Re: [PATCH v5 4/4] iommu: rockchip: Add support for iommu v2

[Heiko Stübner]

Am Freitag, 21. Mai 2021, 10:36:37 CEST schrieb Benjamin Gaignard:
> This second version of the hardware block has a different bits
> mapping for page table entries.
> Add the ops matching to this new mapping.
> Define a new compatible to distinguish it from the first version.
> 
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>

Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx>

> ---
> version 5:
>  - Use internal ops to support v2 hardware block
>  - Use GENMASK macro.
>  - Keep rk_dte_pt_address() and rk_dte_pt_address_v2() separated
>    because I believe that is more readable like this.
>  - Do not duplicate code.
> 
>  drivers/iommu/rockchip-iommu.c | 78 ++++++++++++++++++++++++++++++++++
>  1 file changed, 78 insertions(+)
> 
> diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
> index e7b9bcf174b1..23253a2f269e 100644
> --- a/drivers/iommu/rockchip-iommu.c
> +++ b/drivers/iommu/rockchip-iommu.c
> @@ -189,6 +189,33 @@ static inline phys_addr_t rk_dte_pt_address(u32 dte)
>  	return (phys_addr_t)dte & RK_DTE_PT_ADDRESS_MASK;
>  }
>  
> +/*
> + * In v2:
> + * 31:12 - PT address bit 31:0
> + * 11: 8 - PT address bit 35:32
> + *  7: 4 - PT address bit 39:36
> + *  3: 1 - Reserved
> + *     0 - 1 if PT @ PT address is valid
> + */
> +#define RK_DTE_PT_ADDRESS_MASK_V2 GENMASK_ULL(31, 4)
> +#define DTE_HI_MASK1	GENMASK(11, 8)
> +#define DTE_HI_MASK2	GENMASK(7, 4)
> +#define DTE_HI_SHIFT1	24 /* shift bit 8 to bit 32 */
> +#define DTE_HI_SHIFT2	32 /* shift bit 4 to bit 36 */
> +#define PAGE_DESC_HI_MASK1	GENMASK_ULL(39, 36)
> +#define PAGE_DESC_HI_MASK2	GENMASK_ULL(35, 32)
> +
> +static inline phys_addr_t rk_dte_pt_address_v2(u32 dte)
> +{
> +	u64 dte_v2 = dte;
> +
> +	dte_v2 = ((dte_v2 & DTE_HI_MASK2) << DTE_HI_SHIFT2) |
> +		 ((dte_v2 & DTE_HI_MASK1) << DTE_HI_SHIFT1) |
> +		 (dte_v2 & RK_DTE_PT_ADDRESS_MASK);
> +
> +	return (phys_addr_t)dte_v2;
> +}
> +
>  static inline bool rk_dte_is_pt_valid(u32 dte)
>  {
>  	return dte & RK_DTE_PT_VALID;
> @@ -199,6 +226,15 @@ static inline u32 rk_mk_dte(dma_addr_t pt_dma)
>  	return (pt_dma & RK_DTE_PT_ADDRESS_MASK) | RK_DTE_PT_VALID;
>  }
>  
> +static inline u32 rk_mk_dte_v2(dma_addr_t pt_dma)
> +{
> +	pt_dma = (pt_dma & RK_DTE_PT_ADDRESS_MASK) |
> +		 ((pt_dma & PAGE_DESC_HI_MASK1) >> DTE_HI_SHIFT1) |
> +		 (pt_dma & PAGE_DESC_HI_MASK2) >> DTE_HI_SHIFT2;
> +
> +	return (pt_dma & RK_DTE_PT_ADDRESS_MASK_V2) | RK_DTE_PT_VALID;
> +}
> +
>  /*
>   * Each PTE has a Page address, some flags and a valid bit:
>   * +---------------------+---+-------+-+
> @@ -240,6 +276,29 @@ static u32 rk_mk_pte(phys_addr_t page, int prot)
>  	return page | flags | RK_PTE_PAGE_VALID;
>  }
>  
> +/*
> + * In v2:
> + * 31:12 - Page address bit 31:0
> + *  11:9 - Page address bit 34:32
> + *   8:4 - Page address bit 39:35
> + *     3 - Security
> + *     2 - Readable
> + *     1 - Writable
> + *     0 - 1 if Page @ Page address is valid
> + */
> +#define RK_PTE_PAGE_READABLE_V2      BIT(2)
> +#define RK_PTE_PAGE_WRITABLE_V2      BIT(1)
> +
> +static u32 rk_mk_pte_v2(phys_addr_t page, int prot)
> +{
> +	u32 flags = 0;
> +
> +	flags |= (prot & IOMMU_READ) ? RK_PTE_PAGE_READABLE_V2 : 0;
> +	flags |= (prot & IOMMU_WRITE) ? RK_PTE_PAGE_WRITABLE_V2 : 0;
> +
> +	return rk_mk_dte_v2(page) | flags ;
> +}
> +
>  static u32 rk_mk_pte_invalid(u32 pte)
>  {
>  	return pte & ~RK_PTE_PAGE_VALID;
> @@ -480,6 +539,14 @@ static inline phys_addr_t rk_dte_addr_phys(phys_addr_t addr)
>  	return addr;
>  }
>  
> +#define DT_HI_MASK GENMASK_ULL(39, 32)
> +#define DT_SHIFT   28
> +
> +static inline phys_addr_t rk_dte_addr_phys_v2(phys_addr_t addr)
> +{
> +	return (addr & RK_DTE_PT_ADDRESS_MASK) | ((addr & DT_HI_MASK) << DT_SHIFT);
> +}
> +
>  static void log_iova(struct rk_iommu *iommu, int index, dma_addr_t iova)
>  {
>  	void __iomem *base = iommu->bases[index];
> @@ -1305,10 +1372,21 @@ static struct rk_iommu_ops iommu_data_ops_v1 = {
>  	.pt_address_mask = RK_DTE_PT_ADDRESS_MASK,
>  };
>  
> +static struct rk_iommu_ops iommu_data_ops_v2 = {
> +	.pt_address = &rk_dte_pt_address_v2,
> +	.mk_dtentries = &rk_mk_dte_v2,
> +	.mk_ptentries = &rk_mk_pte_v2,
> +	.dte_addr_phys = &rk_dte_addr_phys_v2,
> +	.pt_address_mask = RK_DTE_PT_ADDRESS_MASK_V2,
> +};
> +
>  static const struct of_device_id rk_iommu_dt_ids[] = {
>  	{	.compatible = "rockchip,iommu",
>  		.data = &iommu_data_ops_v1,
>  	},
> +	{	.compatible = "rockchip,rk3568-iommu",
> +		.data = &iommu_data_ops_v2,
> +	},
>  	{ /* sentinel */ }
>  };
>  MODULE_DEVICE_TABLE(of, rk_iommu_dt_ids);
>