nand: Extend nand_(read|write)_skip_bad with *actual and limit parameters

We make these two functions take a size_t pointer to how much space
was used on NAND to read or write the buffer (when reads/writes happen)
so that bad blocks can be accounted for.  We also make them take an
loff_t limit on how much data can be read or written.  This means that
we can now catch the case of when writing to a partition would exceed
the partition size due to bad blocks.  To do this we also need to make
check_skip_len count not just complete blocks used but partial ones as
well.  All callers of nand_(read|write)_skip_bad are adjusted to call
these with the most sensible limits available.

The changes were started by Pantelis and finished by Tom.

Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Tom Rini <trini@ti.com>

diff --git a/board/cm_t35/cm_t35.c b/board/cm_t35/cm_t35.c
index 629ce4a5054e4ab4f6f65c6f88e3c24b9895247d..84c36bafb414d56004fa8de98682bd2995ab5c1d 100644 (file)
--- a/board/cm_t35/cm_t35.c
+++ b/board/cm_t35/cm_t35.c
@@ -91,6 +91,7 @@ static int splash_load_from_nand(u32 bmp_load_addr)
 
        res = nand_read_skip_bad(&nand_info[nand_curr_device],
                        splash_screen_nand_offset, &bmp_header_size,
+                       NULL, nand_info[nand_curr_device].size,
                        (u_char *)bmp_load_addr);
        if (res < 0)
                return res;
@@ -103,6 +104,7 @@ static int splash_load_from_nand(u32 bmp_load_addr)
 
        return nand_read_skip_bad(&nand_info[nand_curr_device],
                        splash_screen_nand_offset, &bmp_size,
+                       NULL, nand_info[nand_curr_device].size,
                        (u_char *)bmp_load_addr);
 
 splash_address_too_high:

diff --git a/common/cmd_nand.c b/common/cmd_nand.c
index 32348f37737116e8cf7563c5c8cda73d096edbfe..110c78c1877c936b6a552d46d9548ecfa62112bb 100644 (file)
--- a/common/cmd_nand.c
+++ b/common/cmd_nand.c
@@ -137,7 +137,8 @@ static inline int str2long(const char *p, ulong *num)
        return *p != '\0' && *endptr == '\0';
 }
 
-static int get_part(const char *partname, int *idx, loff_t *off, loff_t *size)
+static int get_part(const char *partname, int *idx, loff_t *off, loff_t *size,
+               loff_t *maxsize)
 {
 #ifdef CONFIG_CMD_MTDPARTS
        struct mtd_device *dev;
@@ -160,6 +161,7 @@ static int get_part(const char *partname, int *idx, loff_t *off, loff_t *size)
 
        *off = part->offset;
        *size = part->size;
+       *maxsize = part->size;
        *idx = dev->id->num;
 
        ret = set_dev(*idx);
@@ -173,10 +175,11 @@ static int get_part(const char *partname, int *idx, loff_t *off, loff_t *size)
 #endif
 }
 
-static int arg_off(const char *arg, int *idx, loff_t *off, loff_t *maxsize)
+static int arg_off(const char *arg, int *idx, loff_t *off, loff_t *size,
+               loff_t *maxsize)
 {
        if (!str2off(arg, off))
-               return get_part(arg, idx, off, maxsize);
+               return get_part(arg, idx, off, size, maxsize);
 
        if (*off >= nand_info[*idx].size) {
                puts("Offset exceeds device limit\n");
@@ -184,36 +187,35 @@ static int arg_off(const char *arg, int *idx, loff_t *off, loff_t *maxsize)
        }
 
        *maxsize = nand_info[*idx].size - *off;
+       *size = *maxsize;
        return 0;
 }
 
 static int arg_off_size(int argc, char *const argv[], int *idx,
-                       loff_t *off, loff_t *size)
+                       loff_t *off, loff_t *size, loff_t *maxsize)
 {
        int ret;
-       loff_t maxsize = 0;
 
        if (argc == 0) {
                *off = 0;
                *size = nand_info[*idx].size;
+               *maxsize = *size;
                goto print;
        }
 
-       ret = arg_off(argv[0], idx, off, &maxsize);
+       ret = arg_off(argv[0], idx, off, size, maxsize);
        if (ret)
                return ret;
 
