Message-ID: <20240903202541.430225-2-adrian.larumbe@collabora.com>
Date: Tue,  3 Sep 2024 21:25:35 +0100
From: Adrián Larumbe <adrian.larumbe@...labora.com>
To: Boris Brezillon <boris.brezillon@...labora.com>,
	Steven Price <steven.price@....com>,
	Liviu Dudau <liviu.dudau@....com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Daniel Vetter <daniel@...ll.ch>,
	Sumit Semwal <sumit.semwal@...aro.org>,
	Christian König <christian.koenig@....com>
Cc: kernel@...labora.com,
	Adrián Larumbe <adrian.larumbe@...labora.com>,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org,
	linux-media@...r.kernel.org,
	linaro-mm-sig@...ts.linaro.org
Subject: [PATCH v5 1/4] drm/panthor: introduce job cycle and timestamp accounting

Enable calculations of job submission times in clock cycles and wall
time. This is done by expanding the boilerplate command stream when running
a job to include instructions that compute said times right before an after
a user CS.

A separate kernel BO is created per queue to store those values. Jobs can
access their sampled data through a slots buffer-specific index different
from that of the queue's ringbuffer. The reason for this is saving memory
on the profiling information kernel BO, since the amount of simultaneous
profiled jobs we can write into the queue's ringbuffer might be much
smaller than for regular jobs, as the former take more CSF instructions.

This commit is done in preparation for enabling DRM fdinfo support in the
Panthor driver, which depends on the numbers calculated herein.

A profile mode mask has been added that will in a future commit allow UM to
toggle performance metric sampling behaviour, which is disabled by default
to save power. When a ringbuffer CS is constructed, timestamp and cycling
sampling instructions are added depending on the enabled flags in the
profiling mask.

A helper was provided that calculates the number of instructions for a
given set of enablement mask, and these are passed as the number of credits
when initialising a DRM scheduler job.

Signed-off-by: Adrián Larumbe <adrian.larumbe@...labora.com>
---
 drivers/gpu/drm/panthor/panthor_device.h |  22 ++
 drivers/gpu/drm/panthor/panthor_sched.c  | 327 ++++++++++++++++++++---
 2 files changed, 305 insertions(+), 44 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
index e388c0472ba7..a48e30d0af30 100644
--- a/drivers/gpu/drm/panthor/panthor_device.h
+++ b/drivers/gpu/drm/panthor/panthor_device.h
@@ -66,6 +66,25 @@ struct panthor_irq {
 	atomic_t suspended;
 };
 
+/**
+ * enum panthor_device_profiling_mode - Profiling state
+ */
+enum panthor_device_profiling_flags {
+	/** @PANTHOR_DEVICE_PROFILING_DISABLED: Profiling is disabled. */
+	PANTHOR_DEVICE_PROFILING_DISABLED = 0,
+
+	/** @PANTHOR_DEVICE_PROFILING_CYCLES: Sampling job cycles. */
+	PANTHOR_DEVICE_PROFILING_CYCLES = BIT(0),
+
+	/** @PANTHOR_DEVICE_PROFILING_TIMESTAMP: Sampling job timestamp. */
+	PANTHOR_DEVICE_PROFILING_TIMESTAMP = BIT(1),
+
+	/** @PANTHOR_DEVICE_PROFILING_ALL: Sampling everything. */
+	PANTHOR_DEVICE_PROFILING_ALL =
+	PANTHOR_DEVICE_PROFILING_CYCLES |
+	PANTHOR_DEVICE_PROFILING_TIMESTAMP,
+};
+
 /**
  * struct panthor_device - Panthor device
  */
@@ -162,6 +181,9 @@ struct panthor_device {
 		 */
 		struct page *dummy_latest_flush;
 	} pm;
+
+	/** @profile_mask: User-set profiling flags for job accounting. */
+	u32 profile_mask;
 };
 
 /**
diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index c426a392b081..b087648bf59a 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -93,6 +93,9 @@
 #define MIN_CSGS				3
 #define MAX_CSG_PRIO				0xf
 
+#define NUM_INSTRS_PER_CACHE_LINE		(64 / sizeof(u64))
+#define MAX_INSTRS_PER_JOB			32
+
 struct panthor_group;
 
 /**
@@ -476,6 +479,18 @@ struct panthor_queue {
 		 */
 		struct list_head in_flight_jobs;
 	} fence_ctx;
+
+	/** @profiling_info: Job profiling data slots and access information. */
+	struct {
+		/** @slots: Kernel BO holding the slots. */
+		struct panthor_kernel_bo *slots;
+
+		/** @slot_count: Number of jobs ringbuffer can hold at once. */
+		u32 slot_count;
+
+		/** @profiling_seqno: Index of the next available profiling information slot. */
+		u32 profiling_seqno;
+	} profiling_info;
 };
 
