Re: [PATCH v3 06/13] iommu/arm-smmu-v3: Add context descriptor tables allocators

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

Hi Jean,

On 12/9/19 7:05 PM, Jean-Philippe Brucker wrote:
> Support for SSID will require allocating context descriptor tables. Move
> the context descriptor allocation to separate functions.
> 
> 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 | 57 ++++++++++++++++++++++++++++++-------
>  1 file changed, 46 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index b287e303b1d7..43d6a7ded6e4 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -568,6 +568,7 @@ struct arm_smmu_cd_table {
>  struct arm_smmu_s1_cfg {
>  	struct arm_smmu_cd_table	table;
>  	struct arm_smmu_ctx_desc	cd;
> +	u8				s1cdmax;
>  };
>  
>  struct arm_smmu_s2_cfg {
> @@ -1455,6 +1456,31 @@ static int arm_smmu_cmdq_issue_sync(struct arm_smmu_device *smmu)
>  }
>  
>  /* Context descriptor manipulation functions */
> +static int arm_smmu_alloc_cd_leaf_table(struct arm_smmu_device *smmu,
> +					struct arm_smmu_cd_table *table,
> +					size_t num_entries)
> +{
> +	size_t size = num_entries * (CTXDESC_CD_DWORDS << 3);
> +
> +	table->ptr = dmam_alloc_coherent(smmu->dev, size, &table->ptr_dma,
> +					 GFP_KERNEL);
> +	if (!table->ptr) {
> +		dev_warn(smmu->dev,
> +			 "failed to allocate context descriptor table\n");
> +		return -ENOMEM;
> +	}
> +	return 0;
> +}
> +
> +static void arm_smmu_free_cd_leaf_table(struct arm_smmu_device *smmu,
> +					struct arm_smmu_cd_table *table,
> +					size_t num_entries)
> +{
> +	size_t size = num_entries * (CTXDESC_CD_DWORDS << 3);
> +
> +	dmam_free_coherent(smmu->dev, size, table->ptr, table->ptr_dma);
> +}
> +
>  static u64 arm_smmu_cpu_tcr_to_cd(u64 tcr)
>  {
>  	u64 val = 0;
> @@ -1502,6 +1528,23 @@ static void arm_smmu_write_ctx_desc(struct arm_smmu_device *smmu,
>  	cdptr[3] = cpu_to_le64(cfg->cd.mair);
>  }
>  
> +static int arm_smmu_alloc_cd_tables(struct arm_smmu_domain *smmu_domain)
> +{
> +	struct arm_smmu_device *smmu = smmu_domain->smmu;
> +	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
> +
> +	return arm_smmu_alloc_cd_leaf_table(smmu, &cfg->table,
> +					    1 << cfg->s1cdmax);
> +}
> +
> +static void arm_smmu_free_cd_tables(struct arm_smmu_domain *smmu_domain)
> +{
> +	struct arm_smmu_device *smmu = smmu_domain->smmu;
> +	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
> +
> +	arm_smmu_free_cd_leaf_table(smmu, &cfg->table, 1 << cfg->s1cdmax);
> +}
> +
>  /* Stream table manipulation functions */
>  static void
>  arm_smmu_write_strtab_l1_desc(__le64 *dst, struct arm_smmu_strtab_l1_desc *desc)
> @@ -2145,11 +2188,7 @@ static void arm_smmu_domain_free(struct iommu_domain *domain)
>  		struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
>  
>  		if (cfg->table.ptr) {
> -			dmam_free_coherent(smmu_domain->smmu->dev,
> -					   CTXDESC_CD_DWORDS << 3,
> -					   cfg->table.ptr,
> -					   cfg->table.ptr_dma);
> -
> +			arm_smmu_free_cd_tables(smmu_domain);
>  			arm_smmu_bitmap_free(smmu->asid_map, cfg->cd.asid);
>  		}
>  	} else {
> @@ -2173,13 +2212,9 @@ static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
>  	if (asid < 0)
>  		return asid;
>  
> -	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;
> +	ret = arm_smmu_alloc_cd_tables(smmu_domain);
> +	if (ret)
>  		goto out_free_asid;
> -	}
>  
>  	cfg->cd.asid	= (u16)asid;
>  	cfg->cd.ttbr	= pgtbl_cfg->arm_lpae_s1_cfg.ttbr[0];
>