[JFFS2] Fix dataflash support

- assume wbuf may be of size which is not power of 2
- don't make strange assumption about not padding wbuf for DataFlash
- use wbuf = DataFlash page and eraseblock >= 8 Dataflash pages

From: Peter Menzebach <pm-mtd@mw-itcon.de>
Acked-by: Artem B. Bityutskiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 34 insertions, 16 deletions

diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c
index 11e05bc014f1..44d8a894a41b 100644
--- a/fs/jffs2/wbuf.c
+++ b/fs/jffs2/wbuf.c
@@ -9,7 +9,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: wbuf.c,v 1.99 2005/09/21 16:11:04 dedekind Exp $
+ * $Id: wbuf.c,v 1.100 2005/09/30 13:59:13 dedekind Exp $
  *
  */
 
@@ -30,6 +30,9 @@
 static unsigned char *brokenbuf;
 #endif
 
+#define PAGE_DIV(x) ( ((unsigned long)(x) / (unsigned long)(c->wbuf_pagesize)) * (unsigned long)(c->wbuf_pagesize) )
+#define PAGE_MOD(x) ( (unsigned long)(x) % (unsigned long)(c->wbuf_pagesize) )
+
 /* max. erase failures before we mark a block bad */
 #define MAX_ERASE_FAILURES      2
 
@@ -433,7 +436,7 @@ static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int pad)
            if we have a switch to next page, we will not have
            enough remaining space for this. 
         */
-        if (pad && !jffs2_dataflash(c)) {
+        if (pad ) {
                 c->wbuf_len = PAD(c->wbuf_len);
 
                 /* Pad with JFFS2_DIRTY_BITMASK initially.  this helps out ECC'd NOR
@@ -482,9 +485,9 @@ static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int pad)
         }
 
         spin_lock(&c->erase_completion_lock);
-
+        
         /* Adjust free size of the block if we padded. */
-        if (pad && !jffs2_dataflash(c)) {
+        if (pad) {
                 struct jffs2_eraseblock *jeb;
 
                 jeb = &c->blocks[c->wbuf_ofs / c->sector_size];
@@ -601,15 +604,6 @@ int jffs2_flush_wbuf_pad(struct jffs2_sb_info *c)
 
         return ret;
 }
-
-#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
-#define PAGE_DIV(x) ( ((unsigned long)(x) / (unsigned long)(c->wbuf_pagesize)) * (unsigned long)(c->wbuf_pagesize) )
-#define PAGE_MOD(x) ( (unsigned long)(x) % (unsigned long)(c->wbuf_pagesize) )
-#else
-#define PAGE_DIV(x) ( (x) & (~(c->wbuf_pagesize - 1)) )
-#define PAGE_MOD(x) ( (x) & (c->wbuf_pagesize - 1) )
-#endif
-
 int jffs2_flash_writev(struct jffs2_sb_info *c, const struct kvec *invecs, unsigned long count, loff_t to, size_t *retlen, uint32_t ino)
 {
         struct kvec outvecs[3];
@@ -1203,14 +1197,38 @@ int jffs2_dataflash_setup(struct jffs2_sb_info *c) {
         
         /* Initialize write buffer */
         init_rwsem(&c->wbuf_sem);
-        c->wbuf_pagesize = c->sector_size;
-        c->wbuf_ofs = 0xFFFFFFFF;
+        
+        
+        c->wbuf_pagesize =  c->mtd->erasesize;
+        
+        /* Find a suitable c->sector_size
+         * - Not too much sectors
+         * - Sectors have to be at least 4 K + some bytes
+         * - All known dataflashes have erase sizes of 528 or 1056
+         * - we take at least 8 eraseblocks and want to have at least 8K size
+         * - The concatenation should be a power of 2
+        */
+
+        c->sector_size = 8 * c->mtd->erasesize;
+        
+        while (c->sector_size < 8192) {
+                c->sector_size *= 2;
+        }
+                
+        /* It may be necessary to adjust the flash size */
+        c->flash_size = c->mtd->size;
 
+        if ((c->flash_size % c->sector_size) != 0) {
+                c->flash_size = (c->flash_size / c->sector_size) * c->sector_size;
+                printk(KERN_WARNING "JFFS2 flash size adjusted to %dKiB\n", c->flash_size);
+        };
+        
+        c->wbuf_ofs = 0xFFFFFFFF;
         c->wbuf = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
         if (!c->wbuf)
                 return -ENOMEM;
 
-        printk(KERN_INFO "JFFS2 write-buffering enabled (%i)\n", c->wbuf_pagesize);
+        printk(KERN_INFO "JFFS2 write-buffering enabled buffer (%d) erasesize (%d)\n", c->wbuf_pagesize, c->sector_size);
 
         return 0;
 }