linux/drivers/gpu/drm/msm/msm_ringbuffer.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2013 Red Hat
 * Author: Rob Clark <robdclark@gmail.com>
 */

#ifndef __MSM_RINGBUFFER_H__
#define __MSM_RINGBUFFER_H__

#include "drm/gpu_scheduler.h"
#include "msm_drv.h"

#define rbmemptr(ring, member)  \
	((ring)->memptrs_iova + offsetof(struct msm_rbmemptrs, member))

#define rbmemptr_stats(ring, index, member) \
	(rbmemptr((ring), stats) + \
	 ((index) * sizeof(struct msm_gpu_submit_stats)) + \
	 offsetof(struct msm_gpu_submit_stats, member))

struct msm_gpu_submit_stats {
	u64 cpcycles_start;
	u64 cpcycles_end;
	u64 alwayson_start;
	u64 alwayson_end;
};

#define MSM_GPU_SUBMIT_STATS_COUNT 64

struct msm_rbmemptrs {
	volatile uint32_t rptr;
	volatile uint32_t fence;
	/* Introduced on A7xx */
	volatile uint32_t bv_rptr;
	volatile uint32_t bv_fence;

	volatile struct msm_gpu_submit_stats stats[MSM_GPU_SUBMIT_STATS_COUNT];
	volatile u64 ttbr0;
	volatile u32 context_idr;
};

struct msm_cp_state {
	uint64_t ib1_base, ib2_base;
	uint32_t ib1_rem, ib2_rem;
};

struct msm_ringbuffer {
	struct msm_gpu *gpu;
	int id;
	struct drm_gem_object *bo;
	uint32_t *start, *end, *cur, *next;

	/*
	 * The job scheduler for this ring.
	 */
	struct drm_gpu_scheduler sched;

	/*
	 * List of in-flight submits on this ring.  Protected by submit_lock.
	 *
	 * Currently just submits that are already written into the ring, not
	 * submits that are still in drm_gpu_scheduler's queues.  At a later
	 * step we could probably move to letting drm_gpu_scheduler manage
	 * hangcheck detection and keep track of submit jobs that are in-
	 * flight.
	 */
	struct list_head submits;
	spinlock_t submit_lock;

	uint64_t iova;
	uint32_t hangcheck_fence;
	struct msm_rbmemptrs *memptrs;
	uint64_t memptrs_iova;
	struct msm_fence_context *fctx;

	/**
	 * hangcheck_progress_retries:
	 *
	 * The number of extra hangcheck duration cycles that we have given
	 * due to it appearing that the GPU is making forward progress.
	 *
	 * For GPU generations which support progress detection (see.
	 * msm_gpu_funcs::progress()), if the GPU appears to be making progress
	 * (ie. the CP has advanced in the command stream, we'll allow up to
	 * DRM_MSM_HANGCHECK_PROGRESS_RETRIES expirations of the hangcheck timer
	 * before killing the job.  But to detect progress we need two sample
	 * points, so the duration of the hangcheck timer is halved.  In other
	 * words we'll let the submit run for up to:
	 *
	 * (DRM_MSM_HANGCHECK_DEFAULT_PERIOD / 2) * (DRM_MSM_HANGCHECK_PROGRESS_RETRIES + 1)
	 */
	int hangcheck_progress_retries;

	/**
	 * last_cp_state: The state of the CP at the last call to gpu->progress()
	 */
	struct msm_cp_state last_cp_state;

	/*
	 * preempt_lock protects preemption and serializes wptr updates against
	 * preemption.  Can be aquired from irq context.
	 */
	spinlock_t preempt_lock;

	/*
	 * Whether we skipped writing wptr and it needs to be updated in the
	 * future when the ring becomes current.
	 */
	bool restore_wptr;

	/**
	 * cur_ctx_seqno:
	 *
	 * The ctx->seqno value of the last context to submit to this ring
	 * Tracked by seqno rather than pointer value to avoid dangling
	 * pointers, and cases where a ctx can be freed and a new one created
	 * with the same address.
	 */
	int cur_ctx_seqno;
};

struct msm_ringbuffer *msm_ringbuffer_new(struct msm_gpu *gpu, int id,
		void *memptrs, uint64_t memptrs_iova);
void msm_ringbuffer_destroy(struct msm_ringbuffer *ring);

/* ringbuffer helpers (the parts that are same for a3xx/a2xx/z180..) */

static inline void
OUT_RING(struct msm_ringbuffer *ring, uint32_t data)
{
	/*
	 * ring->next points to the current command being written - it won't be
	 * committed as ring->cur until the flush
	 */
	if (ring->next == ring->end)
		ring->next = ring->start;
	*(ring->next++) = data;
}

#endif /* __MSM_RINGBUFFER_H__ */