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-rw-r--r--arch/x86/kernel/bugs_64.c1
-rw-r--r--arch/x86/kernel/cpu/mtrr/generic.c8
-rw-r--r--arch/x86/kernel/cpu/mtrr/if.c8
-rw-r--r--arch/x86/kernel/cpu/mtrr/main.c140
-rw-r--r--arch/x86/kernel/cpu/mtrr/mtrr.h3
-rw-r--r--arch/x86/kernel/setup_64.c7
6 files changed, 129 insertions, 38 deletions
diff --git a/arch/x86/kernel/bugs_64.c b/arch/x86/kernel/bugs_64.c
index 9a189cef640..8f520f93ffd 100644
--- a/arch/x86/kernel/bugs_64.c
+++ b/arch/x86/kernel/bugs_64.c
@@ -13,7 +13,6 @@
void __init check_bugs(void)
{
identify_cpu(&boot_cpu_data);
- mtrr_bp_init();
#if !defined(CONFIG_SMP)
printk("CPU: ");
print_cpu_info(&boot_cpu_data);
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index 55d31ff118f..103d61a59b1 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -14,7 +14,7 @@
#include "mtrr.h"
struct mtrr_state {
- struct mtrr_var_range *var_ranges;
+ struct mtrr_var_range var_ranges[MAX_VAR_RANGES];
mtrr_type fixed_ranges[NUM_FIXED_RANGES];
unsigned char enabled;
unsigned char have_fixed;
@@ -86,12 +86,6 @@ void __init get_mtrr_state(void)
struct mtrr_var_range *vrs;
unsigned lo, dummy;
- if (!mtrr_state.var_ranges) {
- mtrr_state.var_ranges = kmalloc(num_var_ranges * sizeof (struct mtrr_var_range),
- GFP_KERNEL);
- if (!mtrr_state.var_ranges)
- return;
- }
vrs = mtrr_state.var_ranges;
rdmsr(MTRRcap_MSR, lo, dummy);
diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c
index 14535686c09..91e150acb46 100644
--- a/arch/x86/kernel/cpu/mtrr/if.c
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -11,10 +11,6 @@
#include <asm/mtrr.h>
#include "mtrr.h"
-/* RED-PEN: this is accessed without any locking */
-extern unsigned int *usage_table;
-
-
#define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
static const char *const mtrr_strings[MTRR_NUM_TYPES] =
@@ -397,7 +393,7 @@ static int mtrr_seq_show(struct seq_file *seq, void *offset)
for (i = 0; i < max; i++) {
mtrr_if->get(i, &base, &size, &type);
if (size == 0)
- usage_table[i] = 0;
+ mtrr_usage_table[i] = 0;
else {
if (size < (0x100000 >> PAGE_SHIFT)) {
/* less than 1MB */
@@ -411,7 +407,7 @@ static int mtrr_seq_show(struct seq_file *seq, void *offset)
len += seq_printf(seq,
"reg%02i: base=0x%05lx000 (%4luMB), size=%4lu%cB: %s, count=%d\n",
i, base, base >> (20 - PAGE_SHIFT), size, factor,
- mtrr_attrib_to_str(type), usage_table[i]);
+ mtrr_attrib_to_str(type), mtrr_usage_table[i]);
}
}
return 0;
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 60af5ed2b5c..ccd36ed2187 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -38,8 +38,8 @@
#include <linux/cpu.h>
#include <linux/mutex.h>
+#include <asm/e820.h>
#include <asm/mtrr.h>
-
#include <asm/uaccess.h>
#include <asm/processor.h>
#include <asm/msr.h>
@@ -47,7 +47,7 @@
u32 num_var_ranges = 0;
-unsigned int *usage_table;
+unsigned int mtrr_usage_table[MAX_VAR_RANGES];
static DEFINE_MUTEX(mtrr_mutex);
u64 size_or_mask, size_and_mask;
@@ -121,13 +121,8 @@ static void __init init_table(void)
int i, max;
max = num_var_ranges;
- if ((usage_table = kmalloc(max * sizeof *usage_table, GFP_KERNEL))