 /**
@@ -661,6 +676,18 @@ struct panthor_group {
 	struct list_head wait_node;
 };
 
+struct panthor_job_profiling_data {
+	struct {
+		u64 before;
+		u64 after;
+	} cycles;
+
+	struct {
+		u64 before;
+		u64 after;
+	} time;
+};
+
 /**
  * group_queue_work() - Queue a group work
  * @group: Group to queue the work for.
@@ -774,6 +801,12 @@ struct panthor_job {
 
 	/** @done_fence: Fence signaled when the job is finished or cancelled. */
 	struct dma_fence *done_fence;
+
+	/** @profile_mask: Current device job profiling enablement bitmask. */
+	u32 profile_mask;
+
+	/** @profile_slot: Job profiling information index in the profiling slots BO. */
+	u32 profiling_slot;
 };
 
 static void
@@ -838,6 +871,7 @@ static void group_free_queue(struct panthor_group *group, struct panthor_queue *
 
 	panthor_kernel_bo_destroy(queue->ringbuf);
 	panthor_kernel_bo_destroy(queue->iface.mem);
+	panthor_kernel_bo_destroy(queue->profiling_info.slots);
 
 	/* Release the last_fence we were holding, if any. */
 	dma_fence_put(queue->fence_ctx.last_fence);
@@ -1982,8 +2016,6 @@ tick_ctx_init(struct panthor_scheduler *sched,
 	}
 }
 
-#define NUM_INSTRS_PER_SLOT		16
-
 static void
 group_term_post_processing(struct panthor_group *group)
 {
@@ -2815,65 +2847,211 @@ static void group_sync_upd_work(struct work_struct *work)
 	group_put(group);
 }
 
-static struct dma_fence *
-queue_run_job(struct drm_sched_job *sched_job)
+struct panthor_job_ringbuf_instrs {
+	u64 buffer[MAX_INSTRS_PER_JOB];
+	u32 count;
+};
+
+struct panthor_job_instr {
+	u32 profile_mask;
+	u64 instr;
+};
+
+#define JOB_INSTR(__prof, __instr) \
+	{ \
+		.profile_mask = __prof, \
+		.instr = __instr, \
+	}
+
+static void
+copy_instrs_to_ringbuf(struct panthor_queue *queue,
+		       struct panthor_job *job,
+		       struct panthor_job_ringbuf_instrs *instrs)
+{
+	ssize_t ringbuf_size = panthor_kernel_bo_size(queue->ringbuf);
+	u32 start = job->ringbuf.start & (ringbuf_size - 1);
+	ssize_t size, written;
+
+	/*
+	 * We need to write a whole slot, including any trailing zeroes
+	 * that may come at the end of it. Also, because instrs.buffer had
+	 * been zero-initialised, there's no need to pad it with 0's
+	 */
+	instrs->count = ALIGN(instrs->count, NUM_INSTRS_PER_CACHE_LINE);
+	size = instrs->count * sizeof(u64);
+	written = min(ringbuf_size - start, size);
+
+	memcpy(queue->ringbuf->kmap + start, instrs->buffer, written);
+
+	if (written < size)
+		memcpy(queue->ringbuf->kmap,
+		       &instrs->buffer[(ringbuf_size - start)/sizeof(u64)],
+		       size - written);
+}
+
+struct panthor_job_cs_params {
+	u32 profile_mask;
+	u64 addr_reg; u64 val_reg;
+	u64 cycle_reg; u64 time_reg;
+	u64 sync_addr; u64 times_addr;
+	u64 cs_start; u64 cs_size;
+	u32 last_flush; u32 waitall_mask;
+};
+
+static void
+get_job_cs_params(struct panthor_job *job, struct panthor_job_cs_params *params)
 {
-	struct panthor_job *job = container_of(sched_job, struct panthor_job, base);
 	struct panthor_group *group = job->group;
 	struct panthor_queue *queue = group->queues[job->queue_idx];
 	struct panthor_device *ptdev = group->ptdev;
 	struct panthor_scheduler *sched = ptdev->scheduler;
-	u32 ringbuf_size = panthor_kernel_bo_size(queue->ringbuf);
-	u32 ringbuf_insert = queue->iface.input->insert & (ringbuf_size - 1);
-	u64 addr_reg = ptdev->csif_info.cs_reg_count -
-		       ptdev->csif_info.unpreserved_cs_reg_count;
-	u64 val_reg = addr_reg + 2;
-	u64 sync_addr = panthor_kernel_bo_gpuva(group->syncobjs) +
-			job->queue_idx * sizeof(struct panthor_syncobj_64b);
-	u32 waitall_mask = GENMASK(sched->sb_slot_count - 1, 0);
-	struct dma_fence *done_fence;
-	int ret;
 
