patch-2.4.21 linux-2.4.21/drivers/ieee1394/dma.c
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- Lines: 237
- Date:
2003-06-13 07:51:34.000000000 -0700
- Orig file:
linux-2.4.20/drivers/ieee1394/dma.c
- Orig date:
1969-12-31 16:00:00.000000000 -0800
diff -urN linux-2.4.20/drivers/ieee1394/dma.c linux-2.4.21/drivers/ieee1394/dma.c
@@ -0,0 +1,236 @@
+/*
+ * 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 "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 = round_up_to_page(n_bytes);
+
+ prog->n_pages = n_bytes / PAGE_SIZE;
+
+ prog->kvirt = pci_alloc_consistent(dev, prog->n_pages * PAGE_SIZE, &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_SIZE, 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, n_pages;
+
+ /* round up to page size */
+ n_bytes = round_up_to_page(n_bytes);
+
+ n_pages = n_bytes / PAGE_SIZE;
+
+ dma->kvirt = vmalloc_32(n_pages * PAGE_SIZE);
+ if(!dma->kvirt) {
+ printk(KERN_ERR "dma_region_alloc: vmalloc_32() failed\n");
+ goto err;
+ }
+
+ dma->n_pages = n_pages;
+
+ /* Clear the ram out, no junk to the user */
+ memset(dma->kvirt, 0, n_pages * PAGE_SIZE);
+
+ /* allocate scatter/gather list */
+ dma->sglist = kmalloc(dma->n_pages * sizeof(struct scatterlist), GFP_KERNEL);
+ if(!dma->sglist) {
+ printk(KERN_ERR "dma_region_alloc: kmalloc(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(struct scatterlist));
+
+ /* fill scatter/gather list with pages */
+ for(i = 0; i < dma->n_pages; i++) {
+ unsigned long va = (unsigned long) dma->kvirt + i * PAGE_SIZE;
+
+ 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[0], 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;
+ }
+
+ if(dma->sglist) {
+ kfree(dma->sglist);
+ dma->sglist = NULL;
+ }
+
+ if(dma->kvirt) {
+ 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;
+ return i;
+ }
+
+ off -= sg_dma_len(&dma->sglist[i]);
+ }
+
+ panic("dma_region_find: offset %lu beyond end of DMA mapping\n", offset);
+}
+
+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(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(dma->dev, &dma->sglist[first], last - first + 1, dma->direction);
+}
+
+/* nopage() handler for mmap access */
+
+static struct page*
+dma_region_pagefault(struct vm_area_struct *area, unsigned long address, int write_access)
+{
+ 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 + (PAGE_SIZE * dma->n_pages)) )
+ goto out;
+
+ 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 > (PAGE_SIZE * dma->n_pages))
+ 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;
+}
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