[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;

	printk("dma_alloc_coherent(%s,%zu,,%x)\n", 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
012c79ba DH	28	printk("dma_alloc_coherent(%s,%zu,,%x)\n", dev_name(dev), size, gfp);
	29
	30	if (0xbe000000 - pci_sram_allocated >= size) {
	31	size = (size + 255) & ~255;
	32	addr = pci_sram_allocated;
	33	pci_sram_allocated += size;
	34	ret = (void *) addr;
	35	goto done;
	36	}
	37
b920de1b DH	38	/* ignore region specifiers */
	39	gfp &= ~(__GFP_DMA \| __GFP_HIGHMEM);
	40
	41	if (dev == NULL \|\| dev->coherent_dma_mask < 0xffffffff)
	42	gfp \|= GFP_DMA;
	43
	44	addr = __get_free_pages(gfp, get_order(size));
	45	if (!addr)
	46	return NULL;
	47
	48	/* map the coherent memory through the uncached memory window */
	49	ret = (void *) (addr \| 0x20000000);
	50
	51	/* fill the memory with obvious rubbish */
	52	memset((void *) addr, 0xfb, size);
	53
	54	/* write back and evict all cache lines covering this region */
	55	mn10300_dcache_flush_inv_range2(virt_to_phys((void *) addr), PAGE_SIZE);
	56
012c79ba	57	done:
b920de1b	58	dma_handle = virt_to_bus((void ) addr);
012c79ba	59	printk("dma_alloc_coherent() = %p [%x]\n", ret, *dma_handle);
b920de1b DH	60	return ret;
	61	}
	62	EXPORT_SYMBOL(dma_alloc_coherent);
	63
	64	void dma_free_coherent(struct device dev, size_t size, void vaddr,
	65	dma_addr_t dma_handle)
	66	{
	67	unsigned long addr = (unsigned long) vaddr & ~0x20000000;
	68
012c79ba DH	69	if (addr >= 0x9c000000)
	70	return;
	71
b920de1b DH	72	free_pages(addr, get_order(size));
	73	}
	74	EXPORT_SYMBOL(dma_free_coherent);