Re: [PATCH v5 4/5] mmc: sdhci-tegra: Implement alternative_gpt_sector()

[Ulf Hansson <ulf.hansson@linaro.org>]

On Wed, 18 Aug 2021 at 02:57, Dmitry Osipenko <digetx@gmail.com> wrote:
>
> Tegra20/30/114/124 Android devices place GPT at a non-standard location.
> Implement alternative_gpt_sector() callback of the MMC host ops which
> specifies that GPT location for the partition scanner.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/mmc/host/sdhci-tegra.c | 42 ++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index 387ce9cdbd7c..24a713689d5b 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -116,6 +116,8 @@
>   */
>  #define NVQUIRK_HAS_TMCLK                              BIT(10)
>
> +#define NVQUIRK_HAS_ANDROID_GPT_SECTOR                 BIT(11)
> +
>  /* SDMMC CQE Base Address for Tegra Host Ver 4.1 and Higher */
>  #define SDHCI_TEGRA_CQE_BASE_ADDR                      0xF000
>
> @@ -1361,6 +1363,7 @@ static const struct sdhci_tegra_soc_data soc_data_tegra20 = {
>         .pdata = &sdhci_tegra20_pdata,
>         .dma_mask = DMA_BIT_MASK(32),
>         .nvquirks = NVQUIRK_FORCE_SDHCI_SPEC_200 |
> +                   NVQUIRK_HAS_ANDROID_GPT_SECTOR |
>                     NVQUIRK_ENABLE_BLOCK_GAP_DET,
>  };
>
> @@ -1390,6 +1393,7 @@ static const struct sdhci_tegra_soc_data soc_data_tegra30 = {
>         .nvquirks = NVQUIRK_ENABLE_SDHCI_SPEC_300 |
>                     NVQUIRK_ENABLE_SDR50 |
>                     NVQUIRK_ENABLE_SDR104 |
> +                   NVQUIRK_HAS_ANDROID_GPT_SECTOR |
>                     NVQUIRK_HAS_PADCALIB,
>  };
>
> @@ -1422,6 +1426,7 @@ static const struct sdhci_pltfm_data sdhci_tegra114_pdata = {
>  static const struct sdhci_tegra_soc_data soc_data_tegra114 = {
>         .pdata = &sdhci_tegra114_pdata,
>         .dma_mask = DMA_BIT_MASK(32),
> +       .nvquirks = NVQUIRK_HAS_ANDROID_GPT_SECTOR,
>  };
>
>  static const struct sdhci_pltfm_data sdhci_tegra124_pdata = {
> @@ -1438,6 +1443,7 @@ static const struct sdhci_pltfm_data sdhci_tegra124_pdata = {
>  static const struct sdhci_tegra_soc_data soc_data_tegra124 = {
>         .pdata = &sdhci_tegra124_pdata,
>         .dma_mask = DMA_BIT_MASK(34),
> +       .nvquirks = NVQUIRK_HAS_ANDROID_GPT_SECTOR,
>  };
>
>  static const struct sdhci_ops tegra210_sdhci_ops = {
> @@ -1590,6 +1596,38 @@ static int sdhci_tegra_add_host(struct sdhci_host *host)
>         return ret;
>  }
>
> +static int sdhci_tegra_alternative_gpt_sector(struct mmc_card *card,
> +                                             sector_t *gpt_sector)
> +{
> +       unsigned int boot_sectors_num;
> +
> +       /* filter out unrelated cards */
> +       if (card->ext_csd.rev < 3 ||
> +           !mmc_card_mmc(card) ||
> +           !mmc_card_is_blockaddr(card) ||
> +            mmc_card_is_removable(card->host))
> +               return -ENOENT;
> +
> +       /*
> +        * eMMC storage has two special boot partitions in addition to the
> +        * main one.  NVIDIA's bootloader linearizes eMMC boot0->boot1->main
> +        * accesses, this means that the partition table addresses are shifted
> +        * by the size of boot partitions.  In accordance with the eMMC
> +        * specification, the boot partition size is calculated as follows:
> +        *
> +        *      boot partition size = 128K byte x BOOT_SIZE_MULT
> +        *
> +        * Calculate number of sectors occupied by the both boot partitions.
> +        */
> +       boot_sectors_num = card->ext_csd.raw_boot_mult * SZ_128K /
> +                          SZ_512 * MMC_NUM_BOOT_PARTITION;
> +
> +       /* Defined by NVIDIA and used by Android devices. */
> +       *gpt_sector = card->ext_csd.sectors - boot_sectors_num - 1;
> +
> +       return 0;
> +}

I suggest you move this code into the mmc core/block layer instead (it
better belongs there).

Additionally, let's add a new host cap, MMC_CAP_ALTERNATIVE_GPT, to
let the core know when it should use the code above.

> +
>  static int sdhci_tegra_probe(struct platform_device *pdev)
>  {
>         const struct of_device_id *match;
> @@ -1616,6 +1654,10 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
>         tegra_host->pad_control_available = false;
>         tegra_host->soc_data = soc_data;
>
> +       if (soc_data->nvquirks & NVQUIRK_HAS_ANDROID_GPT_SECTOR)
> +               host->mmc_host_ops.alternative_gpt_sector =
> +                               sdhci_tegra_alternative_gpt_sector;
> +
>         if (soc_data->nvquirks & NVQUIRK_NEEDS_PAD_CONTROL) {
>                 rc = tegra_sdhci_init_pinctrl_info(&pdev->dev, tegra_host);
>                 if (rc == 0)
> --
> 2.32.0
>

Kind regards
Uffe