linux-kernel - [PATCH 18/21] dma-iommu: don't depend on CONFIG_DMA_DIRECT

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Message-Id: <20190327080448.5500-19-hch@lst.de>
Date:   Wed, 27 Mar 2019 09:04:45 +0100
From:   Christoph Hellwig <hch@....de>
To:     Robin Murphy <robin.murphy@....com>
Cc:     Joerg Roedel <joro@...tes.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will.deacon@....com>,
        Tom Lendacky <thomas.lendacky@....com>,
        iommu@...ts.linux-foundation.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH 18/21] dma-iommu: don't depend on CONFIG_DMA_DIRECT_REMAP

For entirely dma coherent architectures there is no requirement to ever
remap dma coherent allocation.  Move all the remap and pool code under
CONFIG_DMA_DIRECT_REMAP ifdefs, and drop the Kconfig dependency.

Signed-off-by: Christoph Hellwig <hch@....de>
---
 drivers/iommu/Kconfig     |  1 -
 drivers/iommu/dma-iommu.c | 10 ++++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index bdc14baf2ee5..6f07f3b21816 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -95,7 +95,6 @@ config IOMMU_DMA
 	select IOMMU_API
 	select IOMMU_IOVA
 	select NEED_SG_DMA_LENGTH
-	depends on DMA_DIRECT_REMAP
 
 config FSL_PAMU
 	bool "Freescale IOMMU support"
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index f65dd19b0953..092b689c1c54 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -500,6 +500,7 @@ static void *iommu_dma_alloc_contiguous(struct device *dev, size_t size,
 	return page_address(page);
 }
 
+#ifdef CONFIG_DMA_DIRECT_REMAP
 static void __iommu_dma_free_pages(struct page **pages, int count)
 {
 	while (count--)
@@ -782,6 +783,7 @@ static void *iommu_dma_alloc_noncoherent(struct device *dev, size_t size,
 				gfp, attrs);
 	return iommu_dma_alloc_remap(dev, size, dma_handle, gfp, attrs);
 }
+#endif /* CONFIG_DMA_DIRECT_REMAP */
 
 static void iommu_dma_sync_single_for_cpu(struct device *dev,
 		dma_addr_t dma_handle, size_t size, enum dma_data_direction dir)
@@ -1064,6 +1066,7 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
 	 */
 	gfp |= __GFP_ZERO;
 
+#ifdef CONFIG_DMA_DIRECT_REMAP
 	if (!dev_is_dma_coherent(dev))
 		return iommu_dma_alloc_noncoherent(dev, size, dma_handle, gfp,
 				attrs);
@@ -1071,6 +1074,7 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
 	if (gfpflags_allow_blocking(gfp) &&
 	    !(attrs & DMA_ATTR_FORCE_CONTIGUOUS))
 		return iommu_dma_alloc_remap(dev, size, dma_handle, gfp, attrs);
+#endif
 
 	return iommu_dma_alloc_contiguous(dev, size, dma_handle, gfp, attrs);
 }
@@ -1090,6 +1094,7 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
 	 *
 	 * Hence how dodgy the below logic looks...
 	 */
+#ifdef CONFIG_DMA_DIRECT_REMAP
 	if (dma_in_atomic_pool(cpu_addr, PAGE_ALIGN(size))) {
 		iommu_dma_free_pool(dev, size, cpu_addr, dma_handle);
 		return;
@@ -1103,6 +1108,7 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
 		page = vmalloc_to_page(cpu_addr);
 		dma_common_free_remap(cpu_addr, PAGE_ALIGN(size), VM_USERMAP);
 	} else
+#endif
 		page = virt_to_page(cpu_addr);
 
 	iommu_dma_free_contiguous(dev, size, page, dma_handle);
@@ -1125,11 +1131,13 @@ 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;
 
+#ifdef CONFIG_DMA_DIRECT_REMAP
 	if (is_vmalloc_addr(cpu_addr)) {
 		if (!(attrs & DMA_ATTR_FORCE_CONTIGUOUS))
 			return iommu_dma_mmap_remap(cpu_addr, size, vma);
 		pfn = vmalloc_to_pfn(cpu_addr);
 	} else
+#endif
 		pfn = page_to_pfn(virt_to_page(cpu_addr));
 
 	return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
@@ -1143,11 +1151,13 @@ static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
 	struct page *page;
 	int ret;
 
+#ifdef CONFIG_DMA_DIRECT_REMAP
 	if (is_vmalloc_addr(cpu_addr)) {
 		if (!(attrs & DMA_ATTR_FORCE_CONTIGUOUS))
 			return iommu_dma_get_sgtable_remap(sgt, cpu_addr, size);
 		page = vmalloc_to_page(cpu_addr);
 	} else
+#endif
 		page = virt_to_page(cpu_addr);
 
 	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
-- 
2.20.1