/* * arch/xtensa/kernel/pci-dma.c * * DMA coherent memory allocation. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. * * Copyright (C) 2002 - 2005 Tensilica Inc. * * Based on version for i386. * * Chris Zankel <chris@zankel.net> * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> */ #include <linux/types.h> #include <linux/mm.h> #include <linux/string.h> #include <linux/pci.h> #include <asm/io.h> #include <asm/cacheflush.h> /* * Note: We assume that the full memory space is always mapped to 'kseg' * Otherwise we have to use page attributes (not implemented). */ void * dma_alloc_coherent(struct device *dev,size_t size,dma_addr_t *handle,gfp_t flag) { unsigned long ret; unsigned long uncached = 0; /* ignore region speicifiers */ flag &= ~(__GFP_DMA | __GFP_HIGHMEM); if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff)) flag |= GFP_DMA; ret = (unsigned long)__get_free_pages(flag, get_order(size)); if (ret == 0) return NULL; /* We currently don't support coherent memory outside KSEG */ if (ret < XCHAL_KSEG_CACHED_VADDR || ret >= XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE) BUG(); if (ret != 0) { memset((void*) ret, 0, size); uncached = ret+XCHAL_KSEG_BYPASS_VADDR-XCHAL_KSEG_CACHED_VADDR; *handle = virt_to_bus((void*)ret); __flush_invalidate_dcache_range(ret, size); } return (void*)uncached; } void dma_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle) { long addr=(long)vaddr+XCHAL_KSEG_CACHED_VADDR-XCHAL_KSEG_BYPASS_VADDR; if (addr < 0 || addr >= XCHAL_KSEG_SIZE) BUG(); free_pages(addr, get_order(size)); } void consistent_sync(void *vaddr, size_t size, int direction) { switch (direction) { case PCI_DMA_NONE: BUG(); case PCI_DMA_FROMDEVICE: /* invalidate only */ __invalidate_dcache_range((unsigned long)vaddr, (unsigned long)size); break; case PCI_DMA_TODEVICE: /* writeback only */ case PCI_DMA_BIDIRECTIONAL: /* writeback and invalidate */ __flush_invalidate_dcache_range((unsigned long)vaddr, (unsigned long)size); break; } }