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From: Christoph Hellwig <hch@lst.de>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Tom Murphy <tmurphy@arista.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 08/23] iommu/dma: Factor out remapped pages lookup
Date: Thu, 23 May 2019 09:00:13 +0200	[thread overview]
Message-ID: <20190523070028.7435-9-hch@lst.de> (raw)
In-Reply-To: <20190523070028.7435-1-hch@lst.de>

From: Robin Murphy <robin.murphy@arm.com>

Since we duplicate the find_vm_area() logic a few times in places where
we only care aboute the pages, factor out a helper to abstract it.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[hch: don't warn when not finding a region, as we'll rely on that later]
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/iommu/dma-iommu.c | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 4596e4860da8..e870ea59a34d 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -554,6 +554,15 @@ static struct page **__iommu_dma_alloc_pages(struct device *dev,
 	return pages;
 }
 
+static struct page **__iommu_dma_get_pages(void *cpu_addr)
+{
+	struct vm_struct *area = find_vm_area(cpu_addr);
+
+	if (!area || !area->pages)
+		return NULL;
+	return area->pages;
+}
+
 /**
  * iommu_dma_free - Free a buffer allocated by __iommu_dma_alloc()
  * @dev: Device which owns this buffer
@@ -1042,11 +1051,11 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
 		dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
 		dma_common_free_remap(cpu_addr, size, VM_USERMAP);
 	} else if (is_vmalloc_addr(cpu_addr)){
-		struct vm_struct *area = find_vm_area(cpu_addr);
+		struct page **pages = __iommu_dma_get_pages(cpu_addr);
 
-		if (WARN_ON(!area || !area->pages))
+		if (!pages)
 			return;
-		__iommu_dma_free(dev, area->pages, iosize, &handle);
+		__iommu_dma_free(dev, pages, iosize, &handle);
 		dma_common_free_remap(cpu_addr, size, VM_USERMAP);
 	} else {
 		__iommu_dma_unmap(dev, handle, iosize);
@@ -1078,7 +1087,7 @@ static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 {
 	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 	unsigned long off = vma->vm_pgoff;
-	struct vm_struct *area;
+	struct page **pages;
 	int ret;
 
 	vma->vm_page_prot = arch_dma_mmap_pgprot(dev, vma->vm_page_prot, attrs);
@@ -1103,11 +1112,10 @@ static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 		return __iommu_dma_mmap_pfn(vma, pfn, size);
 	}
 
-	area = find_vm_area(cpu_addr);
-	if (WARN_ON(!area || !area->pages))
+	pages = __iommu_dma_get_pages(cpu_addr);
+	if (!pages)
 		return -ENXIO;
-
-	return __iommu_dma_mmap(area->pages, size, vma);
+	return __iommu_dma_mmap(pages, size, vma);
 }
 
 static int __iommu_dma_get_sgtable_page(struct sg_table *sgt, struct page *page,
@@ -1125,7 +1133,7 @@ static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
 		unsigned long attrs)
 {
 	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	struct vm_struct *area = find_vm_area(cpu_addr);
+	struct page **pages;
 
 	if (!is_vmalloc_addr(cpu_addr)) {
 		struct page *page = virt_to_page(cpu_addr);
@@ -1141,10 +1149,10 @@ static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
 		return __iommu_dma_get_sgtable_page(sgt, page, size);
 	}
 
-	if (WARN_ON(!area || !area->pages))
+	pages = __iommu_dma_get_pages(cpu_addr);
+	if (!pages)
 		return -ENXIO;
-
-	return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size,
+	return sg_alloc_table_from_pages(sgt, pages, count, 0, size,
 					 GFP_KERNEL);
 }
 
-- 
2.20.1


  parent reply	other threads:[~2019-05-23  7:01 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-23  7:00 implement generic dma_map_ops for IOMMUs v6 Christoph Hellwig
2019-05-23  7:00 ` [PATCH 01/23] iommu/dma: Cleanup dma-iommu.h Christoph Hellwig
2019-05-23  7:00 ` [PATCH 02/23] iommu/dma: Remove the flush_page callback Christoph Hellwig
2019-05-23  7:00 ` [PATCH 03/23] iommu/dma: Use for_each_sg in iommu_dma_alloc Christoph Hellwig
2019-05-23  7:00 ` [PATCH 04/23] iommu/dma: move the arm64 wrappers to common code Christoph Hellwig
2019-05-23  7:00 ` [PATCH 05/23] iommu/dma: Move __iommu_dma_map Christoph Hellwig
2019-05-23  7:00 ` [PATCH 06/23] iommu/dma: Move domain lookup into __iommu_dma_{map,unmap} Christoph Hellwig
2019-05-23  7:00 ` [PATCH 07/23] iommu/dma: Squash __iommu_dma_{map,unmap}_page helpers Christoph Hellwig
2019-05-23  7:00 ` Christoph Hellwig [this message]
2019-05-23  7:00 ` [PATCH 09/23] iommu/dma: Refactor the page array remapping allocator Christoph Hellwig
2019-05-23  7:00 ` [PATCH 10/23] iommu/dma: Remove __iommu_dma_free Christoph Hellwig
2019-05-23  7:00 ` [PATCH 11/23] iommu/dma: Refactor iommu_dma_free Christoph Hellwig
2019-05-23  7:00 ` [PATCH 12/23] iommu/dma: Refactor iommu_dma_alloc Christoph Hellwig
2019-05-23  7:00 ` [PATCH 13/23] iommu/dma: Don't remap CMA unnecessarily Christoph Hellwig
2019-05-23  7:00 ` [PATCH 14/23] iommu/dma: Merge the CMA and alloc_pages allocation paths Christoph Hellwig
2019-05-23  7:00 ` [PATCH 15/23] iommu/dma: Split iommu_dma_free Christoph Hellwig
2019-05-23  7:00 ` [PATCH 16/23] iommu/dma: Cleanup variable naming in iommu_dma_alloc Christoph Hellwig
2019-05-23  7:00 ` [PATCH 17/23] iommu/dma: Refactor iommu_dma_alloc, part 2 Christoph Hellwig
2019-05-23  7:00 ` [PATCH 18/23] iommu/dma: Refactor iommu_dma_get_sgtable Christoph Hellwig
2019-05-23  7:00 ` [PATCH 19/23] iommu/dma: Refactor iommu_dma_mmap Christoph Hellwig
2019-05-23  7:00 ` [PATCH 20/23] iommu/dma: Don't depend on CONFIG_DMA_DIRECT_REMAP Christoph Hellwig
2019-05-23  7:00 ` [PATCH 21/23] iommu/dma: Switch copyright boilerplace to SPDX Christoph Hellwig
2019-05-23  7:00 ` [PATCH 22/23] arm64: switch copyright boilerplace to SPDX in dma-mapping.c Christoph Hellwig
2019-05-23  7:00 ` [PATCH 23/23] arm64: trim includes " Christoph Hellwig
2019-05-23 12:33 ` implement generic dma_map_ops for IOMMUs v6 Robin Murphy

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