[MTD] writev support for cfi-cmdset-0001

While this might be useful for all supported flash types, it is mandatory
for proper JFFS2 support with Sibley flash.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index 10c50604bcd5a18f8889c17f2e6a25bd784a8d14..adaad7c8fd46017014d4c1bd54078668c325e55d 100644 (file)
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -4,7 +4,7 @@
  *
  * (C) 2000 Red Hat. GPL'd
  *
- * $Id: cfi_cmdset_0001.c,v 1.182 2005/08/06 04:40:41 nico Exp $
+ * $Id: cfi_cmdset_0001.c,v 1.183 2005/08/06 04:46:56 nico Exp $
  *
  * 
  * 10/10/2000  Nicolas Pitre <nico@cam.org>
@@ -51,6 +51,7 @@
 static int cfi_intelext_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
 static int cfi_intelext_write_words(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
 static int cfi_intelext_write_buffers(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
+static int cfi_intelext_writev(struct mtd_info *, const struct kvec *, unsigned long, loff_t, size_t *);
 static int cfi_intelext_erase_varsize(struct mtd_info *, struct erase_info *);
 static void cfi_intelext_sync (struct mtd_info *);
 static int cfi_intelext_lock(struct mtd_info *mtd, loff_t ofs, size_t len);
@@ -215,6 +216,7 @@ static void fixup_use_write_buffers(struct mtd_info *mtd, void *param)
        if (cfi->cfiq->BufWriteTimeoutTyp) {
                printk(KERN_INFO "Using buffer write method\n" );
                mtd->write = cfi_intelext_write_buffers;
+               mtd->writev = cfi_intelext_writev;
        }
 }
 
@@ -1445,12 +1447,15 @@ static int cfi_intelext_write_words (struct mtd_info *mtd, loff_t to , size_t le
 
 
 static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip, 
-                                   unsigned long adr, const u_char *buf, int len)
+                                   unsigned long adr, const struct kvec **pvec,
+                                   unsigned long *pvec_seek, int len)
 {
        struct cfi_private *cfi = map->fldrv_priv;
-       map_word status, status_OK, write_cmd;
+       map_word status, status_OK, write_cmd, datum;
        unsigned long cmd_adr, timeo;
-       int wbufsize, z, ret=0, bytes, words;
+       int wbufsize, z, ret=0, word_gap, words;
+       const struct kvec *vec;
+       unsigned long vec_seek;
 
        wbufsize = cfi_interleave(cfi) << cfi->cfiq->MaxBufWriteSize;
        adr += chip->start;
@@ -1515,28 +1520,53 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
                }
        }
 
+       /* Figure out the number of words to write */
+       word_gap = (-adr & (map_bankwidth(map)-1));
+       words = (len - word_gap + map_bankwidth(map) - 1) / map_bankwidth(map);
+       if (!word_gap) {
+               words--;
+       } else {
+               word_gap = map_bankwidth(map) - word_gap;
+               adr -= word_gap;
+               datum = map_word_ff(map);
+       }
+
        /* Write length of data to come */
-       bytes = len & (map_bankwidth(map)-1);
-       words = len / map_bankwidth(map);
-       map_write(map, CMD(words - !bytes), cmd_adr );
+       map_write(map, CMD(words), cmd_adr );
 
        /* Write data */
-       z = 0;
-       while(z < words * map_bankwidth(map)) {
-               map_word datum = map_word_load(map, buf);
-               map_write(map, datum, adr+z);
-
-               z += map_bankwidth(map);
-               buf += map_bankwidth(map);
-       }
+       vec = *pvec;
+       vec_seek = *pvec_seek;
+       do {
+               int n = map_bankwidth(map) - word_gap;
+               if (n > vec->iov_len - vec_seek)
+                       n = vec->iov_len - vec_seek;
+               if (n > len)
+                       n = len;
+
+               if (!word_gap && len < map_bankwidth(map))
+                       datum = map_word_ff(map);
+                       
+               datum = map_word_load_partial(map, datum,
+                                             vec->iov_base + vec_seek, 
+                                             word_gap, n);
 
