On 02/07/2022 23:37, Sam Protsenko wrote:
> SysMMU v7 can have Virtual Machine registers, which implement multiple
> translation domains. The driver should know if it's true or not, as VM
> registers shouldn't be accessed if not present. Read corresponding
> capabilities register to obtain that info, and store it in driver data.
>
> Signed-off-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx>
> ---
> drivers/iommu/exynos-iommu.c | 42 ++++++++++++++++++++++++++++++------
> 1 file changed, 36 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> index 28f8c8d93aa3..df6ddbebbe2b 100644
> --- a/drivers/iommu/exynos-iommu.c
> +++ b/drivers/iommu/exynos-iommu.c
> @@ -135,6 +135,9 @@ static u32 lv2ent_offset(sysmmu_iova_t iova)
> #define CFG_SYSSEL (1 << 22) /* System MMU 3.2 only */
> #define CFG_FLPDCACHE (1 << 20) /* System MMU 3.2+ only */
>
> +#define CAPA0_CAPA1_EXIST BIT(11)
> +#define CAPA1_VCR_ENABLED BIT(14)
> +
> /* common registers */
> #define REG_MMU_CTRL 0x000
> #define REG_MMU_CFG 0x004
> @@ -171,6 +174,10 @@ static u32 lv2ent_offset(sysmmu_iova_t iova)
> #define REG_V5_FAULT_AR_VA 0x070
> #define REG_V5_FAULT_AW_VA 0x080
>
> +/* v7.x registers */
> +#define REG_V7_CAPA0 0x870
> +#define REG_V7_CAPA1 0x874
> +
> #define has_sysmmu(dev) (dev_iommu_priv_get(dev) != NULL)
>
> static struct device *dma_dev;
> @@ -274,6 +281,9 @@ struct sysmmu_drvdata {
> unsigned int version; /* our version */
>
> struct iommu_device iommu; /* IOMMU core handle */
> +
> + /* v7 fields */
> + bool has_vcr; /* virtual machine control register */
> };
>
> static struct exynos_iommu_domain *to_exynos_domain(struct iommu_domain *dom)
> @@ -364,11 +374,7 @@ static void __sysmmu_disable_clocks(struct sysmmu_drvdata *data)
>
> static void __sysmmu_get_version(struct sysmmu_drvdata *data)
> {
> - u32 ver;
> -
> - __sysmmu_enable_clocks(data);
> -
> - ver = readl(data->sfrbase + REG_MMU_VERSION);
> + const u32 ver = readl(data->sfrbase + REG_MMU_VERSION);
No need for const for local, non-pointer variables. There is no benefit
in preventing the modification and it is not a constant.
>
> /* controllers on some SoCs don't report proper version */
> if (ver == 0x80000001u)
> @@ -378,6 +384,29 @@ static void __sysmmu_get_version(struct sysmmu_drvdata *data)
>
> dev_dbg(data->sysmmu, "hardware version: %d.%d\n",
> MMU_MAJ_VER(data->version), MMU_MIN_VER(data->version));
> +}
> +
> +static bool __sysmmu_has_capa1(struct sysmmu_drvdata *data)
> +{
> + const u32 capa0 = readl(data->sfrbase + REG_V7_CAPA0);
Same here and further.
Best regards,
Krzysztof
