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/* SPDX-License-Identifier: MIT */
/*
* Copyright © 2019 Intel Corporation
*/
#ifndef __INTEL_RUNTIME_PM_H__
#define __INTEL_RUNTIME_PM_H__
#include <linux/types.h>
#include "intel_wakeref.h"
#include "i915_utils.h"
struct device;
struct drm_i915_private;
struct drm_printer;
/*
* 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.dev */
bool available;
bool suspended;
bool irqs_enabled;
bool no_wakeref_tracking;
/*
* Protects access to lmem usefault list.
* It is required, if we are outside of the runtime suspend path,
* access to @lmem_userfault_list requires always first grabbing the
* runtime pm, to ensure we can't race against runtime suspend.
* Once we have that we also need to grab @lmem_userfault_lock,
* at which point we have exclusive access.
* The runtime suspend path is special since it doesn't really hold any locks,
* but instead has exclusive access by virtue of all other accesses requiring
* holding the runtime pm wakeref.
*/
spinlock_t lmem_userfault_lock;
/*
* Keep list of userfaulted gem obj, which require to release their
* mmap mappings at runtime suspend path.
*/
struct list_head lmem_userfault_list;
/* Manual runtime pm autosuspend delay for user GGTT/lmem mmaps */
struct intel_wakeref_auto userfault_wakeref;
#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(typeof_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_driver_release(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_if_active(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)
#define with_intel_runtime_pm_if_active(rpm, wf) \
for ((wf) = intel_runtime_pm_get_if_active(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__ */
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