1 /* MN10300 Dynamic DMA mapping support
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * Derived from: arch/i386/kernel/pci-dma.c
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public Licence
9 * as published by the Free Software Foundation; either version
10 * 2 of the Licence, or (at your option) any later version.
13 #include <linux/types.h>
15 #include <linux/string.h>
16 #include <linux/pci.h>
19 static unsigned long pci_sram_allocated = 0xbc000000;
21 void *dma_alloc_coherent(struct device *dev, size_t size,
22 dma_addr_t *dma_handle, int gfp)
27 printk("dma_alloc_coherent(%s,%zu,,%x)\n", dev_name(dev), size, gfp);
29 if (0xbe000000 - pci_sram_allocated >= size) {
30 size = (size + 255) & ~255;
31 addr = pci_sram_allocated;
32 pci_sram_allocated += size;
37 /* ignore region specifiers */
38 gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
40 if (dev == NULL || dev->coherent_dma_mask < 0xffffffff)
43 addr = __get_free_pages(gfp, get_order(size));
47 /* map the coherent memory through the uncached memory window */
48 ret = (void *) (addr | 0x20000000);
50 /* fill the memory with obvious rubbish */
51 memset((void *) addr, 0xfb, size);
53 /* write back and evict all cache lines covering this region */
54 mn10300_dcache_flush_inv_range2(virt_to_phys((void *) addr), PAGE_SIZE);
57 *dma_handle = virt_to_bus((void *) addr);
58 printk("dma_alloc_coherent() = %p [%x]\n", ret, *dma_handle);
61 EXPORT_SYMBOL(dma_alloc_coherent);
63 void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
64 dma_addr_t dma_handle)
66 unsigned long addr = (unsigned long) vaddr & ~0x20000000;
68 if (addr >= 0x9c000000)
71 free_pages(addr, get_order(size));
73 EXPORT_SYMBOL(dma_free_coherent);