6 files changed, 153 insertions, 10 deletions

diff --git a/arch/arm/include/asm/cpuidle.h b/arch/arm/include/asm/cpuidle.h
index 3848259bebf8..baefe1d51517 100644
--- a/arch/arm/include/asm/cpuidle.h
+++ b/arch/arm/include/asm/cpuidle.h
@@ -36,7 +36,7 @@ struct cpuidle_ops {
 
 struct of_cpuidle_method {
         const char *method;
-        struct cpuidle_ops *ops;
+        const struct cpuidle_ops *ops;
 };
 
 #define CPUIDLE_METHOD_OF_DECLARE(name, _method, _ops)                  \
diff --git a/arch/arm/kernel/cpuidle.c b/arch/arm/kernel/cpuidle.c
index 703926e7007b..a44b268e12e1 100644
--- a/arch/arm/kernel/cpuidle.c
+++ b/arch/arm/kernel/cpuidle.c
@@ -70,7 +70,7 @@ int arm_cpuidle_suspend(int index)
  *
  * Returns a struct cpuidle_ops pointer, NULL if not found.
  */
-static struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method)
+static const struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method)
 {
         struct of_cpuidle_method *m = __cpuidle_method_of_table;
 
@@ -88,7 +88,7 @@ static struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method)
  *
  * Get the method name defined in the 'enable-method' property, retrieve the
  * associated cpuidle_ops and do a struct copy. This copy is needed because all
- * cpuidle_ops are tagged __initdata and will be unloaded after the init
+ * cpuidle_ops are tagged __initconst and will be unloaded after the init
  * process.
  *
  * Return 0 on sucess, -ENOENT if no 'enable-method' is defined, -EOPNOTSUPP if
@@ -97,7 +97,7 @@ static struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method)
 static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
 {
         const char *enable_method;
-        struct cpuidle_ops *ops;
+        const struct cpuidle_ops *ops;
 
         enable_method = of_get_property(dn, "enable-method", NULL);
         if (!enable_method)
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index f996efc56605..2b8e6ce62e81 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -173,7 +173,7 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
 
         struct cpuidle_state *target_state = &drv->states[index];
         bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP);
-        ktime_t time_start, time_end;
+        u64 time_start, time_end;
         s64 diff;
 
         /*
@@ -195,13 +195,13 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
         sched_idle_set_state(target_state);
 
         trace_cpu_idle_rcuidle(index, dev->cpu);
-        time_start = ktime_get();
+        time_start = local_clock();
 
         stop_critical_timings();
         entered_state = target_state->enter(dev, drv, index);
         start_critical_timings();
 
-        time_end = ktime_get();
+        time_end = local_clock();
         trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
 
         /* The cpu is no longer idle or about to enter idle. */
@@ -217,7 +217,11 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
         if (!cpuidle_state_is_coupled(drv, entered_state))
                 local_irq_enable();
 
-        diff = ktime_to_us(ktime_sub(time_end, time_start));
+        /*
+         * local_clock() returns the time in nanosecond, let's shift
+         * by 10 (divide by 1024) to have microsecond based time.
+         */
+        diff = (time_end - time_start) >> 10;
         if (diff > INT_MAX)
                 diff = INT_MAX;
 
@@ -433,6 +437,8 @@ static void __cpuidle_unregister_device(struct cpuidle_device *dev)
         list_del(&dev->device_list);
         per_cpu(cpuidle_devices, dev->cpu) = NULL;
         module_put(drv->owner);
+
+        dev->registered = 0;
 }
 
 static void __cpuidle_device_init(struct cpuidle_device *dev)
diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index b5d05807e6ec..fa4ea22ca12e 100644
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -355,7 +355,7 @@ int psci_cpu_suspend_enter(unsigned long index)
 
 /* ARM specific CPU idle operations */
 #ifdef CONFIG_ARM
-static struct cpuidle_ops psci_cpuidle_ops __initdata = {
+static const struct cpuidle_ops psci_cpuidle_ops __initconst = {
         .suspend = psci_cpu_suspend_enter,
         .init = psci_dt_cpu_init_idle,
 };
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index c6935de425fa..c96649292b55 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -766,6 +766,67 @@ static struct cpuidle_state knl_cstates[] = {
                 .enter = NULL }
 };
 
