1 /* 2 * arch/xtensa/pci-dma.c 3 * 4 * DMA coherent memory allocation. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published by the 8 * Free Software Foundation; either version 2 of the License, or (at your 9 * option) any later version. 10 * 11 * Copyright (C) 2002 - 2005 Tensilica Inc. 12 * 13 * Based on version for i386. 14 * 15 * Chris Zankel <chris@zankel.net> 16 * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> 17 */ 18 19 #include <linux/types.h> 20 #include <linux/mm.h> 21 #include <linux/string.h> 22 #include <linux/pci.h> 23 #include <asm/io.h> 24 #include <asm/cacheflush.h> 25 26 /* 27 * Note: We assume that the full memory space is always mapped to 'kseg' 28 * Otherwise we have to use page attributes (not implemented). 29 */ 30 31 void * 32 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp) 33 { 34 void *ret; 35 36 /* ignore region speicifiers */ 37 gfp &= ~(__GFP_DMA | __GFP_HIGHMEM); 38 39 if (dev == NULL || (*dev->dma_mask < 0xffffffff)) 40 gfp |= GFP_DMA; 41 ret = (void *)__get_free_pages(gfp, get_order(size)); 42 43 if (ret != NULL) { 44 memset(ret, 0, size); 45 *handle = virt_to_bus(ret); 46 } 47 return (void*) BYPASS_ADDR((unsigned long)ret); 48 } 49 50 void dma_free_coherent(struct device *hwdev, size_t size, 51 void *vaddr, dma_addr_t dma_handle) 52 { 53 free_pages(CACHED_ADDR((unsigned long)vaddr), get_order(size)); 54 } 55 56 57 void consistent_sync(void *vaddr, size_t size, int direction) 58 { 59 switch (direction) { 60 case PCI_DMA_NONE: 61 BUG(); 62 case PCI_DMA_FROMDEVICE: /* invalidate only */ 63 __invalidate_dcache_range((unsigned long)vaddr, 64 (unsigned long)size); 65 break; 66 67 case PCI_DMA_TODEVICE: /* writeback only */ 68 case PCI_DMA_BIDIRECTIONAL: /* writeback and invalidate */ 69 __flush_invalidate_dcache_range((unsigned long)vaddr, 70 (unsigned long)size); 71 break; 72 } 73 } 74