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linux/drivers/gpu/drm/panfrost/panfrost_gpu.h
AngeloGioacchino Del Regno 157ad4ccff drm/panfrost: Synchronize and disable interrupts before powering off
To make sure that we don't unintentionally perform any unclocked and/or
unpowered R/W operation on GPU registers, before turning off clocks and
regulators we must make sure that no GPU, JOB or MMU ISR execution is
pending: doing that requires to add a mechanism to synchronize the
interrupts on suspend.

Add functions panfrost_{gpu,job,mmu}_suspend_irq() which will perform
interrupts masking and ISR execution synchronization, and then call
those in the panfrost_device_runtime_suspend() handler in the exact
sequence of job (may require mmu!) -> mmu -> gpu.

As a side note, JOB and MMU suspend_irq functions needed some special
treatment: as their interrupt handlers will unmask interrupts, it was
necessary to add an `is_suspended` bitmap which is used to address the
possible corner case of unintentional IRQ unmasking because of ISR
execution after a call to synchronize_irq().

At resume, clear each is_suspended bit in the reset path of JOB/MMU
to allow unmasking the interrupts.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231204114215.54575-4-angelogioacchino.delregno@collabora.com
2023-12-05 11:39:59 +01:00

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/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright 2018 Marty E. Plummer <hanetzer@startmail.com> */
/* Copyright 2019 Collabora ltd. */
#ifndef __PANFROST_GPU_H__
#define __PANFROST_GPU_H__
struct panfrost_device;
int panfrost_gpu_init(struct panfrost_device *pfdev);
void panfrost_gpu_fini(struct panfrost_device *pfdev);
u32 panfrost_gpu_get_latest_flush_id(struct panfrost_device *pfdev);
int panfrost_gpu_soft_reset(struct panfrost_device *pfdev);
void panfrost_gpu_power_on(struct panfrost_device *pfdev);
void panfrost_gpu_power_off(struct panfrost_device *pfdev);
void panfrost_gpu_suspend_irq(struct panfrost_device *pfdev);
void panfrost_cycle_counter_get(struct panfrost_device *pfdev);
void panfrost_cycle_counter_put(struct panfrost_device *pfdev);
unsigned long long panfrost_cycle_counter_read(struct panfrost_device *pfdev);
void panfrost_gpu_amlogic_quirk(struct panfrost_device *pfdev);
#endif