[PATCH v4 3/3] mtd: add SMEM parser for QCOM platforms
Bjorn Andersson
bjorn.andersson at sonymobile.com
Wed Aug 19 09:37:52 PDT 2015
On Tue 18 Aug 14:04 PDT 2015, Mathieu Olivari wrote:
> On QCOM platforms using MTD devices storage (such as IPQ806x), SMEM is
> used to store partition layout. This new parser can now be used to read
> SMEM and use it to register an MTD layout according to its content.
>
Still looks good, but you should have added:
Acked-by: Bjorn Andersson <bjorn.andersson at sonymobile.com>
> Signed-off-by: Mathieu Olivari <mathieu at codeaurora.org>
> ---
>
> Notes:
> v2:
> *Release the SPI device reference after looking it up (put_device())
> *Represent SMEM data as __le32 rather than u32
> *Move new DT nodes in their proper respective location
> *Address readability concerns in MTD parser
>
> v3:
> *Redefine SMEM functions prototypes for better readability
> *Duplicate MTD name instead of pointing to SMEM string location in case
> mtd layer tries to free it
> *Rework some of the comments
>
> v4:
> *Fix case in the license string
>
> drivers/mtd/Kconfig | 7 ++
> drivers/mtd/Makefile | 1 +
> drivers/mtd/qcom_smem_part.c | 246 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 254 insertions(+)
> create mode 100644 drivers/mtd/qcom_smem_part.c
>
> diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
> index a03ad29..debc887 100644
> --- a/drivers/mtd/Kconfig
> +++ b/drivers/mtd/Kconfig
> @@ -155,6 +155,13 @@ config MTD_BCM47XX_PARTS
> This provides partitions parser for devices based on BCM47xx
> boards.
>
> +config MTD_QCOM_SMEM_PARTS
> + tristate "QCOM SMEM partitioning support"
> + depends on QCOM_SMEM
> + help
> + This provides partitions parser for QCOM devices using SMEM
> + such as IPQ806x.
> +
> comment "User Modules And Translation Layers"
>
> #
> diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
> index 99bb9a1..b3c7de4 100644
> --- a/drivers/mtd/Makefile
> +++ b/drivers/mtd/Makefile
> @@ -13,6 +13,7 @@ obj-$(CONFIG_MTD_AFS_PARTS) += afs.o
> obj-$(CONFIG_MTD_AR7_PARTS) += ar7part.o
> obj-$(CONFIG_MTD_BCM63XX_PARTS) += bcm63xxpart.o
> obj-$(CONFIG_MTD_BCM47XX_PARTS) += bcm47xxpart.o
> +obj-$(CONFIG_MTD_QCOM_SMEM_PARTS) += qcom_smem_part.o
>
> # 'Users' - code which presents functionality to userspace.
> obj-$(CONFIG_MTD_BLKDEVS) += mtd_blkdevs.o
> diff --git a/drivers/mtd/qcom_smem_part.c b/drivers/mtd/qcom_smem_part.c
> new file mode 100644
> index 0000000..b4f8acc
> --- /dev/null
> +++ b/drivers/mtd/qcom_smem_part.c
> @@ -0,0 +1,246 @@
> +/*
> + * Copyright (c) 2015, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/slab.h>
> +
> +#include <linux/mtd/mtd.h>
> +#include <linux/mtd/partitions.h>
> +#include <linux/spi/spi.h>
> +#include <linux/module.h>
> +
> +#include <linux/soc/qcom/smem.h>
> +
> +/* Processor/host identifier for the application processor */
> +#define QCOM_SMEM_GLOBAL 0
> +
> +/* SMEM items index */
> +#define SMEM_AARM_PARTITION_TABLE 9
> +#define SMEM_BOOT_FLASH_TYPE 421
> +#define SMEM_BOOT_FLASH_BLOCK_SIZE 424
> +
> +/* SMEM Flash types */
> +#define SMEM_FLASH_NAND 2
> +#define SMEM_FLASH_SPI 6
> +
> +#define SMEM_PART_NAME_SZ 16
> +#define SMEM_PARTS_MAX 32
> +
> +struct smem_partition {
> + char name[SMEM_PART_NAME_SZ];
> + __le32 start;
> + __le32 size;
> + __le32 attr;
> +};
> +
> +struct smem_partition_table {
> + u8 magic[8];
> + __le32 version;
> + __le32 len;
> + struct smem_partition parts[SMEM_PARTS_MAX];
> +};
> +
> +/* SMEM Magic values in partition table */
> +static const u8 SMEM_PTABLE_MAGIC[] = {
> + 0xaa, 0x73, 0xee, 0x55,
> + 0xdb, 0xbd, 0x5e, 0xe3,
> +};
> +
> +static int qcom_smem_get_flash_blksz(void)
> +{
> + int ret;
> + size_t size;
> + u64 *smem_blksz;
> +
> + ret = qcom_smem_get(QCOM_SMEM_GLOBAL, SMEM_BOOT_FLASH_BLOCK_SIZE,
> + (void **) &smem_blksz, &size);
> +
> + if (ret < 0) {
> + pr_err("Unable to read flash blksz from SMEM\n");
> + return -ENOENT;
> + }
> +
> + if (size != sizeof(*smem_blksz)) {
> + pr_err("Invalid flash blksz size in SMEM\n");
> + return -EINVAL;
> + }
> +
> + /* Sanity check block size value before casting it */
> + if (*smem_blksz > INT_MAX) {
> + pr_err("Invalid flash block size in SMEM\n");
> + return -EINVAL;
> + }
> +
> + return (int) *smem_blksz;
> +}
> +
> +static int qcom_smem_get_flash_type(void)
> +{
> + int ret;
> + size_t size;
