converting MTRR layout from continous to discrete, some time could run out of
MTRRs. So add gran_sizek to prevent that by dumpping small RAM piece less than
gran_sizek.

previous trimming only can handle highest_pfn from mtrr to end_pfn from e820.
when have more than 4g RAM installed, there will be holes below 4g. so need to
check ram below 4g is coverred well.

need to be applied after
	[PATCH] x86: mtrr cleanup for converting continuous to discrete layout v7

Signed-off-by: Yinghai Lu <yinghai.lu@gmail.com>

Index: linux-2.6/arch/x86/kernel/cpu/mtrr/main.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/mtrr/main.c
+++ linux-2.6/arch/x86/kernel/cpu/mtrr/main.c
@@ -1093,6 +1093,17 @@ 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
@@ -1108,8 +1119,13 @@ int __init mtrr_trim_uncached_memory(uns
 {
 	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:
@@ -1121,9 +1137,6 @@ int __init mtrr_trim_uncached_memory(uns
 	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);
@@ ...
[ message continues ]

s/find_end/final_end

i hope it boots ;-)

	Ingo
--

[ message continues ]

thanks

that report trimmed size. so it still boot. but report wrong trimmed
size. it will upset Gabriel.

it passed compiling, ..., that's funny.

YH
--

[ message continues ]

that is in 32bit...

will send you new one.

YH
--

[ message continues ]

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

Signed-off-by: Yinghai Lu <yinghai.lu@gmail.com>

Index: linux-2.6/arch/x86/kernel/cpu/mtrr/main.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/mtrr/main.c
+++ linux-2.6/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(uns
 	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(uns
 	}
 	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 += ...
[ message continues ]

thanks, applied.

	Ingo
--

[ message continues ]