Re: [PATCH v10] mmc : general purpose partition support.

From: S, Venkatraman
Date: Tue Oct 04 2011 - 14:19:37 EST


On Tue, Oct 4, 2011 at 11:15 PM, Namjae Jeon <linkinjeon@xxxxxxxxx> wrote:
> It allows gerneral purpose partitions in MMC Device.
> And I try to simpliy make mmc_blk_alloc_parts using mmc_part structure suggested by Andrei Warkentin.
> After patching, we can see general purpose partitions like this.
>> cat /proc/partitions
>          179 0 847872 mmcblk0
>          179 192 4096 mmcblk0gp3
>          179 160 4096 mmcblk0gp2
>          179 128 4096 mmcblk0gp1
>          179 96  1052672 mmcblk0gp0
>          179 64  1024 mmcblk0boot1
>          179 32  1024 mmcblk0boot0
>
> Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxx>
> ---
>  drivers/mmc/card/block.c |   34 +++++++++++++++++------------
>  drivers/mmc/core/mmc.c   |   52 ++++++++++++++++++++++++++++++++++++++++++---
>  include/linux/mmc/card.h |   34 +++++++++++++++++++++++++++++-
>  include/linux/mmc/mmc.h  |    5 +++-
>  4 files changed, 105 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 782d5f8..fb6f1e9 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -1470,26 +1470,32 @@ static int mmc_blk_alloc_part(struct mmc_card *card,
>        return 0;
>  }
>
> +/* MMC Physical partition consist of two boot partitions and
> + * up to four general purpose partitions.
> + * For each partitions enabled in EXT_CSD
> + * The block device will allocated to provide access to the partition.
> + */
> +
>  static int mmc_blk_alloc_parts(struct mmc_card *card, struct mmc_blk_data *md)
>  {
> -       int ret = 0;
> +       int idx, ret = 0;
>
>        if (!mmc_card_mmc(card))
>                return 0;
>
> -       if (card->ext_csd.boot_size && mmc_boot_partition_access(card->host)) {
> -               ret = mmc_blk_alloc_part(card, md, EXT_CSD_PART_CONFIG_ACC_BOOT0,
> -                                        card->ext_csd.boot_size >> 9,
> -                                        true,
> -                                        "boot0");
> -               if (ret)
> -                       return ret;
> -               ret = mmc_blk_alloc_part(card, md, EXT_CSD_PART_CONFIG_ACC_BOOT1,
> -                                        card->ext_csd.boot_size >> 9,
> -                                        true,
> -                                        "boot1");
> -               if (ret)
> -                       return ret;
> +       for (idx = 0; idx < card->nr_parts; idx++) {
> +               if ((idx == 0 || idx == 1) &&
> +                       !mmc_boot_partition_access(card->host))
> +                       continue;
> +               if (card->part[idx].size) {
> +                       ret = mmc_blk_alloc_part(card, md,
> +                               card->part[idx].part_cfg,
> +                               card->part[idx].size >> 9,
> +                               card->part[idx].force_ro,
> +                               card->part[idx].name);
> +                       if (ret)
> +                               return ret;
> +               }
>        }
>
>        return ret;
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index c632b1f..2f458a0 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -239,7 +239,9 @@ static int mmc_get_ext_csd(struct mmc_card *card, u8 **new_ext_csd)
>  */
>  static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
>  {
> -       int err = 0;
> +       int err = 0, idx;
> +       unsigned int part_size;
> +       u8 hc_erase_grp_sz = 0, hc_wp_grp_sz = 0;
>
>        BUG_ON(!card);
>
> @@ -340,7 +342,14 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
>                 * There are two boot regions of equal size, defined in
>                 * multiples of 128K.
>                 */
> -               card->ext_csd.boot_size = ext_csd[EXT_CSD_BOOT_MULT] << 17;
> +               if (ext_csd[EXT_CSD_BOOT_MULT]) {
> +                       for (idx = 0; idx < MMC_NUM_BOOT_PARTITION; idx++) {
> +                               part_size = ext_csd[EXT_CSD_BOOT_MULT] << 17;
> +                               mmc_part_add(card, part_size,
> +                                       EXT_CSD_PART_CONFIG_ACC_BOOT0 + idx,
> +                                       "boot%d", idx, true);
> +                       }
> +               }
>        }
>
>        card->ext_csd.raw_hc_erase_gap_size =
> @@ -362,9 +371,9 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
>                card->ext_csd.raw_partition_support = ext_csd[EXT_CSD_PARTITION_SUPPORT];
>                if ((ext_csd[EXT_CSD_PARTITION_SUPPORT] & 0x2) &&
>                    (ext_csd[EXT_CSD_PARTITION_ATTRIBUTE] & 0x1)) {
> -                       u8 hc_erase_grp_sz =
> +                       hc_erase_grp_sz =
>                                ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE];
> -                       u8 hc_wp_grp_sz =
> +                       hc_wp_grp_sz =
>                                ext_csd[EXT_CSD_HC_WP_GRP_SIZE];
>
>                        card->ext_csd.enhanced_area_en = 1;
> @@ -393,6 +402,41 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
>                        card->ext_csd.enhanced_area_offset = -EINVAL;
>                        card->ext_csd.enhanced_area_size = -EINVAL;
>                }
> +
> +               /*
> +                * General purpose partition feature support --
> +                * If ext_csd have the size of general purpose partitions,
> +                * set size, part_cfg, partition name in mmc_part.
