xref: /linux/arch/arm64/mm/dma-mapping.c (revision b8d312aa075f33282565467662c4628dae0a2aff)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2012 ARM Ltd.
4  * Author: Catalin Marinas <catalin.marinas@arm.com>
5  */
6 
7 #include <linux/gfp.h>
8 #include <linux/cache.h>
9 #include <linux/dma-noncoherent.h>
10 #include <linux/dma-iommu.h>
11 
12 #include <asm/cacheflush.h>
13 
14 pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,
15 		unsigned long attrs)
16 {
17 	if (!dev_is_dma_coherent(dev) || (attrs & DMA_ATTR_WRITE_COMBINE))
18 		return pgprot_writecombine(prot);
19 	return prot;
20 }
21 
22 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
23 		size_t size, enum dma_data_direction dir)
24 {
25 	__dma_map_area(phys_to_virt(paddr), size, dir);
26 }
27 
28 void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
29 		size_t size, enum dma_data_direction dir)
30 {
31 	__dma_unmap_area(phys_to_virt(paddr), size, dir);
32 }
33 
34 void arch_dma_prep_coherent(struct page *page, size_t size)
35 {
36 	__dma_flush_area(page_address(page), size);
37 }
38 
39 static int __init arm64_dma_init(void)
40 {
41 	return dma_atomic_pool_init(GFP_DMA32, __pgprot(PROT_NORMAL_NC));
42 }
43 arch_initcall(arm64_dma_init);
44 
45 #ifdef CONFIG_IOMMU_DMA
46 void arch_teardown_dma_ops(struct device *dev)
47 {
48 	dev->dma_ops = NULL;
49 }
50 #endif
51 
52 void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
53 			const struct iommu_ops *iommu, bool coherent)
54 {
55 	int cls = cache_line_size_of_cpu();
56 
57 	WARN_TAINT(!coherent && cls > ARCH_DMA_MINALIGN,
58 		   TAINT_CPU_OUT_OF_SPEC,
59 		   "%s %s: ARCH_DMA_MINALIGN smaller than CTR_EL0.CWG (%d < %d)",
60 		   dev_driver_string(dev), dev_name(dev),
61 		   ARCH_DMA_MINALIGN, cls);
62 
63 	dev->dma_coherent = coherent;
64 	if (iommu)
65 		iommu_setup_dma_ops(dev, dma_base, size);
66 
67 #ifdef CONFIG_XEN
68 	if (xen_initial_domain())
69 		dev->dma_ops = xen_dma_ops;
70 #endif
71 }
72