NAND based Qualcomm platforms have the partition table populated in the
Shared Memory (SMEM). Hence, add a parser for parsing the partitions
from it.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasi...@linaro.org>
---
 drivers/mtd/parsers/Kconfig        |   8 ++
 drivers/mtd/parsers/Makefile       |   1 +
 drivers/mtd/parsers/qcomsmempart.c | 170 +++++++++++++++++++++++++++++
 3 files changed, 179 insertions(+)
 create mode 100644 drivers/mtd/parsers/qcomsmempart.c

diff --git a/drivers/mtd/parsers/Kconfig b/drivers/mtd/parsers/Kconfig
index e72354322f62..d90c30229052 100644
--- a/drivers/mtd/parsers/Kconfig
+++ b/drivers/mtd/parsers/Kconfig
@@ -160,3 +160,11 @@ config MTD_REDBOOT_PARTS_READONLY
          'FIS directory' images, enable this option.
 
 endif # MTD_REDBOOT_PARTS
+
+config MTD_QCOMSMEM_PARTS
+       tristate "Qualcomm SMEM NAND flash partition parser"
+       depends on MTD_NAND_QCOM || COMPILE_TEST
+       depends on QCOM_SMEM
+       help
+         This provides support for parsing partitions from Shared Memory (SMEM)
+         for NAND flash on Qualcomm platforms.
diff --git a/drivers/mtd/parsers/Makefile b/drivers/mtd/parsers/Makefile
index b0c5f62f9e85..50eb0b0a2210 100644
--- a/drivers/mtd/parsers/Makefile
+++ b/drivers/mtd/parsers/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_MTD_AFS_PARTS)             += afs.o
 obj-$(CONFIG_MTD_PARSER_TRX)           += parser_trx.o
 obj-$(CONFIG_MTD_SHARPSL_PARTS)                += sharpslpart.o
 obj-$(CONFIG_MTD_REDBOOT_PARTS)                += redboot.o
+obj-$(CONFIG_MTD_QCOMSMEM_PARTS)       += qcomsmempart.o
diff --git a/drivers/mtd/parsers/qcomsmempart.c 
b/drivers/mtd/parsers/qcomsmempart.c
new file mode 100644
index 000000000000..808cb33d71f8
--- /dev/null
+++ b/drivers/mtd/parsers/qcomsmempart.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Qualcomm SMEM NAND flash partition parser
+ *
+ * Copyright (C) 2020, Linaro Ltd.
+ */
+
+#include <linux/ctype.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/slab.h>
+#include <linux/soc/qcom/smem.h>
+
+#define SMEM_AARM_PARTITION_TABLE      9
+#define SMEM_APPS                      0
+
+#define SMEM_FLASH_PART_MAGIC1         0x55ee73aa
+#define SMEM_FLASH_PART_MAGIC2         0xe35ebddb
+#define SMEM_FLASH_PTABLE_V3           3
+#define SMEM_FLASH_PTABLE_V4           4
+#define SMEM_FLASH_PTABLE_MAX_PARTS_V3 16
+#define SMEM_FLASH_PTABLE_MAX_PARTS_V4 48
+#define SMEM_FLASH_PTABLE_HDR_LEN      (4 * sizeof(u32))
+#define SMEM_FLASH_PTABLE_NAME_SIZE    16
+
+/**
+ * struct smem_flash_pentry - SMEM Flash partition entry
+ * @name: Name of the partition
+ * @offset: Offset in blocks
+ * @length: Length of the partition in blocks
+ * @attr: Flags for this partition
+ */
+struct smem_flash_pentry {
+       char name[SMEM_FLASH_PTABLE_NAME_SIZE];
+       __le32 offset;
+       __le32 length;
+       u8 attr;
+} __packed __aligned(4);
+
+/**
+ * struct smem_flash_ptable - SMEM Flash partition table
+ * @magic1: Partition table Magic 1
+ * @magic2: Partition table Magic 2
+ * @version: Partition table version
+ * @numparts: Number of partitions in this ptable
+ * @pentry: Flash partition entries belonging to this ptable
+ */
+struct smem_flash_ptable {
+       __le32 magic1;
+       __le32 magic2;
+       __le32 version;
+       __le32 numparts;
+       struct smem_flash_pentry pentry[SMEM_FLASH_PTABLE_MAX_PARTS_V4];
+} __packed __aligned(4);
+
+static int parse_qcomsmem_part(struct mtd_info *mtd,
+                              const struct mtd_partition **pparts,
+                              struct mtd_part_parser_data *data)
+{
+       struct smem_flash_pentry *pentry;
+       struct smem_flash_ptable *ptable;
+       size_t len = SMEM_FLASH_PTABLE_HDR_LEN;
+       struct mtd_partition *parts;
+       int ret, i, numparts;
+       char *name, *c;
+
+       pr_debug("Parsing partition table info from SMEM\n");
