[net-next-2.6.git] / arch / mn10300 / mm / dma-alloc.c

/* MN10300 Dynamic DMA mapping support
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 * Derived from: arch/i386/kernel/pci-dma.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#include <linux/types.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/pci.h>
#include <linux/gfp.h>
#include <asm/io.h>

static unsigned long pci_sram_allocated = 0xbc000000;

void *dma_alloc_coherent(struct device *dev, size_t size,
			 dma_addr_t *dma_handle, int gfp)
{
	unsigned long addr;
	void *ret;

	pr_debug("dma_alloc_coherent(%s,%zu,%x)\n",
		 dev ? dev_name(dev) : "?", size, gfp);

	if (0xbe000000 - pci_sram_allocated >= size) {
		size = (size + 255) & ~255;
		addr = pci_sram_allocated;
		pci_sram_allocated += size;
		ret = (void *) addr;
		goto done;
	}

	/* ignore region specifiers */
	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);

	if (dev == NULL || dev->coherent_dma_mask < 0xffffffff)
		gfp |= GFP_DMA;

	addr = __get_free_pages(gfp, get_order(size));
	if (!addr)
		return NULL;

	/* map the coherent memory through the uncached memory window */
	ret = (void *) (addr | 0x20000000);

	/* fill the memory with obvious rubbish */
	memset((void *) addr, 0xfb, size);

	/* write back and evict all cache lines covering this region */
	mn10300_dcache_flush_inv_range2(virt_to_phys((void *) addr), PAGE_SIZE);

done:
	*dma_handle = virt_to_bus((void *) addr);
	printk("dma_alloc_coherent() = %p [%x]\n", ret, *dma_handle);
	return ret;
}
EXPORT_SYMBOL(dma_alloc_coherent);

void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
		       dma_addr_t dma_handle)
{
	unsigned long addr = (unsigned long) vaddr & ~0x20000000;

	if (addr >= 0x9c000000)
		return;

	free_pages(addr, get_order(size));
}
EXPORT_SYMBOL(dma_free_coherent);
Commit	Line	Data
b920de1b DH	1	/* MN10300 Dynamic DMA mapping support
	2	*
	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
	6	*
	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.
	11	*/
	12
	13	#include <linux/types.h>
	14	#include <linux/mm.h>
	15	#include <linux/string.h>
	16	#include <linux/pci.h>
5a0e3ad6	17	#include <linux/gfp.h>
b920de1b DH	18	#include <asm/io.h>
b920de1b DH	19
012c79ba DH	20	static unsigned long pci_sram_allocated = 0xbc000000;
012c79ba DH	21
b920de1b DH	22	void dma_alloc_coherent(struct device dev, size_t size,
	23	dma_addr_t *dma_handle, int gfp)
	24	{
	25	unsigned long addr;
	26	void *ret;
	27
6e0c64f4 JL	28	pr_debug("dma_alloc_coherent(%s,%zu,%x)\n",
6e0c64f4 JL	29	dev ? dev_name(dev) : "?", size, gfp);
012c79ba DH	30
	31	if (0xbe000000 - pci_sram_allocated >= size) {
	32	size = (size + 255) & ~255;
	33	addr = pci_sram_allocated;
	34	pci_sram_allocated += size;
	35	ret = (void *) addr;
	36	goto done;
	37	}
	38
b920de1b DH	39	/* ignore region specifiers */
	40	gfp &= ~(__GFP_DMA \| __GFP_HIGHMEM);
	41
	42	if (dev == NULL \|\| dev->coherent_dma_mask < 0xffffffff)
	43	gfp \|= GFP_DMA;
	44
	45	addr = __get_free_pages(gfp, get_order(size));
	46	if (!addr)
	47	return NULL;
	48
	49	/* map the coherent memory through the uncached memory window */
	50	ret = (void *) (addr \| 0x20000000);
	51
	52	/* fill the memory with obvious rubbish */
	53	memset((void *) addr, 0xfb, size);
	54
	55	/* write back and evict all cache lines covering this region */
	56	mn10300_dcache_flush_inv_range2(virt_to_phys((void *) addr), PAGE_SIZE);
	57
012c79ba	58	done:
b920de1b	59	dma_handle = virt_to_bus((void ) addr);
012c79ba	60	printk("dma_alloc_coherent() = %p [%x]\n", ret, *dma_handle);
b920de1b DH	61	return ret;
	62	}
	63	EXPORT_SYMBOL(dma_alloc_coherent);
	64
	65	void dma_free_coherent(struct device dev, size_t size, void vaddr,
	66	dma_addr_t dma_handle)
	67	{
	68	unsigned long addr = (unsigned long) vaddr & ~0x20000000;
	69
012c79ba DH	70	if (addr >= 0x9c000000)
	71	return;
	72
b920de1b DH	73	free_pages(addr, get_order(size));
	74	}
	75	EXPORT_SYMBOL(dma_free_coherent);