Add new flush_iotlb_range and handle freelists when using iommu_unmap…

…_fast

Add a flush_iotlb_range to allow flushing of an iova range instead of a
full flush in the dma-iommu path.

Allow the iommu_unmap_fast to return newly freed page table pages and
pass the freelist to queue_iova in the dma-iommu ops path.

This patch is useful for iommu drivers (in this case the intel iommu
driver) which need to wait for the ioTLB to be flushed before newly
free/unmapped page table pages can be freed. This way we can still batch
ioTLB free operations and handle the freelists.

Signed-off-by: Tom Murphy <murphyt7@tcd.ie>

drivers/iommu/amd/iommu.c

@@ -2513,7 +2513,8 @@ static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova,
 
 static size_t amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova,
 			      size_t page_size,
-			      struct iommu_iotlb_gather *gather)
+			      struct iommu_iotlb_gather *gather,
+			      struct page **freelist)
 {
 	struct protection_domain *domain = to_pdomain(dom);
 	struct domain_pgtable pgtable;
@@ -2636,6 +2637,16 @@ static void amd_iommu_flush_iotlb_all(struct iommu_domain *domain)
 	spin_unlock_irqrestore(&dom->lock, flags);
 }
 
+static void amd_iommu_flush_iotlb_range(struct iommu_domain *domain,
+					unsigned long iova, size_t size,
+					struct page *freelist)
+{
+	struct protection_domain *dom = to_pdomain(domain);
+
+	domain_flush_pages(dom, iova, size);
+	domain_flush_complete(dom);
+}
+
 static void amd_iommu_iotlb_sync(struct iommu_domain *domain,
 				 struct iommu_iotlb_gather *gather)
 {
@@ -2675,6 +2686,7 @@ const struct iommu_ops amd_iommu_ops = {
 	.is_attach_deferred = amd_iommu_is_attach_deferred,
 	.pgsize_bitmap	= AMD_IOMMU_PGSIZES,
 	.flush_iotlb_all = amd_iommu_flush_iotlb_all,
+	.flush_iotlb_range = amd_iommu_flush_iotlb_range,
 	.iotlb_sync = amd_iommu_iotlb_sync,
 	.def_domain_type = amd_iommu_def_domain_type,
 };

drivers/iommu/arm-smmu-v3.c

@@ -2854,7 +2854,8 @@ static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
 }
 
 static size_t arm_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
-			     size_t size, struct iommu_iotlb_gather *gather)
+			     size_t size, struct iommu_iotlb_gather *gather,
+			     struct page **freelist)
 {
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 	struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;

drivers/iommu/arm-smmu.c

@@ -1234,7 +1234,8 @@ static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
 }
 
 static size_t arm_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
-			     size_t size, struct iommu_iotlb_gather *gather)
+			     size_t size, struct iommu_iotlb_gather *gather,
+			     struct page **freelist)
 {
 	struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops;
 	struct arm_smmu_device *smmu = to_smmu_domain(domain)->smmu;

drivers/iommu/dma-iommu.c

@@ -50,6 +50,19 @@ struct iommu_dma_cookie {
 	struct iommu_domain		*fq_domain;
 };
 
+
+static void iommu_dma_entry_dtor(unsigned long data)
+{
+	struct page *freelist = (struct page *)data;
+
+	while (freelist != NULL) {
+		unsigned long p = (unsigned long)page_address(freelist);
+
+		freelist = freelist->freelist;
+		free_page(p);
+	}
+}
+
 static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)
 {
 	if (cookie->type == IOMMU_DMA_IOVA_COOKIE)
@@ -344,7 +357,8 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 	if (!cookie->fq_domain && !iommu_domain_get_attr(domain,
 			DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE, &attr) && attr) {
 		cookie->fq_domain = domain;
-		init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all, NULL);
+		init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all,
+				iommu_dma_entry_dtor);
 	}
 
 	if (!dev)
@@ -438,7 +452,7 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
 }
 
 static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
-		dma_addr_t iova, size_t size)
+		dma_addr_t iova, size_t size, struct page *freelist)
 {
 	struct iova_domain *iovad = &cookie->iovad;
 
