Re: [PATCH v3 05/13] iommu/arm-smmu-v3: Prepare arm_smmu_s1_cfg for SSID support

[Auger Eric <eric.auger@redhat.com>]

Hi Jean,

On 12/9/19 7:05 PM, Jean-Philippe Brucker wrote:
> When adding SSID support to the SMMUv3 driver, we'll need to manipulate
> leaf pasid tables and context descriptors. Extract the context
> descriptor structure and introduce a new table structure.
> 
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Thanks

Eric

> ---
>  drivers/iommu/arm-smmu-v3.c | 44 +++++++++++++++++++++----------------
>  1 file changed, 25 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 837b4283b4dc..b287e303b1d7 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -553,16 +553,21 @@ struct arm_smmu_strtab_l1_desc {
>  	dma_addr_t			l2ptr_dma;
>  };
>  
> +struct arm_smmu_ctx_desc {
> +	u16				asid;
> +	u64				ttbr;
> +	u64				tcr;
> +	u64				mair;
> +};
> +
> +struct arm_smmu_cd_table {
> +	__le64				*ptr;
> +	dma_addr_t			ptr_dma;
> +};
> +
>  struct arm_smmu_s1_cfg {
> -	__le64				*cdptr;
> -	dma_addr_t			cdptr_dma;
> -
> -	struct arm_smmu_ctx_desc {
> -		u16	asid;
> -		u64	ttbr;
> -		u64	tcr;
> -		u64	mair;
> -	}				cd;
> +	struct arm_smmu_cd_table	table;
> +	struct arm_smmu_ctx_desc	cd;
>  };
>  
>  struct arm_smmu_s2_cfg {
> @@ -1471,6 +1476,7 @@ static void arm_smmu_write_ctx_desc(struct arm_smmu_device *smmu,
>  				    struct arm_smmu_s1_cfg *cfg)
>  {
>  	u64 val;
> +	__le64 *cdptr = cfg->table.ptr;
>  
>  	/*
>  	 * We don't need to issue any invalidation here, as we'll invalidate
> @@ -1488,12 +1494,12 @@ static void arm_smmu_write_ctx_desc(struct arm_smmu_device *smmu,
>  	if (smmu->features & ARM_SMMU_FEAT_STALL_FORCE)
>  		val |= CTXDESC_CD_0_S;
>  
> -	cfg->cdptr[0] = cpu_to_le64(val);
> +	cdptr[0] = cpu_to_le64(val);
>  
>  	val = cfg->cd.ttbr & CTXDESC_CD_1_TTB0_MASK;
> -	cfg->cdptr[1] = cpu_to_le64(val);
> +	cdptr[1] = cpu_to_le64(val);
>  
> -	cfg->cdptr[3] = cpu_to_le64(cfg->cd.mair);
> +	cdptr[3] = cpu_to_le64(cfg->cd.mair);
>  }
>  
>  /* Stream table manipulation functions */
> @@ -1624,7 +1630,7 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
>  		   !(smmu->features & ARM_SMMU_FEAT_STALL_FORCE))
>  			dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD);
>  
> -		val |= (s1_cfg->cdptr_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
> +		val |= (s1_cfg->table.ptr_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
>  			FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_S1_TRANS);
>  	}
>  
> @@ -2138,11 +2144,11 @@ static void arm_smmu_domain_free(struct iommu_domain *domain)
>  	if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
>  		struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
>  
> -		if (cfg->cdptr) {
> +		if (cfg->table.ptr) {
>  			dmam_free_coherent(smmu_domain->smmu->dev,
>  					   CTXDESC_CD_DWORDS << 3,
> -					   cfg->cdptr,
> -					   cfg->cdptr_dma);
> +					   cfg->table.ptr,
> +					   cfg->table.ptr_dma);
>  
>  			arm_smmu_bitmap_free(smmu->asid_map, cfg->cd.asid);
>  		}
> @@ -2167,9 +2173,9 @@ static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
>  	if (asid < 0)
>  		return asid;
>  
> -	cfg->cdptr = dmam_alloc_coherent(smmu->dev, CTXDESC_CD_DWORDS << 3,
> -					 &cfg->cdptr_dma, GFP_KERNEL);
> -	if (!cfg->cdptr) {
> +	cfg->table.ptr = dmam_alloc_coherent(smmu->dev, CTXDESC_CD_DWORDS << 3,
> +					     &cfg->table.ptr_dma, GFP_KERNEL);
> +	if (!cfg->table.ptr) {
>  		dev_warn(smmu->dev, "failed to allocate context descriptor\n");
>  		ret = -ENOMEM;
>  		goto out_free_asid;
>