[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>

1 files changed, 75 insertions, 50 deletions

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index 10c50604bcd5..adaad7c8fd46 100644
--- 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)
 {