-	u64 call_instrs[NUM_INSTRS_PER_SLOT] = {
+	params->addr_reg = ptdev->csif_info.cs_reg_count -
+			   ptdev->csif_info.unpreserved_cs_reg_count;
+	params->val_reg = params->addr_reg + 2;
+	params->cycle_reg = params->addr_reg;
+	params->time_reg = params->val_reg;
+
+	params->sync_addr = panthor_kernel_bo_gpuva(group->syncobjs) +
+			    job->queue_idx * sizeof(struct panthor_syncobj_64b);
+	params->times_addr = panthor_kernel_bo_gpuva(queue->profiling_info.slots) +
+			     (job->profiling_slot * sizeof(struct panthor_job_profiling_data));
+	params->waitall_mask = GENMASK(sched->sb_slot_count - 1, 0);
+
+	params->cs_start = job->call_info.start;
+	params->cs_size = job->call_info.size;
+	params->last_flush = job->call_info.latest_flush;
+
+	params->profile_mask = job->profile_mask;
+}
+
+static void
+prepare_job_instrs(const struct panthor_job_cs_params *params,
+		   struct panthor_job_ringbuf_instrs *instrs)
+{
+	const struct panthor_job_instr instr_seq[] = {
 		/* MOV32 rX+2, cs.latest_flush */
-		(2ull << 56) | (val_reg << 48) | job->call_info.latest_flush,
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_DISABLED,
+			  (2ull << 56) | (params->val_reg << 48) | params->last_flush),
 
 		/* FLUSH_CACHE2.clean_inv_all.no_wait.signal(0) rX+2 */
-		(36ull << 56) | (0ull << 48) | (val_reg << 40) | (0 << 16) | 0x233,
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_DISABLED,
+			  (36ull << 56) | (0ull << 48) | (params->val_reg << 40) | (0 << 16) | 0x233),
+
+		/* MOV48 rX:rX+1, cycles_offset */
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_CYCLES,
+			  (1ull << 56) | (params->cycle_reg << 48) |
+			  (params->times_addr +
+			   offsetof(struct panthor_job_profiling_data, cycles.before))),
+		/* STORE_STATE cycles */
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_CYCLES,
+			  (40ull << 56) | (params->cycle_reg << 40) | (1ll << 32)),
+		/* MOV48 rX:rX+1, time_offset */
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_TIMESTAMP,
+			  (1ull << 56) | (params->time_reg << 48) |
+			  (params->times_addr +
+			   offsetof(struct panthor_job_profiling_data, time.before))),
+		/* STORE_STATE timer */
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_TIMESTAMP,
+			  (40ull << 56) | (params->time_reg << 40) | (0ll << 32)),
 
 		/* MOV48 rX:rX+1, cs.start */
-		(1ull << 56) | (addr_reg << 48) | job->call_info.start,
-
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_DISABLED,
+			  (1ull << 56) | (params->addr_reg << 48) | params->cs_start),
 		/* MOV32 rX+2, cs.size */
-		(2ull << 56) | (val_reg << 48) | job->call_info.size,
-
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_DISABLED,
+			  (2ull << 56) | (params->val_reg << 48) | params->cs_size),
 		/* WAIT(0) => waits for FLUSH_CACHE2 instruction */
-		(3ull << 56) | (1 << 16),
-
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_DISABLED, (3ull << 56) | (1 << 16)),
 		/* CALL rX:rX+1, rX+2 */
-		(32ull << 56) | (addr_reg << 40) | (val_reg << 32),
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_DISABLED,
+			  (32ull << 56) | (params->addr_reg << 40) | (params->val_reg << 32)),
+
+		/* MOV48 rX:rX+1, cycles_offset */
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_CYCLES,
+			  (1ull << 56) | (params->cycle_reg << 48) |
+			  (params->times_addr +
+			   offsetof(struct panthor_job_profiling_data, cycles.after))),
+		/* STORE_STATE cycles */
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_CYCLES,
+			  (40ull << 56) | (params->cycle_reg << 40) | (1ll << 32)),
+
+		/* MOV48 rX:rX+1, time_offset */
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_TIMESTAMP,
+			  (1ull << 56) | (params->time_reg << 48) |
+			  (params->times_addr +
+			   offsetof(struct panthor_job_profiling_data, time.after))),
+		/* STORE_STATE timer */
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_TIMESTAMP,
+			  (40ull << 56) | (params->time_reg << 40) | (0ll << 32)),
 
