x86: fix trimming e820 with MTRR holes. - fix

v2: process hole then end_pfn
    fix update_memory_range with whole cover comparing

Signed-off-by: Yinghai Lu <yinghai.lu@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

3 files changed, 19 insertions, 31 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 9ab5c16b0d52..5a2a4c146333 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -1098,11 +1098,12 @@ int __init amd_special_default_mtrr(void)
 static u64 __init real_trim_memory(unsigned long start_pfn, unsigned long limit_pfn)
 {
         u64 trim_start, trim_size;
-        trim_start =  start_pfn;
+        trim_start = start_pfn;
         trim_start <<= PAGE_SHIFT;
         trim_size = limit_pfn;
         trim_size <<= PAGE_SHIFT;
         trim_size -= trim_start;
+
         return update_memory_range(trim_start, trim_size, E820_RAM,
                                 E820_RESERVED);
 }
@@ -1124,7 +1125,6 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
         struct res_range range[RANGE_NUM];
         int nr_range;
         u64 total_real_trim_size;
-        int changed;
 
         /* extra one for all 0 */
         int num[MTRR_NUM_TYPES + 1];
@@ -1189,49 +1189,35 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
         }
         nr_range = x86_get_mtrr_mem_range(range, nr_range, 0, 0);
 
-        changed = 0;
-        total_real_trim_size = 0;
-
-        /* check the top at first */
-        i = nr_range - 1;
-        if (range[i].end + 1 < end_pfn) {
-                        total_real_trim_size += real_trim_memory(range[i].end + 1, end_pfn);
-        }
-
-        if (total_real_trim_size) {
-                printk(KERN_WARNING "WARNING: BIOS bug: CPU MTRRs don't cover"
-                        " all of memory, losing %lluMB of RAM.\n",
-                        total_real_trim_size >> 20);
-
-                WARN_ON(1);
-
-                printk(KERN_INFO "update e820 for mtrr -- end_pfn\n");
-                update_e820();
-                changed = 1;
-        }
-
         total_real_trim_size = 0;
+        /* check the head */
         if (range[0].start)
                 total_real_trim_size += real_trim_memory(0, range[0].start);
-
-        for (i = 0; i < nr_range - 1; i--) {
+        /* check the holes */
+        for (i = 0; i < nr_range - 1; i++) {
                 if (range[i].end + 1 < range[i+1].start)
                         total_real_trim_size += real_trim_memory(range[i].end + 1, range[i+1].start);
         }
+        /* check the top */
+        i = nr_range - 1;
+        if (range[i].end + 1 < end_pfn)
+                total_real_trim_size += real_trim_memory(range[i].end + 1, end_pfn);
 
         if (total_real_trim_size) {
                 printk(KERN_WARNING "WARNING: BIOS bug: CPU MTRRs don't cover"
                         " all of memory, losing %lluMB of RAM.\n",
                         total_real_trim_size >> 20);
 
-                WARN_ON(1);
+                if (enable_mtrr_cleanup < 1)
+                        WARN_ON(1);
 
-                printk(KERN_INFO "update e820 for mtrr -- holes\n");
+                printk(KERN_INFO "update e820 for mtrr\n");
                 update_e820();
-                changed = 1;
+
+                return 1;
         }
 
-        return changed;
+        return 0;
 }
 
 /**
diff --git a/arch/x86/kernel/e820_32.c b/arch/x86/kernel/e820_32.c
index 857f706273a8..751d517d802c 100644
--- a/arch/x86/kernel/e820_32.c
+++ b/arch/x86/kernel/e820_32.c
@@ -797,7 +797,8 @@ u64 __init update_memory_range(u64 start, u64 size, unsigned old_type,
                 if (ei->type != old_type)
                         continue;
                 /* totally covered? */
-                if (ei->addr >= start && ei->size <= size) {
+                if (ei->addr >= start &&
+                    (ei->addr + ei->size) <= (start + size)) {
                         ei->type = new_type;
                         real_updated_size += ei->size;
                         continue;
diff --git a/arch/x86/kernel/e820_64.c b/arch/x86/kernel/e820_64.c
index 848b2cd2d1dd..c45b4dea4055 100644
--- a/arch/x86/kernel/e820_64.c
+++ b/arch/x86/kernel/e820_64.c
@@ -843,7 +843,8 @@ u64 __init update_memory_range(u64 start, u64 size, unsigned old_type,
                 if (ei->type != old_type)
                         continue;
                 /* totally covered? */
-                if (ei->addr >= start && ei->size <= size) {
+                if (ei->addr >= start &&
+                    (ei->addr + ei->size) <= (start + size)) {
                         ei->type = new_type;
                         real_updated_size += ei->size;
                         continue;