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-rw-r--r--arch/x86/mm/memtest.c123
1 files changed, 123 insertions, 0 deletions
diff --git a/arch/x86/mm/memtest.c b/arch/x86/mm/memtest.c
new file mode 100644
index 000000000000..672e17f8262a
--- /dev/null
+++ b/arch/x86/mm/memtest.c
@@ -0,0 +1,123 @@
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/pfn.h>
+
+#include <asm/e820.h>
+
+static void __init memtest(unsigned long start_phys, unsigned long size,
+ unsigned pattern)
+{
+ unsigned long i;
+ unsigned long *start;
+ unsigned long start_bad;
+ unsigned long last_bad;
+ unsigned long val;
+ unsigned long start_phys_aligned;
+ unsigned long count;
+ unsigned long incr;
+
+ switch (pattern) {
+ case 0:
+ val = 0UL;
+ break;
+ case 1:
+ val = -1UL;
+ break;
+ case 2:
+#ifdef CONFIG_X86_64
+ val = 0x5555555555555555UL;
+#else
+ val = 0x55555555UL;
+#endif
+ break;
+ case 3:
+#ifdef CONFIG_X86_64
+ val = 0xaaaaaaaaaaaaaaaaUL;
+#else
+ val = 0xaaaaaaaaUL;
+#endif
+ break;
+ default:
+ return;
+ }
+
+ incr = sizeof(unsigned long);
+ start_phys_aligned = ALIGN(start_phys, incr);
+ count = (size - (start_phys_aligned - start_phys))/incr;
+ start = __va(start_phys_aligned);
+ start_bad = 0;
+ last_bad = 0;
+
+ for (i = 0; i < count; i++)
+ start[i] = val;
+ for (i = 0; i < count; i++, start++, start_phys_aligned += incr) {
+ if (*start != val) {
+ if (start_phys_aligned == last_bad + incr) {
+ last_bad += incr;
+ } else {
+ if (start_bad) {
+ printk(KERN_CONT "\n %010lx bad mem addr %010lx - %010lx reserved",
+ val, start_bad, last_bad + incr);
+ reserve_early(start_bad, last_bad - start_bad, "BAD RAM");
+ }
+ start_bad = last_bad = start_phys_aligned;
+ }
+ }
+ }
+ if (start_bad) {
+ printk(KERN_CONT "\n %016lx bad mem addr %010lx - %010lx reserved",
+ val, start_bad, last_bad + incr);
+ reserve_early(start_bad, last_bad - start_bad, "BAD RAM");
+ }
+
+}
+
+/* default is disabled */
+static int memtest_pattern __initdata;
+
+static int __init parse_memtest(char *arg)
+{
+ if (arg)
+ memtest_pattern = simple_strtoul(arg, NULL, 0);
+ return 0;
+}
+
+early_param("memtest", parse_memtest);
+
+void __init early_memtest(unsigned long start, unsigned long end)
+{
+ u64 t_start, t_size;
+ unsigned pattern;
+
+ if (!memtest_pattern)
+ return;
+
+ printk(KERN_INFO "early_memtest: pattern num %d", memtest_pattern);
+ for (pattern = 0; pattern < memtest_pattern; pattern++) {
+ t_start = start;
+ t_size = 0;
+ while (t_start < end) {
+ t_start = find_e820_area_size(t_start, &t_size, 1);
+
+ /* done ? */
+ if (t_start >= end)
+ break;
+ if (t_start + t_size > end)
+ t_size = end - t_start;
+
+ printk(KERN_CONT "\n %010llx - %010llx pattern %d",
+ (unsigned long long)t_start,
+ (unsigned long long)t_start + t_size, pattern);
+
+ memtest(t_start, t_size, pattern);
+
+ t_start += t_size;
+ }
+ }
+ printk(KERN_CONT "\n");
+}