 		/* MOV48 rX:rX+1, sync_addr */
-		(1ull << 56) | (addr_reg << 48) | sync_addr,
-
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_DISABLED,
+			  (1ull << 56) | (params->addr_reg << 48) | params->sync_addr),
 		/* MOV48 rX+2, #1 */
-		(1ull << 56) | (val_reg << 48) | 1,
-
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_DISABLED,
+			  (1ull << 56) | (params->val_reg << 48) | 1),
 		/* WAIT(all) */
-		(3ull << 56) | (waitall_mask << 16),
-
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_DISABLED,
+			  (3ull << 56) | (params->waitall_mask << 16)),
 		/* SYNC_ADD64.system_scope.propage_err.nowait rX:rX+1, rX+2*/
-		(51ull << 56) | (0ull << 48) | (addr_reg << 40) | (val_reg << 32) | (0 << 16) | 1,
-
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_DISABLED,
+			  (51ull << 56) | (0ull << 48) | (params->addr_reg << 40) |
+			  (params->val_reg << 32) | (0 << 16) | 1),
 		/* ERROR_BARRIER, so we can recover from faults at job
 		 * boundaries.
 		 */
-		(47ull << 56),
+		JOB_INSTR(PANTHOR_DEVICE_PROFILING_DISABLED, (47ull << 56)),
+	};
+	u32 pad;
+
+	/* NEED to be cacheline aligned to please the prefetcher. */
+	static_assert(sizeof(instrs->buffer) % 64 == 0,
+		      "panthor_job_ringbuf_instrs::buffer is not aligned on a cacheline");
+
+	/* Make sure we have enough storage to store the whole sequence. */
+	static_assert(ALIGN(ARRAY_SIZE(instr_seq), NUM_INSTRS_PER_CACHE_LINE) <=
+		      ARRAY_SIZE(instrs->buffer),
+		      "instr_seq vs panthor_job_ringbuf_instrs::buffer size mismatch");
+
+	for (u32 i = 0; i < ARRAY_SIZE(instr_seq); i++) {
+		/* If the profile mask of this instruction is not enabled, skip it. */
+		if (instr_seq[i].profile_mask &&
+		    !(instr_seq[i].profile_mask & params->profile_mask))
+			continue;
+
+		instrs->buffer[instrs->count++] = instr_seq[i].instr;
+	}
+
+	pad = ALIGN(instrs->count, NUM_INSTRS_PER_CACHE_LINE);
+	memset(&instrs->buffer[instrs->count], 0,
+	       (pad - instrs->count) * sizeof(instrs->buffer[0]));
+	instrs->count = pad;
+}
+
+static u32 calc_job_credits(u32 profile_mask)
+{
+	struct panthor_job_ringbuf_instrs instrs;
+	struct panthor_job_cs_params params = {
+		.profile_mask = profile_mask,
 	};
 
-	/* Need to be cacheline aligned to please the prefetcher. */
-	static_assert(sizeof(call_instrs) % 64 == 0,
-		      "call_instrs is not aligned on a cacheline");
+	prepare_job_instrs(&params, &instrs);
+	return instrs.count;
+}
+
+static struct dma_fence *
+queue_run_job(struct drm_sched_job *sched_job)
+{
+	struct panthor_job *job = container_of(sched_job, struct panthor_job, base);
+	struct panthor_group *group = job->group;
+	struct panthor_queue *queue = group->queues[job->queue_idx];
+	struct panthor_device *ptdev = group->ptdev;
+	struct panthor_scheduler *sched = ptdev->scheduler;
+	struct panthor_job_ringbuf_instrs instrs;
+	struct panthor_job_cs_params cs_params;
+	struct dma_fence *done_fence;
+	int ret;
 
 	/* Stream size is zero, nothing to do except making sure all previously
 	 * submitted jobs are done before we signal the
@@ -2900,17 +3078,23 @@ queue_run_job(struct drm_sched_job *sched_job)
 		       queue->fence_ctx.id,
 		       atomic64_inc_return(&queue->fence_ctx.seqno));
 