> + u64 *smem_flash_type;
> +
> + ret = qcom_smem_get(QCOM_SMEM_GLOBAL, SMEM_BOOT_FLASH_TYPE,
> + (void **) &smem_flash_type, &size);
> +
> + if (ret < 0) {
> + pr_err("Unable to read flash type from SMEM\n");
> + return -ENOENT;
> + }
> +
> + if (size != sizeof(*smem_flash_type)) {
> + pr_err("Invalid flash type size in SMEM\n");
> + return -EINVAL;
> + }
> +
> + /* Sanity check flash type value before casting it */
> + if (*smem_flash_type > INT_MAX) {
> + pr_err("Invalid flash type in SMEM\n");
> + return -EINVAL;
> + }
> +
> + return (int) *smem_flash_type;
> +}
> +
> +static struct smem_partition *qcom_smem_get_flash_partitions(size_t *count)
> +{
> + struct smem_partition_table *smem_parts;
> + int ret;
> +
> + ret = qcom_smem_get(QCOM_SMEM_GLOBAL, SMEM_AARM_PARTITION_TABLE,
> + (void **) &smem_parts, NULL);
> +
> + if (ret < 0) {
> + pr_err("Unable to read partition table from SMEM\n");
> + return ERR_PTR(-ENOENT);
> + }
> +
> + if (memcmp(SMEM_PTABLE_MAGIC, smem_parts->magic,
> + sizeof(SMEM_PTABLE_MAGIC))) {
> + pr_err("SMEM partition magic invalid\n");
> + return ERR_PTR(-EINVAL);
> + }
> +
> + if (le32_to_cpu(smem_parts->version) != 3) {
> + pr_err("SMEM version unsupported\n");
> + return ERR_PTR(-EINVAL);
> + }
> +
> + *count = le32_to_cpu(smem_parts->len);
> +
> + return smem_parts->parts;
> +}
> +
> +static int of_dev_node_match(struct device *dev, void *data)
> +{
> + return dev->of_node == data;
> +}
> +
> +static bool is_spi_device(struct device_node *np)
> +{
> + struct device *dev;
> +
> + dev = bus_find_device(&spi_bus_type, NULL, np, of_dev_node_match);
> + if (!dev)
> + return false;
> +
> + put_device(dev);
> + return true;
> +}
> +
> +static int parse_qcom_smem_partitions(struct mtd_info *master,
> + struct mtd_partition **pparts,
> + struct mtd_part_parser_data *data)
> +{
> + struct smem_partition *smem_part;
> + int smem_flash_type, smem_blksz;
> + size_t nbparts = 0, len;
> + struct mtd_partition *mtd_parts;
> + struct device_node *of_node = data->of_node;
> +
> + /* Only parse partitions on the specified memory type */
> + smem_flash_type = qcom_smem_get_flash_type();
> + if (smem_flash_type < 0)
> + return smem_flash_type;
> +
> + if ((smem_flash_type == SMEM_FLASH_NAND && !mtd_type_is_nand(master))
> + || (smem_flash_type == SMEM_FLASH_SPI && !is_spi_device(of_node)))
> + return 0;
> +
> + /* Make sure the block size in SMEM matches the block size in MTD */
> + smem_blksz = qcom_smem_get_flash_blksz();
> + if (smem_blksz < 0)
> + return smem_blksz;
> +
> + if (smem_blksz != master->erasesize) {
> + pr_err("SMEM block size differs from MTD block size\n");
> + return -EINVAL;
> + }
> +
> + /* Get partition pointer from SMEM */
> + smem_part = qcom_smem_get_flash_partitions(&nbparts);
> + if (IS_ERR_OR_NULL(smem_part))
> + return -EINVAL;
> +
> + /* Allocate and populate the mtd structures */
> + mtd_parts = kcalloc(nbparts, sizeof(*mtd_parts), GFP_KERNEL);
> + if (!mtd_parts)
> + return -ENOMEM;
> +
> + *pparts = mtd_parts;
> + len = nbparts;
> +
> + while (len--) {
> + mtd_parts->name = kstrdup(smem_part->name, GFP_KERNEL);
> + mtd_parts->size = le32_to_cpu(smem_part->size) * smem_blksz;
> + mtd_parts->offset = le32_to_cpu(smem_part->start) * smem_blksz;
> +
> + /*
> + * The last SMEM partition may have its size marked as
> + * something like 0xffffffff, which means "until the end of the
> + * flash device". In this case, truncate it.
> + */
> + if (mtd_parts->offset + mtd_parts->size > master->size)
> + mtd_parts->size = master->size - mtd_parts->offset;
> +
> + smem_part++;
> + mtd_parts++;
> + }
> +
> + return nbparts;
> +}
> +
> +static struct mtd_part_parser qcom_smem_parser = {
> + .owner = THIS_MODULE,
> + .parse_fn = parse_qcom_smem_partitions,
> + .name = "qcom-smem",
> +};
> +
> +static int __init qcom_smem_parser_init(void)
> +{
> + register_mtd_parser(&qcom_smem_parser);
> + return 0;
> +}
> +
> +static void __exit qcom_smem_parser_exit(void)
> +{
> + deregister_mtd_parser(&qcom_smem_parser);
> +}
> +
> +module_init(qcom_smem_parser_init);
> +module_exit(qcom_smem_parser_exit);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Mathieu Olivari <mathieu at codeaurora.org>");
> +MODULE_DESCRIPTION("Parsing code for SMEM based partition tables");
> --
> 2.1.4
>
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