-       if (argc == 1) {
-               *size = maxsize;
+       if (argc == 1)
                goto print;
-       }
 
        if (!str2off(argv[1], size)) {
                printf("'%s' is not a number\n", argv[1]);
                return -1;
        }
 
-       if (*size > maxsize) {
+       if (*size > *maxsize) {
                puts("Size exceeds partition or device limit\n");
                return -1;
        }
@@ -307,7 +309,8 @@ int do_nand_env_oob(cmd_tbl_t *cmdtp, int argc, char *const argv[])
                if (argc < 3)
                        goto usage;
 
-               if (arg_off(argv[2], &idx, &addr, &maxsize)) {
+               /* We don't care about size, or maxsize. */
+               if (arg_off(argv[2], &idx, &addr, &maxsize, &maxsize)) {
                        puts("Offset or partition name expected\n");
                        return 1;
                }
@@ -426,7 +429,7 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
        int i, ret = 0;
        ulong addr;
-       loff_t off, size;
+       loff_t off, size, maxsize;
        char *cmd, *s;
        nand_info_t *nand;
 #ifdef CONFIG_SYS_NAND_QUIET
@@ -551,7 +554,8 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 
                printf("\nNAND %s: ", cmd);
                /* skip first two or three arguments, look for offset and size */
-               if (arg_off_size(argc - o, argv + o, &dev, &off, &size) != 0)
+               if (arg_off_size(argc - o, argv + o, &dev, &off, &size,
+                                &maxsize) != 0)
                        return 1;
 
                nand = &nand_info[dev];
@@ -619,7 +623,7 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
                if (s && !strcmp(s, ".raw")) {
                        raw = 1;
 
-                       if (arg_off(argv[3], &dev, &off, &size))
+                       if (arg_off(argv[3], &dev, &off, &size, &maxsize))
                                return 1;
 
                        if (argc > 4 && !str2long(argv[4], &pagecount)) {
@@ -635,7 +639,7 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
                        rwsize = pagecount * (nand->writesize + nand->oobsize);
                } else {
                        if (arg_off_size(argc - 3, argv + 3, &dev,
-                                               &off, &size) != 0)
+                                               &off, &size, &maxsize) != 0)
                                return 1;
 
                        rwsize = size;
@@ -645,9 +649,11 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
                    !strcmp(s, ".e") || !strcmp(s, ".i")) {
                        if (read)
                                ret = nand_read_skip_bad(nand, off, &rwsize,
+                                                        NULL, maxsize,
                                                         (u_char *)addr);
                        else
                                ret = nand_write_skip_bad(nand, off, &rwsize,
+                                                         NULL, maxsize,
                                                          (u_char *)addr, 0);
 #ifdef CONFIG_CMD_NAND_TRIMFFS
                } else if (!strcmp(s, ".trimffs")) {
@@ -655,8 +661,8 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
                                printf("Unknown nand command suffix '%s'\n", s);
                                return 1;
                        }
-                       ret = nand_write_skip_bad(nand, off, &rwsize,
-                                               (u_char *)addr,
+                       ret = nand_write_skip_bad(nand, off, &rwsize, NULL,
+                                               maxsize, (u_char *)addr,
                                                WITH_DROP_FFS);
 #endif
 #ifdef CONFIG_CMD_NAND_YAFFS
@@ -665,8 +671,8 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
                                printf("Unknown nand command suffix '%s'.\n", s);
                                return 1;
                        }
-                       ret = nand_write_skip_bad(nand, off, &rwsize,
-                                               (u_char *)addr,
+                       ret = nand_write_skip_bad(nand, off, &rwsize, NULL,
+                                               maxsize, (u_char *)addr,
                                                WITH_INLINE_OOB);
 #endif
                } else if (!strcmp(s, ".oob")) {
@@ -775,7 +781,8 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
                if (s && !strcmp(s, ".allexcept"))
                        allexcept = 1;
 
