| Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 1 | /* Glue code to lib/swiotlb.c */ |
| 2 | |
| 3 | #include <linux/pci.h> |
| 4 | #include <linux/cache.h> |
| 5 | #include <linux/module.h> |
| 6 | #include <linux/swiotlb.h> |
| 7 | #include <linux/bootmem.h> |
| 8 | #include <linux/dma-mapping.h> |
| 9 | |
| 10 | #include <asm/iommu.h> |
| 11 | #include <asm/swiotlb.h> |
| 12 | #include <asm/dma.h> |
| 13 | #include <asm/xen/swiotlb-xen.h> |
| 14 | #include <asm/iommu_table.h> |
| 15 | int swiotlb __read_mostly; |
| 16 | |
| 17 | void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size, |
| 18 | dma_addr_t *dma_handle, gfp_t flags, |
| 19 | struct dma_attrs *attrs) |
| 20 | { |
| 21 | void *vaddr; |
| 22 | |
| 23 | /* |
| 24 | * Don't print a warning when the first allocation attempt fails. |
| 25 | * swiotlb_alloc_coherent() will print a warning when the DMA |
| 26 | * memory allocation ultimately failed. |
| 27 | */ |
| 28 | flags |= __GFP_NOWARN; |
| 29 | |
| 30 | vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags, |
| 31 | attrs); |
| 32 | if (vaddr) |
| 33 | return vaddr; |
| 34 | |
| 35 | return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags); |
| 36 | } |
| 37 | |
| 38 | void x86_swiotlb_free_coherent(struct device *dev, size_t size, |
| 39 | void *vaddr, dma_addr_t dma_addr, |
| 40 | struct dma_attrs *attrs) |
| 41 | { |
| 42 | if (is_swiotlb_buffer(dma_to_phys(dev, dma_addr))) |
| 43 | swiotlb_free_coherent(dev, size, vaddr, dma_addr); |
| 44 | else |
| 45 | dma_generic_free_coherent(dev, size, vaddr, dma_addr, attrs); |
| 46 | } |
| 47 | |
| 48 | static struct dma_map_ops swiotlb_dma_ops = { |
| 49 | .mapping_error = swiotlb_dma_mapping_error, |
| 50 | .alloc = x86_swiotlb_alloc_coherent, |
| 51 | .free = x86_swiotlb_free_coherent, |
| 52 | .sync_single_for_cpu = swiotlb_sync_single_for_cpu, |
| 53 | .sync_single_for_device = swiotlb_sync_single_for_device, |
| 54 | .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu, |
| 55 | .sync_sg_for_device = swiotlb_sync_sg_for_device, |
| 56 | .map_sg = swiotlb_map_sg_attrs, |
| 57 | .unmap_sg = swiotlb_unmap_sg_attrs, |
| 58 | .map_page = swiotlb_map_page, |
| 59 | .unmap_page = swiotlb_unmap_page, |
| 60 | .dma_supported = NULL, |
| 61 | }; |
| 62 | |
| 63 | /* |
| 64 | * pci_swiotlb_detect_override - set swiotlb to 1 if necessary |
| 65 | * |
| 66 | * This returns non-zero if we are forced to use swiotlb (by the boot |
| 67 | * option). |
| 68 | */ |
| 69 | int __init pci_swiotlb_detect_override(void) |
| 70 | { |
| 71 | int use_swiotlb = swiotlb | swiotlb_force; |
| 72 | |
| 73 | if (swiotlb_force) |
| 74 | swiotlb = 1; |
| 75 | |
| 76 | return use_swiotlb; |
| 77 | } |
| 78 | IOMMU_INIT_FINISH(pci_swiotlb_detect_override, |
| 79 | pci_xen_swiotlb_detect, |
| 80 | pci_swiotlb_init, |
| 81 | pci_swiotlb_late_init); |
| 82 | |
| 83 | /* |
| 84 | * if 4GB or more detected (and iommu=off not set) return 1 |
| 85 | * and set swiotlb to 1. |
| 86 | */ |
| 87 | int __init pci_swiotlb_detect_4gb(void) |
| 88 | { |
| 89 | /* don't initialize swiotlb if iommu=off (no_iommu=1) */ |
| 90 | #ifdef CONFIG_X86_64 |
| 91 | if (!no_iommu && max_pfn > MAX_DMA32_PFN) |
| 92 | swiotlb = 1; |
| 93 | #endif |
| 94 | return swiotlb; |
| 95 | } |
| 96 | IOMMU_INIT(pci_swiotlb_detect_4gb, |
| 97 | pci_swiotlb_detect_override, |
| 98 | pci_swiotlb_init, |
| 99 | pci_swiotlb_late_init); |
| 100 | |
| 101 | void __init pci_swiotlb_init(void) |
| 102 | { |
| 103 | if (swiotlb) { |
| 104 | swiotlb_init(0); |
| 105 | dma_ops = &swiotlb_dma_ops; |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | void __init pci_swiotlb_late_init(void) |
| 110 | { |
| 111 | /* An IOMMU turned us off. */ |
| 112 | if (!swiotlb) |
| 113 | swiotlb_free(); |
| 114 | else { |
| 115 | printk(KERN_INFO "PCI-DMA: " |
| 116 | "Using software bounce buffering for IO (SWIOTLB)\n"); |
| 117 | swiotlb_print_info(); |
| 118 | } |
| 119 | } |