xref: /openbmc/linux/arch/sh/mm/consistent.c (revision f21e49be)
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 
14 static int __init memchunk_setup(char *str)
15 {
16 	return 1; /* accept anything that begins with "memchunk." */
17 }
18 __setup("memchunk.", memchunk_setup);
19 
20 static 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(p, NULL);
30 			pr_info("%s: forcing memory chunk size to 0x%08lx\n",
31 				name, *sizep);
32 			break;
33 		}
34 	}
35 }
36 
37 int __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, &memsize);
51 	if (!memsize)
52 		return 0;
53 
54 	buf = dma_alloc_coherent(&pdev->dev, memsize, &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