Re: [PATCH v4 2/9] mmc: sd: Add Extension memory addressing

[Adrian Hunter <adrian.hunter@intel.com>]

On 25/08/24 10:41, Avri Altman 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 | 16 ++++++++++++++++
>  drivers/mmc/core/sd_ops.h |  1 +
>  include/linux/mmc/sd.h    |  3 +++
>  3 files changed, 20 insertions(+)
> 
> diff --git a/drivers/mmc/core/sd_ops.c b/drivers/mmc/core/sd_ops.c
> index 8b9b34286ef3..780c5dd7266f 100644
> --- a/drivers/mmc/core/sd_ops.c
> +++ b/drivers/mmc/core/sd_ops.c
> @@ -16,6 +16,7 @@
>  #include <linux/mmc/sd.h>
>  
>  #include "core.h"
> +#include "card.h"
>  #include "sd_ops.h"
>  #include "mmc_ops.h"
>  
> @@ -188,6 +189,21 @@ 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),

If addr were outside the acceptable range, then the command
should fail, which is what we want, so better to leave out
the mask i.e.

		.arg = (u32)(addr >> 32),


> +		.flags = MMC_RSP_R1 | MMC_CMD_AC,
> +	};
> +
> +	if (!mmc_card_ult_capacity(host->card))
> +		return 0;
> +
> +	return mmc_wait_for_cmd(host, &cmd, 0);
> +}
> +EXPORT_SYMBOL_GPL(mmc_send_ext_addr);
> +
>  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  */
>