mtd: parsers: Move BCM47xx parser

This moves the BCM47xx partition parser down into the
parser subdirectory. No functional change.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Richard Weinberger <richard@nod.at>

3 files changed, 325 insertions, 0 deletions

diff --git a/drivers/mtd/parsers/Kconfig b/drivers/mtd/parsers/Kconfig
index 3b3675b8d672..e5288b9bb8c5 100644
--- a/drivers/mtd/parsers/Kconfig
+++ b/drivers/mtd/parsers/Kconfig
@@ -4,6 +4,13 @@ config MTD_AR7_PARTS
 	help
 	  TI AR7 partitioning parser support
 
+config MTD_BCM47XX_PARTS
+	tristate "BCM47XX partitioning parser"
+	depends on BCM47XX || ARCH_BCM_5301X
+	help
+	  This provides partitions parser for devices based on BCM47xx
+	  boards.
+
 config MTD_PARSER_IMAGETAG
 	tristate "Parser for BCM963XX Image Tag format partitions"
 	depends on BCM63XX || BMIPS_GENERIC || COMPILE_TEST
diff --git a/drivers/mtd/parsers/Makefile b/drivers/mtd/parsers/Makefile
index 0bc06386bfcd..3e020c66af64 100644
--- a/drivers/mtd/parsers/Makefile
+++ b/drivers/mtd/parsers/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_MTD_AR7_PARTS)		+= ar7part.o
+obj-$(CONFIG_MTD_BCM47XX_PARTS)		+= bcm47xxpart.o
 obj-$(CONFIG_MTD_PARSER_IMAGETAG)	+= parser_imagetag.o
 obj-$(CONFIG_MTD_AFS_PARTS)		+= afs.o
 obj-$(CONFIG_MTD_PARSER_TRX)		+= parser_trx.o
diff --git a/drivers/mtd/parsers/bcm47xxpart.c b/drivers/mtd/parsers/bcm47xxpart.c
new file mode 100644
index 000000000000..6012a10f10c8
--- /dev/null
+++ b/drivers/mtd/parsers/bcm47xxpart.c
@@ -0,0 +1,317 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * BCM47XX MTD partitioning
+ *
+ * Copyright © 2012 Rafał Miłecki <zajec5@gmail.com>
+ */
+
+#include <linux/bcm47xx_nvram.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+
+#include <uapi/linux/magic.h>
+
+/*
+ * NAND flash on Netgear R6250 was verified to contain 15 partitions.
+ * This will result in allocating too big array for some old devices, but the
+ * memory will be freed soon anyway (see mtd_device_parse_register).
+ */
+#define BCM47XXPART_MAX_PARTS		20
+
+/*
+ * Amount of bytes we read when analyzing each block of flash memory.
+ * Set it big enough to allow detecting partition and reading important data.
+ */
+#define BCM47XXPART_BYTES_TO_READ	0x4e8
+
+/* Magics */
+#define BOARD_DATA_MAGIC		0x5246504D	/* MPFR */
+#define BOARD_DATA_MAGIC2		0xBD0D0BBD
+#define CFE_MAGIC			0x43464531	/* 1EFC */
+#define FACTORY_MAGIC			0x59544346	/* FCTY */
+#define NVRAM_HEADER			0x48534C46	/* FLSH */
+#define POT_MAGIC1			0x54544f50	/* POTT */
+#define POT_MAGIC2			0x504f		/* OP */
+#define ML_MAGIC1			0x39685a42
+#define ML_MAGIC2			0x26594131
+#define TRX_MAGIC			0x30524448
+#define SHSQ_MAGIC			0x71736873	/* shsq (weird ZTE H218N endianness) */
+
+static const char * const trx_types[] = { "trx", NULL };
+
+struct trx_header {
+	uint32_t magic;
+	uint32_t length;
+	uint32_t crc32;
+	uint16_t flags;
+	uint16_t version;
+	uint32_t offset[3];
+} __packed;
+
+static void bcm47xxpart_add_part(struct mtd_partition *part, const char *name,
+				 u64 offset, uint32_t mask_flags)
+{
+	part->name = name;
+	part->offset = offset;
+	part->mask_flags = mask_flags;
+}
+
+/**
+ * bcm47xxpart_bootpartition - gets index of TRX partition used by bootloader
+ *
+ * Some devices may have more than one TRX partition. In such case one of them
+ * is the main one and another a failsafe one. Bootloader may fallback to the
+ * failsafe firmware if it detects corruption of the main image.
+ *
+ * This function provides info about currently used TRX partition. It's the one
+ * containing kernel started by the bootloader.
