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path: root/drivers/idle/intel_idle.c
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Diffstat (limited to 'drivers/idle/intel_idle.c')
-rw-r--r--drivers/idle/intel_idle.c76
1 files changed, 46 insertions, 30 deletions
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 424ef470223d..9515a3146dc9 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.
@@ -154,7 +162,31 @@ static __cpuidle int intel_idle_irq(struct cpuidle_device *dev,
raw_local_irq_enable();
ret = __intel_idle(dev, drv, index);
- raw_local_irq_disable();
+
+ /*
+ * The lockdep hardirqs state may be changed to 'on' with timer
+ * tick interrupt followed by __do_softirq(). Use local_irq_disable()
+ * to keep the hardirqs state correct.
+ */
+ local_irq_disable();
+
+ 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;
}
@@ -680,7 +712,7 @@ 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 +720,7 @@ 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 +728,7 @@ 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 +736,7 @@ 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 +744,7 @@ 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 +773,7 @@ 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,
@@ -879,16 +911,6 @@ static struct cpuidle_state adl_l_cstates[] __initdata = {
.enter = NULL }
};
-/*
- * On Sapphire Rapids Xeon C1 has to be disabled if C1E is enabled, and vice
- * versa. On SPR C1E is enabled only if "C1E promotion" bit is set in
- * MSR_IA32_POWER_CTL. But in this case there effectively no C1, because C1
- * requests are promoted to C1E. If the "C1E promotion" bit is cleared, then
- * both C1 and C1E requests end up with C1, so there is effectively no C1E.
- *
- * By default we enable C1 and disable C1E by marking it with
- * 'CPUIDLE_FLAG_UNUSABLE'.
- */
static struct cpuidle_state spr_cstates[] __initdata = {
{
.name = "C1",
@@ -901,8 +923,7 @@ static struct cpuidle_state spr_cstates[] __initdata = {
{
.name = "C1E",
.desc = "MWAIT 0x01",
- .flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE |
- CPUIDLE_FLAG_UNUSABLE,
+ .flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
.exit_latency = 2,
.target_residency = 4,
.enter = &intel_idle,
@@ -1724,17 +1745,6 @@ static void __init spr_idle_state_table_update(void)
{
unsigned long long msr;
- /* Check if user prefers C1E over C1. */
- if ((preferred_states_mask & BIT(2)) &&
- !(preferred_states_mask & BIT(1))) {
- /* Disable C1 and enable C1E. */
- spr_cstates[0].flags |= CPUIDLE_FLAG_UNUSABLE;
- spr_cstates[1].flags &= ~CPUIDLE_FLAG_UNUSABLE;
-
- /* Enable C1E using the "C1E promotion" bit. */
- c1e_promotion = C1E_PROMOTION_ENABLE;
- }
-
/*
* By default, the C6 state assumes the worst-case scenario of package
* C6. However, if PC6 is disabled, we update the numbers to match
@@ -1819,6 +1829,12 @@ 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) &&