mtd: bcm63xxpart: Remove dependency on mach-bcm63xx

Read nvram directly from flash instead of using the in-memory copy that
mach-bcm63xx has, to remove the dependency on mach-bcm63xx and allow the
parser to work on bmips too.

Rename remaining BCM63XX defines to BCM963XX as these are properties of
the flash layout on the board.

BCM963XX_DEFAULT_PSI_SIZE changes from SZ_64K to 64 because it will be
multiplied by SZ_1K later on.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

2 files changed, 58 insertions, 16 deletions

diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index 42cc953309f1..e83a279f1217 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -142,7 +142,7 @@ config MTD_AR7_PARTS
 
 config MTD_BCM63XX_PARTS
         tristate "BCM63XX CFE partitioning support"
-        depends on BCM63XX
+        depends on BCM63XX || BMIPS_GENERIC || COMPILE_TEST
         select CRC32
         help
           This provides partions parsing for BCM63xx devices with CFE
diff --git a/drivers/mtd/bcm63xxpart.c b/drivers/mtd/bcm63xxpart.c
index cec3188a170d..1eea8b6bc66a 100644
--- a/drivers/mtd/bcm63xxpart.c
+++ b/drivers/mtd/bcm63xxpart.c
@@ -24,6 +24,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/bcm963xx_nvram.h>
 #include <linux/bcm963xx_tag.h>
 #include <linux/crc32.h>
 #include <linux/module.h>
@@ -34,12 +35,11 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
 
-#include <asm/mach-bcm63xx/bcm63xx_nvram.h>
-#include <asm/mach-bcm63xx/board_bcm963xx.h>
+#define BCM963XX_CFE_BLOCK_SIZE         SZ_64K  /* always at least 64KiB */
 
-#define BCM63XX_CFE_BLOCK_SIZE  SZ_64K          /* always at least 64KiB */
-
-#define BCM63XX_CFE_MAGIC_OFFSET 0x4e0
+#define BCM963XX_CFE_MAGIC_OFFSET       0x4e0
+#define BCM963XX_CFE_VERSION_OFFSET     0x570
+#define BCM963XX_NVRAM_OFFSET           0x580
 
 static int bcm63xx_detect_cfe(struct mtd_info *master)
 {
@@ -58,20 +58,45 @@ static int bcm63xx_detect_cfe(struct mtd_info *master)
                 return 0;
 
         /* very old CFE's do not have the cfe-v string, so check for magic */
-        ret = mtd_read(master, BCM63XX_CFE_MAGIC_OFFSET, 8, &retlen,
+        ret = mtd_read(master, BCM963XX_CFE_MAGIC_OFFSET, 8, &retlen,
                        (void *)buf);
         buf[retlen] = 0;
 
         return strncmp("CFE1CFE1", buf, 8);
 }
 
+static int bcm63xx_read_nvram(struct mtd_info *master,
+        struct bcm963xx_nvram *nvram)
+{
+        u32 actual_crc, expected_crc;
+        size_t retlen;
+        int ret;
+
+        /* extract nvram data */
+        ret = mtd_read(master, BCM963XX_NVRAM_OFFSET, BCM963XX_NVRAM_V5_SIZE,
+                        &retlen, (void *)nvram);
+        if (ret)
+                return ret;
+
+        ret = bcm963xx_nvram_checksum(nvram, &expected_crc, &actual_crc);
+        if (ret)
+                pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
+                        expected_crc, actual_crc);
+
+        if (!nvram->psi_size)
+                nvram->psi_size = BCM963XX_DEFAULT_PSI_SIZE;
+
+        return 0;
+}
+
 static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
                                         const struct mtd_partition **pparts,
                                         struct mtd_part_parser_data *data)
 {
         /* CFE, NVRAM and global Linux are always present */
         int nrparts = 3, curpart = 0;
-        struct bcm_tag *buf;
+        struct bcm963xx_nvram *nvram = NULL;
+        struct bcm_tag *buf = NULL;
         struct mtd_partition *parts;
         int ret;
         size_t retlen;
@@ -86,25 +111,35 @@ static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
         if (bcm63xx_detect_cfe(master))
                 return -EINVAL;
 
+        nvram = vzalloc(sizeof(*nvram));
+        if (!nvram)
+                return -ENOMEM;
+
+        ret = bcm63xx_read_nvram(master, nvram);
+        if (ret)
+                goto out;
+
         cfe_erasesize = max_t(uint32_t, master->erasesize,
-                              BCM63XX_CFE_BLOCK_SIZE);
+                              BCM963XX_CFE_BLOCK_SIZE);
 
         cfelen = cfe_erasesize;
-        nvramlen = bcm63xx_nvram_get_psi_size() * SZ_1K;
+        nvramlen = nvram->psi_size * SZ_1K;
         nvramlen = roundup(nvramlen, cfe_erasesize);
 
         /* Allocate memory for buffer */
         buf = vmalloc(sizeof(struct bcm_tag));
-        if (!buf)
-                return -ENOMEM;
+        if (!buf) {
+                ret = -ENOMEM;
+                goto out;
+        }
 
         /* Get the tag */
         ret = mtd_read(master, cfelen, sizeof(struct bcm_tag), &retlen,
                        (void *)buf);
 
         if (retlen != sizeof(struct bcm_tag)) {
-                vfree(buf);
-                return -EIO;
+                ret = -EIO;
+                goto out;
         }
 
         computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
@@ -154,8 +189,8 @@ static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
         /* Ask kernel for more memory */
         parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
         if (!parts) {
-                vfree(buf);
-                return -ENOMEM;
+                ret = -ENOMEM;
+                goto out;
         }
 
         /* Start building partition list */
@@ -206,8 +241,15 @@ static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
                 sparelen);
 
         *pparts = parts;
+        ret = 0;
+
+out:
+        vfree(nvram);
         vfree(buf);
 
+        if (ret)
+                return ret;
+
         return nrparts;
 };