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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 19/23] iommu/dma: Refactor iommu_dma_mmap
Date: Thu, 23 May 2019 09:00:24 +0200	[thread overview]
Message-ID: <20190523070028.7435-20-hch@lst.de> (raw)
In-Reply-To: <20190523070028.7435-1-hch@lst.de>

Inline __iommu_dma_mmap and __iommu_dma_mmap_pfn into the main function,
and use the fact that __iommu_dma_get_pages return NULL for remapped
contigous allocations to simplify the code flow a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/dma-iommu.c | 60 +++++++--------------------------------
 1 file changed, 11 insertions(+), 49 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index b56bd8e7d5f9..ea2797d10070 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -650,21 +650,6 @@ static void *iommu_dma_alloc_remap(struct device *dev, size_t size,
 	return NULL;
 }
 
-/**
- * __iommu_dma_mmap - Map a buffer into provided user VMA
- * @pages: Array representing buffer from __iommu_dma_alloc()
- * @size: Size of buffer in bytes
- * @vma: VMA describing requested userspace mapping
- *
- * Maps the pages of the buffer in @pages into @vma. The caller is responsible
- * for verifying the correct size and protection of @vma beforehand.
- */
-static int __iommu_dma_mmap(struct page **pages, size_t size,
-		struct vm_area_struct *vma)
-{
-	return vm_map_pages(vma, pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
-}
-
 static void iommu_dma_sync_single_for_cpu(struct device *dev,
 		dma_addr_t dma_handle, size_t size, enum dma_data_direction dir)
 {
@@ -1042,31 +1027,13 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
 	return cpu_addr;
 }
 
-static int __iommu_dma_mmap_pfn(struct vm_area_struct *vma,
-			      unsigned long pfn, size_t size)
-{
-	int ret = -ENXIO;
-	unsigned long nr_vma_pages = vma_pages(vma);
-	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	unsigned long off = vma->vm_pgoff;
-
-	if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
-		ret = remap_pfn_range(vma, vma->vm_start,
-				      pfn + off,
-				      vma->vm_end - vma->vm_start,
-				      vma->vm_page_prot);
-	}
-
-	return ret;
-}
-
 static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 		void *cpu_addr, dma_addr_t dma_addr, size_t size,
 		unsigned long attrs)
 {
 	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 	unsigned long off = vma->vm_pgoff;
-	struct page **pages;
+	unsigned long pfn;
 	int ret;
 
 	vma->vm_page_prot = arch_dma_mmap_pgprot(dev, vma->vm_page_prot, attrs);
@@ -1077,24 +1044,19 @@ static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 	if (off >= nr_pages || vma_pages(vma) > nr_pages - off)
 		return -ENXIO;
 
-	if (!is_vmalloc_addr(cpu_addr)) {
-		unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
-		return __iommu_dma_mmap_pfn(vma, pfn, size);
-	}
+	if (is_vmalloc_addr(cpu_addr)) {
+		struct page **pages = __iommu_dma_get_pages(cpu_addr);
 
-	if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
-		/*
-		 * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,
-		 * hence in the vmalloc space.
-		 */
-		unsigned long pfn = vmalloc_to_pfn(cpu_addr);
-		return __iommu_dma_mmap_pfn(vma, pfn, size);
+		if (pages)
+			return vm_map_pages(vma, pages, nr_pages);
+		pfn = vmalloc_to_pfn(cpu_addr);
+	} else {
+		pfn = page_to_pfn(virt_to_page(cpu_addr));
 	}
 
-	pages = __iommu_dma_get_pages(cpu_addr);
-	if (!pages)
-		return -ENXIO;
-	return __iommu_dma_mmap(pages, size, vma);
+	return remap_pfn_range(vma, vma->vm_start, pfn + off,
+			       vma->vm_end - vma->vm_start,
+			       vma->vm_page_prot);
 }
 
 static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
-- 
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 ` [PATCH 08/23] iommu/dma: Factor out remapped pages lookup Christoph Hellwig
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 ` Christoph Hellwig [this message]
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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