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 bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp); 34 #define arch_dma_alloc_attrs arch_dma_alloc_attrs 35 36 extern void *dma_generic_alloc_coherent(struct device *dev, size_t size, 37 dma_addr_t *dma_addr, gfp_t flag, 38 unsigned long attrs); 39 40 extern void dma_generic_free_coherent(struct device *dev, size_t size, 41 void *vaddr, dma_addr_t dma_addr, 42 unsigned long attrs); 43 44 static inline unsigned long dma_alloc_coherent_mask(struct device *dev, 45 gfp_t gfp) 46 { 47 unsigned long dma_mask = 0; 48 49 dma_mask = dev->coherent_dma_mask; 50 if (!dma_mask) 51 dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32); 52 53 return dma_mask; 54 } 55 56 static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp) 57 { 58 unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp); 59 60 if (dma_mask <= DMA_BIT_MASK(24)) 61 gfp |= GFP_DMA; 62 #ifdef CONFIG_X86_64 63 if (dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA)) 64 gfp |= GFP_DMA32; 65 #endif 66 return gfp; 67 } 68 69 #endif 70