[PATCH] x86_32: trim memory by updating e820 v3
when mtrr is not covering all e820 table, need to trim the ram, need to update e820
reuse some code for x86_64
here need to add early_get_cap and use it in early_cpu_detect, and move mtrr_bp_init early
need Justine to test with his special system with bug bios.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Index: linux-2.6/arch/x86/kernel/cpu/common.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/common.c
+++ linux-2.6/arch/x86/kernel/cpu/common.c
@@ -278,6 +278,33 @@ void __init cpu_detect(struct cpuinfo_x8
c->x86_cache_alignment = ((misc >> 8) & 0xff) * 8;
}
}
+static void __cpuinit early_get_cap(struct cpuinfo_x86 *c)
+{
+ u32 tfms, xlvl;
+ int ebx;
+
+ memset(&c->x86_capability, 0, sizeof c->x86_capability);
+ if (have_cpuid_p()) {
+ /* Intel-defined flags: level 0x00000001 */
+ if (c->cpuid_level >= 0x00000001) {
+ u32 capability, excap;
+ cpuid(0x00000001, &tfms, &ebx, &excap, &capability);
+ c->x86_capability[0] = capability;
+ c->x86_capability[4] = excap;
+ }
+
+ /* AMD-defined flags: level 0x80000001 */
+ xlvl = cpuid_eax(0x80000000);
+ if ((xlvl & 0xffff0000) == 0x80000000) {
+ if (xlvl >= 0x80000001) {
+ c->x86_capability[1] = cpuid_edx(0x80000001);
+ c->x86_capability[6] = cpuid_ecx(0x80000001);
+ }
+ }
+
+ }
+
+}
/* Do minimum CPU detection early.
Fields really needed: vendor, cpuid_level, family, model, mask, cache alignment.
@@ -306,6 +333,8 @@ static void __init early_cpu_detect(void
early_init_intel(c);
break;
}
+
+ early_get_cap(c);
}
static void __cpuinit generic_identify(struct cpuinfo_x86 * c)
@@ -485,7 +514,6 @@ void __init identify_boot_cpu(void)
identify_cpu(&boot_cpu_data);
sysenter_setup();
enable_sep_cpu();
- mtrr_bp_init();
}
void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
Index: linux-2.6/arch/x86/kernel/setup_32.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/setup_32.c
+++ linux-2.6/arch/x86/kernel/setup_32.c
@@ -49,6 +49,7 @@
#include <video/edid.h>
+#include <asm/mtrr.h>
#include <asm/apic.h>
#include <asm/e820.h>
#include <asm/mpspec.h>
@@ -762,6 +763,11 @@ void __init setup_arch(char **cmdline_p)
max_low_pfn = setup_memory();
+ /* update e820 for memory not covered by WB MTRRs */
+ mtrr_bp_init();
+ if (mtrr_trim_uncached_memory(max_pfn))
+ max_low_pfn = setup_memory();
+
#ifdef CONFIG_VMI
/*
* Must be after max_low_pfn is determined, and before kernel
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
@@ -624,7 +624,6 @@ static struct sysdev_driver mtrr_sysdev_
.resume = mtrr_restore,
};
-#ifdef CONFIG_X86_64
static int disable_mtrr_trim;
static int __init disable_mtrr_trim_setup(char *str)
@@ -726,7 +725,6 @@ int __init mtrr_trim_uncached_memory(uns
return 0;
}
-#endif
/**
* mtrr_bp_init - initialize mtrrs on the boot CPU
Index: linux-2.6/Documentation/kernel-parameters.txt
===================================================================
--- linux-2.6.orig/Documentation/kernel-parameters.txt
+++ linux-2.6/Documentation/kernel-parameters.txt
@@ -575,7 +575,7 @@ and is between 256 and 4096 characters.
See drivers/char/README.epca and
Documentation/digiepca.txt.
- disable_mtrr_trim [X86-64, Intel only]
+ disable_mtrr_trim [X86, Intel and AMD only]
By default the kernel will trim any uncacheable
memory out of your available memory pool based on
MTRR settings. This parameter disables that behavior,
Index: linux-2.6/arch/x86/kernel/e820_32.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/e820_32.c
+++ linux-2.6/arch/x86/kernel/e820_32.c
@@ -749,3 +749,14 @@ static int __init parse_memmap(char *arg
return 0;
}
early_param("memmap", parse_memmap);
+void __init update_e820(void)
+{
+ u8 nr_map;
+
+ nr_map = e820.nr_map;
+ if (sanitize_e820_map(e820.map, &nr_map))
+ return;
+ e820.nr_map = nr_map;
+ printk(KERN_INFO "modified physical RAM map:\n");
+ print_memory_map("modified");
+}
Index: linux-2.6/include/asm-x86/e820_32.h
===================================================================
--- linux-2.6.orig/include/asm-x86/e820_32.h
+++ linux-2.6/include/asm-x86/e820_32.h
@@ -19,12 +19,15 @@
#ifndef __ASSEMBLY__
extern struct e820map e820;
+extern void update_e820(void);
extern int e820_all_mapped(unsigned long start, unsigned long end,
unsigned type);
extern int e820_any_mapped(u64 start, u64 end, unsigned type);
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 e820_register_memory(void);
extern void limit_regions(unsigned long long size);
extern void print_memory_map(char *who);
--
