2 #include <linux/dma-mapping.h>
3 #include <linux/bootmem.h>
5 #include <linux/highmem.h>
6 #include <linux/export.h>
7 #include <linux/memblock.h>
8 #include <linux/of_address.h>
9 #include <linux/slab.h>
10 #include <linux/types.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/vmalloc.h>
13 #include <linux/swiotlb.h>
16 #include <xen/interface/grant_table.h>
17 #include <xen/interface/memory.h>
19 #include <xen/swiotlb-xen.h>
21 #include <asm/cacheflush.h>
22 #include <asm/xen/hypercall.h>
23 #include <asm/xen/interface.h>
25 unsigned long xen_get_swiotlb_free_pages(unsigned int order)
27 struct memblock_region *reg;
28 gfp_t flags = __GFP_NOWARN;
30 for_each_memblock(memory, reg) {
31 if (reg->base < (phys_addr_t)0xffffffff) {
36 return __get_free_pages(flags, order);
43 static bool hypercall_cflush = false;
45 /* functions called by SWIOTLB */
47 static void dma_cache_maint(dma_addr_t handle, unsigned long offset,
48 size_t size, enum dma_data_direction dir, enum dma_cache_op op)
50 struct gnttab_cache_flush cflush;
54 pfn = (handle >> PAGE_SHIFT) + offset / PAGE_SIZE;
60 /* buffers in highmem or foreign pages cannot cross page
62 if (len + offset > PAGE_SIZE)
63 len = PAGE_SIZE - offset;
66 cflush.a.dev_bus_addr = pfn << PAGE_SHIFT;
67 cflush.offset = offset;
70 if (op == DMA_UNMAP && dir != DMA_TO_DEVICE)
71 cflush.op = GNTTAB_CACHE_INVAL;
73 if (dir == DMA_FROM_DEVICE)
74 cflush.op = GNTTAB_CACHE_INVAL;
76 cflush.op = GNTTAB_CACHE_CLEAN;
79 HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1);
87 static void __xen_dma_page_dev_to_cpu(struct device *hwdev, dma_addr_t handle,
88 size_t size, enum dma_data_direction dir)
90 dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_UNMAP);
93 static void __xen_dma_page_cpu_to_dev(struct device *hwdev, dma_addr_t handle,
94 size_t size, enum dma_data_direction dir)
96 dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_MAP);
99 void __xen_dma_map_page(struct device *hwdev, struct page *page,
100 dma_addr_t dev_addr, unsigned long offset, size_t size,
101 enum dma_data_direction dir, struct dma_attrs *attrs)
103 if (is_device_dma_coherent(hwdev))
105 if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
108 __xen_dma_page_cpu_to_dev(hwdev, dev_addr, size, dir);
111 void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
112 size_t size, enum dma_data_direction dir,
113 struct dma_attrs *attrs)
116 if (is_device_dma_coherent(hwdev))
118 if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
121 __xen_dma_page_dev_to_cpu(hwdev, handle, size, dir);
124 void __xen_dma_sync_single_for_cpu(struct device *hwdev,
125 dma_addr_t handle, size_t size, enum dma_data_direction dir)
127 if (is_device_dma_coherent(hwdev))
129 __xen_dma_page_dev_to_cpu(hwdev, handle, size, dir);
132 void __xen_dma_sync_single_for_device(struct device *hwdev,
133 dma_addr_t handle, size_t size, enum dma_data_direction dir)
135 if (is_device_dma_coherent(hwdev))
137 __xen_dma_page_cpu_to_dev(hwdev, handle, size, dir);
140 bool xen_arch_need_swiotlb(struct device *dev,
144 return (!hypercall_cflush && (pfn != bfn) && !is_device_dma_coherent(dev));
147 int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
148 unsigned int address_bits,
149 dma_addr_t *dma_handle)
151 if (!xen_initial_domain())
154 /* we assume that dom0 is mapped 1:1 for now */
155 *dma_handle = pstart;
158 EXPORT_SYMBOL_GPL(xen_create_contiguous_region);
160 void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order)
164 EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region);
166 struct dma_map_ops *xen_dma_ops;
167 EXPORT_SYMBOL(xen_dma_ops);
169 static struct dma_map_ops xen_swiotlb_dma_ops = {
170 .mapping_error = xen_swiotlb_dma_mapping_error,
171 .alloc = xen_swiotlb_alloc_coherent,
172 .free = xen_swiotlb_free_coherent,
173 .sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu,
174 .sync_single_for_device = xen_swiotlb_sync_single_for_device,
175 .sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu,
176 .sync_sg_for_device = xen_swiotlb_sync_sg_for_device,
177 .map_sg = xen_swiotlb_map_sg_attrs,
178 .unmap_sg = xen_swiotlb_unmap_sg_attrs,
179 .map_page = xen_swiotlb_map_page,
180 .unmap_page = xen_swiotlb_unmap_page,
181 .dma_supported = xen_swiotlb_dma_supported,
182 .set_dma_mask = xen_swiotlb_set_dma_mask,
185 int __init xen_mm_init(void)
187 struct gnttab_cache_flush cflush;
188 if (!xen_initial_domain())
190 xen_swiotlb_init(1, false);
191 xen_dma_ops = &xen_swiotlb_dma_ops;
194 cflush.a.dev_bus_addr = 0;
197 if (HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1) != -ENOSYS)
198 hypercall_cflush = true;
201 arch_initcall(xen_mm_init);