5 files changed, 97 insertions, 21 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 8a6f68b45e3..9ab5c16b0d5 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -1095,6 +1095,17 @@ int __init amd_special_default_mtrr(void)
         return 0;
 }
 
+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 <<= 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);
+}
 /**
  * mtrr_trim_uncached_memory - trim RAM not covered by MTRRs
  * @end_pfn: ending page frame number
@@ -1110,8 +1121,13 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
 {
         unsigned long i, base, size, highest_pfn = 0, def, dummy;
         mtrr_type type;
-        u64 trim_start, trim_size;
+        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];
         /*
          * Make sure we only trim uncachable memory on machines that
          * support the Intel MTRR architecture:
@@ -1123,9 +1139,6 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
         if (def != MTRR_TYPE_UNCACHABLE)
                 return 0;
 
-        if (amd_special_default_mtrr())
-                return 0;
-
         /* Find highest cached pfn */
         for (i = 0; i < num_var_ranges; i++) {
                 mtrr_if->get(i, &base, &size, &type);
@@ -1145,26 +1158,80 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
                 return 0;
         }
 
-        if (highest_pfn < end_pfn) {
+        /* check entries number */
+        memset(num, 0, sizeof(num));
+        for (i = 0; i < num_var_ranges; i++) {
+                mtrr_if->get(i, &base, &size, &type);
+                if (type >= MTRR_NUM_TYPES)
+                        continue;
+                if (!size)
+                        type = MTRR_NUM_TYPES;
+                num[type]++;
+        }
+
+        /* no entry for WB? */
+        if (!num[MTRR_TYPE_WRBACK])
+                return 0;
+
+        /* check if we only had WB and UC */
+        if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] !=
+                num_var_ranges - num[MTRR_NUM_TYPES])
+                return 0;
+
+        memset(range, 0, sizeof(range));
+        nr_range = 0;
+        if (mtrr_tom2) {
+                range[nr_range].start = (1ULL<<(32 - PAGE_SHIFT));
+                range[nr_range].end = (mtrr_tom2 >> PAGE_SHIFT) - 1;
+                if (highest_pfn < range[nr_range].end + 1)
+                        highest_pfn = range[nr_range].end + 1;
+                nr_range++;
+        }
+        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 %luMB of RAM.\n",
-                        (end_pfn - highest_pfn) >> (20 - PAGE_SHIFT));
+                        " all of memory, losing %lluMB of RAM.\n",
+                        total_real_trim_size >> 20);
 
                 WARN_ON(1);
 
-                printk(KERN_INFO "update e820 for mtrr\n");
-                trim_start = highest_pfn;
-                trim_start <<= PAGE_SHIFT;
-                trim_size = end_pfn;
-                trim_size <<= PAGE_SHIFT;
-                trim_size -= trim_start;
-                update_memory_range(trim_start, trim_size, E820_RAM,
-                                        E820_RESERVED);
+                printk(KERN_INFO "update e820 for mtrr -- end_pfn\n");
                 update_e820();
-                return 1;
+                changed = 1;
         }
 
-        return 0;
+        total_real_trim_size = 0;
+        if (range[0].start)
+                total_real_trim_size += real_trim_memory(0, range[0].start);
+
+        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);
+        }
+
+        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 -- holes\n");
+                update_e820();
+                changed = 1;
+        }
+
+        return changed;
 }
 
 /**
diff --git a/arch/x86/kernel/e820_32.c b/arch/x86/kernel/e820_32.c
index 31ea2bb8c91..857f706273a 100644
--- a/arch/x86/kernel/e820_32.c
+++ b/arch/x86/kernel/e820_32.c
@@ -783,10 +783,11 @@ static int __init parse_memmap(char *arg)
         return 0;
 }
 early_param("memmap", parse_memmap);
-void __init update_memory_range(u64 start, u64 size, unsigned old_type,
+u64 __init update_memory_range(u64 start, u64 size, unsigned old_type,
                                 unsigned new_type)
 {
         int i;
+        u64 real_updated_size = 0;
 
         BUG_ON(old_type == new_type);
 
@@ -798,6 +799,7 @@ void __init update_memory_range(u64 start, u64 size, unsigned old_type,
                 /* totally covered? */
                 if (ei->addr >= start && ei->size <= size) {
                         ei->type = new_type;
+                        real_updated_size += ei->size;
                         continue;
                 }
                 /* partially covered */
@@ -807,7 +809,10 @@ void __init update_memory_range(u64 start, u64 size, unsigned old_type,
                         continue;
                 add_memory_region(final_start, final_end - final_start,
                                          new_type);
+                real_updated_size += final_end - final_start;
         }
+
+        return real_updated_size;
 }
 
 void __init finish_e820_parsing(void)
diff --git a/arch/x86/kernel/e820_64.c b/arch/x86/kernel/e820_64.c
index 124480c0008..848b2cd2d1d 100644
--- a/arch/x86/kernel/e820_64.c
+++ b/arch/x86/kernel/e820_64.c
@@ -829,10 +829,11 @@ void __init finish_e820_parsing(void)
         }
 }
 
-void __init update_memory_range(u64 start, u64 size, unsigned old_type,
+u64 __init update_memory_range(u64 start, u64 size, unsigned old_type,
                                 unsigned new_type)
 {
         int i;
+        u64 real_updated_size = 0;
 
         BUG_ON(old_type == new_type);
 
@@ -844,6 +845,7 @@ void __init update_memory_range(u64 start, u64 size, unsigned old_type,
                 /* totally covered? */
                 if (ei->addr >= start && ei->size <= size) {
                         ei->type = new_type;
+                        real_updated_size += ei->size;
                         continue;
                 }
                 /* partially covered */
@@ -853,7 +855,9 @@ void __init update_memory_range(u64 start, u64 size, unsigned old_type,
                         continue;
                 add_memory_region(final_start, final_end - final_start,
                                          new_type);
+                real_updated_size += final_end - final_start;
         }
+        return real_updated_size;
 }
 
 void __init update_e820(void)
diff --git a/include/asm-x86/e820_32.h b/include/asm-x86/e820_32.h
index e1f10c60901..af0711b220d 100644
--- a/include/asm-x86/e820_32.h
+++ b/include/asm-x86/e820_32.h
@@ -31,7 +31,7 @@ extern void propagate_e820_map(void);
 extern void register_bootmem_low_pages(unsigned long max_low_pfn);
 extern void add_memory_region(unsigned long long start,
                               unsigned long long size, int type);
-extern void update_memory_range(u64 start, u64 size, unsigned old_type,
+extern u64 update_memory_range(u64 start, u64 size, unsigned old_type,
                                 unsigned new_type);
 extern void e820_register_memory(void);
 extern void limit_regions(unsigned long long size);
diff --git a/include/asm-x86/e820_64.h b/include/asm-x86/e820_64.h
index 71c4d685d30..6ae3e280328 100644
--- a/include/asm-x86/e820_64.h
+++ b/include/asm-x86/e820_64.h
@@ -21,7 +21,7 @@ extern unsigned long find_e820_area_size(unsigned long start,
                                          unsigned long align);
 extern void add_memory_region(unsigned long start, unsigned long size,
                               int type);
-extern void update_memory_range(u64 start, u64 size, unsigned old_type,
+extern u64 update_memory_range(u64 start, u64 size, unsigned old_type,
                                 unsigned new_type);
 extern void setup_memory_region(void);
 extern void contig_e820_setup(void);