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authorJohn Crispin <blogic@openwrt.org>2013-04-13 13:15:47 +0200
committerRalf Baechle <ralf@linux-mips.org>2013-05-08 01:19:11 +0200
commit4d9f77d2526840fc2b3d4dcaedfd2f633a6d5426 (patch)
tree7efbfc22a32c23dc886855b325b88e7356a4f355
parent9d50094dfec829a1361e595d5d09dfa0f2fe5057 (diff)
MIPS: add detect_memory_region()
Add a generic way of detecting the available RAM. This function is based on the implementation already used by ath79. Signed-off-by: John Crispin <blogic@openwrt.org> Patchwork: http://patchwork.linux-mips.org/patch/5178/
-rw-r--r--arch/mips/include/asm/bootinfo.h1
-rw-r--r--arch/mips/kernel/setup.c22
2 files changed, 23 insertions, 0 deletions
diff --git a/arch/mips/include/asm/bootinfo.h b/arch/mips/include/asm/bootinfo.h
index b71dd5b16085..4d2cdea5aa37 100644
--- a/arch/mips/include/asm/bootinfo.h
+++ b/arch/mips/include/asm/bootinfo.h
@@ -104,6 +104,7 @@ struct boot_mem_map {
extern struct boot_mem_map boot_mem_map;
extern void add_memory_region(phys_t start, phys_t size, long type);
+extern void detect_memory_region(phys_t start, phys_t sz_min, phys_t sz_max);
extern void prom_init(void);
extern void prom_free_prom_memory(void);
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 4c774d5d5087..c7f90519e58c 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -23,6 +23,7 @@
#include <linux/pfn.h>
#include <linux/debugfs.h>
#include <linux/kexec.h>
+#include <linux/sizes.h>
#include <asm/addrspace.h>
#include <asm/bootinfo.h>
@@ -77,6 +78,8 @@ EXPORT_SYMBOL(mips_io_port_base);
static struct resource code_resource = { .name = "Kernel code", };
static struct resource data_resource = { .name = "Kernel data", };
+static void *detect_magic __initdata = detect_memory_region;
+
void __init add_memory_region(phys_t start, phys_t size, long type)
{
int x = boot_mem_map.nr_map;
@@ -122,6 +125,25 @@ void __init add_memory_region(phys_t start, phys_t size, long type)
boot_mem_map.nr_map++;
}
+void __init detect_memory_region(phys_t start, phys_t sz_min, phys_t sz_max)
+{
+ void *dm = &detect_magic;
+ phys_t size;
+
+ for (size = sz_min; size < sz_max; size <<= 1) {
+ if (!memcmp(dm, dm + size, sizeof(detect_magic)))
+ break;
+ }
+
+ pr_debug("Memory: %lluMB of RAM detected at 0x%llx (min: %lluMB, max: %lluMB)\n",
+ ((unsigned long long) size) / SZ_1M,
+ (unsigned long long) start,
+ ((unsigned long long) sz_min) / SZ_1M,
+ ((unsigned long long) sz_max) / SZ_1M);
+
+ add_memory_region(start, size, BOOT_MEM_RAM);
+}
+
static void __init print_memory_map(void)
{
int i;