From 5dca6a1bb014875a17289fdaae8c31e0a3641c99 Mon Sep 17 00:00:00 2001
From: Yinghai Lu <yhlu.kernel.send@gmail.com>
Date: Tue, 18 Mar 2008 16:44:19 -0700
Subject: [PATCH] x86: trim mtrr don't close gap for resource allocation.
fix the bug reported here:
http://bugzilla.kernel.org/show_bug.cgi?id=10232
use update_memory_range() instead of add_memory_range() directly
to avoid closing the gap.
( the new code only affects and runs on systems where the MTRR
workaround triggers. )
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/cpu/mtrr/main.c | 3 ++-
arch/x86/kernel/e820_32.c | 26 ++++++++++++++++++++++++++
arch/x86/kernel/e820_64.c | 27 +++++++++++++++++++++++++++
include/asm-x86/e820_32.h | 2 ++
include/asm-x86/e820_64.h | 2 ++
5 files changed, 59 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index be83336fddba..a6450b3ae759 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -711,7 +711,8 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
trim_size = end_pfn;
trim_size <<= PAGE_SHIFT;
trim_size -= trim_start;
- add_memory_region(trim_start, trim_size, E820_RESERVED);
+ update_memory_range(trim_start, trim_size, E820_RAM,
+ E820_RESERVED);
update_e820();
return 1;
}
diff --git a/arch/x86/kernel/e820_32.c b/arch/x86/kernel/e820_32.c
index 4e16ef4a2659..80444c5c9b14 100644
--- a/arch/x86/kernel/e820_32.c
+++ b/arch/x86/kernel/e820_32.c
@@ -749,6 +749,32 @@ 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,
+ unsigned new_type)
+{
+ int i;
+
+ BUG_ON(old_type == new_type);
+
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+ u64 final_start, final_end;
+ if (ei->type != old_type)
+ continue;
+ /* totally covered? */
+ if (ei->addr >= start && ei->size <= size) {
+ ei->type = new_type;
+ continue;
+ }
+ /* partially covered */
+ final_start = max(start, ei->addr);
+ final_end = min(start + size, ei->addr + ei->size);
+ if (final_start >= final_end)
+ continue;
+ add_memory_region(final_start, final_end - final_start,
+ new_type);
+ }
+}
void __init update_e820(void)
{
u8 nr_map;
diff --git a/arch/x86/kernel/e820_64.c b/arch/x86/kernel/e820_64.c
index 9f65b4cc323c..9be697126013 100644
--- a/arch/x86/kernel/e820_64.c
+++ b/arch/x86/kernel/e820_64.c
@@ -744,6 +744,33 @@ void __init finish_e820_parsing(void)
}
}
+void __init update_memory_range(u64 start, u64 size, unsigned old_type,
+ unsigned new_type)
+{
+ int i;
+
+ BUG_ON(old_type == new_type);
+
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+ u64 final_start, final_end;
+ if (ei->type != old_type)
+ continue;
+ /* totally covered? */
+ if (ei->addr >= start && ei->size <= size) {
+ ei->type = new_type;
+ continue;
+ }
+ /* partially covered */
+ final_start = max(start, ei->addr);
+ final_end = min(start + size, ei->addr + ei->size);
+ if (final_start >= final_end)
+ continue;
+ add_memory_region(final_start, final_end - final_start,
+ new_type);
+ }
+}
+
void __init update_e820(void)
{
u8 nr_map;
diff --git a/include/asm-x86/e820_32.h b/include/asm-x86/e820_32.h
index f1da7ebd1905..e7207a6de3e0 100644
--- a/include/asm-x86/e820_32.h
+++ b/include/asm-x86/e820_32.h
@@ -28,6 +28,8 @@ extern void find_max_pfn(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,
+ unsigned new_type);
extern void e820_register_memory(void);
extern void limit_regions(unsigned long long size);
extern void print_memory_map(char *who);
diff --git a/include/asm-x86/e820_64.h b/include/asm-x86/e820_64.h
index a560c4f5d500..22ede73ae724 100644
--- a/include/asm-x86/e820_64.h
+++ b/include/asm-x86/e820_64.h
@@ -18,6 +18,8 @@ extern unsigned long find_e820_area(unsigned long start, unsigned long end,
unsigned size, 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,
+ unsigned new_type);
extern void setup_memory_region(void);
extern void contig_e820_setup(void);
extern unsigned long e820_end_of_ram(void);