1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_DMA_MAPPING_H 3 #define _ASM_X86_DMA_MAPPING_H 4 5 /* 6 * IOMMU interface. See Documentation/DMA-API-HOWTO.txt and 7 * Documentation/DMA-API.txt for documentation. 8 */ 9 10 #include <linux/scatterlist.h> 11 #include <linux/dma-debug.h> 12 #include <asm/io.h> 13 #include <asm/swiotlb.h> 14 #include <linux/dma-contiguous.h> 15 16 #ifdef CONFIG_ISA 17 # define ISA_DMA_BIT_MASK DMA_BIT_MASK(24) 18 #else 19 # define ISA_DMA_BIT_MASK DMA_BIT_MASK(32) 20 #endif 21 22 extern int iommu_merge; 23 extern struct device x86_dma_fallback_dev; 24 extern int panic_on_overflow; 25 26 extern const struct dma_map_ops *dma_ops; 27 28 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) 29 { 30 return dma_ops; 31 } 32 33 int arch_dma_supported(struct device *dev, u64 mask); 34 #define arch_dma_supported arch_dma_supported 35 36 bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp); 37 #define arch_dma_alloc_attrs arch_dma_alloc_attrs 38 39 extern void *dma_generic_alloc_coherent(struct device *dev, size_t size, 40 dma_addr_t *dma_addr, gfp_t flag, 41 unsigned long attrs); 42 43 extern void dma_generic_free_coherent(struct device *dev, size_t size, 44 void *vaddr, dma_addr_t dma_addr, 45 unsigned long attrs); 46 47 static inline unsigned long dma_alloc_coherent_mask(struct device *dev, 48 gfp_t gfp) 49 { 50 unsigned long dma_mask = 0; 51 52 dma_mask = dev->coherent_dma_mask; 53 if (!dma_mask) 54 dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32); 55 56 return dma_mask; 57 } 58 59 static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp) 60 { 61 unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp); 62 63 if (dma_mask <= DMA_BIT_MASK(24)) 64 gfp |= GFP_DMA; 65 #ifdef CONFIG_X86_64 66 if (dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA)) 67 gfp |= GFP_DMA32; 68 #endif 69 return gfp; 70 } 71 72 #endif 73