@@ -447,7 +461,8 @@ static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
 		cookie->msi_iova -= size;
 	else if (cookie->fq_domain)	/* non-strict mode */
 		queue_iova(iovad, iova_pfn(iovad, iova),
-				size >> iova_shift(iovad), 0);
+				size >> iova_shift(iovad),
+				(unsigned long) freelist);
 	else
 		free_iova_fast(iovad, iova_pfn(iovad, iova),
 				size >> iova_shift(iovad));
@@ -461,18 +476,26 @@ static void __iommu_dma_unmap(struct device *dev, dma_addr_t dma_addr,
 	struct iova_domain *iovad = &cookie->iovad;
 	size_t iova_off = iova_offset(iovad, dma_addr);
 	struct iommu_iotlb_gather iotlb_gather;
+	struct page *freelist = NULL;
 	size_t unmapped;
 
 	dma_addr -= iova_off;
 	size = iova_align(iovad, size + iova_off);
 	iommu_iotlb_gather_init(&iotlb_gather);
 
-	unmapped = iommu_unmap_fast(domain, dma_addr, size, &iotlb_gather);
+	unmapped = iommu_unmap_fast(domain, dma_addr, size, &iotlb_gather,
+			&freelist);
 	WARN_ON(unmapped != size);
 
-	if (!cookie->fq_domain)
-		iommu_tlb_sync(domain, &iotlb_gather);
-	iommu_dma_free_iova(cookie, dma_addr, size);
+	if (!cookie->fq_domain) {
+		if (domain->ops->flush_iotlb_range)
+			domain->ops->flush_iotlb_range(domain, dma_addr, size,
+					freelist);
+		else
+			iommu_tlb_sync(domain, &iotlb_gather);
+	}
+
+	iommu_dma_free_iova(cookie, dma_addr, size, freelist);
 }
 
 static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
@@ -494,7 +517,7 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
 		return DMA_MAPPING_ERROR;
 
 	if (iommu_map_atomic(domain, iova, phys - iova_off, size, prot)) {
-		iommu_dma_free_iova(cookie, iova, size);
+		iommu_dma_free_iova(cookie, iova, size, NULL);
 		return DMA_MAPPING_ERROR;
 	}
 	return iova + iova_off;
@@ -649,7 +672,7 @@ static void *iommu_dma_alloc_remap(struct device *dev, size_t size,
 out_free_sg:
 	sg_free_table(&sgt);
 out_free_iova:
-	iommu_dma_free_iova(cookie, iova, size);
+	iommu_dma_free_iova(cookie, iova, size, NULL);
 out_free_pages:
 	__iommu_dma_free_pages(pages, count);
 	return NULL;
@@ -900,7 +923,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
 	return __finalise_sg(dev, sg, nents, iova);
 
 out_free_iova:
-	iommu_dma_free_iova(cookie, iova, iova_len);
+	iommu_dma_free_iova(cookie, iova, iova_len, NULL);
 out_restore_sg:
 	__invalidate_sg(sg, nents);
 	return 0;
@@ -1194,7 +1217,7 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 	return msi_page;
 
 out_free_iova:
-	iommu_dma_free_iova(cookie, iova, size);
+	iommu_dma_free_iova(cookie, iova, size, NULL);
 out_free_page:
 	kfree(msi_page);
 	return NULL;

drivers/iommu/exynos-iommu.c

@@ -1129,7 +1129,8 @@ static void exynos_iommu_tlb_invalidate_entry(struct exynos_iommu_domain *domain
 
 static size_t exynos_iommu_unmap(struct iommu_domain *iommu_domain,
 				 unsigned long l_iova, size_t size,
-				 struct iommu_iotlb_gather *gather)
+				 struct iommu_iotlb_gather *gather,
+				 struct page **freelist)
 {
 	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
 	sysmmu_iova_t iova = (sysmmu_iova_t)l_iova;

drivers/iommu/intel/iommu.c

@@ -1154,17 +1154,17 @@ static struct page *dma_pte_clear_level(struct dmar_domain *domain, int level,
    pages can only be freed after the IOTLB flush has been done. */
 static struct page *domain_unmap(struct dmar_domain *domain,
 				 unsigned long start_pfn,
-				 unsigned long last_pfn)
+				 unsigned long last_pfn,
+				 struct page *freelist)
 {
-	struct page *freelist;
-
 	BUG_ON(!domain_pfn_supported(domain, start_pfn));
 	BUG_ON(!domain_pfn_supported(domain, last_pfn));
 	BUG_ON(start_pfn > last_pfn);
 
