proc_dir_entry *dp)