96 lines
2.4 KiB
C
96 lines
2.4 KiB
C
/*
|
|
* 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 */
|