sh: select memchunk size using kernel cmdline

PATCH New Magnus Damm 1 participant 1 message Aug 11, 2008 SuperH

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Magnus Damm

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2008-08-11 06:13 UTC #0 lore raw

PATCH 1/1 sh: select memchunk size using kernel cmdline

From: Magnus Damm <[email protected]>

Allow user to pass parameters on kernel command line to override default size for physically contiguous memory buffers. The default VPU buffer size is too small for VGA harware encoding, but instead of just bumping up the number we allow the user to override the default size using the command line. Supports SuperH Mobile hardware blocks such as VEU, VPU and CEU.

Signed-off-by Magnus Damm <[email protected]>

---

 arch/sh/mm/consistent.c |   27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

arch/sh/mm/consistent.c +27 -0

@@ -95,6 +95,29 @@ void dma_cache_sync(struct device *dev, 
 }
 EXPORT_SYMBOL(dma_cache_sync);
 
+static int __init memchunk_setup(char *str)
+{
+	return 1; /* accept anything that begins with "memchunk." */
+}
+__setup("memchunk.", memchunk_setup);
+
+static void memchunk_cmdline_override(char *name, unsigned long *sizep)
+{
+	char *p = boot_command_line;
+	int k = strlen(name);
+
+	while ((p = strstr(p, "memchunk."))) {
+		p += 9; /* strlen("memchunk.") */
+		if (!strncmp(name, p, k) && p[k] = '=') {
+			p += k + 1;
+			*sizep = memparse(p, NULL);
+			pr_info("%s: forcing memory chunk size to 0x%08lx\n",
+				name, *sizep);
+			break;
+		}
+	}
+}
+
 int platform_resource_setup_memory(struct platform_device *pdev,
 				   char *name, unsigned long memsize)
 {

@@ -109,6 +132,10 @@ int platform_resource_setup_memory(struc
 		return -EINVAL;
 	}
 
+	memchunk_cmdline_override(name, &memsize);
+	if (!memsize)
+		return 0;
+
 	buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
 	if (!buf) {
 		pr_warning("%s: unable to allocate memory\n", name);