From 4c293add5874038dc82ef579663dd86744d8e872 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 10 Mar 2025 10:47:49 +0800 Subject: [PATCH] iommu/vt-d: Cleanup intel_context_flush_present() The intel_context_flush_present() is called in places where either the scalable mode is disabled, or scalable mode is enabled but all PASID entries are known to be non-present. In these cases, the flush_domains path within intel_context_flush_present() will never execute. This dead code is therefore removed. Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Tested-by: Zhangfei Gao Link: https://lore.kernel.org/r/20250228092631.3425464-7-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/intel/iommu.c | 2 +- drivers/iommu/intel/iommu.h | 5 ++--- drivers/iommu/intel/pasid.c | 41 +++++++------------------------------ 3 files changed, 10 insertions(+), 38 deletions(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 9ed8bdb3e9da..072223fe6fe7 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -1783,7 +1783,7 @@ static void domain_context_clear_one(struct device_domain_info *info, u8 bus, u8 context_clear_entry(context); __iommu_flush_cache(iommu, context, sizeof(*context)); spin_unlock(&iommu->lock); - intel_context_flush_present(info, context, did, true); + intel_context_flush_no_pasid(info, context, did); } int __domain_setup_first_level(struct intel_iommu *iommu, diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index 42b4e500989b..c4916886da5a 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -1286,9 +1286,8 @@ void cache_tag_flush_all(struct dmar_domain *domain); void cache_tag_flush_range_np(struct dmar_domain *domain, unsigned long start, unsigned long end); -void intel_context_flush_present(struct device_domain_info *info, - struct context_entry *context, - u16 did, bool affect_domains); +void intel_context_flush_no_pasid(struct device_domain_info *info, + struct context_entry *context, u16 did); int intel_iommu_enable_prq(struct intel_iommu *iommu); int intel_iommu_finish_prq(struct intel_iommu *iommu); diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c index c2742e256552..7ee18bb48bd4 100644 --- a/drivers/iommu/intel/pasid.c +++ b/drivers/iommu/intel/pasid.c @@ -932,7 +932,7 @@ static void device_pasid_table_teardown(struct device *dev, u8 bus, u8 devfn) context_clear_entry(context); __iommu_flush_cache(iommu, context, sizeof(*context)); spin_unlock(&iommu->lock); - intel_context_flush_present(info, context, did, false); + intel_context_flush_no_pasid(info, context, did); } static int pci_pasid_table_teardown(struct pci_dev *pdev, u16 alias, void *data) @@ -1119,17 +1119,15 @@ static void __context_flush_dev_iotlb(struct device_domain_info *info) /* * Cache invalidations after change in a context table entry that was present - * according to the Spec 6.5.3.3 (Guidance to Software for Invalidations). If - * IOMMU is in scalable mode and all PASID table entries of the device were - * non-present, set flush_domains to false. Otherwise, true. + * according to the Spec 6.5.3.3 (Guidance to Software for Invalidations). + * This helper can only be used when IOMMU is working in the legacy mode or + * IOMMU is in scalable mode but all PASID table entries of the device are + * non-present. */ -void intel_context_flush_present(struct device_domain_info *info, - struct context_entry *context, - u16 did, bool flush_domains) +void intel_context_flush_no_pasid(struct device_domain_info *info, + struct context_entry *context, u16 did) { struct intel_iommu *iommu = info->iommu; - struct pasid_entry *pte; - int i; /* * Device-selective context-cache invalidation. The Domain-ID field @@ -1152,30 +1150,5 @@ void intel_context_flush_present(struct device_domain_info *info, return; } - /* - * For scalable mode: - * - Domain-selective PASID-cache invalidation to affected domains - * - Domain-selective IOTLB invalidation to affected domains - * - Global Device-TLB invalidation to affected functions - */ - if (flush_domains) { - /* - * If the IOMMU is running in scalable mode and there might - * be potential PASID translations, the caller should hold - * the lock to ensure that context changes and cache flushes - * are atomic. - */ - assert_spin_locked(&iommu->lock); - for (i = 0; i < info->pasid_table->max_pasid; i++) { - pte = intel_pasid_get_entry(info->dev, i); - if (!pte || !pasid_pte_is_present(pte)) - continue; - - did = pasid_get_domain_id(pte); - qi_flush_pasid_cache(iommu, did, QI_PC_ALL_PASIDS, 0); - iommu->flush.flush_iotlb(iommu, did, 0, 0, DMA_TLB_DSI_FLUSH); - } - } - __context_flush_dev_iotlb(info); }