 	/* we don't need lock here; nobody else touches the iova range */
 	freelist = dma_pte_clear_level(domain, agaw_to_level(domain->agaw),
-				       domain->pgd, 0, start_pfn, last_pfn, NULL);
+				       domain->pgd, 0, start_pfn, last_pfn,
+				       freelist);
 
 	/* free pgd */
 	if (start_pfn == 0 && last_pfn == DOMAIN_MAX_PFN(domain->gaw)) {
@@ -1918,7 +1918,8 @@ static void domain_exit(struct dmar_domain *domain)
 	if (domain->pgd) {
 		struct page *freelist;
 
-		freelist = domain_unmap(domain, 0, DOMAIN_MAX_PFN(domain->gaw));
+		freelist = domain_unmap(domain, 0, DOMAIN_MAX_PFN(domain->gaw),
+				NULL);
 		dma_free_pagelist(freelist);
 	}
 
@@ -3472,7 +3473,7 @@ static void intel_unmap(struct device *dev, dma_addr_t dev_addr, size_t size)
 	if (dev_is_pci(dev))
 		pdev = to_pci_dev(dev);
 
-	freelist = domain_unmap(domain, start_pfn, last_pfn);
+	freelist = domain_unmap(domain, start_pfn, last_pfn, NULL);
 	if (intel_iommu_strict || (pdev && pdev->untrusted) ||
 			!has_iova_flush_queue(&domain->iovad)) {
 		iommu_flush_iotlb_psi(iommu, domain, start_pfn,
@@ -4567,7 +4568,8 @@ static int intel_iommu_memory_notifier(struct notifier_block *nb,
 			struct page *freelist;
 
 			freelist = domain_unmap(si_domain,
-						start_vpfn, last_vpfn);
+						start_vpfn, last_vpfn,
+						NULL);
 
 			rcu_read_lock();
 			for_each_active_iommu(iommu, drhd)
@@ -5532,13 +5534,12 @@ static int intel_iommu_map(struct iommu_domain *domain,
 
 static size_t intel_iommu_unmap(struct iommu_domain *domain,
 				unsigned long iova, size_t size,
-				struct iommu_iotlb_gather *gather)
+				struct iommu_iotlb_gather *gather,
+				struct page **freelist)
 {
 	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
-	struct page *freelist = NULL;
 	unsigned long start_pfn, last_pfn;
-	unsigned int npages;
-	int iommu_id, level = 0;
+	int level = 0;
 
 	/* Cope with horrid API which requires us to unmap more than the
 	   size argument if it happens to be a large-page mapping. */
@@ -5550,22 +5551,36 @@ static size_t intel_iommu_unmap(struct iommu_domain *domain,
 	start_pfn = iova >> VTD_PAGE_SHIFT;
 	last_pfn = (iova + size - 1) >> VTD_PAGE_SHIFT;
 
-	freelist = domain_unmap(dmar_domain, start_pfn, last_pfn);
+	*freelist = domain_unmap(dmar_domain, start_pfn, last_pfn, *freelist);
+
+	if (dmar_domain->max_addr == iova + size)
+		dmar_domain->max_addr = iova;
 
-	npages = last_pfn - start_pfn + 1;
+	return size;
+}
+
+static void intel_iommu_flush_iotlb_range(struct iommu_domain *domain, unsigned
+		long iova, size_t size,
+		struct page *freelist)
+{
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	unsigned long start_pfn, last_pfn;
+	unsigned long iova_pfn = IOVA_PFN(iova);
+	unsigned long nrpages;
+	int iommu_id;
+
+	nrpages = aligned_nrpages(iova, size);
+	start_pfn = mm_to_dma_pfn(iova_pfn);
+	last_pfn = start_pfn + nrpages - 1;
 
 	for_each_domain_iommu(iommu_id, dmar_domain)
 		iommu_flush_iotlb_psi(g_iommus[iommu_id], dmar_domain,
-				      start_pfn, npages, !freelist, 0);
+				      start_pfn, nrpages, !freelist, 0);
 
 	dma_free_pagelist(freelist);
-
-	if (dmar_domain->max_addr == iova + size)
-		dmar_domain->max_addr = iova;
-
-	return size;
 }
 
