arch/arm64/mm/dma-mapping.c

   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         return pgprot_writecombine(prot);
  18 }
  19
  20 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
  21                 size_t size, enum dma_data_direction dir)
  22 {
  23         __dma_map_area(phys_to_virt(paddr), size, dir);
  24 }
  25
  26 void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
  27                 size_t size, enum dma_data_direction dir)
  28 {
  29         __dma_unmap_area(phys_to_virt(paddr), size, dir);
  30 }
  31
  32 void arch_dma_prep_coherent(struct page *page, size_t size)
  33 {
  34         __dma_flush_area(page_address(page), size);
  35 }
  36
  37 static int __init arm64_dma_init(void)
  38 {
  39         return dma_atomic_pool_init(GFP_DMA32, __pgprot(PROT_NORMAL_NC));
  40 }
  41 arch_initcall(arm64_dma_init);
  42
  43 #ifdef CONFIG_IOMMU_DMA
  44 void arch_teardown_dma_ops(struct device *dev)
  45 {
  46         dev->dma_ops = NULL;
  47 }
  48 #endif
  49
  50 void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
  51                         const struct iommu_ops *iommu, bool coherent)
  52 {
  53         int cls = cache_line_size_of_cpu();
  54
  55         WARN_TAINT(!coherent && cls > ARCH_DMA_MINALIGN,
  56                    TAINT_CPU_OUT_OF_SPEC,
  57                    "%s %s: ARCH_DMA_MINALIGN smaller than CTR_EL0.CWG (%d < %d)",
  58                    dev_driver_string(dev), dev_name(dev),
  59                    ARCH_DMA_MINALIGN, cls);
  60
  61         dev->dma_coherent = coherent;
  62         if (iommu)
  63                 iommu_setup_dma_ops(dev, dma_base, size);
  64
  65 #ifdef CONFIG_XEN
  66         if (xen_initial_domain())
  67                 dev->dma_ops = xen_dma_ops;
  68 #endif
  69 }