1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Copyright (C) 2004 - 2007  Paul Mundt
 4 */
 5#include <linux/mm.h>
 6#include <linux/init.h>
 7#include <linux/dma-noncoherent.h>
 8#include <linux/module.h>
 9#include <asm/cacheflush.h>
10#include <asm/addrspace.h>
11
12void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
13		gfp_t gfp, unsigned long attrs)
14{
15	void *ret, *ret_nocache;
16	int order = get_order(size);
17
18	gfp |= __GFP_ZERO;
19
20	ret = (void *)__get_free_pages(gfp, order);
21	if (!ret)
22		return NULL;
23
24	/*
25	 * Pages from the page allocator may have data present in
26	 * cache. So flush the cache before using uncached memory.
27	 */
28	arch_sync_dma_for_device(dev, virt_to_phys(ret), size,
29			DMA_BIDIRECTIONAL);
30
31	ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size);
32	if (!ret_nocache) {
33		free_pages((unsigned long)ret, order);
34		return NULL;
35	}
36
37	split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
38
39	*dma_handle = virt_to_phys(ret);
40	if (!WARN_ON(!dev))
41		*dma_handle -= PFN_PHYS(dev->dma_pfn_offset);
42
43	return ret_nocache;
44}
45
46void arch_dma_free(struct device *dev, size_t size, void *vaddr,
47		dma_addr_t dma_handle, unsigned long attrs)
48{
49	int order = get_order(size);
50	unsigned long pfn = (dma_handle >> PAGE_SHIFT);
51	int k;
52
53	if (!WARN_ON(!dev))
54		pfn += dev->dma_pfn_offset;
55
56	for (k = 0; k < (1 << order); k++)
57		__free_pages(pfn_to_page(pfn + k), 0);
58
59	iounmap(vaddr);
60}
61
62void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
63		size_t size, enum dma_data_direction dir)
64{
65	void *addr = sh_cacheop_vaddr(phys_to_virt(paddr));
66
67	switch (dir) {
68	case DMA_FROM_DEVICE:		/* invalidate only */
69		__flush_invalidate_region(addr, size);
70		break;
71	case DMA_TO_DEVICE:		/* writeback only */
72		__flush_wback_region(addr, size);
73		break;
74	case DMA_BIDIRECTIONAL:		/* writeback and invalidate */
75		__flush_purge_region(addr, size);
76		break;
77	default:
78		BUG();
79	}
80}