- == NULL) {
- printk(KERN_ERR "mtrr: could not allocate\n");
- return;
- }
for (i = 0; i < max; i++)
- usage_table[i] = 1;
+ mtrr_usage_table[i] = 1;
}
struct set_mtrr_data {
@@ -383,7 +378,7 @@ int mtrr_add_page(unsigned long base, unsigned long size,
goto out;
}
if (increment)
- ++usage_table[i];
+ ++mtrr_usage_table[i];
error = i;
goto out;
}
@@ -391,15 +386,15 @@ int mtrr_add_page(unsigned long base, unsigned long size,
i = mtrr_if->get_free_region(base, size, replace);
if (i >= 0) {
set_mtrr(i, base, size, type);
- if (likely(replace < 0))
- usage_table[i] = 1;
- else {
- usage_table[i] = usage_table[replace];
+ if (likely(replace < 0)) {
+ mtrr_usage_table[i] = 1;
+ } else {
+ mtrr_usage_table[i] = mtrr_usage_table[replace];
if (increment)
- usage_table[i]++;
+ mtrr_usage_table[i]++;
if (unlikely(replace != i)) {
set_mtrr(replace, 0, 0, 0);
- usage_table[replace] = 0;
+ mtrr_usage_table[replace] = 0;
}
}
} else
@@ -529,11 +524,11 @@ int mtrr_del_page(int reg, unsigned long base, unsigned long size)
printk(KERN_WARNING "mtrr: MTRR %d not used\n", reg);
goto out;
}
- if (usage_table[reg] < 1) {
+ if (mtrr_usage_table[reg] < 1) {
printk(KERN_WARNING "mtrr: reg: %d has count=0\n", reg);
goto out;
}
- if (--usage_table[reg] < 1)
+ if (--mtrr_usage_table[reg] < 1)
set_mtrr(reg, 0, 0, 0);
error = reg;
out:
@@ -593,16 +588,11 @@ struct mtrr_value {
unsigned long lsize;
};
-static struct mtrr_value * mtrr_state;
+static struct mtrr_value mtrr_state[MAX_VAR_RANGES];
static int mtrr_save(struct sys_device * sysdev, pm_message_t state)
{
int i;
- int size = num_var_ranges * sizeof(struct mtrr_value);
-
- mtrr_state = kzalloc(size,GFP_ATOMIC);
- if (!mtrr_state)
- return -ENOMEM;
for (i = 0; i < num_var_ranges; i++) {
mtrr_if->get(i,
@@ -624,7 +614,6 @@ static int mtrr_restore(struct sys_device * sysdev)
mtrr_state[i].lsize,
mtrr_state[i].ltype);
}
- kfree(mtrr_state);
return 0;
}
@@ -635,6 +624,109 @@ static struct sysdev_driver mtrr_sysdev_driver = {
.resume = mtrr_restore,
};
+#ifdef CONFIG_X86_64
+static int disable_mtrr_trim;
+
+static int __init disable_mtrr_trim_setup(char *str)
+{
+ disable_mtrr_trim = 1;
+ return 0;
+}
+early_param("disable_mtrr_trim", disable_mtrr_trim_setup);
+
+/*
+ * Newer AMD K8s and later CPUs have a special magic MSR way to force WB
+ * for memory >4GB. Check for that here.
+ * Note this won't check if the MTRRs < 4GB where the magic bit doesn't
+ * apply to are wrong, but so far we don't know of any such case in the wild.
+ */
+#define Tom2Enabled (1U << 21)
+#define Tom2ForceMemTypeWB (1U << 22)
+
+static __init int amd_special_default_mtrr(unsigned long end_pfn)
+{
+ u32 l, h;
+
+ /* Doesn't apply to memory < 4GB */
+ if (end_pfn <= (0xffffffff >> PAGE_SHIFT))
+ return 0;
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
+ return 0;
+ if (boot_cpu_data.x86 < 0xf || boot_cpu_data.x86 > 0x11)
+ return 0;
+ /* In case some hypervisor doesn't pass SYSCFG through */
+ if (rdmsr_safe(MSR_K8_SYSCFG, &l, &h) < 0)
+ return 0;
+ /*
+ * Memory between 4GB and top of mem is forced WB by this magic bit.
