mtd: bcm63xxpart: move imagetag parsing to its own parser

Move the bcm963xx Image Tag parsing into its own partition parser. This
Allows reusing the parser with different full flash parsers.

While moving it, rename it to bcm963* to better reflect it isn't chip,
but reference implementation specific.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Author: KanjiMonster

drivers/mtd/Kconfig

@@ -94,6 +94,7 @@ config MTD_BCM63XX_PARTS
 	tristate "BCM63XX CFE partitioning support"
 	depends on BCM63XX || BMIPS_GENERIC || COMPILE_TEST
 	select CRC32
+	select MTD_PARSER_IMAGETAG
 	help
 	  This provides partition parsing for BCM63xx devices with CFE
 	  bootloaders.

drivers/mtd/bcm63xxpart.c

@@ -94,51 +94,19 @@ static int bcm63xx_read_nvram(struct mtd_info *master,
 	return 0;
 }
 
-static int bcm63xx_read_image_tag(struct mtd_info *master, const char *name,
-	loff_t tag_offset, struct bcm_tag *buf)
-{
-	int ret;
-	size_t retlen;
-	u32 computed_crc;
-
-	ret = mtd_read(master, tag_offset, sizeof(*buf), &retlen, (void *)buf);
-	if (ret)
-		return ret;
-
-	if (retlen != sizeof(*buf))
-		return -EIO;
-
-	computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
-				offsetof(struct bcm_tag, header_crc));
-	if (computed_crc == buf->header_crc) {
-		STR_NULL_TERMINATE(buf->board_id);
-		STR_NULL_TERMINATE(buf->tag_version);
-
-		pr_info("%s: CFE image tag found at 0x%llx with version %s, board type %s\n",
-			name, tag_offset, buf->tag_version, buf->board_id);
-
-		return 0;
-	}
-
-	pr_warn("%s: CFE image tag at 0x%llx CRC invalid (expected %08x, actual %08x)\n",
-		name, tag_offset, buf->header_crc, computed_crc);
-	return 1;
-}
+static const char * const bcm63xx_cfe_part_types[] = {
+	"bcm963xx-imagetag",
+	NULL,
+};
 
 static int bcm63xx_parse_cfe_nor_partitions(struct mtd_info *master,
 	const struct mtd_partition **pparts, struct bcm963xx_nvram *nvram)
 {
-	/* CFE, NVRAM and global Linux are always present */
-	int nrparts = 3, curpart = 0;
-	struct bcm_tag *buf = NULL;
 	struct mtd_partition *parts;
-	int ret;
-	unsigned int rootfsaddr, kerneladdr, spareaddr;
-	unsigned int rootfslen, kernellen, sparelen, totallen;
+	int nrparts = 3, curpart = 0;
 	unsigned int cfelen, nvramlen;
 	unsigned int cfe_erasesize;
 	int i;
-	bool rootfs_first = false;
 
 	cfe_erasesize = max_t(uint32_t, master->erasesize,
 			      BCM963XX_CFE_BLOCK_SIZE);
@@ -147,114 +115,16 @@ static int bcm63xx_parse_cfe_nor_partitions(struct mtd_info *master,
 	nvramlen = nvram->psi_size * SZ_1K;
 	nvramlen = roundup(nvramlen, cfe_erasesize);
 