-               if (arg_off_size(argc - 2, argv + 2, &dev, &off, &size) < 0)
+               if (arg_off_size(argc - 2, argv + 2, &dev, &off, &size,
+                                &maxsize) < 0)
                        return 1;
 
                if (!nand_unlock(&nand_info[dev], off, size, allexcept)) {
@@ -873,7 +880,8 @@ static int nand_load_image(cmd_tbl_t *cmdtp, nand_info_t *nand,
        printf("\nLoading from %s, offset 0x%lx\n", nand->name, offset);
 
        cnt = nand->writesize;
-       r = nand_read_skip_bad(nand, offset, &cnt, (u_char *) addr);
+       r = nand_read_skip_bad(nand, offset, &cnt, NULL, nand->size,
+                       (u_char *)addr);
        if (r) {
                puts("** Read error\n");
                bootstage_error(BOOTSTAGE_ID_NAND_HDR_READ);
@@ -905,7 +913,8 @@ static int nand_load_image(cmd_tbl_t *cmdtp, nand_info_t *nand,
        }
        bootstage_mark(BOOTSTAGE_ID_NAND_TYPE);
 
-       r = nand_read_skip_bad(nand, offset, &cnt, (u_char *) addr);
+       r = nand_read_skip_bad(nand, offset, &cnt, NULL, nand->size,
+                       (u_char *)addr);
        if (r) {
                puts("** Read error\n");
                bootstage_error(BOOTSTAGE_ID_NAND_READ);

diff --git a/common/env_nand.c b/common/env_nand.c
index 5b69889c02a70fc7f167eab7a04864ac3a2ebdfc..b745822be781fe3e4f14c1682032a2448e4be4f7 100644 (file)
--- a/common/env_nand.c
+++ b/common/env_nand.c
@@ -281,7 +281,8 @@ int readenv(size_t offset, u_char *buf)
                } else {
                        char_ptr = &buf[amount_loaded];
                        if (nand_read_skip_bad(&nand_info[0], offset,
-                                              &len, char_ptr))
+                                              &len, NULL,
+                                              nand_info[0].size, char_ptr))
                                return 1;
 
                        offset += blocksize;

diff --git a/drivers/mtd/nand/nand_util.c b/drivers/mtd/nand/nand_util.c
index ff2d3483076b1a5d92868270d136d8b599ea5b08..4727f9c9892517df97b5951e88f11b384177ba01 100644 (file)
--- a/drivers/mtd/nand/nand_util.c
+++ b/drivers/mtd/nand/nand_util.c
@@ -416,11 +416,13 @@ int nand_unlock(struct mtd_info *mtd, loff_t start, size_t length,
  * @param nand NAND device
  * @param offset offset in flash
  * @param length image length
+ * @param used length of flash needed for the requested length
  * @return 0 if the image fits and there are no bad blocks
  *         1 if the image fits, but there are bad blocks
  *        -1 if the image does not fit
  */
-static int check_skip_len(nand_info_t *nand, loff_t offset, size_t length)
+static int check_skip_len(nand_info_t *nand, loff_t offset, size_t length,
+               size_t *used)
 {
        size_t len_excl_bad = 0;
        int ret = 0;
@@ -442,8 +444,13 @@ static int check_skip_len(nand_info_t *nand, loff_t offset, size_t length)
                        ret = 1;
 
                offset += block_len;
+               *used += block_len;
        }
 
+       /* If the length is not a multiple of block_len, adjust. */
+       if (len_excl_bad > length)
+               *used -= (len_excl_bad - length);
+
        return ret;
 }
 
@@ -476,23 +483,36 @@ static size_t drop_ffs(const nand_info_t *nand, const u_char *buf,
  * Write image to NAND flash.
  * Blocks that are marked bad are skipped and the is written to the next
  * block instead as long as the image is short enough to fit even after
- * skipping the bad blocks.
+ * skipping the bad blocks.  Due to bad blocks we may not be able to
+ * perform the requested write.  In the case where the write would
+ * extend beyond the end of the NAND device, both length and actual (if
+ * not NULL) are set to 0.  In the case where the write would extend
+ * beyond the limit we are passed, length is set to 0 and actual is set
+ * to the required length.
  *
  * @param nand         NAND device
  * @param offset       offset in flash
  * @param length       buffer length
+ * @param actual       set to size required to write length worth of
+ *                     buffer or 0 on error, if not NULL
+ * @param lim          maximum size that actual may be in order to not
+ *                     exceed the buffer
  * @param buffer        buffer to read from
  * @param flags                flags modifying the behaviour of the write to NAND
  * @return             0 in case of success
  */
 int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
-                       u_char *buffer, int flags)
+               size_t *actual, loff_t lim, u_char *buffer, int flags)
 {
        int rval = 0, blocksize;
        size_t left_to_write = *length;
+       size_t used_for_write = 0;
        u_char *p_buffer = buffer;
        int need_skip;
 
