2 * DMA region bookkeeping routines
4 * Copyright (C) 2002 Maas Digital LLC
6 * This code is licensed under the GPL. See the file COPYING in the root
7 * directory of the kernel sources for details.
10 #include <linux/module.h>
11 #include <linux/vmalloc.h>
12 #include <linux/slab.h>
18 void dma_prog_region_init(struct dma_prog_region *prog)
26 int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes, struct pci_dev *dev)
28 /* round up to page size */
29 n_bytes = PAGE_ALIGN(n_bytes);
31 prog->n_pages = n_bytes >> PAGE_SHIFT;
33 prog->kvirt = pci_alloc_consistent(dev, n_bytes, &prog->bus_addr);
35 printk(KERN_ERR "dma_prog_region_alloc: pci_alloc_consistent() failed\n");
36 dma_prog_region_free(prog);
45 void dma_prog_region_free(struct dma_prog_region *prog)
48 pci_free_consistent(prog->dev, prog->n_pages << PAGE_SHIFT, prog->kvirt, prog->bus_addr);
59 void dma_region_init(struct dma_region *dma)
68 int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes, struct pci_dev *dev, int direction)
72 /* round up to page size */
73 n_bytes = PAGE_ALIGN(n_bytes);
75 dma->n_pages = n_bytes >> PAGE_SHIFT;
77 dma->kvirt = vmalloc_32(n_bytes);
79 printk(KERN_ERR "dma_region_alloc: vmalloc_32() failed\n");
83 /* Clear the ram out, no junk to the user */
84 memset(dma->kvirt, 0, n_bytes);
86 /* allocate scatter/gather list */
87 dma->sglist = vmalloc(dma->n_pages * sizeof(*dma->sglist));
89 printk(KERN_ERR "dma_region_alloc: vmalloc(sglist) failed\n");
93 /* just to be safe - this will become unnecessary once sglist->address goes away */
94 memset(dma->sglist, 0, dma->n_pages * sizeof(*dma->sglist));
96 /* fill scatter/gather list with pages */
97 for (i = 0; i < dma->n_pages; i++) {
98 unsigned long va = (unsigned long) dma->kvirt + (i << PAGE_SHIFT);
100 dma->sglist[i].page = vmalloc_to_page((void *)va);
101 dma->sglist[i].length = PAGE_SIZE;
104 /* map sglist to the IOMMU */
105 dma->n_dma_pages = pci_map_sg(dev, dma->sglist, dma->n_pages, direction);
107 if (dma->n_dma_pages == 0) {
108 printk(KERN_ERR "dma_region_alloc: pci_map_sg() failed\n");
113 dma->direction = direction;
118 dma_region_free(dma);
122 void dma_region_free(struct dma_region *dma)
124 if (dma->n_dma_pages) {
125 pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages, dma->direction);
126 dma->n_dma_pages = 0;
142 /* find the scatterlist index and remaining offset corresponding to a
143 given offset from the beginning of the buffer */
144 static inline int dma_region_find(struct dma_region *dma, unsigned long offset, unsigned long *rem)
147 unsigned long off = offset;
149 for (i = 0; i < dma->n_dma_pages; i++) {
150 if (off < sg_dma_len(&dma->sglist[i])) {
155 off -= sg_dma_len(&dma->sglist[i]);
158 BUG_ON(i >= dma->n_dma_pages);
163 dma_addr_t dma_region_offset_to_bus(struct dma_region *dma, unsigned long offset)
167 struct scatterlist *sg = &dma->sglist[dma_region_find(dma, offset, &rem)];
168 return sg_dma_address(sg) + rem;
171 void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset, unsigned long len)
179 first = dma_region_find(dma, offset, &rem);
180 last = dma_region_find(dma, offset + len - 1, &rem);
182 pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1, dma->direction);
185 void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset, unsigned long len)
193 first = dma_region_find(dma, offset, &rem);
194 last = dma_region_find(dma, offset + len - 1, &rem);
196 pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first], last - first + 1, dma->direction);
201 /* nopage() handler for mmap access */
204 dma_region_pagefault(struct vm_area_struct *area, unsigned long address, int *type)
206 unsigned long offset;
207 unsigned long kernel_virt_addr;
208 struct page *ret = NOPAGE_SIGBUS;
210 struct dma_region *dma = (struct dma_region*) area->vm_private_data;
215 if ( (address < (unsigned long) area->vm_start) ||
216 (address > (unsigned long) area->vm_start + (dma->n_pages << PAGE_SHIFT)) )
220 *type = VM_FAULT_MINOR;
221 offset = address - area->vm_start;
222 kernel_virt_addr = (unsigned long) dma->kvirt + offset;
223 ret = vmalloc_to_page((void*) kernel_virt_addr);
229 static struct vm_operations_struct dma_region_vm_ops = {
230 .nopage = dma_region_pagefault,
233 int dma_region_mmap(struct dma_region *dma, struct file *file, struct vm_area_struct *vma)
240 /* must be page-aligned */
241 if (vma->vm_pgoff != 0)
244 /* check the length */
245 size = vma->vm_end - vma->vm_start;
246 if (size > (dma->n_pages << PAGE_SHIFT))
249 vma->vm_ops = &dma_region_vm_ops;
250 vma->vm_private_data = dma;
252 vma->vm_flags |= VM_RESERVED;
257 #else /* CONFIG_MMU */
259 int dma_region_mmap(struct dma_region *dma, struct file *file, struct vm_area_struct *vma)
264 #endif /* CONFIG_MMU */