1/*
2 * Copyright (C) 2004 - 2007 Paul Mundt
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 */
8#include <linux/mm.h>
9#include <linux/init.h>
10#include <linux/platform_device.h>
11#include <linux/dma-mapping.h>
12#include <linux/io.h>
13
14static int __init memchunk_setup(char *str)
15{
16 return 1; /* accept anything that begins with "memchunk." */
17}
18__setup("memchunk.", memchunk_setup);
19
20static void __init memchunk_cmdline_override(char *name, unsigned long *sizep)
21{
22 char *p = boot_command_line;
23 int k = strlen(name);
24
25 while ((p = strstr(p, "memchunk."))) {
26 p += 9; /* strlen("memchunk.") */
27 if (!strncmp(name, p, k) && p[k] == '=') {
28 p += k + 1;
29 *sizep = memparse(ptr: p, NULL);
30 pr_info("%s: forcing memory chunk size to 0x%08lx\n",
31 name, *sizep);
32 break;
33 }
34 }
35}
36
37int __init platform_resource_setup_memory(struct platform_device *pdev,
38 char *name, unsigned long memsize)
39{
40 struct resource *r;
41 dma_addr_t dma_handle;
42 void *buf;
43
44 r = pdev->resource + pdev->num_resources - 1;
45 if (r->flags) {
46 pr_warn("%s: unable to find empty space for resource\n", name);
47 return -EINVAL;
48 }
49
50 memchunk_cmdline_override(name, sizep: &memsize);
51 if (!memsize)
52 return 0;
53
54 buf = dma_alloc_coherent(dev: &pdev->dev, size: memsize, dma_handle: &dma_handle, GFP_KERNEL);
55 if (!buf) {
56 pr_warn("%s: unable to allocate memory\n", name);
57 return -ENOMEM;
58 }
59
60 r->flags = IORESOURCE_MEM;
61 r->start = dma_handle;
62 r->end = r->start + memsize - 1;
63 r->name = name;
64 return 0;
65}
66

source code of linux/arch/sh/mm/consistent.c