+ */
+static int bcm47xxpart_bootpartition(void)
+{
+	char buf[4];
+	int bootpartition;
+
+	/* Check CFE environment variable */
+	if (bcm47xx_nvram_getenv("bootpartition", buf, sizeof(buf)) > 0) {
+		if (!kstrtoint(buf, 0, &bootpartition))
+			return bootpartition;
+	}
+
+	return 0;
+}
+
+static int bcm47xxpart_parse(struct mtd_info *master,
+			     const struct mtd_partition **pparts,
+			     struct mtd_part_parser_data *data)
+{
+	struct mtd_partition *parts;
+	uint8_t i, curr_part = 0;
+	uint32_t *buf;
+	size_t bytes_read;
+	uint32_t offset;
+	uint32_t blocksize = master->erasesize;
+	int trx_parts[2]; /* Array with indexes of TRX partitions */
+	int trx_num = 0; /* Number of found TRX partitions */
+	int possible_nvram_sizes[] = { 0x8000, 0xF000, 0x10000, };
+	int err;
+
+	/*
+	 * Some really old flashes (like AT45DB*) had smaller erasesize-s, but
+	 * partitions were aligned to at least 0x1000 anyway.
+	 */
+	if (blocksize < 0x1000)
+		blocksize = 0x1000;
+
+	/* Alloc */
+	parts = kcalloc(BCM47XXPART_MAX_PARTS, sizeof(struct mtd_partition),
+			GFP_KERNEL);
+	if (!parts)
+		return -ENOMEM;
+
+	buf = kzalloc(BCM47XXPART_BYTES_TO_READ, GFP_KERNEL);
+	if (!buf) {
+		kfree(parts);
+		return -ENOMEM;
+	}
+
+	/* Parse block by block looking for magics */
+	for (offset = 0; offset <= master->size - blocksize;
+	     offset += blocksize) {
+		/* Nothing more in higher memory on BCM47XX (MIPS) */
+		if (IS_ENABLED(CONFIG_BCM47XX) && offset >= 0x2000000)
+			break;
+
+		if (curr_part >= BCM47XXPART_MAX_PARTS) {
+			pr_warn("Reached maximum number of partitions, scanning stopped!\n");
+			break;
+		}
+
+		/* Read beginning of the block */
+		err = mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ,
+			       &bytes_read, (uint8_t *)buf);
+		if (err && !mtd_is_bitflip(err)) {
+			pr_err("mtd_read error while parsing (offset: 0x%X): %d\n",
+			       offset, err);
+			continue;
+		}
+
+		/* Magic or small NVRAM at 0x400 */
+		if ((buf[0x4e0 / 4] == CFE_MAGIC && buf[0x4e4 / 4] == CFE_MAGIC) ||
+		    (buf[0x400 / 4] == NVRAM_HEADER)) {
+			bcm47xxpart_add_part(&parts[curr_part++], "boot",
+					     offset, MTD_WRITEABLE);
+			continue;
+		}
+
+		/*
+		 * board_data starts with board_id which differs across boards,
+		 * but we can use 'MPFR' (hopefully) magic at 0x100
+		 */
+		if (buf[0x100 / 4] == BOARD_DATA_MAGIC) {
+			bcm47xxpart_add_part(&parts[curr_part++], "board_data",
+					     offset, MTD_WRITEABLE);
+			continue;
+		}
+
+		/* Found on Huawei E970 */
+		if (buf[0x000 / 4] == FACTORY_MAGIC) {
+			bcm47xxpart_add_part(&parts[curr_part++], "factory",
+					     offset, MTD_WRITEABLE);
+			continue;
+		}
+
+		/* POT(TOP) */
+		if (buf[0x000 / 4] == POT_MAGIC1 &&
+		    (buf[0x004 / 4] & 0xFFFF) == POT_MAGIC2) {
+			bcm47xxpart_add_part(&parts[curr_part++], "POT", offset,
+					     MTD_WRITEABLE);
+			continue;
+		}
+
+		/* ML */
+		if (buf[0x010 / 4] == ML_MAGIC1 &&
+		    buf[0x014 / 4] == ML_MAGIC2) {
+			bcm47xxpart_add_part(&parts[curr_part++], "ML", offset,
+					     MTD_WRITEABLE);
+			continue;
+		}
+
+		/* TRX */
+		if (buf[0x000 / 4] == TRX_MAGIC) {
+			struct trx_header *trx;
+			uint32_t last_subpart;
+			uint32_t trx_size;
+
+			if (trx_num >= ARRAY_SIZE(trx_parts))
+				pr_warn("No enough space to store another TRX found at 0x%X\n",
+					offset);
+			else
+				trx_parts[trx_num++] = curr_part;
+			bcm47xxpart_add_part(&parts[curr_part++], "firmware",
+					     offset, 0);
+
+			/*
+			 * Try to find TRX size. The "length" field isn't fully
+			 * reliable as it could be decreased to make CRC32 cover
+			 * only part of TRX data. It's commonly used as checksum
+			 * can't cover e.g. ever-changing rootfs partition.
