Re: [PATCH v5 2/3] mmc: sdhci-tegra: Add support to program MC stream ID

From: Adrian Hunter
Date: Tue Sep 27 2022 - 08:45:59 EST


On 27/09/22 14:13, Prathamesh Shete wrote:
> SMMU clients are supposed to program stream ID from
> their respective address spaces instead of MC override.
> Define NVQUIRK_PROGRAM_STREAMID and use it to program
> SMMU stream ID from the SDMMC client address space.
>
> Signed-off-by: Aniruddha TVS Rao <anrao@xxxxxxxxxx>
> Signed-off-by: Prathamesh Shete <pshete@xxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-tegra.c | 47 ++++++++++++++++++++++++++++++++++
> 1 file changed, 47 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index a6c5bbae77b4..46f37cc26dbb 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -25,6 +25,9 @@
> #include <linux/mmc/slot-gpio.h>
> #include <linux/gpio/consumer.h>
> #include <linux/ktime.h>
> +#ifdef CONFIG_IOMMU_API
> +#include <linux/iommu.h>
> +#endif
>
> #include <soc/tegra/common.h>
>
> @@ -94,6 +97,8 @@
> #define SDHCI_TEGRA_AUTO_CAL_STATUS 0x1ec
> #define SDHCI_TEGRA_AUTO_CAL_ACTIVE BIT(31)
>
> +#define SDHCI_TEGRA_CIF2AXI_CTRL_0 0x1fc
> +
> #define NVQUIRK_FORCE_SDHCI_SPEC_200 BIT(0)
> #define NVQUIRK_ENABLE_BLOCK_GAP_DET BIT(1)
> #define NVQUIRK_ENABLE_SDHCI_SPEC_300 BIT(2)
> @@ -121,6 +126,7 @@
> #define NVQUIRK_HAS_TMCLK BIT(10)
>
> #define NVQUIRK_HAS_ANDROID_GPT_SECTOR BIT(11)
> +#define NVQUIRK_PROGRAM_STREAMID BIT(12)
>
> /* SDMMC CQE Base Address for Tegra Host Ver 4.1 and Higher */
> #define SDHCI_TEGRA_CQE_BASE_ADDR 0xF000
> @@ -128,6 +134,8 @@
> #define SDHCI_TEGRA_CQE_TRNS_MODE (SDHCI_TRNS_MULTI | \
> SDHCI_TRNS_BLK_CNT_EN | \
> SDHCI_TRNS_DMA)
> +#define SDHCI_TEGRA_STREAMID_MASK 0xff
> +#define SDHCI_TEGRA_WRITE_STREAMID_SHIFT 0x8
>
> struct sdhci_tegra_soc_data {
> const struct sdhci_pltfm_data *pdata;
> @@ -177,6 +185,9 @@ struct sdhci_tegra {
> bool enable_hwcq;
> unsigned long curr_clk_rate;
> u8 tuned_tap_delay;
> +#ifdef CONFIG_IOMMU_API
> + u32 streamid;
> +#endif
> };
>
> static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
> @@ -1564,6 +1575,7 @@ static const struct sdhci_tegra_soc_data soc_data_tegra234 = {
> NVQUIRK_DIS_CARD_CLK_CONFIG_TAP |
> NVQUIRK_ENABLE_SDR50 |
> NVQUIRK_ENABLE_SDR104 |
> + NVQUIRK_PROGRAM_STREAMID |
> NVQUIRK_HAS_TMCLK,
> .min_tap_delay = 95,
> .max_tap_delay = 111,
> @@ -1636,6 +1648,9 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
> struct sdhci_host *host;
> struct sdhci_pltfm_host *pltfm_host;
> struct sdhci_tegra *tegra_host;
> +#ifdef CONFIG_IOMMU_API
> + struct iommu_fwspec *fwspec;
> +#endif

Move this below

> struct clk *clk;
> int rc;
>
> @@ -1775,6 +1790,25 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
> if (rc)
> goto err_add_host;
>
> + /* Program MC streamID for DMA transfers */
> +#ifdef CONFIG_IOMMU_API
> + if (soc_data->nvquirks & NVQUIRK_PROGRAM_STREAMID) {

Can put it here

struct iommu_fwspec *fwspec;


> + fwspec = dev_iommu_fwspec_get(&pdev->dev);
> + if (fwspec == NULL) {
> + dev_warn(mmc_dev(host->mmc),
> + "iommu fwspec is NULL, continue without stream ID\n");
> + } else {
> + tegra_host->streamid = fwspec->ids[0] & 0xffff;
> + tegra_sdhci_writel(host, (tegra_host->streamid &
> + SDHCI_TEGRA_STREAMID_MASK) |
> + ((tegra_host->streamid <<
> + SDHCI_TEGRA_WRITE_STREAMID_SHIFT)
> + & SDHCI_TEGRA_STREAMID_MASK),
> + SDHCI_TEGRA_CIF2AXI_CTRL_0);

This is hard to read. Maybe use GENMASK and FIELD_PREP, or if the bytes
need swapping, one of the byte swapping macros.

Also, isn't this always zero ?

((tegra_host->streamid << SDHCI_TEGRA_WRITE_STREAMID_SHIFT) & SDHCI_TEGRA_STREAMID_MASK),


> + }
> + }
> +#endif
> +
> return 0;
>
> err_add_host:
> @@ -1861,6 +1895,10 @@ static int sdhci_tegra_suspend(struct device *dev)
> static int sdhci_tegra_resume(struct device *dev)
> {
> struct sdhci_host *host = dev_get_drvdata(dev);
> +#ifdef CONFIG_IOMMU_API
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
> +#endif
> int ret;
>
> ret = mmc_gpio_set_cd_wake(host->mmc, false);
> @@ -1871,6 +1909,15 @@ static int sdhci_tegra_resume(struct device *dev)
> if (ret)
> return ret;
>
> + /* Re-program MC streamID for DMA transfers */
> +#ifdef CONFIG_IOMMU_API
> + if (tegra_host->soc_data->nvquirks & NVQUIRK_PROGRAM_STREAMID) {
> + tegra_sdhci_writel(host, tegra_host->streamid |
> + (tegra_host->streamid << 8),

This looks like it ought to be the same calculation as above ?

> + SDHCI_TEGRA_CIF2AXI_CTRL_0);
> + }
> +#endif
> +
> ret = sdhci_resume_host(host);
> if (ret)
> goto disable_clk;