1 files changed, 290 insertions, 0 deletions
diff --git a/drivers/ieee1394/dma.c b/drivers/ieee1394/dma.c
new file mode 100644
index 0000000..1aba8c1
--- /dev/null
+++ b/drivers/ieee1394/dma.c
@@ -0,0 +1,290 @@
+/*
+ * DMA region bookkeeping routines
+ *
+ * Copyright (C) 2002 Maas Digital LLC
+ *
+ * This code is licensed under the GPL.  See the file COPYING in the root
+ * directory of the kernel sources for details.
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/scatterlist.h>
+
+#include "dma.h"
+
+/* dma_prog_region */
+
+void dma_prog_region_init(struct dma_prog_region *prog)
+{
+	prog->kvirt = NULL;
+	prog->dev = NULL;
+	prog->n_pages = 0;
+	prog->bus_addr = 0;
+}
+
+int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes,
+			  struct pci_dev *dev)
+{
+	/* round up to page size */
+	n_bytes = PAGE_ALIGN(n_bytes);
+
+	prog->n_pages = n_bytes >> PAGE_SHIFT;
+
+	prog->kvirt = pci_alloc_consistent(dev, n_bytes, &prog->bus_addr);
+	if (!prog->kvirt) {
+		printk(KERN_ERR
+		       "dma_prog_region_alloc: pci_alloc_consistent() failed\n");
+		dma_prog_region_free(prog);
+		return -ENOMEM;
+	}
+
+	prog->dev = dev;
+
+	return 0;
+}
+
+void dma_prog_region_free(struct dma_prog_region *prog)
+{
+	if (prog->kvirt) {
+		pci_free_consistent(prog->dev, prog->n_pages << PAGE_SHIFT,
+				    prog->kvirt, prog->bus_addr);
+	}
+
+	prog->kvirt = NULL;
+	prog->dev = NULL;
+	prog->n_pages = 0;
+	prog->bus_addr = 0;
+}
+
+/* dma_region */
+
+/**
+ * dma_region_init - clear out all fields but do not allocate anything
+ */
+void dma_region_init(struct dma_region *dma)
+{
+	dma->kvirt = NULL;
+	dma->dev = NULL;
+	dma->n_pages = 0;
+	dma->n_dma_pages = 0;
+	dma->sglist = NULL;
+}
+
+/**
+ * dma_region_alloc - allocate the buffer and map it to the IOMMU
+ */
+int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes,
+		     struct pci_dev *dev, int direction)
+{
+	unsigned int i;
+
+	/* round up to page size */
+	n_bytes = PAGE_ALIGN(n_bytes);
+
+	dma->n_pages = n_bytes >> PAGE_SHIFT;
+
+	dma->kvirt = vmalloc_32(n_bytes);
+	if (!dma->kvirt) {
+		printk(KERN_ERR "dma_region_alloc: vmalloc_32() failed\n");
+		goto err;
+	}
+
+	/* Clear the ram out, no junk to the user */
+	memset(dma->kvirt, 0, n_bytes);
+
+	/* allocate scatter/gather list */
+	dma->sglist = vmalloc(dma->n_pages * sizeof(*dma->sglist));
+	if (!dma->sglist) {
+		printk(KERN_ERR "dma_region_alloc: vmalloc(sglist) failed\n");
+		goto err;
+	}
+
+	sg_init_table(dma->sglist, dma->n_pages);
+
+	/* fill scatter/gather list with pages */
+	for (i = 0; i < dma->n_pages; i++) {
+		unsigned long va =
+		    (unsigned long)dma->kvirt + (i << PAGE_SHIFT);
+
+		sg_set_page(&dma->sglist[i], vmalloc_to_page((void *)va),
+				PAGE_SIZE, 0);
+	}
+
+	/* map sglist to the IOMMU */
+	dma->n_dma_pages =
+	    pci_map_sg(dev, dma->sglist, dma->n_pages, direction);
+
+	if (dma->n_dma_pages == 0) {
+		printk(KERN_ERR "dma_region_alloc: pci_map_sg() failed\n");
+		goto err;
+	}
+
+	dma->dev = dev;
+	dma->direction = direction;
+
+	return 0;
+
+      err:
+	dma_region_free(dma);
+	return -ENOMEM;
+}
+
+/**
+ * dma_region_free - unmap and free the buffer
+ */
+void dma_region_free(struct dma_region *dma)
+{
+	if (dma->n_dma_pages) {
+		pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages,
+			     dma->direction);
+		dma->n_dma_pages = 0;
+		dma->dev = NULL;
+	}
+
+	vfree(dma->sglist);
+	dma->sglist = NULL;
+
+	vfree(dma->kvirt);
+	dma->kvirt = NULL;
+	dma->n_pages = 0;
+}
+
+/* find the scatterlist index and remaining offset corresponding to a
+   given offset from the beginning of the buffer */
+static inline int dma_region_find(struct dma_region *dma, unsigned long offset,
+				  unsigned int start, unsigned long *rem)
+{
+	int i;
+	unsigned long off = offset;
+
+	for (i = start; i < dma->n_dma_pages; i++) {
+		if (off < sg_dma_len(&dma->sglist[i])) {
+			*rem = off;
+			break;
+		}
+
+		off -= sg_dma_len(&dma->sglist[i]);
+	}
+
+	BUG_ON(i >= dma->n_dma_pages);
+
+	return i;
+}
+
+/**
+ * dma_region_offset_to_bus - get bus address of an offset within a DMA region
+ *
+ * Returns the DMA bus address of the byte with the given @offset relative to
+ * the beginning of the @dma.
