1 files changed, 95 insertions, 0 deletions
diff --git a/drivers/usb/mon/mon_dma.c b/drivers/usb/mon/mon_dma.c
new file mode 100644
index 0000000..140cc80
--- /dev/null
+++ b/drivers/usb/mon/mon_dma.c
@@ -0,0 +1,95 @@
+/*
+ * 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 */