146 lines
3.4 KiB
C
146 lines
3.4 KiB
C
/* pci-dma-nommu.c: Dynamic DMA mapping support for the FRV
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*
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* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
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* Written by David Woodhouse (dwmw2@infradead.org)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/dma-mapping.h>
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#include <linux/list.h>
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#include <linux/pci.h>
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#include <asm/io.h>
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#if 1
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#define DMA_SRAM_START dma_coherent_mem_start
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#define DMA_SRAM_END dma_coherent_mem_end
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#else // Use video RAM on Matrox
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#define DMA_SRAM_START 0xe8900000
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#define DMA_SRAM_END 0xe8a00000
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#endif
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struct dma_alloc_record {
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struct list_head list;
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unsigned long ofs;
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unsigned long len;
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};
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static DEFINE_SPINLOCK(dma_alloc_lock);
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static LIST_HEAD(dma_alloc_list);
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void *dma_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t gfp)
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{
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struct dma_alloc_record *new;
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struct list_head *this = &dma_alloc_list;
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unsigned long flags;
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unsigned long start = DMA_SRAM_START;
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unsigned long end;
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if (!DMA_SRAM_START) {
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printk("%s called without any DMA area reserved!\n", __func__);
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return NULL;
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}
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new = kmalloc(sizeof (*new), GFP_ATOMIC);
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if (!new)
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return NULL;
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/* Round up to a reasonable alignment */
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new->len = (size + 31) & ~31;
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spin_lock_irqsave(&dma_alloc_lock, flags);
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list_for_each (this, &dma_alloc_list) {
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struct dma_alloc_record *this_r = list_entry(this, struct dma_alloc_record, list);
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end = this_r->ofs;
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if (end - start >= size)
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goto gotone;
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start = this_r->ofs + this_r->len;
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}
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/* Reached end of list. */
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end = DMA_SRAM_END;
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this = &dma_alloc_list;
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if (end - start >= size) {
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gotone:
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new->ofs = start;
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list_add_tail(&new->list, this);
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spin_unlock_irqrestore(&dma_alloc_lock, flags);
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*dma_handle = start;
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return (void *)start;
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}
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kfree(new);
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spin_unlock_irqrestore(&dma_alloc_lock, flags);
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return NULL;
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}
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EXPORT_SYMBOL(dma_alloc_coherent);
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void dma_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle)
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{
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struct dma_alloc_record *rec;
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unsigned long flags;
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spin_lock_irqsave(&dma_alloc_lock, flags);
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list_for_each_entry(rec, &dma_alloc_list, list) {
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if (rec->ofs == dma_handle) {
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list_del(&rec->list);
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kfree(rec);
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spin_unlock_irqrestore(&dma_alloc_lock, flags);
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return;
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}
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}
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spin_unlock_irqrestore(&dma_alloc_lock, flags);
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BUG();
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}
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EXPORT_SYMBOL(dma_free_coherent);
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dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
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enum dma_data_direction direction)
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{
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BUG_ON(direction == DMA_NONE);
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frv_cache_wback_inv((unsigned long) ptr, (unsigned long) ptr + size);
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return virt_to_bus(ptr);
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}
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EXPORT_SYMBOL(dma_map_single);
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int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
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enum dma_data_direction direction)
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{
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int i;
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for (i=0; i<nents; i++)
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frv_cache_wback_inv(sg_dma_address(&sg[i]),
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sg_dma_address(&sg[i]) + sg_dma_len(&sg[i]));
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BUG_ON(direction == DMA_NONE);
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return nents;
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}
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EXPORT_SYMBOL(dma_map_sg);
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dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
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size_t size, enum dma_data_direction direction)
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{
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BUG_ON(direction == DMA_NONE);
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flush_dcache_page(page);
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return (dma_addr_t) page_to_phys(page) + offset;
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}
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EXPORT_SYMBOL(dma_map_page);
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