+ */
+dma_addr_t dma_region_offset_to_bus(struct dma_region * dma,
+				    unsigned long offset)
+{
+	unsigned long rem = 0;
+
+	struct scatterlist *sg =
+	    &dma->sglist[dma_region_find(dma, offset, 0, &rem)];
+	return sg_dma_address(sg) + rem;
+}
+
+/**
+ * dma_region_sync_for_cpu - sync the CPU's view of the buffer
+ */
+void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset,
+			     unsigned long len)
+{
+	int first, last;
+	unsigned long rem = 0;
+
+	if (!len)
+		len = 1;
+
+	first = dma_region_find(dma, offset, 0, &rem);
+	last = dma_region_find(dma, rem + len - 1, first, &rem);
+
+	pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1,
+				dma->direction);
+}
+
+/**
+ * dma_region_sync_for_device - sync the IO bus' view of the buffer
+ */
+void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset,
+				unsigned long len)
+{
+	int first, last;
+	unsigned long rem = 0;
+
+	if (!len)
+		len = 1;
+
+	first = dma_region_find(dma, offset, 0, &rem);
+	last = dma_region_find(dma, rem + len - 1, first, &rem);
+
+	pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first],
+				   last - first + 1, dma->direction);
+}
+
+#ifdef CONFIG_MMU
+
+static int dma_region_pagefault(struct vm_area_struct *vma,
+				struct vm_fault *vmf)
+{
+	struct dma_region *dma = (struct dma_region *)vma->vm_private_data;
+
+	if (!dma->kvirt)
+		return VM_FAULT_SIGBUS;
+
+	if (vmf->pgoff >= dma->n_pages)
+		return VM_FAULT_SIGBUS;
+
+	vmf->page = vmalloc_to_page(dma->kvirt + (vmf->pgoff << PAGE_SHIFT));
+	get_page(vmf->page);
+	return 0;
+}
+
+static struct vm_operations_struct dma_region_vm_ops = {
+	.fault = dma_region_pagefault,
+};
+
+/**
+ * dma_region_mmap - map the buffer into a user space process
+ */
+int dma_region_mmap(struct dma_region *dma, struct file *file,
+		    struct vm_area_struct *vma)
+{
+	unsigned long size;
+
+	if (!dma->kvirt)
+		return -EINVAL;
+
+	/* must be page-aligned (XXX: comment is wrong, we could allow pgoff) */
+	if (vma->vm_pgoff != 0)
+		return -EINVAL;
+
+	/* check the length */
+	size = vma->vm_end - vma->vm_start;
+	if (size > (dma->n_pages << PAGE_SHIFT))
+		return -EINVAL;
+
+	vma->vm_ops = &dma_region_vm_ops;
+	vma->vm_private_data = dma;
+	vma->vm_file = file;
+	vma->vm_flags |= VM_RESERVED | VM_ALWAYSDUMP;
+
+	return 0;
+}
+
+#else				/* CONFIG_MMU */
+
+int dma_region_mmap(struct dma_region *dma, struct file *file,
+		    struct vm_area_struct *vma)
+{
+	return -EINVAL;
+}
+
+#endif				/* CONFIG_MMU */