+       if (actual)
+               *actual = 0;
+
 #ifdef CONFIG_CMD_NAND_YAFFS
        if (flags & WITH_YAFFS_OOB) {
                if (flags & ~WITH_YAFFS_OOB)
@@ -529,13 +549,23 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
                return -EINVAL;
        }
 
-       need_skip = check_skip_len(nand, offset, *length);
+       need_skip = check_skip_len(nand, offset, *length, &used_for_write);
+
+       if (actual)
+               *actual = used_for_write;
+
        if (need_skip < 0) {
                printf("Attempt to write outside the flash area\n");
                *length = 0;
                return -EINVAL;
        }
 
+       if (used_for_write > lim) {
+               puts("Size of write exceeds partition or device limit\n");
+               *length = 0;
+               return -EFBIG;
+       }
+
        if (!need_skip && !(flags & WITH_DROP_FFS)) {
                rval = nand_write(nand, offset, length, buffer);
                if (rval == 0)
@@ -626,36 +656,58 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
  *
  * Read image from NAND flash.
  * Blocks that are marked bad are skipped and the next block is read
- * instead as long as the image is short enough to fit even after skipping the
- * bad blocks.
+ * instead as long as the image is short enough to fit even after
+ * skipping the bad blocks.  Due to bad blocks we may not be able to
+ * perform the requested read.  In the case where the read would extend
+ * beyond the end of the NAND device, both length and actual (if not
+ * NULL) are set to 0.  In the case where the read would extend beyond
+ * the limit we are passed, length is set to 0 and actual is set to the
+ * required length.
  *
  * @param nand NAND device
  * @param offset offset in flash
  * @param length buffer length, on return holds number of read bytes
+ * @param actual set to size required to read length worth of buffer or 0
+ * on error, if not NULL
+ * @param lim maximum size that actual may be in order to not exceed the
+ * buffer
  * @param buffer buffer to write to
  * @return 0 in case of success
  */
 int nand_read_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
-                      u_char *buffer)
+               size_t *actual, loff_t lim, u_char *buffer)
 {
        int rval;
        size_t left_to_read = *length;
+       size_t used_for_read = 0;
        u_char *p_buffer = buffer;
        int need_skip;
 
        if ((offset & (nand->writesize - 1)) != 0) {
                printf("Attempt to read non page-aligned data\n");
                *length = 0;
+               if (actual)
+                       *actual = 0;
                return -EINVAL;
        }
 
-       need_skip = check_skip_len(nand, offset, *length);
+       need_skip = check_skip_len(nand, offset, *length, &used_for_read);
+
+       if (actual)
+               *actual = used_for_read;
+
        if (need_skip < 0) {
                printf("Attempt to read outside the flash area\n");
                *length = 0;
                return -EINVAL;
        }
 
+       if (used_for_read > lim) {
+               puts("Size of read exceeds partition or device limit\n");
+               *length = 0;
+               return -EFBIG;
+       }
+
        if (!need_skip) {
                rval = nand_read(nand, offset, length, buffer);
                if (!rval || rval == -EUCLEAN)

diff --git a/include/nand.h b/include/nand.h
index dded4e27f059d6c6fb4e3987009a722433cf2ad6..f0f3bf94b555d4c6055d65cdc81d30c264cdd9a9 100644 (file)
--- a/include/nand.h
+++ b/include/nand.h
@@ -129,7 +129,7 @@ struct nand_erase_options {
 typedef struct nand_erase_options nand_erase_options_t;
 
 int nand_read_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
-                      u_char *buffer);
+                      size_t *actual, loff_t lim, u_char *buffer);
 
 #define WITH_YAFFS_OOB (1 << 0) /* whether write with yaffs format. This flag
                                  * is a 'mode' meaning it cannot be mixed with
@@ -137,7 +137,7 @@ int nand_read_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
 #define WITH_DROP_FFS  (1 << 1) /* drop trailing all-0xff pages */
 
 int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
-                       u_char *buffer, int flags);
+                       size_t *actual, loff_t lim, u_char *buffer, int flags);
 int nand_erase_opts(nand_info_t *meminfo, const nand_erase_options_t *opts);
 int nand_torture(nand_info_t *nand, loff_t offset);