x86: early memtest to find bad ram
do simple memtest after init_memory_mapping
use find_e820_area_size to find all ram range that is not reserved.
and do some simple bits test to find some bad ram.
if find some bad ram, use reserve_early to exclude that range.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/e820_64.c b/arch/x86/kernel/e820_64.c
index 4a09538..4509757 100644
--- a/arch/x86/kernel/e820_64.c
+++ b/arch/x86/kernel/e820_64.c
@@ -114,6 +114,40 @@
return changed;
}
+/* Check for already reserved areas */
+static inline int
+bad_addr_size(unsigned long *addrp, unsigned long *sizep, unsigned long align)
+{
+ int i;
+ unsigned long addr = *addrp, last;
+ unsigned long size = *sizep;
+ int changed = 0;
+again:
+ last = addr + size;
+ for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
+ struct early_res *r = &early_res[i];
+ if (last > r->start && addr < r->start) {
+ size = r->start - addr;
+ changed = 1;
+ goto again;
+ }
+ if (last > r->end && addr < r->end) {
+ addr = round_up(r->end, align);
+ size = last - addr;
+ changed = 1;
+ goto again;
+ }
+ if (last <= r->end && addr >= r->start) {
+ (*sizep)++;
+ return 0;
+ }
+ }
+ if (changed) {
+ *addrp = addr;
+ *sizep = size;
+ }
+ return changed;
+}
/*
* This function checks if any part of the range <start,end> is mapped
* with type.
@@ -190,7 +224,7 @@
ei_last = ei->addr + ei->size;
if (addr < start)
addr = round_up(start, align);
- if (addr > ei_last)
+ if (addr >= ei_last)
continue;
while (bad_addr(&addr, size, align) && addr+size <= ei_last)
;
@@ -205,6 +239,40 @@
}
/*
+ * Find next free range after *start
+ */
+unsigned long __init find_e820_area_size(unsigned long start, unsigned long *sizep, unsigned long align)
+{
+ int i;
+
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+ unsigned long addr, last;
+ unsigned long ei_last;
+
+ if (ei->type != E820_RAM)
+ continue;
+ addr = round_up(ei->addr, align);
+ ei_last = ei->addr + ei->size;
+// printk(KERN_DEBUG "find_e820_area_size : e820 %d [%llx, %lx]\n", i, ei->addr, ei_last);
+ if (addr < start)
+ addr = round_up(start, align);
+// printk(KERN_DEBUG "find_e820_area_size : 0 [%lx, %lx]\n", addr, ei_last);
+ if (addr >= ei_last)
+ continue;
+ *sizep = ei_last - addr;
+ while (bad_addr_size(&addr, sizep, align) && addr+ *sizep <= ei_last)
+ ;
+ last = addr + *sizep;
+// printk(KERN_DEBUG "find_e820_area_size : 1 [%lx, %lx]\n", addr, last);
+ if (last > ei_last)
+ continue;
+ return addr;
+ }
+ return -1UL;
+
+}
+/*
* Find the highest page frame number we have available
*/
unsigned long __init e820_end_of_ram(void)