Re: [PATCH v4 17/22] iommu/vt-d: Avoid duplicated code for PASID setup

Auger Eric
2019-07-16T09:52:36Z

Hi Jacob,

On 6/9/19 3:44 PM, Jacob Pan wrote:
> After each setup for PASID entry, related translation caches must be flushed.
> We can combine duplicated code into one function which is less error prone.
>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
> drivers/iommu/intel-pasid.c | 48 +++++++++++++++++----------------------------
> 1 file changed, 18 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/iommu/intel-pasid.c b/drivers/iommu/intel-pasid.c
> index 1e25539..1ff2ecc 100644
> --- a/drivers/iommu/intel-pasid.c
> +++ b/drivers/iommu/intel-pasid.c
> @@ -522,6 +522,21 @@ void intel_pasid_tear_down_entry(struct intel_iommu *iommu,
> devtlb_invalidation_with_pasid(iommu, dev, pasid);
> }
>
> +static inline void pasid_flush_caches(struct intel_iommu *iommu,
> + struct pasid_entry *pte,
> + int pasid, u16 did)
> +{
> + if (!ecap_coherent(iommu->ecap))
> + clflush_cache_range(pte, sizeof(*pte));
> +
> + if (cap_caching_mode(iommu->cap)) {
> + pasid_cache_invalidation_with_pasid(iommu, did, pasid);
> + iotlb_invalidation_with_pasid(iommu, did, pasid);
> + } else
> + iommu_flush_write_buffer(iommu);
Besides the style issue reported by Jonathan and the fact this function
may not deserve the inline (chapt 15 of
https://www.kernel.org/doc/html/v5.1/process/coding-style.html),

Reviewed-by: Eric Auger <eric.auger@redhat.com>

Thanks

Eric
> +
> +}
> +
> /*
> * Set up the scalable mode pasid table entry for first only
> * translation type.
> @@ -567,16 +582,7 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu,
> /* Setup Present and PASID Granular Transfer Type: */
> pasid_set_translation_type(pte, 1);
> pasid_set_present(pte);
> -
> - if (!ecap_coherent(iommu->ecap))
> - clflush_cache_range(pte, sizeof(*pte));
> -
> - if (cap_caching_mode(iommu->cap)) {
> - pasid_cache_invalidation_with_pasid(iommu, did, pasid);
> - iotlb_invalidation_with_pasid(iommu, did, pasid);
> - } else {
> - iommu_flush_write_buffer(iommu);
> - }
> + pasid_flush_caches(iommu, pte, pasid, did);
>
> return 0;
> }
> @@ -640,16 +646,7 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu,
> */
> pasid_set_sre(pte);
> pasid_set_present(pte);
> -
> - if (!ecap_coherent(iommu->ecap))
> - clflush_cache_range(pte, sizeof(*pte));
> -
> - if (cap_caching_mode(iommu->cap)) {
> - pasid_cache_invalidation_with_pasid(iommu, did, pasid);
> - iotlb_invalidation_with_pasid(iommu, did, pasid);
> - } else {
> - iommu_flush_write_buffer(iommu);
> - }
> + pasid_flush_caches(iommu, pte, pasid, did);
>
> return 0;
> }
> @@ -683,16 +680,7 @@ int intel_pasid_setup_pass_through(struct intel_iommu *iommu,
> */
> pasid_set_sre(pte);
> pasid_set_present(pte);
> -
> - if (!ecap_coherent(iommu->ecap))
> - clflush_cache_range(pte, sizeof(*pte));
> -
> - if (cap_caching_mode(iommu->cap)) {
> - pasid_cache_invalidation_with_pasid(iommu, did, pasid);
> - iotlb_invalidation_with_pasid(iommu, did, pasid);
> - } else {
> - iommu_flush_write_buffer(iommu);
> - }
> + pasid_flush_caches(iommu, pte, pasid, did);
>
> return 0;
> }