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-rw-r--r--drivers/ieee1394/dma.c260
1 files changed, 260 insertions, 0 deletions
diff --git a/drivers/ieee1394/dma.c b/drivers/ieee1394/dma.c
new file mode 100644
index 000000000000..758819d1999d
--- /dev/null
+++ b/drivers/ieee1394/dma.c
@@ -0,0 +1,260 @@
+/*
+ * 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/module.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/mm.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 */
+
+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;
+}
+
+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;
+ }
+
+ /* just to be safe - this will become unnecessary once sglist->address goes away */
+ memset(dma->sglist, 0, dma->n_pages * sizeof(*dma->sglist));
+
+ /* fill scatter/gather list with pages */
+ for (i = 0; i < dma->n_pages; i++) {
+ unsigned long va = (unsigned long) dma->kvirt + (i << PAGE_SHIFT);
+
+ dma->sglist[i].page = vmalloc_to_page((void *)va);
+ dma->sglist[i].length = PAGE_SIZE;
+ }
+
+ /* 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;
+}
+
+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 long *rem)
+{
+ int i;
+ unsigned long off = offset;
+
+ for (i = 0; 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_addr_t dma_region_offset_to_bus(struct dma_region *dma, unsigned long offset)
+{
+ unsigned long rem;
+
+ struct scatterlist *sg = &dma->sglist[dma_region_find(dma, offset, &rem)];
+ return sg_dma_address(sg) + rem;
+}
+
+void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset, unsigned long len)
+{
+ int first, last;
+ unsigned long rem;
+
+ if (!len)
+ len = 1;
+
+ first = dma_region_find(dma, offset, &rem);
+ last = dma_region_find(dma, offset + len - 1, &rem);
+
+ pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1, dma->direction);
+}
+
+void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset, unsigned long len)
+{
+ int first, last;
+ unsigned long rem;
+
+ if (!len)
+ len = 1;
+
+ first = dma_region_find(dma, offset, &rem);
+ last = dma_region_find(dma, offset + len - 1, &rem);
+
+ pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first], last - first + 1, dma->direction);
+}
+
+#ifdef CONFIG_MMU
+
+/* nopage() handler for mmap access */
+
+static struct page*
+dma_region_pagefault(struct vm_area_struct *area, unsigned long address, int *type)
+{
+ unsigned long offset;
+ unsigned long kernel_virt_addr;
+ struct page *ret = NOPAGE_SIGBUS;
+
+ struct dma_region *dma = (struct dma_region*) area->vm_private_data;
+
+ if (!dma->kvirt)
+ goto out;
+
+ if ( (address < (unsigned long) area->vm_start) ||
+ (address > (unsigned long) area->vm_start + (dma->n_pages << PAGE_SHIFT)) )
+ goto out;
+
+ if (type)
+ *type = VM_FAULT_MINOR;
+ offset = address - area->vm_start;
+ kernel_virt_addr = (unsigned long) dma->kvirt + offset;
+ ret = vmalloc_to_page((void*) kernel_virt_addr);
+ get_page(ret);
+out:
+ return ret;
+}
+
+static struct vm_operations_struct dma_region_vm_ops = {
+ .nopage = dma_region_pagefault,
+};
+
+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 */
+ 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;
+
+ 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 */
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