-       if (bytes) {
-               map_word datum;
+               len -= n;
+               word_gap += n;
+               if (!len || word_gap == map_bankwidth(map)) {
+                       map_write(map, datum, adr);
+                       adr += map_bankwidth(map);
+                       word_gap = 0;
+               }
 
-               datum = map_word_ff(map);
-               datum = map_word_load_partial(map, datum, buf, 0, bytes);
-               map_write(map, datum, adr+z);
-       }
+               vec_seek += n;
+               if (vec_seek == vec->iov_len) {
+                       vec++;
+                       vec_seek = 0;
+               }
+       } while (len);
+       *pvec = vec;
+       *pvec_seek = vec_seek;
 
        /* GO GO GO */
        map_write(map, CMD(0xd0), cmd_adr);
@@ -1619,57 +1649,40 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
        return ret;
 }
 
-static int cfi_intelext_write_buffers (struct mtd_info *mtd, loff_t to, 
-                                      size_t len, size_t *retlen, const u_char *buf)
+static int cfi_intelext_writev (struct mtd_info *mtd, const struct kvec *vecs,
+                               unsigned long count, loff_t to, size_t *retlen)
 {
        struct map_info *map = mtd->priv;
        struct cfi_private *cfi = map->fldrv_priv;
        int wbufsize = cfi_interleave(cfi) << cfi->cfiq->MaxBufWriteSize;
        int ret = 0;
        int chipnum;
-       unsigned long ofs;
+       unsigned long ofs, vec_seek, i;
+       size_t len = 0;
+
+       for (i = 0; i < count; i++)
+               len += vecs[i].iov_len;
 
        *retlen = 0;
        if (!len)
                return 0;
 
        chipnum = to >> cfi->chipshift;
-       ofs = to  - (chipnum << cfi->chipshift);
+       ofs = to - (chipnum << cfi->chipshift);
+       vec_seek = 0;
 
-       /* If it's not bus-aligned, do the first word write */
-       if (ofs & (map_bankwidth(map)-1)) {
-               size_t local_len = (-ofs)&(map_bankwidth(map)-1);
-               if (local_len > len)
-                       local_len = len;
-               ret = cfi_intelext_write_words(mtd, to, local_len,
-                                              retlen, buf);
-               if (ret)
-                       return ret;
-               ofs += local_len;
-               buf += local_len;
-               len -= local_len;
-
-               if (ofs >> cfi->chipshift) {
-                       chipnum ++;
-                       ofs = 0;
-                       if (chipnum == cfi->numchips)
-                               return 0;
-               }
-       }
-
-       while(len) {
+       do {
                /* We must not cross write block boundaries */
                int size = wbufsize - (ofs & (wbufsize-1));
 
                if (size > len)
                        size = len;
                ret = do_write_buffer(map, &cfi->chips[chipnum], 
-                                     ofs, buf, size);
+                                     ofs, &vecs, &vec_seek, size);
                if (ret)
                        return ret;
 
                ofs += size;
-               buf += size;
                (*retlen) += size;
                len -= size;
 
@@ -1679,10 +1692,22 @@ static int cfi_intelext_write_buffers (struct mtd_info *mtd, loff_t to,
                        if (chipnum == cfi->numchips)
                                return 0;
                }
-       }
+       } while (len);
+
        return 0;
 }
 
+static int cfi_intelext_write_buffers (struct mtd_info *mtd, loff_t to,
+                                      size_t len, size_t *retlen, const u_char *buf)
+{
+       struct kvec vec;
+
+       vec.iov_base = (void *) buf;
+       vec.iov_len = len;
+
+       return cfi_intelext_writev(mtd, &vec, 1, to, retlen);
+}
+
 static int __xipram do_erase_oneblock(struct map_info *map, struct flchip *chip,
                                      unsigned long adr, int len, void *thunk)
 {