+ * Reserved before K8RevF, but should be zero there.
+ */
+ if ((l & (Tom2Enabled | Tom2ForceMemTypeWB)) ==
+ (Tom2Enabled | Tom2ForceMemTypeWB))
+ return 1;
+ return 0;
+}
+
+/**
+ * mtrr_trim_uncached_memory - trim RAM not covered by MTRRs
+ *
+ * Some buggy BIOSes don't setup the MTRRs properly for systems with certain
+ * memory configurations. This routine checks that the highest MTRR matches
+ * the end of memory, to make sure the MTRRs having a write back type cover
+ * all of the memory the kernel is intending to use. If not, it'll trim any
+ * memory off the end by adjusting end_pfn, removing it from the kernel's
+ * allocation pools, warning the user with an obnoxious message.
+ */
+int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
+{
+ unsigned long i, base, size, highest_addr = 0, def, dummy;
+ mtrr_type type;
+ u64 trim_start, trim_size;
+
+ /*
+ * Make sure we only trim uncachable memory on machines that
+ * support the Intel MTRR architecture:
+ */
+ rdmsr(MTRRdefType_MSR, def, dummy);
+ def &= 0xff;
+ if (!is_cpu(INTEL) || disable_mtrr_trim || def != MTRR_TYPE_UNCACHABLE)
+ return 0;
+
+ /* Find highest cached pfn */
+ for (i = 0; i < num_var_ranges; i++) {
+ mtrr_if->get(i, &base, &size, &type);
+ if (type != MTRR_TYPE_WRBACK)
+ continue;
+ base <<= PAGE_SHIFT;
+ size <<= PAGE_SHIFT;
+ if (highest_addr < base + size)
+ highest_addr = base + size;
+ }
+
+ if (amd_special_default_mtrr(end_pfn))
+ return 0;
+
+ if ((highest_addr >> PAGE_SHIFT) < end_pfn) {
+ printk(KERN_WARNING "***************\n");
+ printk(KERN_WARNING "**** WARNING: likely BIOS bug\n");
+ printk(KERN_WARNING "**** MTRRs don't cover all of "
+ "memory, trimmed %ld pages\n", end_pfn -
+ (highest_addr >> PAGE_SHIFT));
+ printk(KERN_WARNING "***************\n");
+
+ printk(KERN_INFO "update e820 for mtrr\n");
+ trim_start = highest_addr;
+ trim_size = end_pfn;
+ trim_size <<= PAGE_SHIFT;
+ trim_size -= trim_start;
+ add_memory_region(trim_start, trim_size, E820_RESERVED);
+ update_e820();
+ return 1;
+ }
+
+ return 0;
+}
+#endif
/**
* mtrr_bp_init - initialize mtrrs on the boot CPU
diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.h b/arch/x86/kernel/cpu/mtrr/mtrr.h
index 54347e9a95c..fb74a2c2081 100644
--- a/arch/x86/kernel/cpu/mtrr/mtrr.h
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.h
@@ -12,6 +12,7 @@
#define MTRRphysMask_MSR(reg) (0x200 + 2 * (reg) + 1)
#define NUM_FIXED_RANGES 88
+#define MAX_VAR_RANGES 256
#define MTRRfix64K_00000_MSR 0x250
#define MTRRfix16K_80000_MSR 0x258
#define MTRRfix16K_A0000_MSR 0x259
@@ -32,6 +33,8 @@
an 8 bit field: */
typedef u8 mtrr_type;
+extern unsigned int mtrr_usage_table[MAX_VAR_RANGES];
+
struct mtrr_ops {
u32 vendor;
u32 use_intel_if;
diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 6cbd15625dc..12948316e6a 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -310,6 +310,13 @@ void __init setup_arch(char **cmdline_p)
* we are rounding upwards:
*/
end_pfn = e820_end_of_ram();
+ /* update e820 for memory not covered by WB MTRRs */
+ mtrr_bp_init();
+ if (mtrr_trim_uncached_memory(end_pfn)) {
+ e820_register_active_regions(0, 0, -1UL);
+ end_pfn = e820_end_of_ram();
+ }
+
num_physpages = end_pfn;
check_efer();