Revert "intel_idle: Add support for using intel_idle in a VM guest using just hlt"

This reverts commit 2f3d08f074b0 ("intel_idle: Add support for using
intel_idle in a VM guest using just hlt"), because it causes functional
issues to appear and it is not really useful without a related commit
that got reverted previously.

Link: https://lore.kernel.org/linux-pm/5c7de6d5-7706-c4a5-7c41-146db1269aff@intel.com
Reported-by: Xiaoyao Li <xiaoyao.li@intel.com>
Requested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index a80e1f5..256c2d4 100644 (file)
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -199,43 +199,6 @@ static __cpuidle int intel_idle_xstate(struct cpuidle_device *dev,
        return __intel_idle(dev, drv, index);
 }
 
-static __always_inline int __intel_idle_hlt(struct cpuidle_device *dev,
-                                       struct cpuidle_driver *drv, int index)
-{
-       raw_safe_halt();
-       raw_local_irq_disable();
-       return index;
-}
-
-/**
- * intel_idle_hlt - Ask the processor to enter the given idle state using hlt.
- * @dev: cpuidle device of the target CPU.
- * @drv: cpuidle driver (assumed to point to intel_idle_driver).
- * @index: Target idle state index.
- *
- * Use the HLT instruction to notify the processor that the CPU represented by
- * @dev is idle and it can try to enter the idle state corresponding to @index.
- *
- * Must be called under local_irq_disable().
- */
-static __cpuidle int intel_idle_hlt(struct cpuidle_device *dev,
-                               struct cpuidle_driver *drv, int index)
-{
-       return __intel_idle_hlt(dev, drv, index);
-}
-
-static __cpuidle int intel_idle_hlt_irq_on(struct cpuidle_device *dev,
-                                   struct cpuidle_driver *drv, int index)
-{
-       int ret;
-
-       raw_local_irq_enable();
-       ret = __intel_idle_hlt(dev, drv, index);
-       raw_local_irq_disable();
-
-       return ret;
-}
-
 /**
  * intel_idle_s2idle - Ask the processor to enter the given idle state.
  * @dev: cpuidle device of the target CPU.
@@ -1279,18 +1242,6 @@ static struct cpuidle_state snr_cstates[] __initdata = {
                .enter = NULL }
 };
 
-static struct cpuidle_state vmguest_cstates[] __initdata = {
-       {
-               .name = "C1",
-               .desc = "HLT",
-               .flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_IRQ_ENABLE,
-               .exit_latency = 5,
-               .target_residency = 10,
-               .enter = &intel_idle_hlt, },
-       {
-               .enter = NULL }
-};
-
 static const struct idle_cpu idle_cpu_nehalem __initconst = {
        .state_table = nehalem_cstates,
        .auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
@@ -1890,16 +1841,6 @@ static bool __init intel_idle_verify_cstate(unsigned int mwait_hint)
 
 static void state_update_enter_method(struct cpuidle_state *state, int cstate)
 {
-       if (state->enter == intel_idle_hlt) {
-               if (force_irq_on) {
-                       pr_info("forced intel_idle_irq for state %d\n", cstate);
-                       state->enter = intel_idle_hlt_irq_on;
-               }
-               return;
-       }
-       if (state->enter == intel_idle_hlt_irq_on)
-               return; /* no update scenarios */
-
        if (state->flags & CPUIDLE_FLAG_INIT_XSTATE) {
                /*
                 * Combining with XSTATE with IBRS or IRQ_ENABLE flags
@@ -1933,21 +1874,6 @@ static void state_update_enter_method(struct cpuidle_state *state, int cstate)
        }
 }
 
-/*
- * For mwait based states, we want to verify the cpuid data to see if the state
- * is actually supported by this specific CPU.
- * For non-mwait based states, this check should be skipped.
- */
-static bool should_verify_mwait(struct cpuidle_state *state)
-{
-       if (state->enter == intel_idle_hlt)
-               return false;
-       if (state->enter == intel_idle_hlt_irq_on)
-               return false;
-
-       return true;
-}
-
 static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
 {
        int cstate;
@@ -1996,7 +1922,7 @@ static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
                }
 
                mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
-               if (should_verify_mwait(&cpuidle_state_table[cstate]) && !intel_idle_verify_cstate(mwait_hint))
+               if (!intel_idle_verify_cstate(mwait_hint))
                        continue;
 
                /* Structure copy. */
@@ -2130,45 +2056,6 @@ static void __init intel_idle_cpuidle_devices_uninit(void)
                cpuidle_unregister_device(per_cpu_ptr(intel_idle_cpuidle_devices, i));
 }
 
-static int __init intel_idle_vminit(const struct x86_cpu_id *id)
-{
-       int retval;
-
-       cpuidle_state_table = vmguest_cstates;
-
-       icpu = (const struct idle_cpu *)id->driver_data;
-
-       pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
-                boot_cpu_data.x86_model);
-
-       intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
-       if (!intel_idle_cpuidle_devices)
-               return -ENOMEM;
-
-       intel_idle_cpuidle_driver_init(&intel_idle_driver);
-
-       retval = cpuidle_register_driver(&intel_idle_driver);
-       if (retval) {
-               struct cpuidle_driver *drv = cpuidle_get_driver();
-               printk(KERN_DEBUG pr_fmt("intel_idle yielding to %s\n"),
-                      drv ? drv->name : "none");
-               goto init_driver_fail;
-       }
-
-       retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
-                                  intel_idle_cpu_online, NULL);
-       if (retval < 0)
-               goto hp_setup_fail;
-
-       return 0;
-hp_setup_fail:
-       intel_idle_cpuidle_devices_uninit();
-       cpuidle_unregister_driver(&intel_idle_driver);
-init_driver_fail:
-       free_percpu(intel_idle_cpuidle_devices);
-       return retval;
-}
-
 static int __init intel_idle_init(void)
 {
        const struct x86_cpu_id *id;
@@ -2187,8 +2074,6 @@ static int __init intel_idle_init(void)
        id = x86_match_cpu(intel_idle_ids);
        if (id) {
                if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
-                       if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
-                               return intel_idle_vminit(id);
                        pr_debug("Please enable MWAIT in BIOS SETUP\n");
                        return -ENODEV;
                }