[v3,03/10] mmc: sd: Add Extension memory addressing

SDUC memory addressing spans beyond 2TB and up to 128TB.  Therefore, 38
bits are required to access the entire memory space of all sectors.
Those extra 6 bits are to be carried by CMD22 prior of sending
read/write/erase commands: CMD17, CMD18, CMD24, CMD25, CMD32, and CMD33.

CMD22 will carry the higher order 6 bits, and must precedes any of the
above commands even if it targets sector < 2TB.

No error related to address or length is indicated in CMD22 but rather
in the read/write command itself.

Tested-by: Ricky WU <ricky_wu@realtek.com>
Signed-off-by: Avri Altman <avri.altman@wdc.com>
---
 drivers/mmc/core/sd_ops.c | 15 +++++++++++++++
 drivers/mmc/core/sd_ops.h |  1 +
 include/linux/mmc/sd.h    |  3 +++
 3 files changed, 19 insertions(+)

On Wed, 14 Aug 2024 at 09:31, Avri Altman <avri.altman@wdc.com> wrote:
>
> SDUC memory addressing spans beyond 2TB and up to 128TB.  Therefore, 38
> bits are required to access the entire memory space of all sectors.
> Those extra 6 bits are to be carried by CMD22 prior of sending
> read/write/erase commands: CMD17, CMD18, CMD24, CMD25, CMD32, and CMD33.
>
> CMD22 will carry the higher order 6 bits, and must precedes any of the
> above commands even if it targets sector < 2TB.
>
> No error related to address or length is indicated in CMD22 but rather
> in the read/write command itself.
>
> Tested-by: Ricky WU <ricky_wu@realtek.com>
> Signed-off-by: Avri Altman <avri.altman@wdc.com>
> ---
>  drivers/mmc/core/sd_ops.c | 15 +++++++++++++++
>  drivers/mmc/core/sd_ops.h |  1 +
>  include/linux/mmc/sd.h    |  3 +++
>  3 files changed, 19 insertions(+)
>
> diff --git a/drivers/mmc/core/sd_ops.c b/drivers/mmc/core/sd_ops.c
> index 7f6963dac873..8b69129d7b61 100644
> --- a/drivers/mmc/core/sd_ops.c
> +++ b/drivers/mmc/core/sd_ops.c
> @@ -199,6 +199,21 @@ int mmc_send_app_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
>         return 0;
>  }
>
> +int mmc_send_ext_addr(struct mmc_host *host, sector_t addr)
> +{
> +       struct mmc_command cmd = {
> +               .opcode = SD_ADDR_EXT,
> +               .arg = (u32)((addr >> 32) & 0x3F),
> +               .flags = MMC_RSP_R1 | MMC_CMD_AC,
> +       };
> +
> +       if (!mmc_card_is_sduc(host))
> +               return 0;
> +
> +       return mmc_wait_for_cmd(host, &cmd, 0);
> +}
> +EXPORT_SYMBOL_GPL(mmc_send_ext_addr);

Why is this exported?

I was thinking that it should only be the mmc core (not the mmc block
device driver) that needs to keep track of how the card should be
addressed. In that case, why is the EXPORT_SYMBOL_GPL needed?

Oh well, I guess I need to look at the following patches in the series
to understand better.

> +
>  static int __mmc_send_if_cond(struct mmc_host *host, u32 ocr, u8 pcie_bits,
>                               u32 *resp)
>  {
> diff --git a/drivers/mmc/core/sd_ops.h b/drivers/mmc/core/sd_ops.h
> index 7667fc223b74..462efd43acfa 100644
> --- a/drivers/mmc/core/sd_ops.h
> +++ b/drivers/mmc/core/sd_ops.h
> @@ -21,6 +21,7 @@ int mmc_send_relative_addr(struct mmc_host *host, unsigned int *rca);
>  int mmc_app_send_scr(struct mmc_card *card);
>  int mmc_app_sd_status(struct mmc_card *card, void *ssr);
>  int mmc_app_cmd(struct mmc_host *host, struct mmc_card *card);
> +int mmc_send_ext_addr(struct mmc_host *host, sector_t addr);
>
>  #endif
>
> diff --git a/include/linux/mmc/sd.h b/include/linux/mmc/sd.h
> index 865cc0ca8543..af5fc70e09a2 100644
> --- a/include/linux/mmc/sd.h
> +++ b/include/linux/mmc/sd.h
> @@ -15,6 +15,9 @@
>  #define SD_SEND_IF_COND           8   /* bcr  [11:0] See below   R7  */
>  #define SD_SWITCH_VOLTAGE         11  /* ac                      R1  */
>
> +/* Class 2 */
> +#define SD_ADDR_EXT             22   /* ac   [5:0]              R1  */
> +
>    /* class 10 */
>  #define SD_SWITCH                 6   /* adtc [31:0] See below   R1  */
>
> --
> 2.25.1
>

Kind regards
Uffe

> > +EXPORT_SYMBOL_GPL(mmc_send_ext_addr);
> 
> Why is this exported?
> 
> I was thinking that it should only be the mmc core (not the mmc block device
> driver) that needs to keep track of how the card should be addressed. In that
> case, why is the EXPORT_SYMBOL_GPL needed?
> 
> Oh well, I guess I need to look at the following patches in the series to
> understand better.
I exported it following a kernel test robot warning got a in v1:
>> ERROR: modpost: "mmc_send_ext_addr" [drivers/mmc/core/mmc_block.ko] undefined!

Thanks,
Avri