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Diffstat (limited to 'arch/mips/ralink/mt7621.c')
-rw-r--r--arch/mips/ralink/mt7621.c36
1 files changed, 23 insertions, 13 deletions
diff --git a/arch/mips/ralink/mt7621.c b/arch/mips/ralink/mt7621.c
index d6efffd4dd20..fb0565bc34fd 100644
--- a/arch/mips/ralink/mt7621.c
+++ b/arch/mips/ralink/mt7621.c
@@ -22,7 +22,9 @@
#include "common.h"
-static void *detect_magic __initdata = detect_memory_region;
+#define MT7621_MEM_TEST_PATTERN 0xaa5555aa
+
+static u32 detect_magic __initdata;
int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
{
@@ -58,24 +60,32 @@ phys_addr_t mips_cpc_default_phys_base(void)
panic("Cannot detect cpc address");
}
+static bool __init mt7621_addr_wraparound_test(phys_addr_t size)
+{
+ void *dm = (void *)KSEG1ADDR(&detect_magic);
+
+ if (CPHYSADDR(dm + size) >= MT7621_LOWMEM_MAX_SIZE)
+ return true;
+ __raw_writel(MT7621_MEM_TEST_PATTERN, dm);
+ if (__raw_readl(dm) != __raw_readl(dm + size))
+ return false;
+ __raw_writel(~MT7621_MEM_TEST_PATTERN, dm);
+ return __raw_readl(dm) == __raw_readl(dm + size);
+}
+
static void __init mt7621_memory_detect(void)
{
- void *dm = &detect_magic;
phys_addr_t size;
- for (size = 32 * SZ_1M; size < 256 * SZ_1M; size <<= 1) {
- if (!__builtin_memcmp(dm, dm + size, sizeof(detect_magic)))
- break;
+ for (size = 32 * SZ_1M; size <= 256 * SZ_1M; size <<= 1) {
+ if (mt7621_addr_wraparound_test(size)) {
+ memblock_add(MT7621_LOWMEM_BASE, size);
+ return;
+ }
}
- if ((size == 256 * SZ_1M) &&
- (CPHYSADDR(dm + size) < MT7621_LOWMEM_MAX_SIZE) &&
- __builtin_memcmp(dm, dm + size, sizeof(detect_magic))) {
- memblock_add(MT7621_LOWMEM_BASE, MT7621_LOWMEM_MAX_SIZE);
- memblock_add(MT7621_HIGHMEM_BASE, MT7621_HIGHMEM_SIZE);
- } else {
- memblock_add(MT7621_LOWMEM_BASE, size);
- }
+ memblock_add(MT7621_LOWMEM_BASE, MT7621_LOWMEM_MAX_SIZE);
+ memblock_add(MT7621_HIGHMEM_BASE, MT7621_HIGHMEM_SIZE);
}
void __init ralink_of_remap(void)