| Message ID | 1576096732-3596-2-git-send-email-andrey.grodzovsky@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RESEND,1/5] drm/amdgpu: reverts commit b01245ff54db66073b104ac9d9fbefb7b264b36d. | expand |
[AMD Official Use Only - Internal Distribution Only] -----Original Message----- From: Andrey Grodzovsky <andrey.grodzovsky@amd.com> Sent: Thursday, December 12, 2019 4:39 AM To: dri-devel@lists.freedesktop.org; amd-gfx@lists.freedesktop.org Cc: Deucher, Alexander <Alexander.Deucher@amd.com>; Ma, Le <Le.Ma@amd.com>; Zhang, Hawking <Hawking.Zhang@amd.com>; Quan, Evan <Evan.Quan@amd.com>; Grodzovsky, Andrey <Andrey.Grodzovsky@amd.com> Subject: [RESEND PATCH 2/5] drm: Add Reusable task barrier. It is used to synchronize N threads at a rendevouz point before execution of critical code that has to be started by all the threads at approximatly the same time. Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com<mailto:andrey.grodzovsky@amd.com>> --- include/drm/task_barrier.h | 106 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 include/drm/task_barrier.h diff --git a/include/drm/task_barrier.h b/include/drm/task_barrier.h new file mode 100644 index 0000000..81fb0f7 --- /dev/null +++ b/include/drm/task_barrier.h @@ -0,0 +1,106 @@ +/* + * Copyright 2019 Advanced Micro Devices, Inc. + * + * Permission is hereby granted, free of charge, to any person +obtaining a + * copy of this software and associated documentation files (the +"Software"), + * to deal in the Software without restriction, including without +limitation + * the rights to use, copy, modify, merge, publish, distribute, +sublicense, + * and/or sell copies of the Software, and to permit persons to whom +the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be +included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT +SHALL + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, +DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR +OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE +OR + * OTHER DEALINGS IN THE SOFTWARE. + * + */ +#include <linux/semaphore.h> +#include <linux/atomic.h> + +/* + * Reusable 2 PHASE task barrier (randevouz point) implementation for N tasks. + * Based on the Little book of sempahores - +https://greenteapress.com/wp/semaphores/ + */ + + + +#ifndef DRM_TASK_BARRIER_H_ +#define DRM_TASK_BARRIER_H_ + [Le]: It might be better to prefix "drm_" to the functions and structure below, even this header file name. +/* + * Represents an instance of a task barrier. + */ +struct task_barrier { + unsigned int n; [Le]: We can define it as signed type here for more common use. + atomic_t count; + struct semaphore enter_turnstile; + struct semaphore exit_turnstile; +}; + +static inline void task_barrier_signal_turnstile(struct semaphore *turnstile, + unsigned int n) +{ + int i; + + for (i = 0 ; i < n; i++) + up(turnstile); +} + +static inline void task_barrier_init(struct task_barrier *tb) { + tb->n = 0; + atomic_set(&tb->count, 0); + sema_init(&tb->enter_turnstile, 0); + sema_init(&tb->exit_turnstile, 0); +} + +static inline void task_barrier_add_task(struct task_barrier *tb) { + tb->n++; +} + +static inline void task_barrier_rem_task(struct task_barrier *tb) { + tb->n--; +} + +/* + * Lines up all the threads BEFORE the critical point. + * + * When all thread passed this code the entry barrier is back to locked state. + */ +static inline void task_barrier_enter(struct task_barrier *tb) { + if (atomic_inc_return(&tb->count) == tb->n) + task_barrier_signal_turnstile(&tb->enter_turnstile, tb->n); + + down(&tb->enter_turnstile); +} + +/* + * Lines up all the threads AFTER the critical point. + * + * This function is used to avoid any one thread running ahead of the +reset if [Le]: No need to mention "reset" here. With the above addressed, Acked-by: Le Ma Le.Ma@amd.com<mailto:Le.Ma@amd.com> Regards, Ma Le + * the barrier is used in a loop (repeatedly) . + */ +static inline void task_barrier_exit(struct task_barrier *tb) { + if (atomic_dec_return(&tb->count) == 0) + task_barrier_signal_turnstile(&tb->exit_turnstile, tb->n); + + down(&tb->exit_turnstile); +} + +static inline void task_barrier_full(struct task_barrier *tb) { + task_barrier_enter(tb); + task_barrier_exit(tb); +} + +#endif -- 2.7.4
On 12/11/19 11:04 PM, Ma, Le wrote: > > [AMD Official Use Only - Internal Distribution Only] > > -----Original Message----- > From: Andrey Grodzovsky <andrey.grodzovsky@amd.com> > Sent: Thursday, December 12, 2019 4:39 AM > To: dri-devel@lists.freedesktop.org; amd-gfx@lists.freedesktop.org > Cc: Deucher, Alexander <Alexander.Deucher@amd.com>; Ma, Le > <Le.Ma@amd.com>; Zhang, Hawking <Hawking.Zhang@amd.com>; Quan, Evan > <Evan.Quan@amd.com>; Grodzovsky, Andrey <Andrey.Grodzovsky@amd.com> > Subject: [RESEND PATCH 2/5] drm: Add Reusable task barrier. > > It is used to synchronize N threads at a rendevouz point before > execution of critical code that has to be started by all the threads > at approximatly the same time. > > Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com > <mailto:andrey.grodzovsky@amd.com>> > > --- > > include/drm/task_barrier.h | 106 > +++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 106 insertions(+) > > create mode 100644 include/drm/task_barrier.h > > diff --git a/include/drm/task_barrier.h b/include/drm/task_barrier.h > new file mode 100644 index 0000000..81fb0f7 > > --- /dev/null > > +++ b/include/drm/task_barrier.h > > @@ -0,0 +1,106 @@ > > +/* > > + * Copyright 2019 Advanced Micro Devices, Inc. > > + * > > + * Permission is hereby granted, free of charge, to any person > > +obtaining a > > + * copy of this software and associated documentation files (the > > +"Software"), > > + * to deal in the Software without restriction, including without > > +limitation > > + * the rights to use, copy, modify, merge, publish, distribute, > > +sublicense, > > + * and/or sell copies of the Software, and to permit persons to whom > > +the > > + * Software is furnished to do so, subject to the following conditions: > > + * > > + * The above copyright notice and this permission notice shall be > > +included in > > + * all copies or substantial portions of the Software. > > + * > > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, > > +EXPRESS OR > > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF > > +MERCHANTABILITY, > > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT > > +SHALL > > + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, > > +DAMAGES OR > > + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR > > +OTHERWISE, > > + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE > > +OR > > + * OTHER DEALINGS IN THE SOFTWARE. > > + * > > + */ > > +#include <linux/semaphore.h> > > +#include <linux/atomic.h> > > + > > +/* > > + * Reusable 2 PHASE task barrier (randevouz point) implementation for > N tasks. > > + * Based on the Little book of sempahores - > > +https://greenteapress.com/wp/semaphores/ > > + */ > > + > > + > > + > > +#ifndef DRM_TASK_BARRIER_H_ > > +#define DRM_TASK_BARRIER_H_ > > + > > [Le]: It might be better to prefix “drm_” to the functions and > structure below, even this header file name. > I am not sure about this - see the example of spsc_queue we added for GPU scheduler use. I just followed it as an example of where to place the structure. There is nothing DRM specific about spsc_queue or task_barrier, they are generic constructs that we place in DRM subsystem for common use. > +/* > > + * Represents an instance of a task barrier. > > + */ > > +struct task_barrier { > > + unsigned int n; > > [Le]: We can define it as signed type here for more common use. > This is a counter of number of tasks/threads to synchronize in the barrier it cannot go bellow 0 Andrey > + atomic_t count; > > + struct semaphore enter_turnstile; > > + struct semaphore exit_turnstile; > > +}; > > + > > +static inline void task_barrier_signal_turnstile(struct semaphore > *turnstile, > > + unsigned int n) > > +{ > > + int i; > > + > > + for (i = 0 ; i < n; i++) > > + up(turnstile); > > +} > > + > > +static inline void task_barrier_init(struct task_barrier *tb) { > > + tb->n = 0; > > + atomic_set(&tb->count, 0); > > + sema_init(&tb->enter_turnstile, 0); > > + sema_init(&tb->exit_turnstile, 0); > > +} > > + > > +static inline void task_barrier_add_task(struct task_barrier *tb) { > > + tb->n++; > > +} > > + > > +static inline void task_barrier_rem_task(struct task_barrier *tb) { > > + tb->n--; > > +} > > + > > +/* > > + * Lines up all the threads BEFORE the critical point. > > + * > > + * When all thread passed this code the entry barrier is back to > locked state. > > + */ > > +static inline void task_barrier_enter(struct task_barrier *tb) { > > + if (atomic_inc_return(&tb->count) == tb->n) > > + task_barrier_signal_turnstile(&tb->enter_turnstile, tb->n); > > + > > + down(&tb->enter_turnstile); > > +} > > + > > +/* > > + * Lines up all the threads AFTER the critical point. > > + * > > + * This function is used to avoid any one thread running ahead of the > > +reset if > > [Le]: No need to mention “reset” here. > > With the above addressed, Acked-by: Le Ma Le.Ma@amd.com > <mailto:Le.Ma@amd.com> > > Regards, > > Ma Le > > + * the barrier is used in a loop (repeatedly) . > > + */ > > +static inline void task_barrier_exit(struct task_barrier *tb) { > > + if (atomic_dec_return(&tb->count) == 0) > > + task_barrier_signal_turnstile(&tb->exit_turnstile, tb->n); > > + > > + down(&tb->exit_turnstile); > > +} > > + > > +static inline void task_barrier_full(struct task_barrier *tb) { > > + task_barrier_enter(tb); > > + task_barrier_exit(tb); > > +} > > + > > +#endif > > -- > > 2.7.4 >
diff --git a/include/drm/task_barrier.h b/include/drm/task_barrier.h new file mode 100644 index 0000000..81fb0f7 --- /dev/null +++ b/include/drm/task_barrier.h @@ -0,0 +1,106 @@ +/* + * Copyright 2019 Advanced Micro Devices, Inc. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + * + */ +#include <linux/semaphore.h> +#include <linux/atomic.h> + +/* + * Reusable 2 PHASE task barrier (randevouz point) implementation for N tasks. + * Based on the Little book of sempahores - https://greenteapress.com/wp/semaphores/ + */ + + + +#ifndef DRM_TASK_BARRIER_H_ +#define DRM_TASK_BARRIER_H_ + +/* + * Represents an instance of a task barrier. + */ +struct task_barrier { + unsigned int n; + atomic_t count; + struct semaphore enter_turnstile; + struct semaphore exit_turnstile; +}; + +static inline void task_barrier_signal_turnstile(struct semaphore *turnstile, + unsigned int n) +{ + int i; + + for (i = 0 ; i < n; i++) + up(turnstile); +} + +static inline void task_barrier_init(struct task_barrier *tb) +{ + tb->n = 0; + atomic_set(&tb->count, 0); + sema_init(&tb->enter_turnstile, 0); + sema_init(&tb->exit_turnstile, 0); +} + +static inline void task_barrier_add_task(struct task_barrier *tb) +{ + tb->n++; +} + +static inline void task_barrier_rem_task(struct task_barrier *tb) +{ + tb->n--; +} + +/* + * Lines up all the threads BEFORE the critical point. + * + * When all thread passed this code the entry barrier is back to locked state. + */ +static inline void task_barrier_enter(struct task_barrier *tb) +{ + if (atomic_inc_return(&tb->count) == tb->n) + task_barrier_signal_turnstile(&tb->enter_turnstile, tb->n); + + down(&tb->enter_turnstile); +} + +/* + * Lines up all the threads AFTER the critical point. + * + * This function is used to avoid any one thread running ahead of the reset if + * the barrier is used in a loop (repeatedly) . + */ +static inline void task_barrier_exit(struct task_barrier *tb) +{ + if (atomic_dec_return(&tb->count) == 0) + task_barrier_signal_turnstile(&tb->exit_turnstile, tb->n); + + down(&tb->exit_turnstile); +} + +static inline void task_barrier_full(struct task_barrier *tb) +{ + task_barrier_enter(tb); + task_barrier_exit(tb); +} + +#endif
It is used to synchronize N threads at a rendevouz point before execution of critical code that has to be started by all the threads at approximatly the same time. Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com> --- include/drm/task_barrier.h | 106 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 include/drm/task_barrier.h