[GIT PULL] x86/cpu changes for v3.9

From: Ingo Molnar
Date: Tue Feb 19 2013 - 10:25:17 EST


Linus,

Please pull the latest x86-cpu-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-cpu-for-linus

HEAD: f0322bd341fd63261527bf84afd3272bcc2e8dd3 x86, AMD: Enable WC+ memory type on family 10 processors

The biggest change is the enabling of the WC+ memory type on
family 10 processors. (This is a BIOS bug workaround in essence:
if the BIOS fails to do this then we fall back to uncacheable,
degrading performance, for example for virtualized guests using
nested pages.)

Thanks,

Ingo

------------------>
Boris Ostrovsky (2):
x86, AMD: Clean up init_amd()
x86, AMD: Enable WC+ memory type on family 10 processors

Chen Gang (1):
x86/process: Change %8s to %s for pr_warn() in release_thread()

Kees Cook (1):
x86/cpu/hotplug: Remove CONFIG_EXPERIMENTAL dependency


arch/x86/Kconfig | 4 +--
arch/x86/include/uapi/asm/msr-index.h | 1 +
arch/x86/kernel/cpu/amd.c | 50 ++++++++++++++++++++---------------
arch/x86/kernel/process_64.c | 2 +-
4 files changed, 32 insertions(+), 25 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 79795af..2d62103 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1699,7 +1699,7 @@ config HOTPLUG_CPU
config BOOTPARAM_HOTPLUG_CPU0
bool "Set default setting of cpu0_hotpluggable"
default n
- depends on HOTPLUG_CPU && EXPERIMENTAL
+ depends on HOTPLUG_CPU
---help---
Set whether default state of cpu0_hotpluggable is on or off.

@@ -1728,7 +1728,7 @@ config BOOTPARAM_HOTPLUG_CPU0
config DEBUG_HOTPLUG_CPU0
def_bool n
prompt "Debug CPU0 hotplug"
- depends on HOTPLUG_CPU && EXPERIMENTAL
+ depends on HOTPLUG_CPU
---help---
Enabling this option offlines CPU0 (if CPU0 can be offlined) as
soon as possible and boots up userspace with CPU0 offlined. User
diff --git a/arch/x86/include/uapi/asm/msr-index.h b/arch/x86/include/uapi/asm/msr-index.h
index 433a59f..158cde9 100644
--- a/arch/x86/include/uapi/asm/msr-index.h
+++ b/arch/x86/include/uapi/asm/msr-index.h
@@ -173,6 +173,7 @@
#define MSR_AMD64_OSVW_ID_LENGTH 0xc0010140
#define MSR_AMD64_OSVW_STATUS 0xc0010141
#define MSR_AMD64_DC_CFG 0xc0011022
+#define MSR_AMD64_BU_CFG2 0xc001102a
#define MSR_AMD64_IBSFETCHCTL 0xc0011030
#define MSR_AMD64_IBSFETCHLINAD 0xc0011031
#define MSR_AMD64_IBSFETCHPHYSAD 0xc0011032
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 15239ff..721ef32 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -518,10 +518,9 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
static void __cpuinit init_amd(struct cpuinfo_x86 *c)
{
u32 dummy;
-
-#ifdef CONFIG_SMP
unsigned long long value;

+#ifdef CONFIG_SMP
/*
* Disable TLB flush filter by setting HWCR.FFDIS on K8
* bit 6 of msr C001_0015
@@ -559,12 +558,10 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
* (AMD Erratum #110, docId: 25759).
*/
if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) {
- u64 val;
-
clear_cpu_cap(c, X86_FEATURE_LAHF_LM);
- if (!rdmsrl_amd_safe(0xc001100d, &val)) {
- val &= ~(1ULL << 32);
- wrmsrl_amd_safe(0xc001100d, val);
+ if (!rdmsrl_amd_safe(0xc001100d, &value)) {
+ value &= ~(1ULL << 32);
+ wrmsrl_amd_safe(0xc001100d, value);
}
}

@@ -617,13 +614,12 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
if ((c->x86 == 0x15) &&
(c->x86_model >= 0x10) && (c->x86_model <= 0x1f) &&
!cpu_has(c, X86_FEATURE_TOPOEXT)) {
- u64 val;

- if (!rdmsrl_safe(0xc0011005, &val)) {
- val |= 1ULL << 54;
- wrmsrl_safe(0xc0011005, val);
- rdmsrl(0xc0011005, val);
- if (val & (1ULL << 54)) {
+ if (!rdmsrl_safe(0xc0011005, &value)) {
+ value |= 1ULL << 54;
+ wrmsrl_safe(0xc0011005, value);
+ rdmsrl(0xc0011005, value);
+ if (value & (1ULL << 54)) {
set_cpu_cap(c, X86_FEATURE_TOPOEXT);
printk(KERN_INFO FW_INFO "CPU: Re-enabling "
"disabled Topology Extensions Support\n");
@@ -637,11 +633,10 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
*/
if ((c->x86 == 0x15) &&
(c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
- u64 val;

- if (!rdmsrl_safe(0xc0011021, &val) && !(val & 0x1E)) {
- val |= 0x1E;
- wrmsrl_safe(0xc0011021, val);
+ if (!rdmsrl_safe(0xc0011021, &value) && !(value & 0x1E)) {
+ value |= 0x1E;
+ wrmsrl_safe(0xc0011021, value);
}
}

@@ -703,13 +698,11 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
if (c->x86 > 0x11)
set_cpu_cap(c, X86_FEATURE_ARAT);

- /*
- * Disable GART TLB Walk Errors on Fam10h. We do this here
- * because this is always needed when GART is enabled, even in a
- * kernel which has no MCE support built in.
- */
if (c->x86 == 0x10) {
/*
+ * Disable GART TLB Walk Errors on Fam10h. We do this here
+ * because this is always needed when GART is enabled, even in a
+ * kernel which has no MCE support built in.
* BIOS should disable GartTlbWlk Errors themself. If
* it doesn't do it here as suggested by the BKDG.
*
@@ -723,6 +716,19 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
mask |= (1 << 10);
wrmsrl_safe(MSR_AMD64_MCx_MASK(4), mask);
}
+
+ /*
+ * On family 10h BIOS may not have properly enabled WC+ support,
+ * causing it to be converted to CD memtype. This may result in
+ * performance degradation for certain nested-paging guests.
+ * Prevent this conversion by clearing bit 24 in
+ * MSR_AMD64_BU_CFG2.
+ */
+ if (c->x86 == 0x10) {
+ rdmsrl(MSR_AMD64_BU_CFG2, value);
+ value &= ~(1ULL << 24);
+ wrmsrl(MSR_AMD64_BU_CFG2, value);
+ }
}

rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy);
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 6e68a61..0f49677 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -117,7 +117,7 @@ void release_thread(struct task_struct *dead_task)
{
if (dead_task->mm) {
if (dead_task->mm->context.size) {
- pr_warn("WARNING: dead process %8s still has LDT? <%p/%d>\n",
+ pr_warn("WARNING: dead process %s still has LDT? <%p/%d>\n",
dead_task->comm,
dead_task->mm->context.ldt,
dead_task->mm->context.size);
--
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