+static struct cpuidle_state bxt_cstates[] = {
+        {
+                .name = "C1-BXT",
+                .desc = "MWAIT 0x00",
+                .flags = MWAIT2flg(0x00),
+                .exit_latency = 2,
+                .target_residency = 2,
+                .enter = &intel_idle,
+                .enter_freeze = intel_idle_freeze, },
+        {
+                .name = "C1E-BXT",
+                .desc = "MWAIT 0x01",
+                .flags = MWAIT2flg(0x01),
+                .exit_latency = 10,
+                .target_residency = 20,
+                .enter = &intel_idle,
+                .enter_freeze = intel_idle_freeze, },
+        {
+                .name = "C6-BXT",
+                .desc = "MWAIT 0x20",
+                .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+                .exit_latency = 133,
+                .target_residency = 133,
+                .enter = &intel_idle,
+                .enter_freeze = intel_idle_freeze, },
+        {
+                .name = "C7s-BXT",
+                .desc = "MWAIT 0x31",
+                .flags = MWAIT2flg(0x31) | CPUIDLE_FLAG_TLB_FLUSHED,
+                .exit_latency = 155,
+                .target_residency = 155,
+                .enter = &intel_idle,
+                .enter_freeze = intel_idle_freeze, },
+        {
+                .name = "C8-BXT",
+                .desc = "MWAIT 0x40",
+                .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
+                .exit_latency = 1000,
+                .target_residency = 1000,
+                .enter = &intel_idle,
+                .enter_freeze = intel_idle_freeze, },
+        {
+                .name = "C9-BXT",
+                .desc = "MWAIT 0x50",
+                .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
+                .exit_latency = 2000,
+                .target_residency = 2000,
+                .enter = &intel_idle,
+                .enter_freeze = intel_idle_freeze, },
+        {
+                .name = "C10-BXT",
+                .desc = "MWAIT 0x60",
+                .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
+                .exit_latency = 10000,
+                .target_residency = 10000,
+                .enter = &intel_idle,
+                .enter_freeze = intel_idle_freeze, },
+        {
+                .enter = NULL }
+};
+
 /**
  * intel_idle
  * @dev: cpuidle_device
@@ -950,6 +1011,11 @@ static const struct idle_cpu idle_cpu_knl = {
         .state_table = knl_cstates,
 };
 
+static const struct idle_cpu idle_cpu_bxt = {
+        .state_table = bxt_cstates,
+        .disable_promotion_to_c1e = true,
+};
+
 #define ICPU(model, cpu) \
         { X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
 
@@ -985,6 +1051,7 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = {
         ICPU(0x9e, idle_cpu_skl),
         ICPU(0x55, idle_cpu_skx),
         ICPU(0x57, idle_cpu_knl),
+        ICPU(0x5c, idle_cpu_bxt),
         {}
 };
 MODULE_DEVICE_TABLE(x86cpu, intel_idle_ids);
@@ -1075,6 +1142,73 @@ static void ivt_idle_state_table_update(void)
 
         /* else, 1 and 2 socket systems use default ivt_cstates */
 }
+
+/*
+ * Translate IRTL (Interrupt Response Time Limit) MSR to usec
+ */
+
+static unsigned int irtl_ns_units[] = {
+        1, 32, 1024, 32768, 1048576, 33554432, 0, 0 };
+
+static unsigned long long irtl_2_usec(unsigned long long irtl)
+{
+        unsigned long long ns;
+
+        ns = irtl_ns_units[(irtl >> 10) & 0x3];
+
+        return div64_u64((irtl & 0x3FF) * ns, 1000);
+}
+/*
+ * bxt_idle_state_table_update(void)
+ *
+ * On BXT, we trust the IRTL to show the definitive maximum latency
+ * We use the same value for target_residency.
+ */
+static void bxt_idle_state_table_update(void)
+{
+        unsigned long long msr;
+
+        rdmsrl(MSR_PKGC6_IRTL, msr);
+        if (msr) {
+                unsigned int usec = irtl_2_usec(msr);
+
+                bxt_cstates[2].exit_latency = usec;
+                bxt_cstates[2].target_residency = usec;
+        }
+
+        rdmsrl(MSR_PKGC7_IRTL, msr);
+        if (msr) {
+                unsigned int usec = irtl_2_usec(msr);
+
+                bxt_cstates[3].exit_latency = usec;
+                bxt_cstates[3].target_residency = usec;
+        }
+
+        rdmsrl(MSR_PKGC8_IRTL, msr);
+        if (msr) {
+                unsigned int usec = irtl_2_usec(msr);
+
+                bxt_cstates[4].exit_latency = usec;
+                bxt_cstates[4].target_residency = usec;
+        }
+
+        rdmsrl(MSR_PKGC9_IRTL, msr);
+        if (msr) {
+                unsigned int usec = irtl_2_usec(msr);
+
+                bxt_cstates[5].exit_latency = usec;
+                bxt_cstates[5].target_residency = usec;
+        }
+
+        rdmsrl(MSR_PKGC10_IRTL, msr);
+        if (msr) {
+                unsigned int usec = irtl_2_usec(msr);
+
+                bxt_cstates[6].exit_latency = usec;
+                bxt_cstates[6].target_residency = usec;
+        }
+
+}
 /*
  * sklh_idle_state_table_update(void)
  *
@@ -1130,6 +1264,9 @@ static void intel_idle_state_table_update(void)
         case 0x3e: /* IVT */
                 ivt_idle_state_table_update();
                 break;
+        case 0x5c: /* BXT */
+                bxt_idle_state_table_update();
+                break;
         case 0x5e: /* SKL-H */
                 sklh_idle_state_table_update();
                 break;
diff --git a/drivers/soc/qcom/spm.c b/drivers/soc/qcom/spm.c
index 5548a31e1a39..1fcbb22a4a1c 100644
--- a/drivers/soc/qcom/spm.c
+++ b/drivers/soc/qcom/spm.c
@@ -274,7 +274,7 @@ check_spm:
         return per_cpu(cpu_spm_drv, cpu) ? 0 : -ENXIO;
 }
 
-static struct cpuidle_ops qcom_cpuidle_ops __initdata = {
+static const struct cpuidle_ops qcom_cpuidle_ops __initconst = {
         .suspend = qcom_idle_enter,
         .init = qcom_cpuidle_init,
 };