+       ptable = qcom_smem_get(SMEM_APPS, SMEM_AARM_PARTITION_TABLE, &len);
+       if (IS_ERR(ptable)) {
+               pr_err("Error reading partition table header\n");
+               return PTR_ERR(ptable);
+       }
+
+       /* Verify ptable magic */
+       if (le32_to_cpu(ptable->magic1) != SMEM_FLASH_PART_MAGIC1 ||
+           le32_to_cpu(ptable->magic2) != SMEM_FLASH_PART_MAGIC2) {
+               pr_err("Partition table magic verification failed\n");
+               return -EINVAL;
+       }
+
+       /* Ensure that # of partitions is less than the max we have allocated */
+       numparts = le32_to_cpu(ptable->numparts);
+       if (numparts > SMEM_FLASH_PTABLE_MAX_PARTS_V4) {
+               pr_err("Partition numbers exceed the max limit\n");
+               return -EINVAL;
+       }
+
+       /* Find out length of partition data based on table version */
+       if (le32_to_cpu(ptable->version) <= SMEM_FLASH_PTABLE_V3) {
+               len = SMEM_FLASH_PTABLE_HDR_LEN + 
SMEM_FLASH_PTABLE_MAX_PARTS_V3 *
+                       sizeof(struct smem_flash_pentry);
+       } else if (le32_to_cpu(ptable->version) == SMEM_FLASH_PTABLE_V4) {
+               len = SMEM_FLASH_PTABLE_HDR_LEN + 
SMEM_FLASH_PTABLE_MAX_PARTS_V4 *
+                       sizeof(struct smem_flash_pentry);
+       } else {
+               pr_err("Unknown ptable version (%d)", 
le32_to_cpu(ptable->version));
+               return -EINVAL;
+       }
+
+       /*
+        * Now that the partition table header has been parsed, verified
+        * and the length of the partition table calculated, read the
+        * complete partition table
+        */
+       ptable = qcom_smem_get(SMEM_APPS, SMEM_AARM_PARTITION_TABLE, &len);
+       if (IS_ERR_OR_NULL(ptable)) {
+               pr_err("Error reading partition table\n");
+               return PTR_ERR(ptable);
+       }
+
+       parts = kcalloc(numparts, sizeof(*parts), GFP_KERNEL);
+       if (!parts)
+               return -ENOMEM;
+
+       for (i = 0; i < numparts; i++) {
+               pentry = &ptable->pentry[i];
+               if (pentry->name[0] == '\0')
+                       continue;
+
+               name = kstrdup(pentry->name, GFP_KERNEL);
+               if (!name) {
+                       ret = -ENOMEM;
+                       goto out_free_parts;
+               }
+
+               /* Convert name to lower case */
+               for (c = name; *c != '\0'; c++)
+                       *c = tolower(*c);
+
+               parts[i].name = name;
+               parts[i].offset = le32_to_cpu(pentry->offset) * mtd->erasesize;
+               parts[i].mask_flags = pentry->attr;
+               parts[i].size = le32_to_cpu(pentry->length) * mtd->erasesize;
+               pr_debug("%d: %s offs=0x%08x size=0x%08x attr:0x%08x\n",
+                        i, pentry->name, le32_to_cpu(pentry->offset),
+                        le32_to_cpu(pentry->length), pentry->attr);
+       }
+
+       pr_debug("SMEM partition table found: ver: %d len: %d\n",
+                le32_to_cpu(ptable->version), numparts);
+       *pparts = parts;
+
+       return numparts;
+
+out_free_parts:
+       while (--i >= 0)
+               kfree(parts[i].name);
+       kfree(parts);
+       *pparts = NULL;
+
+       return ret;
+}
+
+static const struct of_device_id qcomsmem_of_match_table[] = {
+       { .compatible = "qcom,smem-part" },
+       {},
+};
+MODULE_DEVICE_TABLE(of, qcomsmem_of_match_table);
+
+static struct mtd_part_parser mtd_parser_qcomsmem = {
+       .parse_fn = parse_qcomsmem_part,
+       .name = "qcomsmem",
+       .of_match_table = qcomsmem_of_match_table,
+};
+module_mtd_part_parser(mtd_parser_qcomsmem);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasi...@linaro.org>");
+MODULE_DESCRIPTION("Qualcomm SMEM NAND flash partition parser");
-- 
2.17.1

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