/* * 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" /* * PC-compatibles, are, fortunately, sufficiently cache-coherent for this. */ #if defined(__i386__) || defined(__x86_64__) /* CONFIG_ARCH_I386 doesn't 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; } void mon_dmapeek_vec(const struct mon_reader_bin *rp, unsigned int offset, dma_addr_t dma_addr, unsigned int length) { unsigned long flags; unsigned int step_len; struct page *pg; unsigned char *map; unsigned long page_off, page_len; local_irq_save(flags); while (length) { /* compute number of bytes we are going to copy in this page */ step_len = length; page_off = dma_addr & (PAGE_SIZE-1); page_len = PAGE_SIZE - page_off; if (page_len < step_len) step_len = page_len; /* copy data and advance pointers */ pg = phys_to_page(dma_addr); map = kmap_atomic(pg, KM_IRQ0); offset = mon_copy_to_buff(rp, offset, map + page_off, step_len); kunmap_atomic(map, KM_IRQ0); dma_addr += step_len; length -= step_len; } local_irq_restore(flags); } #endif /* __i386__ */ #ifndef MON_HAS_UNMAP char mon_dmapeek(unsigned char *dst, dma_addr_t dma_addr, int len) { return 'D'; } void mon_dmapeek_vec(const struct mon_reader_bin *rp, unsigned int offset, dma_addr_t dma_addr, unsigned int length) { ; } #endif /* MON_HAS_UNMAP */