struct dma_map_ops { void* (*alloc)(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, struct dma_attrs *attrs); void (*free)(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, struct dma_attrs *attrs); int (*mmap)(struct device *, ...
include/asm/dma-mapping.h:extern struct dma_map_ops arm_coherent_dma_ops; mach-highbank/highbank.c:set_dma_ops(dev, &arm_coherent_dma_ops); mach-mvebu/coherency.c:set_dma_ops(dev, &arm_coherent_dma_ops); 5.dma_alloc_coherent申请的内存一定是物理连续的吗? 绝大多数的SoC目前都支持和使用...
dma_map_single()和dma_unmap_single()都在include\linux\dma-mapping.h里定义。如果没有特殊情况,会调用dma_direct_map_page()、dma_direct_unmap_page()。 arm64的特殊情况包括iommu和Xen虚拟机。 iommu和Xen虚拟机都需要提供dma_map_ops,于是使用其中的map、unmap函数。iommu的dma_map_ops是drivers\iommu\D...
structdma_map_ops { void* (*alloc)(structdevice *dev,size_tsize, dma_addr_t *dma_handle, gfp_t gfp, structdma_attrs *attrs); void(*free)(structdevice *dev,size_tsize, void*vaddr, dma_addr_t dma_handle, structdma_attrs *attrs); int(*mmap)(structdevice *,structvm_area_struct ...
intel_iommu_init_qi //初始化每个iommu的queued invalidation,具体会去设置iommu->flush_xxx的ops //若硬件支持QI,则初始化QI用作发送invalidation,若不支持则通过register based方式来发送invalidation iommu_init_domains iommu->domain_ids=bitmap_zalloc(ndomains) //ndomains表示dmar能支持的最大domain数,capabili...
│ ├── drm_dma.c │ ├── drm_dp_aux_dev.c--DRM DP Aux设备创建和处理函数。│ ├── drm_dp_cec.c │ ├── drm_dp_dual_mode_helper.c │ ├── drm_dp_helper.c │ ├── drm_dp_mst_topology.c │ ├── drm_drv.c ...
enum dma_data_direction DMA_TO_DEVICE DMA_FROM_DEVICE DMA_BIDIRECTIONAL DMA_NONE dma_addr_t dma_map_single(struct device *dev, void *buffer, size_t size, enum dma_data_direction direction); void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size, enum dma_data_di...
baohua@baohua-VirtualBox:~/develop/linux/arch/arm$ git grep arm_coherent_dma_ops include/asm/dma-mapping.h:extern struct dma_map_ops arm_coherent_dma_ops;mach-highbank/highbank.c:set_dma_ops(dev,&arm_coherent_dma_ops);mach-mvebu/coherency.c:set_dma_ops(dev,&arm_coherent_dma_ops); ...
struct vm_operations_struct generic_file_vm_ops={.fault=filemap_fault,// 将 fault() 回调函数设置为:filemap_fault()};intgeneric_file_mmap(struct file*file,struct vm_area_struct*vma){...vma->vm_ops=&generic_file_vm_ops;...return0;} ...
But an awareness of how to map user-space memory into the kernel (with get_user_pages) can be useful. The final section covers direct memory access (DMA) I/O operations, which provide peripherals with direct access to system memory.