[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <4E8C4163.1090109@intel.com>
Date: Wed, 05 Oct 2011 14:37:07 +0300
From: Adrian Hunter <adrian.hunter@...el.com>
To: NamJae Jeon <linkinjeon@...il.com>
CC: cjb@...top.org, linux-mmc@...r.kernel.org,
linux-kernel@...r.kernel.org, awarkentin@...are.com,
linus.walleij@...aro.org, james_p_freyensee@...ux.intel.com,
sebras@...il.com, Ulf.Hansson@...ricsson.com,
stefan.xk.nilsson@...ricsson.com, per.forlin@...ricsson.com,
johan.rudholm@...ricsson.com
Subject: Re: [PATCH v10] mmc : general purpose partition support.
On 05/10/11 14:22, NamJae Jeon wrote:
> 2011/10/5 NamJae Jeon<linkinjeon@...il.com>:
>> 2011/10/5 Adrian Hunter<adrian.hunter@...el.com>:
>>> On 05/10/11 13:21, NamJae Jeon wrote:
>>>>
>>>> 2011/10/5 Adrian Hunter<adrian.hunter@...el.com>:
>>>>>
>>>>> On 04/10/11 20:45, Namjae Jeon 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@...il.com>
>>>>>> ---
>>>>>> 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;
>>>>>
>>>>> Seems a bit fragile. What if someone decided to put the gp
>>>>> partitions before the boot partitions. What about:
>>>>
>>>> There are the default two boot partition in mmc spec. I think that
>>>> this case can not be happened.
>>>> And boot partition size of EXT CSD is read-only.
>>>> Can you explain which is case put to gp partitions before the boot
>>>> partition ?
>>>
>>> Relying on the partition order in the partition array is fragile.
>>> You cannot predict how someone may want to change it in the future,
>>> and that person will not expect that certain positions have certain meaning.
> 0,1 of Boot partition is fixed if spec is not changed over. but gp
No. 0,1 are an accidental result of the order in which ext-csd is
parsed.
> partition is variable in 2,3,4,5,6 of array.
> If How someone change code, problem occur ?
If you move code around in mmc_read_ext_csd() the order can change,
hence it is fragile.
>>>
>>>>
>>>>>
>>>>> if (mmc_is_boot_partition(&part[idx])&&
>>>>> !mmc_boot_partition_access(card->host)
>>>>> continue;
>>>>>
>>>>> And:
>>>>>
>>>>> int mmc_is_boot_partition(struct mmc_part *part)
>>>>> {
>>>>> return part->part_cfg>= EXT_CSD_PART_CONFIG_ACC_BOOT0&&
>>>>> part->part_cfg<= EXT_CSD_PART_CONFIG_ACC_BOOT0 +
>>>>> MMC_NUM_BOOT_PARTITION;
>>>>> }
>>>>>
>>>>>> + 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)
>>>>>
>>>>>
>>>
>>>
>>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists