For controlling runtime pm of the GT and engines, we would like to have a callback to do extra work the first time we wake up and the last time we drop the wakeref. This first/last access needs serialisation and so we encompass a mutex with the regular intel_wakeref_t tracker.
Signed-off-by: Chris Wilson <[email protected]> --- drivers/gpu/drm/i915/Makefile | 1 + drivers/gpu/drm/i915/Makefile.header-test | 3 +- drivers/gpu/drm/i915/i915_drv.h | 3 +- drivers/gpu/drm/i915/intel_wakeref.c | 51 +++++++++++++++ drivers/gpu/drm/i915/intel_wakeref.h | 77 +++++++++++++++++++++++ 5 files changed, 132 insertions(+), 3 deletions(-) create mode 100644 drivers/gpu/drm/i915/intel_wakeref.c create mode 100644 drivers/gpu/drm/i915/intel_wakeref.h diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index 40130cf5c003..233bad5e361f 100644 --- a/drivers/gpu/drm/i915/Makefile +++ b/drivers/gpu/drm/i915/Makefile @@ -50,6 +50,7 @@ i915-y += i915_drv.o \ intel_device_info.o \ intel_pm.o \ intel_runtime_pm.o \ + intel_wakeref.o \ intel_uncore.o # core library code diff --git a/drivers/gpu/drm/i915/Makefile.header-test b/drivers/gpu/drm/i915/Makefile.header-test index 96a5d90629ec..e6b3e7588860 100644 --- a/drivers/gpu/drm/i915/Makefile.header-test +++ b/drivers/gpu/drm/i915/Makefile.header-test @@ -31,7 +31,8 @@ header_test := \ intel_psr.h \ intel_sdvo.h \ intel_sprite.h \ - intel_tv.h + intel_tv.h \ + intel_wakeref.h quiet_cmd_header_test = HDRTEST $@ cmd_header_test = echo "\#include \"$(<F)\"" > $@ diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index fad5306f07da..62a7e91acd7f 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -74,6 +74,7 @@ #include "intel_opregion.h" #include "intel_uc.h" #include "intel_uncore.h" +#include "intel_wakeref.h" #include "intel_wopcm.h" #include "i915_gem.h" @@ -134,8 +135,6 @@ bool i915_error_injected(void); __i915_printk(i915, i915_error_injected() ? KERN_DEBUG : KERN_ERR, \ fmt, ##__VA_ARGS__) -typedef depot_stack_handle_t intel_wakeref_t; - enum hpd_pin { HPD_NONE = 0, HPD_TV = HPD_NONE, /* TV is known to be unreliable */ diff --git a/drivers/gpu/drm/i915/intel_wakeref.c b/drivers/gpu/drm/i915/intel_wakeref.c new file mode 100644 index 000000000000..c133c91cf277 --- /dev/null +++ b/drivers/gpu/drm/i915/intel_wakeref.c @@ -0,0 +1,51 @@ +/* + * SPDX-License-Identifier: MIT + * + * Copyright © 2019 Intel Corporation + */ + +#include "intel_drv.h" +#include "intel_wakeref.h" + +void __intel_wakeref_get_once(struct drm_i915_private *i915, + struct intel_wakeref_count *wc, + bool (*fn)(struct intel_wakeref_count *wc)) +{ + /* + * Treat get/put as different subclasses, as we may need to run + * the put callback from under the shrinker and do not want to + * cross-contanimate that callback with any extra work performed + * upon acquiring the wakeref. + */ + mutex_lock_nested(&wc->mutex, SINGLE_DEPTH_NESTING); + if (!atomic_read(&wc->count)) { + wc->wakeref = intel_runtime_pm_get(i915); + if (unlikely(!fn(wc))) { + intel_runtime_pm_put(i915, wc->wakeref); + mutex_unlock(&wc->mutex); + return; + } + + smp_mb__before_atomic(); /* release wc->count */ + } + atomic_inc(&wc->count); + mutex_unlock(&wc->mutex); +} + +void __intel_wakeref_put_once(struct drm_i915_private *i915, + struct intel_wakeref_count *wc, + bool (*fn)(struct intel_wakeref_count *wc)) +{ + if (likely(fn(wc))) + intel_runtime_pm_put(i915, wc->wakeref); + else + atomic_inc(&wc->count); + mutex_unlock(&wc->mutex); +} + +void __intel_wakeref_init(struct intel_wakeref_count *wc, + struct lock_class_key *key) +{ + __mutex_init(&wc->mutex, "wakeref", key); + atomic_set(&wc->count, 0); +} diff --git a/drivers/gpu/drm/i915/intel_wakeref.h b/drivers/gpu/drm/i915/intel_wakeref.h new file mode 100644 index 000000000000..cd4d8f57e502 --- /dev/null +++ b/drivers/gpu/drm/i915/intel_wakeref.h @@ -0,0 +1,77 @@ +/* + * SPDX-License-Identifier: MIT + * + * Copyright © 2019 Intel Corporation + */ + +#ifndef INTEL_WAKEREF_H +#define INTEL_WAKEREF_H + +#include <linux/atomic.h> +#include <linux/mutex.h> +#include <linux/stackdepot.h> + +struct drm_i915_private; + +typedef depot_stack_handle_t intel_wakeref_t; + +struct intel_wakeref_count { + atomic_t count; + struct mutex mutex; + intel_wakeref_t wakeref; +}; + +void __intel_wakeref_init(struct intel_wakeref_count *wc, + struct lock_class_key *key); +#define intel_wakeref_init(wc) do { \ + static struct lock_class_key __key; \ + \ + __intel_wakeref_init((wc), &__key); \ +} while (0) + +void __intel_wakeref_get_once(struct drm_i915_private *i915, + struct intel_wakeref_count *wc, + bool (*fn)(struct intel_wakeref_count *wc)); +void __intel_wakeref_put_once(struct drm_i915_private *i915, + struct intel_wakeref_count *wc, + bool (*fn)(struct intel_wakeref_count *wc)); + +static inline void +intel_wakeref_get_once(struct drm_i915_private *i915, + struct intel_wakeref_count *wc, + bool (*fn)(struct intel_wakeref_count *wc)) +{ + if (unlikely(!atomic_inc_not_zero(&wc->count))) + __intel_wakeref_get_once(i915, wc, fn); +} + +static inline void +intel_wakeref_put_once(struct drm_i915_private *i915, + struct intel_wakeref_count *wc, + bool (*fn)(struct intel_wakeref_count *wc)) +{ + if (atomic_dec_and_mutex_lock(&wc->count, &wc->mutex)) + __intel_wakeref_put_once(i915, wc, fn); +} + +static inline void +intel_wakeref_lock(struct intel_wakeref_count *wc) + __acquires(wc->mutex) +{ + mutex_lock(&wc->mutex); +} + +static inline void +intel_wakeref_unlock(struct intel_wakeref_count *wc) + __releases(wc->mutex) +{ + mutex_unlock(&wc->mutex); +} + +static inline bool +intel_wakeref_active(struct intel_wakeref_count *wc) +{ + return atomic_read(&wc->count); +} + +#endif /* INTEL_WAKEREF_H */ -- 2.20.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
