driver core: Replace dev->dma_coherent with dev_dma_coherent()

In C, bitfields are not necessarily safe to modify from multiple
threads without locking. Switch "dma_coherent" over to the "flags"
field so modifications are safe.

Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patch.msgid.link/20260406162231.v5.7.If839f6dde98979fce177f70c6c74689a1904ee76@changeid
[ Since all DEV_FLAG_DMA_COHERENT accessors are exposed unconditionally,
  also drop the CONFIG guards around dev_assign_dma_coherent() in
  device_initialize() to ensure a correct default value. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

2 files changed, 16 insertions, 16 deletions

diff --git a/arch/arm/mm/dma-mapping-nommu.c b/arch/arm/mm/dma-mapping-nommu.c
index fecac107fd0d..c6a70686507b 100644
--- a/arch/arm/mm/dma-mapping-nommu.c
+++ b/arch/arm/mm/dma-mapping-nommu.c
@@ -42,11 +42,11 @@ void arch_setup_dma_ops(struct device *dev, bool coherent)
 		 * enough to check if MPU is in use or not since in absence of
 		 * MPU system memory map is used.
 		 */
-		dev->dma_coherent = cacheid ? coherent : true;
+		dev_assign_dma_coherent(dev, cacheid ? coherent : true);
 	} else {
 		/*
 		 * Assume coherent DMA in case MMU/MPU has not been set up.
 		 */
-		dev->dma_coherent = (get_cr() & CR_M) ? coherent : true;
+		dev_assign_dma_coherent(dev, (get_cr() & CR_M) ? coherent : true);
 	}
 }
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index f304037d1c34..f9bc53b60f99 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1076,7 +1076,7 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
 	pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL);
 	struct page **pages;
 	void *addr = NULL;
-	int coherent_flag = dev->dma_coherent ? COHERENT : NORMAL;
+	int coherent_flag = dev_dma_coherent(dev) ? COHERENT : NORMAL;
 
 	*handle = DMA_MAPPING_ERROR;
 	size = PAGE_ALIGN(size);
@@ -1124,7 +1124,7 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
 	if (vma->vm_pgoff >= nr_pages)
 		return -ENXIO;
 
-	if (!dev->dma_coherent)
+	if (!dev_dma_coherent(dev))
 		vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
 
 	err = vm_map_pages(vma, pages, nr_pages);
@@ -1141,7 +1141,7 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
 static void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
 	dma_addr_t handle, unsigned long attrs)
 {
-	int coherent_flag = dev->dma_coherent ? COHERENT : NORMAL;
+	int coherent_flag = dev_dma_coherent(dev) ? COHERENT : NORMAL;
 	struct page **pages;
 	size = PAGE_ALIGN(size);
 
@@ -1202,7 +1202,7 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
 		phys_addr_t phys = page_to_phys(sg_page(s));
 		unsigned int len = PAGE_ALIGN(s->offset + s->length);
 
-		if (!dev->dma_coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		if (!dev_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 			arch_sync_dma_for_device(sg_phys(s), s->length, dir);
 
 		prot = __dma_info_to_prot(dir, attrs);
@@ -1304,7 +1304,7 @@ static void arm_iommu_unmap_sg(struct device *dev,
 		if (sg_dma_len(s))
 			__iommu_remove_mapping(dev, sg_dma_address(s),
 					       sg_dma_len(s));
-		if (!dev->dma_coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		if (!dev_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 			arch_sync_dma_for_cpu(sg_phys(s), s->length, dir);
 	}
 }
@@ -1323,7 +1323,7 @@ static void arm_iommu_sync_sg_for_cpu(struct device *dev,
 	struct scatterlist *s;
 	int i;
 
-	if (dev->dma_coherent)
+	if (dev_dma_coherent(dev))
 		return;
 
 	for_each_sg(sg, s, nents, i)
@@ -1345,7 +1345,7 @@ static void arm_iommu_sync_sg_for_device(struct device *dev,
 	struct scatterlist *s;
 	int i;
 
-	if (dev->dma_coherent)
+	if (dev_dma_coherent(dev))
 		return;
 
 	for_each_sg(sg, s, nents, i)
@@ -1371,7 +1371,7 @@ static dma_addr_t arm_iommu_map_phys(struct device *dev, phys_addr_t phys,
 	dma_addr_t dma_addr;
 	int ret, prot;
 
-	if (!dev->dma_coherent &&
+	if (!dev_dma_coherent(dev) &&
 	    !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO)))
 		arch_sync_dma_for_device(phys, size, dir);
 
@@ -1412,7 +1412,7 @@ static void arm_iommu_unmap_phys(struct device *dev, dma_addr_t handle,
 	if (!iova)
 		return;
 
-	if (!dev->dma_coherent &&
+	if (!dev_dma_coherent(dev) &&
 	    !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO))) {
 		phys_addr_t phys = iommu_iova_to_phys(mapping->domain, iova);
 
@@ -1431,7 +1431,7 @@ static void arm_iommu_sync_single_for_cpu(struct device *dev,
 	unsigned int offset = handle & ~PAGE_MASK;
 	phys_addr_t phys;
 
-	if (dev->dma_coherent || !iova)
+	if (dev_dma_coherent(dev) || !iova)
 		return;
 
 	phys = iommu_iova_to_phys(mapping->domain, iova);
@@ -1446,7 +1446,7 @@ static void arm_iommu_sync_single_for_device(struct device *dev,
 	unsigned int offset = handle & ~PAGE_MASK;
 	phys_addr_t phys;
 
-	if (dev->dma_coherent || !iova)
+	if (dev_dma_coherent(dev) || !iova)
 		return;
 
 	phys = iommu_iova_to_phys(mapping->domain, iova);
@@ -1701,13 +1701,13 @@ static void arm_teardown_iommu_dma_ops(struct device *dev) { }
 void arch_setup_dma_ops(struct device *dev, bool coherent)
 {
 	/*
-	 * Due to legacy code that sets the ->dma_coherent flag from a bus
-	 * notifier we can't just assign coherent to the ->dma_coherent flag
+	 * Due to legacy code that sets the dma_coherent flag from a bus
+	 * notifier we can't just assign coherent to the dma_coherent flag
 	 * here, but instead have to make sure we only set but never clear it
 	 * for now.
 	 */
 	if (coherent)
-		dev->dma_coherent = true;
+		dev_set_dma_coherent(dev);
 
 	/*
 	 * Don't override the dma_ops if they have already been set. Ideally