Re: [PATCH RFC v1 04/15] iommu/arm-smmu-v3: Update CD base address info for user-space

Vivek Kumar Gautam
2021-03-12T12:33:16Z

Hi Jean,

On 3/3/21 10:44 PM, Jean-Philippe Brucker wrote:
> On Fri, Jan 15, 2021 at 05:43:31PM +0530, Vivek Gautam wrote:
>> Update base address information in vendor pasid table info to pass that
>> to user-space for stage1 table management.
>>
>> Signed-off-by: Vivek Gautam <vivek.gautam@arm.com>
>> Cc: Joerg Roedel <joro@8bytes.org>
>> Cc: Will Deacon <will.deacon@arm.com>
>> Cc: Robin Murphy <robin.murphy@arm.com>
>> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
>> Cc: Eric Auger <eric.auger@redhat.com>
>> Cc: Alex Williamson <alex.williamson@redhat.com>
>> Cc: Kevin Tian <kevin.tian@intel.com>
>> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
>> Cc: Liu Yi L <yi.l.liu@intel.com>
>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>> Cc: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
>> ---
>> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-cd-lib.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-cd-lib.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-cd-lib.c
>> index 8a7187534706..ec37476c8d09 100644
>> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-cd-lib.c
>> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-cd-lib.c
>> @@ -55,6 +55,9 @@ static __le64 *arm_smmu_get_cd_ptr(struct iommu_vendor_psdtable_cfg *pst_cfg,
>> if (arm_smmu_alloc_cd_leaf_table(dev, l1_desc))
>> return NULL;
>>
>> + if (s1cfg->s1fmt == STRTAB_STE_0_S1FMT_LINEAR)
>> + pst_cfg->base = l1_desc->l2ptr_dma;
>> +
>
> This isn't the right place, because this path allocates second-level
> tables for two-level tables. I don't think we need pst_cfg->base at all,
> because for both linear and two-level tables, the base pointer is in
> cdcfg->cdtab_dma, which can be read directly.

Sure, will remove this.

>
> Thanks,
> Jean
>
>> l1ptr = cdcfg->cdtab + idx * CTXDESC_L1_DESC_DWORDS;
>> arm_smmu_write_cd_l1_desc(l1ptr, l1_desc);
>> /* An invalid L1CD can be cached */
>> @@ -211,6 +214,9 @@ static int arm_smmu_alloc_cd_tables(struct iommu_vendor_psdtable_cfg *pst_cfg)
>> goto err_free_l1;
>> }
>>
>> + if (s1cfg->s1fmt == STRTAB_STE_0_S1FMT_64K_L2)
>> + pst_cfg->base = cdcfg->cdtab_dma;
>> +
>> return 0;
>>
>> err_free_l1:
>> --
>> 2.17.1
>>