@@ -62,6 +62,7 @@ static int cfi_intelext_read (struct mtd_info *, loff_t, size_t, size_t *, u_cha
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_panic_write(struct mtd_info *mtd, loff_t to , size_t len, size_t *retlen, const u_char *buf);
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, uint64_t len);
@@ -491,6 +492,7 @@ struct mtd_info *cfi_cmdset_0001(struct map_info *map, int primary)
mtd->writesize = 1;
mtd->writebufsize = cfi_interleave(cfi) << cfi->cfiq->MaxBufWriteSize;
+ mtd->_panic_write = cfi_intelext_panic_write;
mtd->reboot_notifier.notifier_call = cfi_intelext_reboot;
if (cfi->cfi_mode == CFI_MODE_CFI) {
@@ -1903,6 +1905,164 @@ static int cfi_intelext_write_buffers (struct mtd_info *mtd, loff_t to,
return cfi_intelext_writev(mtd, &vec, 1, to, retlen);
}
+
+/*
+ * Write out one word of data to a single flash chip during a kernel panic
+ *
+ * This is only called during the panic_write() path. When panic_write()
+ * is called, the kernel is in the process of a panic, and will soon be
+ * dead. Therefore we don't take any locks, and attempt to get access
+ * to the chip as soon as possible.
+ *
+ * The implementation of this routine is intentionally similar to
+ * do_write_oneword(), in order to ease code maintenance.
+ */
+static int do_panic_write_oneword(struct map_info *map, struct flchip *chip,
+ unsigned long adr, map_word datum)
+{
+ struct cfi_private *cfi = map->fldrv_priv;
+ map_word status, write_cmd;
+ int ret=0;
+
+ adr += chip->start;
+
+ write_cmd = (cfi->cfiq->P_ID != P_ID_INTEL_PERFORMANCE) ? CMD(0x40) : CMD(0x41);
+
+ pr_debug("MTD %s(): PANIC WRITE 0x%.8lx(0x%.8lx)\n",__func__, adr, datum.x[0]);
+
+ ENABLE_VPP(map);
+
+ map_write(map, write_cmd, adr);
+ map_write(map, datum, adr);
+
+ if (ret) {
+ printk(KERN_ERR "%s: word write error (status timeout)\n", map->name);
+ goto out;
+ }
+
+ /* check for errors */
+ status = map_read(map, adr);
+ if (map_word_bitsset(map, status, CMD(0x1a))) {
+ unsigned long chipstatus = MERGESTATUS(status);
+
+ /* reset status */
+ map_write(map, CMD(0x50), adr);
+ map_write(map, CMD(0x70), adr);
+
+ if (chipstatus & 0x02) {
+ ret = -EROFS;
+ } else if (chipstatus & 0x08) {
+ printk(KERN_ERR "%s: word write error (bad VPP)\n", map->name);
+ ret = -EIO;
+ } else {
+ printk(KERN_ERR "%s: word write error (status 0x%lx)\n", map->name, chipstatus);
+ ret = -EINVAL;
+ }
+ goto out;
+ }
+ out:
+ DISABLE_VPP(map);
+ return ret;
+}
+
+/*
+ * Write out some data during a kernel panic
+ *
+ * This is used by the mtdoops driver to save the dying messages from a
+ * kernel which has panic'd.
+ *
+ * This routine ignores all of the locking used throughout the rest of the
+ * driver, in order to ensure that the data gets written out no matter what
+ * state this driver (and the flash chip itself) was in when the kernel crashed.
+ *
+ * The implementation of this routine is intentionally similar to
+ * cfi_intelext_write_words(), in order to ease code maintenance.
+ */
+static int cfi_intelext_panic_write(struct mtd_info *mtd, loff_t to , size_t len,
+ size_t *retlen, const u_char *buf)
+{
+ struct map_info *map = mtd->priv;
+ struct cfi_private *cfi = map->fldrv_priv;
+ int ret = 0;
+ int chipnum;
+ unsigned long ofs;
+
+ chipnum = to >> cfi->chipshift;
+ ofs = to - (chipnum << cfi->chipshift);
+
+ /* If it's not bus-aligned, do the first byte write */
+ if (ofs & (map_bankwidth(map)-1)) {
+ unsigned long bus_ofs = ofs & ~(map_bankwidth(map)-1);
+ int gap = ofs - bus_ofs;
+ int n;
+ map_word datum;
+
+ n = min_t(int, len, map_bankwidth(map)-gap);
+ datum = map_word_ff(map);
+ datum = map_word_load_partial(map, datum, buf, gap, n);
+
+ ret = do_panic_write_oneword(map, &cfi->chips[chipnum],
+ bus_ofs, datum);
+ if (ret)
+ return ret;
+
+ len -= n;
+ ofs += n;
+ buf += n;
+ (*retlen) += n;
+
+ if (ofs >> cfi->chipshift) {
+ chipnum ++;
+ ofs = 0;
+ if (chipnum == cfi->numchips)
+ return 0;
+ }
+ }
+
+ /* We are now aligned, write as much as possible */
+ while(len >= map_bankwidth(map)) {
+ map_word datum = map_word_load(map, buf);
+
+ /* Significamt delay is required, between two write cycles.
+ 300 micro seconds delay is arrived by trial and error.*/
+ udelay(300);
+
+ ret = do_panic_write_oneword(map, &cfi->chips[chipnum],
+ ofs, datum);
+ if (ret)
+ return ret;
+
+ ofs += map_bankwidth(map);
+ buf += map_bankwidth(map);
+ (*retlen) += map_bankwidth(map);
+ len -= map_bankwidth(map);
+
+ if (ofs >> cfi->chipshift) {
+ chipnum ++;
+ ofs = 0;
+ if (chipnum == cfi->numchips)
+ return 0;
+ }
+ }
+
+ /* Write the trailing bytes if any */
+ if (len & (map_bankwidth(map)-1)) {
+ map_word datum;
+
+ datum = map_word_ff(map);
+ datum = map_word_load_partial(map, datum, buf, 0, len);
+
+ ret = do_panic_write_oneword(map, &cfi->chips[chipnum],
+ ofs, datum);
+ if (ret)
+ return ret;
+
+ (*retlen) += len;
+ }
+
+ return 0;
+}
+
static int __xipram do_erase_oneblock(struct map_info *map, struct flchip *chip,
unsigned long adr, int len, void *thunk)
{