1 /*
2 * Copyright (C) 2001 David J. Mckay (david.mckay@st.com)
3 * Copyright (C) 2003 Paul Mundt (lethal@linux-sh.org)
4 *
5 * May be copied or modified under the terms of the GNU General Public
6 * License. See linux/COPYING for more information.
7 *
8 * Dynamic DMA mapping support.
9 */
10 #include <linux/types.h>
11 #include <linux/mm.h>
12 #include <linux/string.h>
13 #include <linux/pci.h>
14 #include <asm/io.h>
15
pci_alloc_consistent(struct pci_dev * hwdev,size_t size,dma_addr_t * dma_handle)16 void *pci_alloc_consistent(struct pci_dev *hwdev, size_t size,
17 dma_addr_t *dma_handle)
18 {
19 void *ret;
20 int gfp = GFP_ATOMIC;
21 void *vp;
22
23 if (hwdev == NULL || hwdev->dma_mask != 0xffffffff)
24 gfp |= GFP_DMA;
25
26 ret = (void *)__get_free_pages(gfp, get_order(size));
27
28 /* now call our friend ioremap_nocache to give us an uncached area */
29 vp = ioremap_nocache(virt_to_phys(ret), size);
30
31 if (vp != NULL) {
32 memset(vp, 0, size);
33 *dma_handle = virt_to_bus(ret);
34 dma_cache_wback_inv((unsigned long)ret, size);
35 }
36
37 return vp;
38 }
39
pci_free_consistent(struct pci_dev * hwdev,size_t size,void * vaddr,dma_addr_t dma_handle)40 void pci_free_consistent(struct pci_dev *hwdev, size_t size,
41 void *vaddr, dma_addr_t dma_handle)
42 {
43 void *alloc;
44
45 alloc = bus_to_virt((unsigned long)dma_handle);
46 free_pages((unsigned long)alloc, get_order(size));
47
48 iounmap(vaddr);
49 }
50
51