-	buf = vmalloc(sizeof(struct bcm_tag));
-	if (!buf)
-		return -ENOMEM;
-
-	/* Get the tag */
-	ret = bcm63xx_read_image_tag(master, "rootfs", cfelen, buf);
-	if (!ret) {
-		STR_NULL_TERMINATE(buf->flash_image_start);
-		if (kstrtouint(buf->flash_image_start, 10, &rootfsaddr) ||
-				rootfsaddr < BCM963XX_EXTENDED_SIZE) {
-			pr_err("invalid rootfs address: %*ph\n",
-				(int)sizeof(buf->flash_image_start),
-				buf->flash_image_start);
-			goto invalid_tag;
-		}
-
-		STR_NULL_TERMINATE(buf->kernel_address);
-		if (kstrtouint(buf->kernel_address, 10, &kerneladdr) ||
-				kerneladdr < BCM963XX_EXTENDED_SIZE) {
-			pr_err("invalid kernel address: %*ph\n",
-				(int)sizeof(buf->kernel_address),
-				buf->kernel_address);
-			goto invalid_tag;
-		}
-
-		STR_NULL_TERMINATE(buf->kernel_length);
-		if (kstrtouint(buf->kernel_length, 10, &kernellen)) {
-			pr_err("invalid kernel length: %*ph\n",
-				(int)sizeof(buf->kernel_length),
-				buf->kernel_length);
-			goto invalid_tag;
-		}
-
-		STR_NULL_TERMINATE(buf->total_length);
-		if (kstrtouint(buf->total_length, 10, &totallen)) {
-			pr_err("invalid total length: %*ph\n",
-				(int)sizeof(buf->total_length),
-				buf->total_length);
-			goto invalid_tag;
-		}
-
-		kerneladdr = kerneladdr - BCM963XX_EXTENDED_SIZE;
-		rootfsaddr = rootfsaddr - BCM963XX_EXTENDED_SIZE;
-		spareaddr = roundup(totallen, master->erasesize) + cfelen;
-
-		if (rootfsaddr < kerneladdr) {
-			/* default Broadcom layout */
-			rootfslen = kerneladdr - rootfsaddr;
-			rootfs_first = true;
-		} else {
-			/* OpenWrt layout */
-			rootfsaddr = kerneladdr + kernellen;
-			rootfslen = spareaddr - rootfsaddr;
-		}
-	} else if (ret > 0) {
-invalid_tag:
-		kernellen = 0;
-		rootfslen = 0;
-		rootfsaddr = 0;
-		spareaddr = cfelen;
-	} else {
-		goto out;
-	}
-	sparelen = master->size - spareaddr - nvramlen;
-
-	/* Determine number of partitions */
-	if (rootfslen > 0)
-		nrparts++;
-
-	if (kernellen > 0)
-		nrparts++;
-
 	parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
-	if (!parts) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	if (!parts)
+		return -ENOMEM;
 
 	/* Start building partition list */
 	parts[curpart].name = "CFE";
 	parts[curpart].offset = 0;
 	parts[curpart].size = cfelen;
 	curpart++;
 
-	if (kernellen > 0) {
-		int kernelpart = curpart;
-
-		if (rootfslen > 0 && rootfs_first)
-			kernelpart++;
-		parts[kernelpart].name = "kernel";
-		parts[kernelpart].offset = kerneladdr;
-		parts[kernelpart].size = kernellen;
-		curpart++;
-	}
-
-	if (rootfslen > 0) {
-		int rootfspart = curpart;
-
-		if (kernellen > 0 && rootfs_first)
-			rootfspart--;
-		parts[rootfspart].name = "rootfs";
-		parts[rootfspart].offset = rootfsaddr;
-		parts[rootfspart].size = rootfslen;
-		if (sparelen > 0  && !rootfs_first)
-			parts[rootfspart].size += sparelen;
-		curpart++;
-	}
-
 	parts[curpart].name = "nvram";
 	parts[curpart].offset = master->size - nvramlen;
 	parts[curpart].size = nvramlen;
@@ -264,22 +134,13 @@ static int bcm63xx_parse_cfe_nor_partitions(struct mtd_info *master,
 	parts[curpart].name = "linux";
 	parts[curpart].offset = cfelen;
 	parts[curpart].size = master->size - cfelen - nvramlen;
+	parts[curpart].types = bcm63xx_cfe_part_types;
 
 	for (i = 0; i < nrparts; i++)
 		pr_info("Partition %d is %s offset %llx and length %llx\n", i,
 			parts[i].name, parts[i].offset,	parts[i].size);
 
-	pr_info("Spare partition is offset %x and length %x\n",	spareaddr,
-		sparelen);
-
 	*pparts = parts;
-	ret = 0;
-
-out:
-	vfree(buf);
-
-	if (ret)
-		return ret;
 
 	return nrparts;
 }

drivers/mtd/parsers/Kconfig

@@ -1,3 +1,14 @@
+config MTD_PARSER_IMAGETAG
+	tristate "Parser for BCM963XX Image Tag format partitions"
+	depends on BCM63XX || BMIPS_GENERIC || COMPILE_TEST
+	select CRC32
+	help
+	  Image Tag is the firmware header used by broadcom on their xDSL line
+	  of devices. It is used to describe the offsets and lengths of kernel
+	  and rootfs partitions.
+	  This driver adds support for parsing a partition with an Image Tag
+	  header and creates up to two partitions, kernel and rootfs.
+
 config MTD_PARSER_TRX
 	tristate "Parser for TRX format partitions"
 	depends on MTD && (BCM47XX || ARCH_BCM_5301X || COMPILE_TEST)

drivers/mtd/parsers/Makefile

@@ -1,3 +1,4 @@
+obj-$(CONFIG_MTD_PARSER_IMAGETAG)	+= parser_imagetag.o
 obj-$(CONFIG_MTD_PARSER_TRX)		+= parser_trx.o
 obj-$(CONFIG_MTD_SHARPSL_PARTS)		+= sharpslpart.o
 obj-$(CONFIG_MTD_REDBOOT_PARTS)		+= redboot.o