[PATCH 3/3] iommu/vt-d: Move clflush'es from iotlb_sync_map() to map_pages()

Lu Baolu
2021-07-20T02:10:54Z

As the Intel VT-d driver has switched to use the iommu_ops.map_pages()
callback, multiple pages of the same size will be mapped in a call.
There's no need to put the clflush'es in iotlb_sync_map() callback.
Move them back into __domain_mapping() to simplify the code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/intel/iommu.c | 48 ++++++-------------------------------
1 file changed, 7 insertions(+), 41 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 6114dac8777d..8c116fe071a2 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2331,9 +2331,9 @@ static int
__domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
unsigned long phys_pfn, unsigned long nr_pages, int prot)
{
+ struct dma_pte *first_pte = NULL, *pte = NULL;
unsigned int largepage_lvl = 0;
unsigned long lvl_pages = 0;
- struct dma_pte *pte = NULL;
phys_addr_t pteval;
u64 attr;

@@ -2366,6 +2366,8 @@ __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
pte = pfn_to_dma_pte(domain, iov_pfn, &largepage_lvl);
if (!pte)
return -ENOMEM;
+ first_pte = pte;
+
/* It is large page*/
if (largepage_lvl > 1) {
unsigned long end_pfn;
@@ -2413,14 +2415,14 @@ __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
* recalculate 'pte' and switch back to smaller pages for the
* end of the mapping, if the trailing size is not enough to
* use another superpage (i.e. nr_pages < lvl_pages).
- *
- * We leave clflush for the leaf pte changes to iotlb_sync_map()
- * callback.
*/
pte++;
if (!nr_pages || first_pte_in_page(pte) ||
- (largepage_lvl > 1 && nr_pages < lvl_pages))
+ (largepage_lvl > 1 && nr_pages < lvl_pages)) {
+ domain_flush_cache(domain, first_pte,
+ (void *)pte - (void *)first_pte);
pte = NULL;
+ }
}

return 0;
@@ -5561,39 +5563,6 @@ static bool risky_device(struct pci_dev *pdev)
return false;
}

-static void clflush_sync_map(struct dmar_domain *domain, unsigned long clf_pfn,
- unsigned long clf_pages)
-{
- struct dma_pte *first_pte = NULL, *pte = NULL;
- unsigned long lvl_pages = 0;
- int level = 0;
-
- while (clf_pages > 0) {
- if (!pte) {
- level = 0;
- pte = pfn_to_dma_pte(domain, clf_pfn, &level);
- if (WARN_ON(!pte))
- return;
- first_pte = pte;
- lvl_pages = lvl_to_nr_pages(level);
- }
-
- if (WARN_ON(!lvl_pages || clf_pages < lvl_pages))
- return;
-
- clf_pages -= lvl_pages;
- clf_pfn += lvl_pages;
- pte++;
-
- if (!clf_pages || first_pte_in_page(pte) ||
- (level > 1 && clf_pages < lvl_pages)) {
- domain_flush_cache(domain, first_pte,
- (void *)pte - (void *)first_pte);
- pte = NULL;
- }
- }
-}
-
static void intel_iommu_iotlb_sync_map(struct iommu_domain *domain,
unsigned long iova, size_t size)
{
@@ -5603,9 +5572,6 @@ static void intel_iommu_iotlb_sync_map(struct iommu_domain *domain,
struct intel_iommu *iommu;
int iommu_id;

- if (!dmar_domain->iommu_coherency)
- clflush_sync_map(dmar_domain, pfn, pages);
-
for_each_domain_iommu(iommu_id, dmar_domain) {
iommu = g_iommus[iommu_id];
__mapping_notify_one(iommu, dmar_domain, pfn, pages);
--
2.25.1