--- /dev/null
- * For more, read the Documentation/power/runtime_pm.txt.
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef __INTEL_RUNTIME_PM_H__
+#define __INTEL_RUNTIME_PM_H__
+
+#include <linux/types.h>
+
+#include "display/intel_display.h"
+
+#include "intel_wakeref.h"
+
+#include "i915_utils.h"
+
+struct device;
+struct drm_i915_private;
+struct drm_printer;
+
+enum i915_drm_suspend_mode {
+ I915_DRM_SUSPEND_IDLE,
+ I915_DRM_SUSPEND_MEM,
+ I915_DRM_SUSPEND_HIBERNATE,
+};
+
+/*
+ * This struct helps tracking the state needed for runtime PM, which puts the
+ * device in PCI D3 state. Notice that when this happens, nothing on the
+ * graphics device works, even register access, so we don't get interrupts nor
+ * anything else.
+ *
+ * Every piece of our code that needs to actually touch the hardware needs to
+ * either call intel_runtime_pm_get or call intel_display_power_get with the
+ * appropriate power domain.
+ *
+ * Our driver uses the autosuspend delay feature, which means we'll only really
+ * suspend if we stay with zero refcount for a certain amount of time. The
+ * default value is currently very conservative (see intel_runtime_pm_enable), but
+ * it can be changed with the standard runtime PM files from sysfs.
+ *
+ * The irqs_disabled variable becomes true exactly after we disable the IRQs and
+ * goes back to false exactly before we reenable the IRQs. We use this variable
+ * to check if someone is trying to enable/disable IRQs while they're supposed
+ * to be disabled. This shouldn't happen and we'll print some error messages in
+ * case it happens.
+ *
++ * For more, read the Documentation/power/runtime_pm.rst.
+ */
+struct intel_runtime_pm {
+ atomic_t wakeref_count;
+ struct device *kdev; /* points to i915->drm.pdev->dev */
+ bool available;
+ bool suspended;
+ bool irqs_enabled;
+
+#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
+ /*
+ * To aide detection of wakeref leaks and general misuse, we
+ * track all wakeref holders. With manual markup (i.e. returning
+ * a cookie to each rpm_get caller which they then supply to their
+ * paired rpm_put) we can remove corresponding pairs of and keep
+ * the array trimmed to active wakerefs.
+ */
+ struct intel_runtime_pm_debug {
+ spinlock_t lock;
+
+ depot_stack_handle_t last_acquire;
+ depot_stack_handle_t last_release;
+
+ depot_stack_handle_t *owners;
+ unsigned long count;
+ } debug;
+#endif
+};
+
+#define BITS_PER_WAKEREF \
+ BITS_PER_TYPE(struct_member(struct intel_runtime_pm, wakeref_count))
+#define INTEL_RPM_WAKELOCK_SHIFT (BITS_PER_WAKEREF / 2)
+#define INTEL_RPM_WAKELOCK_BIAS (1 << INTEL_RPM_WAKELOCK_SHIFT)
+#define INTEL_RPM_RAW_WAKEREF_MASK (INTEL_RPM_WAKELOCK_BIAS - 1)
+
+static inline int
+intel_rpm_raw_wakeref_count(int wakeref_count)
+{
+ return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK;
+}
+
+static inline int
+intel_rpm_wakelock_count(int wakeref_count)
+{
+ return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT;
+}
+
+static inline void
+assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm)
+{
+ WARN_ONCE(rpm->suspended,
+ "Device suspended during HW access\n");
+}
+
+static inline void
+__assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm, int wakeref_count)
+{
+ assert_rpm_device_not_suspended(rpm);
+ WARN_ONCE(!intel_rpm_raw_wakeref_count(wakeref_count),
+ "RPM raw-wakeref not held\n");
+}
+
+static inline void
+__assert_rpm_wakelock_held(struct intel_runtime_pm *rpm, int wakeref_count)
+{
+ __assert_rpm_raw_wakeref_held(rpm, wakeref_count);
+ WARN_ONCE(!intel_rpm_wakelock_count(wakeref_count),
+ "RPM wakelock ref not held during HW access\n");
+}
+
+static inline void
+assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm)
+{
+ __assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count));
+}
+
+static inline void
+assert_rpm_wakelock_held(struct intel_runtime_pm *rpm)
+{
+ __assert_rpm_wakelock_held(rpm, atomic_read(&rpm->wakeref_count));
+}
+
+/**
+ * disable_rpm_wakeref_asserts - disable the RPM assert checks
+ * @rpm: the intel_runtime_pm structure
+ *
+ * This function disable asserts that check if we hold an RPM wakelock
+ * reference, while keeping the device-not-suspended checks still enabled.
+ * It's meant to be used only in special circumstances where our rule about
+ * the wakelock refcount wrt. the device power state doesn't hold. According
+ * to this rule at any point where we access the HW or want to keep the HW in
+ * an active state we must hold an RPM wakelock reference acquired via one of
+ * the intel_runtime_pm_get() helpers. Currently there are a few special spots
+ * where this rule doesn't hold: the IRQ and suspend/resume handlers, the
+ * forcewake release timer, and the GPU RPS and hangcheck works. All other
+ * users should avoid using this function.
+ *
+ * Any calls to this function must have a symmetric call to
+ * enable_rpm_wakeref_asserts().
+ */
+static inline void
+disable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm)
+{
+ atomic_add(INTEL_RPM_WAKELOCK_BIAS + 1,
+ &rpm->wakeref_count);
+}
+
+/**
+ * enable_rpm_wakeref_asserts - re-enable the RPM assert checks
+ * @rpm: the intel_runtime_pm structure
+ *
+ * This function re-enables the RPM assert checks after disabling them with
+ * disable_rpm_wakeref_asserts. It's meant to be used only in special
+ * circumstances otherwise its use should be avoided.
+ *
+ * Any calls to this function must have a symmetric call to
+ * disable_rpm_wakeref_asserts().
+ */
+static inline void
+enable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm)
+{
+ atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1,
+ &rpm->wakeref_count);
+}
+
+void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm);
+void intel_runtime_pm_enable(struct intel_runtime_pm *rpm);
+void intel_runtime_pm_disable(struct intel_runtime_pm *rpm);
+void intel_runtime_pm_cleanup(struct intel_runtime_pm *rpm);
+
+intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm);
+intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm);
+intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm);
+intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm);
+
+#define with_intel_runtime_pm(rpm, wf) \
+ for ((wf) = intel_runtime_pm_get(rpm); (wf); \
+ intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
+
+#define with_intel_runtime_pm_if_in_use(rpm, wf) \
+ for ((wf) = intel_runtime_pm_get_if_in_use(rpm); (wf); \
+ intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
+
+void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm);
+#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
+void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref);
+#else
+static inline void
+intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
+{
+ intel_runtime_pm_put_unchecked(rpm);
+}
+#endif
+void intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref);
+
+#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
+void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
+ struct drm_printer *p);
+#else
+static inline void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
+ struct drm_printer *p)
+{
+}
+#endif
+
+#endif /* __INTEL_RUNTIME_PM_H__ */
projects / thirdparty / linux.git / commitdiff
