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Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/main.c')
-rw-r--r--arch/x86/kernel/cpu/mtrr/main.c170
1 files changed, 125 insertions, 45 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 3b20613325d..b6e136f23d3 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;
@@ -59,12 +59,6 @@ struct mtrr_ops * mtrr_if = NULL;
static void set_mtrr(unsigned int reg, unsigned long base,
unsigned long size, mtrr_type type);
-#ifndef CONFIG_X86_64
-extern int arr3_protected;
-#else
-#define arr3_protected 0
-#endif
-
void set_mtrr_ops(struct mtrr_ops * ops)
{
if (ops->vendor && ops->vendor < X86_VENDOR_NUM)
@@ -121,13 +115,8 @@ 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 {
@@ -311,7 +300,7 @@ static void set_mtrr(unsigned int reg, unsigned long base,
*/
int mtrr_add_page(unsigned long base, unsigned long size,
- unsigned int type, char increment)
+ unsigned int type, bool increment)
{
int i, replace, error;
mtrr_type ltype;
@@ -349,7 +338,7 @@ int mtrr_add_page(unsigned long base, unsigned long size,
replace = -1;
/* No CPU hotplug when we change MTRR entries */
- lock_cpu_hotplug();
+ get_online_cpus();
/* Search for existing MTRR */
mutex_lock(&mtrr_mutex);
for (i = 0; i < num_var_ranges; ++i) {
@@ -383,7 +372,7 @@ 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;
}
@@ -391,13 +380,15 @@ 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] + !!increment;
+ if (likely(replace < 0)) {
+ mtrr_usage_table[i] = 1;
+ } else {
+ mtrr_usage_table[i] = mtrr_usage_table[replace];
+ if (increment)
+ mtrr_usage_table[i]++;
if (unlikely(replace != i)) {
set_mtrr(replace, 0, 0, 0);
- usage_table[replace] = 0;
+ mtrr_usage_table[replace] = 0;
}
}
} else
@@ -405,7 +396,7 @@ int mtrr_add_page(unsigned long base, unsigned long size,
error = i;
out:
mutex_unlock(&mtrr_mutex);
- unlock_cpu_hotplug();
+ put_online_cpus();
return error;
}
@@ -460,7 +451,7 @@ static int mtrr_check(unsigned long base, unsigned long size)
int
mtrr_add(unsigned long base, unsigned long size, unsigned int type,
- char increment)
+ bool increment)
{
if (mtrr_check(base, size))
return -EINVAL;
@@ -495,7 +486,7 @@ int mtrr_del_page(int reg, unsigned long base, unsigned long size)
max = num_var_ranges;
/* No CPU hotplug when we change MTRR entries */
- lock_cpu_hotplug();
+ get_online_cpus();
mutex_lock(&mtrr_mutex);
if (reg < 0) {
/* Search for existing MTRR */
@@ -516,27 +507,21 @@ int mtrr_del_page(int reg, unsigned long base, unsigned long size)
printk(KERN_WARNING "mtrr: register: %d too big\n", reg);
goto out;
}
- if (is_cpu(CYRIX) && !use_intel()) {
- if ((reg == 3) && arr3_protected) {
- printk(KERN_WARNING "mtrr: ARR3 cannot be changed\n");
- goto out;
- }
- }
mtrr_if->get(reg, &lbase, &lsize, &ltype);
if (lsize < 1) {
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:
mutex_unlock(&mtrr_mutex);
- unlock_cpu_hotplug();
+ put_online_cpus();
return error;
}
/**
@@ -569,10 +554,6 @@ EXPORT_SYMBOL(mtrr_del);
* These should be called implicitly, but we can't yet until all the initcall
* stuff is done...
*/
-extern void amd_init_mtrr(void);
-extern void cyrix_init_mtrr(void);
-extern void centaur_init_mtrr(void);
-
static void __init init_ifs(void)
{
#ifndef CONFIG_X86_64
@@ -591,16 +572,11 @@ 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,
@@ -622,7 +598,6 @@ static int mtrr_restore(struct sys_device * sysdev)
mtrr_state[i].lsize,
mtrr_state[i].ltype);
}
- kfree(mtrr_state);
return 0;
}
@@ -633,6 +608,111 @@ static struct sysdev_driver mtrr_sysdev_driver = {
.resume = mtrr_restore,
};
+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(void)
+{
+ u32 l, h;
+
+ 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_pfn = 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:
+ */
+ if (!is_cpu(INTEL) || disable_mtrr_trim)
+ return 0;
+ rdmsr(MTRRdefType_MSR, def, dummy);
+ def &= 0xff;
+ 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);
+ if (type != MTRR_TYPE_WRBACK)
+ continue;
+ if (highest_pfn < base + size)
+ highest_pfn = base + size;
+ }
+
+ /* kvm/qemu doesn't have mtrr set right, don't trim them all */
+ if (!highest_pfn) {
+ printk(KERN_WARNING "WARNING: strange, CPU MTRRs all blank?\n");
+ WARN_ON(1);
+ return 0;
+ }
+
+ if (highest_pfn < end_pfn) {
+ 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));
+
+ 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;
+ add_memory_region(trim_start, trim_size, E820_RESERVED);
+ update_e820();
+ return 1;
+ }
+
+ return 0;
+}
/**
* mtrr_bp_init - initialize mtrrs on the boot CPU
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-16 17:34:27 +0000