+
 static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
 					    dma_addr_t iova)
 {
@@ -6033,6 +6048,7 @@ const struct iommu_ops intel_iommu_ops = {
 	.aux_get_pasid		= intel_iommu_aux_get_pasid,
 	.map			= intel_iommu_map,
 	.unmap			= intel_iommu_unmap,
+	.flush_iotlb_range	= intel_iommu_flush_iotlb_range,
 	.iova_to_phys		= intel_iommu_iova_to_phys,
 	.probe_device		= intel_iommu_probe_device,
 	.probe_finalize		= intel_iommu_probe_finalize,

drivers/iommu/iommu.c

@@ -2245,11 +2245,13 @@ EXPORT_SYMBOL_GPL(iommu_map_atomic);
 
 static size_t __iommu_unmap(struct iommu_domain *domain,
 			    unsigned long iova, size_t size,
-			    struct iommu_iotlb_gather *iotlb_gather)
+			    struct iommu_iotlb_gather *iotlb_gather,
+			    struct page **freelist)
 {
 	const struct iommu_ops *ops = domain->ops;
 	size_t unmapped_page, unmapped = 0;
 	unsigned long orig_iova = iova;
+	struct page *freelist_head = NULL;
 	unsigned int min_pagesz;
 
 	if (unlikely(ops->unmap == NULL ||
@@ -2282,7 +2284,8 @@ static size_t __iommu_unmap(struct iommu_domain *domain,
 	while (unmapped < size) {
 		size_t pgsize = iommu_pgsize(domain, iova, size - unmapped);
 
-		unmapped_page = ops->unmap(domain, iova, pgsize, iotlb_gather);
+		unmapped_page = ops->unmap(domain, iova, pgsize, iotlb_gather,
+				&freelist_head);
 		if (!unmapped_page)
 			break;
 
@@ -2293,29 +2296,39 @@ static size_t __iommu_unmap(struct iommu_domain *domain,
 		unmapped += unmapped_page;
 	}
 
+	if (freelist)
+		*freelist = freelist_head;
+
 	trace_unmap(orig_iova, size, unmapped);
 	return unmapped;
 }
 
 size_t iommu_unmap(struct iommu_domain *domain,
 		   unsigned long iova, size_t size)
 {
+	const struct iommu_ops *ops = domain->ops;
 	struct iommu_iotlb_gather iotlb_gather;
+	struct page *freelist;
 	size_t ret;
 
 	iommu_iotlb_gather_init(&iotlb_gather);
-	ret = __iommu_unmap(domain, iova, size, &iotlb_gather);
-	iommu_tlb_sync(domain, &iotlb_gather);
+	ret = __iommu_unmap(domain, iova, size, &iotlb_gather, &freelist);
+
+	if (ops->flush_iotlb_range)
+		ops->flush_iotlb_range(domain, iova, ret, freelist);
+	else
+		iommu_tlb_sync(domain, &iotlb_gather);
 
 	return ret;
 }
 EXPORT_SYMBOL_GPL(iommu_unmap);
 
 size_t iommu_unmap_fast(struct iommu_domain *domain,
 			unsigned long iova, size_t size,
-			struct iommu_iotlb_gather *iotlb_gather)
+			struct iommu_iotlb_gather *iotlb_gather,
+			struct page **freelist)
 {
-	return __iommu_unmap(domain, iova, size, iotlb_gather);
+	return __iommu_unmap(domain, iova, size, iotlb_gather, freelist);
 }
 EXPORT_SYMBOL_GPL(iommu_unmap_fast);
 

drivers/iommu/ipmmu-vmsa.c

@@ -691,7 +691,8 @@ static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
 }
 
 static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
-			  size_t size, struct iommu_iotlb_gather *gather)
+			  size_t size, struct iommu_iotlb_gather *gather,
+			  struct page **freelist)
 {
 	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 

drivers/iommu/msm_iommu.c

@@ -498,7 +498,8 @@ static int msm_iommu_map(struct iommu_domain *domain, unsigned long iova,
 }
 
 static size_t msm_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
-			      size_t len, struct iommu_iotlb_gather *gather)
+			      size_t len, struct iommu_iotlb_gather *gather,
+			      struct page **freelist)
 {
 	struct msm_priv *priv = to_msm_priv(domain);
 	unsigned long flags;