summaryrefslogtreecommitdiff
path: root/drivers/idle/intel_idle.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/idle/intel_idle.c')
-rw-r--r--drivers/idle/intel_idle.c44
1 files changed, 38 insertions, 6 deletions
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 424ef470223d..f5c6802aa6c3 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -47,11 +47,13 @@
#include <linux/tick.h>
#include <trace/events/power.h>
#include <linux/sched.h>
+#include <linux/sched/smt.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/moduleparam.h>
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>
+#include <asm/nospec-branch.h>
#include <asm/mwait.h>
#include <asm/msr.h>
@@ -106,6 +108,12 @@ static unsigned int mwait_substates __initdata;
#define CPUIDLE_FLAG_ALWAYS_ENABLE BIT(15)
/*
+ * Disable IBRS across idle (when KERNEL_IBRS), is exclusive vs IRQ_ENABLE
+ * above.
+ */
+#define CPUIDLE_FLAG_IBRS BIT(16)
+
+/*
* MWAIT takes an 8-bit "hint" in EAX "suggesting"
* the C-state (top nibble) and sub-state (bottom nibble)
* 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
@@ -159,6 +167,24 @@ static __cpuidle int intel_idle_irq(struct cpuidle_device *dev,
return ret;
}
+static __cpuidle int intel_idle_ibrs(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
+{
+ bool smt_active = sched_smt_active();
+ u64 spec_ctrl = spec_ctrl_current();
+ int ret;
+
+ if (smt_active)
+ wrmsrl(MSR_IA32_SPEC_CTRL, 0);
+
+ ret = __intel_idle(dev, drv, index);
+
+ if (smt_active)
+ wrmsrl(MSR_IA32_SPEC_CTRL, spec_ctrl);
+
+ return ret;
+}
+
/**
* intel_idle_s2idle - Ask the processor to enter the given idle state.
* @dev: cpuidle device of the target CPU.
@@ -680,7 +706,7 @@ static struct cpuidle_state skl_cstates[] __initdata = {
{
.name = "C6",
.desc = "MWAIT 0x20",
- .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED | CPUIDLE_FLAG_IBRS,
.exit_latency = 85,
.target_residency = 200,
.enter = &intel_idle,
@@ -688,7 +714,7 @@ static struct cpuidle_state skl_cstates[] __initdata = {
{
.name = "C7s",
.desc = "MWAIT 0x33",
- .flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED | CPUIDLE_FLAG_IBRS,
.exit_latency = 124,
.target_residency = 800,
.enter = &intel_idle,
@@ -696,7 +722,7 @@ static struct cpuidle_state skl_cstates[] __initdata = {
{
.name = "C8",
.desc = "MWAIT 0x40",
- .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED | CPUIDLE_FLAG_IBRS,
.exit_latency = 200,
.target_residency = 800,
.enter = &intel_idle,
@@ -704,7 +730,7 @@ static struct cpuidle_state skl_cstates[] __initdata = {
{
.name = "C9",
.desc = "MWAIT 0x50",
- .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED | CPUIDLE_FLAG_IBRS,
.exit_latency = 480,
.target_residency = 5000,
.enter = &intel_idle,
@@ -712,7 +738,7 @@ static struct cpuidle_state skl_cstates[] __initdata = {
{
.name = "C10",
.desc = "MWAIT 0x60",
- .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED | CPUIDLE_FLAG_IBRS,
.exit_latency = 890,
.target_residency = 5000,
.enter = &intel_idle,
@@ -741,7 +767,7 @@ static struct cpuidle_state skx_cstates[] __initdata = {
{
.name = "C6",
.desc = "MWAIT 0x20",
- .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED | CPUIDLE_FLAG_IBRS,
.exit_latency = 133,
.target_residency = 600,
.enter = &intel_idle,
@@ -1819,6 +1845,12 @@ static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_IRQ_ENABLE)
drv->states[drv->state_count].enter = intel_idle_irq;
+ if (cpu_feature_enabled(X86_FEATURE_KERNEL_IBRS) &&
+ cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_IBRS) {
+ WARN_ON_ONCE(cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_IRQ_ENABLE);
+ drv->states[drv->state_count].enter = intel_idle_ibrs;
+ }
+
if ((disabled_states_mask & BIT(drv->state_count)) ||
((icpu->use_acpi || force_use_acpi) &&
intel_idle_off_by_default(mwait_hint) &&