| /* |
| * The USB Monitor, inspired by Dave Harding's USBMon. |
| * |
| * mon_dma.c: Library which snoops on DMA areas. |
| * |
| * Copyright (C) 2005 Pete Zaitcev (zaitcev@redhat.com) |
| */ |
| #include <linux/kernel.h> |
| #include <linux/list.h> |
| #include <linux/highmem.h> |
| #include <asm/page.h> |
| |
| #include <linux/usb.h> /* Only needed for declarations in usb_mon.h */ |
| #include "usb_mon.h" |
| |
| #ifdef __i386__ /* CONFIG_ARCH_I386 does not exit */ |
| #define MON_HAS_UNMAP 1 |
| |
| #define phys_to_page(phys) pfn_to_page((phys) >> PAGE_SHIFT) |
| |
| char mon_dmapeek(unsigned char *dst, dma_addr_t dma_addr, int len) |
| { |
| struct page *pg; |
| unsigned long flags; |
| unsigned char *map; |
| unsigned char *ptr; |
| |
| /* |
| * On i386, a DMA handle is the "physical" address of a page. |
| * In other words, the bus address is equal to physical address. |
| * There is no IOMMU. |
| */ |
| pg = phys_to_page(dma_addr); |
| |
| /* |
| * We are called from hardware IRQs in case of callbacks. |
| * But we can be called from softirq or process context in case |
| * of submissions. In such case, we need to protect KM_IRQ0. |
| */ |
| local_irq_save(flags); |
| map = kmap_atomic(pg, KM_IRQ0); |
| ptr = map + (dma_addr & (PAGE_SIZE-1)); |
| memcpy(dst, ptr, len); |
| kunmap_atomic(map, KM_IRQ0); |
| local_irq_restore(flags); |
| return 0; |
| } |
| #endif /* __i386__ */ |
| |
| #ifndef MON_HAS_UNMAP |
| char mon_dmapeek(unsigned char *dst, dma_addr_t dma_addr, int len) |
| { |
| return 'D'; |
| } |
| #endif |