... mappings, for a buffer that will last the lifetime of the driver. PCI _DMA_ TODEVICE PCI _DMA_ FROMDEVICE PCI _DMA_ BIDIRECTIONAL PCI _DMA_ NONE These symbols are used to tell the streaming mapping functions ... struct file *vm_file; Chapter 13 :mmap and DMA This chapter delves into the area of Linux memory management, with an emphasis on techniques that are useful to the device driver writer. The material ... size_t size, dma_ addr_t *bus_addr) void pci_free_consistent(struct pci_dev *pdev, size_t size, void *cpuaddr, dma_ handle_t bus_addr); These functions allocate and free consistent DMA mappings,...