Re: [RFC v3 11/21] iommu/smmuv3: Implement cache_invalidate

Jean-Philippe Brucker
2019-01-11T16:59:55Z

On 08/01/2019 10:26, Eric Auger wrote:
> Implement IOMMU_INV_TYPE_TLB invalidations. When
> nr_pages is null we interpret this as a context
> invalidation.
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>
> ---
>
> The user API needs to be refined to discriminate context
> invalidations from NH_VA invalidations. Also the leaf attribute
> is not yet properly handled.
>
> v2 -> v3:
> - replace __arm_smmu_tlb_sync by arm_smmu_cmdq_issue_sync
>
> v1 -> v2:
> - properly pass the asid
> ---
> drivers/iommu/arm-smmu-v3.c | 40 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 40 insertions(+)
>
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 0e006babc8a6..ca72e0ce92f6 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2293,6 +2293,45 @@ static int arm_smmu_set_pasid_table(struct iommu_domain *domain,
> return ret;
> }
>
> +static int
> +arm_smmu_cache_invalidate(struct iommu_domain *domain, struct device *dev,
> + struct iommu_cache_invalidate_info *inv_info)
> +{
> + struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
> + struct arm_smmu_device *smmu = smmu_domain->smmu;
> +
> + if (smmu_domain->stage != ARM_SMMU_DOMAIN_NESTED)
> + return -EINVAL;
> +
> + if (!smmu)
> + return -EINVAL;
> +
> + switch (inv_info->hdr.type) {
> + case IOMMU_INV_TYPE_TLB:
> + /*
> + * TODO: On context invalidation, the userspace sets nr_pages
> + * to 0. Refine the API to add a dedicated flags and also
> + * properly handle the leaf parameter.
> + */

That's what inv->granularity is for: if inv->granularity is PASID_SEL,
then the invalidation is for the whole context (and nr_pages, size,
addr, etc. should be ignored). If inv->granularity is PAGE_PASID, then
it's a range. The names could probably be improved but it's already in
the API

Thanks,
Jean

> + if (!inv_info->nr_pages) {
> + smmu_domain->s1_cfg.cd.asid = inv_info->arch_id;
> + arm_smmu_tlb_inv_context(smmu_domain);
> + } else {
> + size_t granule = 1 << (inv_info->size + 12);
> + size_t size = inv_info->nr_pages * granule;
> +
> + smmu_domain->s1_cfg.cd.asid = inv_info->arch_id;
> + arm_smmu_tlb_inv_range_nosync(inv_info->addr, size,
> + granule, false,
> + smmu_domain);
> + arm_smmu_cmdq_issue_sync(smmu);
> + }
> + return 0;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> static struct iommu_ops arm_smmu_ops = {
> .capable = arm_smmu_capable,
> .domain_alloc = arm_smmu_domain_alloc,
> @@ -2312,6 +2351,7 @@ static struct iommu_ops arm_smmu_ops = {
> .get_resv_regions = arm_smmu_get_resv_regions,
> .put_resv_regions = arm_smmu_put_resv_regions,
> .set_pasid_table = arm_smmu_set_pasid_table,
> + .cache_invalidate = arm_smmu_cache_invalidate,
> .pgsize_bitmap = -1UL, /* Restricted during device attach */
> };
>
>