+			 * Use offsets as helpers for assuming min TRX size.
+			 */
+			trx = (struct trx_header *)buf;
+			last_subpart = max3(trx->offset[0], trx->offset[1],
+					    trx->offset[2]);
+			trx_size = max(trx->length, last_subpart + blocksize);
+
+			/*
+			 * Skip the TRX data. Decrease offset by block size as
+			 * the next loop iteration will increase it.
+			 */
+			offset += roundup(trx_size, blocksize) - blocksize;
+			continue;
+		}
+
+		/* Squashfs on devices not using TRX */
+		if (le32_to_cpu(buf[0x000 / 4]) == SQUASHFS_MAGIC ||
+		    buf[0x000 / 4] == SHSQ_MAGIC) {
+			bcm47xxpart_add_part(&parts[curr_part++], "rootfs",
+					     offset, 0);
+			continue;
+		}
+
+		/*
+		 * New (ARM?) devices may have NVRAM in some middle block. Last
+		 * block will be checked later, so skip it.
+		 */
+		if (offset != master->size - blocksize &&
+		    buf[0x000 / 4] == NVRAM_HEADER) {
+			bcm47xxpart_add_part(&parts[curr_part++], "nvram",
+					     offset, 0);
+			continue;
+		}
+
+		/* Read middle of the block */
+		err = mtd_read(master, offset + 0x8000, 0x4, &bytes_read,
+			       (uint8_t *)buf);
+		if (err && !mtd_is_bitflip(err)) {
+			pr_err("mtd_read error while parsing (offset: 0x%X): %d\n",
+			       offset, err);
+			continue;
+		}
+
+		/* Some devices (ex. WNDR3700v3) don't have a standard 'MPFR' */
+		if (buf[0x000 / 4] == BOARD_DATA_MAGIC2) {
+			bcm47xxpart_add_part(&parts[curr_part++], "board_data",
+					     offset, MTD_WRITEABLE);
+			continue;
+		}
+	}
+
+	/* Look for NVRAM at the end of the last block. */
+	for (i = 0; i < ARRAY_SIZE(possible_nvram_sizes); i++) {
+		if (curr_part >= BCM47XXPART_MAX_PARTS) {
+			pr_warn("Reached maximum number of partitions, scanning stopped!\n");
+			break;
+		}
+
+		offset = master->size - possible_nvram_sizes[i];
+		err = mtd_read(master, offset, 0x4, &bytes_read,
+			       (uint8_t *)buf);
+		if (err && !mtd_is_bitflip(err)) {
+			pr_err("mtd_read error while reading (offset 0x%X): %d\n",
+			       offset, err);
+			continue;
+		}
+
+		/* Standard NVRAM */
+		if (buf[0] == NVRAM_HEADER) {
+			bcm47xxpart_add_part(&parts[curr_part++], "nvram",
+					     master->size - blocksize, 0);
+			break;
+		}
+	}
+
+	kfree(buf);
+
+	/*
+	 * Assume that partitions end at the beginning of the one they are
+	 * followed by.
+	 */
+	for (i = 0; i < curr_part; i++) {
+		u64 next_part_offset = (i < curr_part - 1) ?
+				       parts[i + 1].offset : master->size;
+
+		parts[i].size = next_part_offset - parts[i].offset;
+	}
+
+	/* If there was TRX parse it now */
+	for (i = 0; i < trx_num; i++) {
+		struct mtd_partition *trx = &parts[trx_parts[i]];
+
+		if (i == bcm47xxpart_bootpartition())
+			trx->types = trx_types;
+		else
+			trx->name = "failsafe";
+	}
+
+	*pparts = parts;
+	return curr_part;
+};
+
+static const struct of_device_id bcm47xxpart_of_match_table[] = {
+	{ .compatible = "brcm,bcm947xx-cfe-partitions" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, bcm47xxpart_of_match_table);
+
+static struct mtd_part_parser bcm47xxpart_mtd_parser = {
+	.parse_fn = bcm47xxpart_parse,
+	.name = "bcm47xxpart",
+	.of_match_table = bcm47xxpart_of_match_table,
+};
+module_mtd_part_parser(bcm47xxpart_mtd_parser);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MTD partitioning for BCM47XX flash memories");