Re: [PATCH 5.10 337/663] iommu: Move iotlb_sync_map out from __iommu_map

Hi!

[ Upstream commit d8c1df02ac7f2c802a9b2afc0f5c888c4217f1d5 ]

In the end of __iommu_map, It alway call iotlb_sync_map.

This patch moves iotlb_sync_map out from __iommu_map since it is unnecessary to call this for each sg segment especially iotlb_sync_map is flush tlb all currently. Add a little helper _iommu_map for this.

Signed-off-by: Sasha Levin sashal@kernel.org

AFAICT this is slight performance optimalization, not a bugfix. It actually introduces a bug, fixed by the next patch. I'd preffer not to have it in stable.

Best regards, Pavel

@@ -2421,18 +2418,31 @@ static int __iommu_map(struct iommu_domain *domain, unsigned long iova, +static int _iommu_map(struct iommu_domain *domain, unsigned long iova,

•       phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
  

+{

• const struct iommu_ops *ops = domain->ops;
• int ret;
• ret = __iommu_map(domain, iova, paddr, size, prot, GFP_KERNEL);
• if (ret == 0 && ops->iotlb_sync_map)

• ops->iotlb_sync_map(domain);
  

• return ret;

+}