> +                */
> +               if (ext_csd[EXT_CSD_PARTITION_SUPPORT] &
> +                       EXT_CSD_PART_SUPPORT_PART_EN) {
> +                       if (card->ext_csd.enhanced_area_en != 1) {
> +                               hc_erase_grp_sz =
> +                                       ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE];
> +                               hc_wp_grp_sz =
> +                                       ext_csd[EXT_CSD_HC_WP_GRP_SIZE];
> +
> +                               card->ext_csd.enhanced_area_en = 1;
> +                       }
> +
> +                       for (idx = 0; idx < MMC_NUM_GP_PARTITION; idx++) {
> +                               if (!ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3] &&
> +                               !ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3 + 1] &&
> +                               !ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3 + 2])
> +                                       continue;
> +                               part_size =
> +                               (ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3 + 2]
> +                                       << 16) +
> +                               (ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3 + 1]
> +                                       << 8) +
> +                               ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3];
> +                               part_size *= (size_t)(hc_erase_grp_sz *
> +                                       hc_wp_grp_sz);
> +                               mmc_part_add(card, part_size << 19,
> +                                       EXT_CSD_PART_CONFIG_ACC_GP0 + idx,
> +                                       "gp%d", idx, false);
> +                       }
> +               }
>                card->ext_csd.sec_trim_mult =
>                        ext_csd[EXT_CSD_SEC_TRIM_MULT];
>                card->ext_csd.sec_erase_mult =
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index 5294ddf..0522627 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -12,6 +12,7 @@
>
>  #include <linux/mmc/core.h>
>  #include <linux/mod_devicetable.h>
> +#include <linux/genhd.h>
>
>  struct mmc_cid {
>        unsigned int            manfid;
> @@ -64,7 +65,6 @@ struct mmc_ext_csd {
>        bool                    enhanced_area_en;       /* enable bit */
>        unsigned long long      enhanced_area_offset;   /* Units: Byte */
>        unsigned int            enhanced_area_size;     /* Units: KB */
> -       unsigned int            boot_size;              /* in bytes */
>        u8                      raw_partition_support;  /* 160 */
>        u8                      raw_erased_mem_count;   /* 181 */
>        u8                      raw_ext_csd_structure;  /* 194 */
> @@ -158,6 +158,23 @@ struct sdio_func_tuple;
>
>  #define SDIO_MAX_FUNCS         7
>
> +/* The number of MMC physical partitions
> + * It consist of boot partitions(2), general purpose partitions(4) in MMC v4.4
> + */
> +#define MMC_NUM_BOOT_PARTITION 2
> +#define MMC_NUM_GP_PARTITION   4
> +#define MMC_NUM_PHY_PARTITION  6
> +
> +/*
> + * MMC Physical partitions
> + */
> +struct mmc_part {
> +       unsigned int    size;   /* partition size (in bytes) */
> +       unsigned int    part_cfg;       /* it used to part_type */
> +       char    name[DISK_NAME_LEN];
> +       bool    force_ro;       /* to make boot parts RO by default */
> +};
> +
>  /*
>  * MMC device
>  */
> @@ -219,9 +236,24 @@ struct mmc_card {
>        unsigned int            sd_bus_speed;   /* Bus Speed Mode set for the card */
>
>        struct dentry           *debugfs_root;
> +       struct mmc_part part[MMC_NUM_PHY_PARTITION]; /* physical partitions */
> +       unsigned int    nr_parts;
>  };
>
>  /*
> + * This function fill contents in mmc_part.
> + */
> +static inline void mmc_part_add(struct mmc_card *card, unsigned int size,
> +                       unsigned int part_cfg, char *name, int idx, bool ro)
> +{
> +       card->part[card->nr_parts].size = size;
> +       card->part[card->nr_parts].part_cfg = part_cfg;
> +       sprintf(card->part[card->nr_parts].name, name, idx);
> +       card->part[card->nr_parts].force_ro = ro;
> +       card->nr_parts++;
> +}
> +
> +/*
>  *  The world is not perfect and supplies us with broken mmc/sdio devices.
>  *  For at least some of these bugs we need a work-around.
>  */
> diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
> index 50af227..ea558eb 100644
> --- a/include/linux/mmc/mmc.h
> +++ b/include/linux/mmc/mmc.h
> @@ -270,6 +270,7 @@ struct _mmc_csd {
>  * EXT_CSD fields
>  */
>
> +#define EXT_CSD_GP_SIZE_MULT           143     /* R/W */
>  #define EXT_CSD_PARTITION_ATTRIBUTE    156     /* R/W */
>  #define EXT_CSD_PARTITION_SUPPORT      160     /* RO */
>  #define EXT_CSD_RST_N_FUNCTION         162     /* R/W */
> @@ -313,7 +314,9 @@ struct _mmc_csd {
>
>  #define EXT_CSD_PART_CONFIG_ACC_MASK   (0x7)
>  #define EXT_CSD_PART_CONFIG_ACC_BOOT0  (0x1)
> -#define EXT_CSD_PART_CONFIG_ACC_BOOT1  (0x2)
> +#define EXT_CSD_PART_CONFIG_ACC_GP0    (0x4)
> +
> +#define EXT_CSD_PART_SUPPORT_PART_EN   (0x1)
>
>  #define EXT_CSD_CMD_SET_NORMAL         (1<<0)
>  #define EXT_CSD_CMD_SET_SECURE         (1<<1)
> --
> 1.7.4.4
>

Stupid question - This will affect all MMC instances, right ? Doesn't
this constitute a ABI breakage for user space scripts ?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/