-	memcpy(queue->ringbuf->kmap + ringbuf_insert,
-	       call_instrs, sizeof(call_instrs));
+	job->profiling_slot = queue->profiling_info.profiling_seqno++;
+	if (queue->profiling_info.profiling_seqno == queue->profiling_info.slot_count)
+		queue->profiling_info.profiling_seqno = 0;
+
+	job->ringbuf.start = queue->iface.input->insert;
+
+	get_job_cs_params(job, &cs_params);
+	prepare_job_instrs(&cs_params, &instrs);
+	copy_instrs_to_ringbuf(queue, job, &instrs);
+
+	job->ringbuf.end = job->ringbuf.start + (instrs.count * sizeof(u64));
 
 	panthor_job_get(&job->base);
 	spin_lock(&queue->fence_ctx.lock);
 	list_add_tail(&job->node, &queue->fence_ctx.in_flight_jobs);
 	spin_unlock(&queue->fence_ctx.lock);
 
-	job->ringbuf.start = queue->iface.input->insert;
-	job->ringbuf.end = job->ringbuf.start + sizeof(call_instrs);
-
 	/* Make sure the ring buffer is updated before the INSERT
 	 * register.
 	 */
@@ -3003,6 +3187,24 @@ static const struct drm_sched_backend_ops panthor_queue_sched_ops = {
 	.free_job = queue_free_job,
 };
 
+static u32 calc_profiling_ringbuf_num_slots(struct panthor_device *ptdev,
+				       u32 cs_ringbuf_size)
+{
+	u32 min_profiled_job_instrs = U32_MAX;
+	u32 last_flag = fls(PANTHOR_DEVICE_PROFILING_ALL);
+
+	for (u32 i = 0; i < last_flag; i++) {
+		if (BIT(i) & PANTHOR_DEVICE_PROFILING_ALL)
+			min_profiled_job_instrs =
+				min(min_profiled_job_instrs, calc_job_credits(BIT(i)));
+	}
+
+	drm_WARN_ON(&ptdev->base,
+		    !IS_ALIGNED(min_profiled_job_instrs, NUM_INSTRS_PER_CACHE_LINE));
+
+	return DIV_ROUND_UP(cs_ringbuf_size, min_profiled_job_instrs * sizeof(u64));
+}
+
 static struct panthor_queue *
 group_create_queue(struct panthor_group *group,
 		   const struct drm_panthor_queue_create *args)
@@ -3056,9 +3258,38 @@ group_create_queue(struct panthor_group *group,
 		goto err_free_queue;
 	}
 
+	queue->profiling_info.slot_count =
+		calc_profiling_ringbuf_num_slots(group->ptdev, args->ringbuf_size);
+
+	queue->profiling_info.slots =
+		panthor_kernel_bo_create(group->ptdev, group->vm,
+					 queue->profiling_info.slot_count *
+					 sizeof(struct panthor_job_profiling_data),
+					 DRM_PANTHOR_BO_NO_MMAP,
+					 DRM_PANTHOR_VM_BIND_OP_MAP_NOEXEC |
+					 DRM_PANTHOR_VM_BIND_OP_MAP_UNCACHED,
+					 PANTHOR_VM_KERNEL_AUTO_VA);
+
+	if (IS_ERR(queue->profiling_info.slots)) {
+		ret = PTR_ERR(queue->profiling_info.slots);
+		goto err_free_queue;
+	}
+
+	ret = panthor_kernel_bo_vmap(queue->profiling_info.slots);
+	if (ret)
+		goto err_free_queue;
+
+	memset(queue->profiling_info.slots->kmap, 0,
+	       queue->profiling_info.slot_count * sizeof(struct panthor_job_profiling_data));
+
+	/*
+	 * Credit limit argument tells us the total number of instructions
+	 * across all CS slots in the ringbuffer, with some jobs requiring
+	 * twice as many as others, depending on their profiling status.
+	 */
 	ret = drm_sched_init(&queue->scheduler, &panthor_queue_sched_ops,
 			     group->ptdev->scheduler->wq, 1,
-			     args->ringbuf_size / (NUM_INSTRS_PER_SLOT * sizeof(u64)),
+			     args->ringbuf_size / sizeof(u64),
 			     0, msecs_to_jiffies(JOB_TIMEOUT_MS),
 			     group->ptdev->reset.wq,
 			     NULL, "panthor-queue", group->ptdev->base.dev);
@@ -3354,6 +3585,7 @@ panthor_job_create(struct panthor_file *pfile,
 {
 	struct panthor_group_pool *gpool = pfile->groups;
 	struct panthor_job *job;
+	u32 credits;
 	int ret;
 
 	if (qsubmit->pad)
@@ -3407,9 +3639,16 @@ panthor_job_create(struct panthor_file *pfile,
 		}
 	}
 
+	job->profile_mask = pfile->ptdev->profile_mask;
+	credits = calc_job_credits(job->profile_mask);
+	if (credits == 0) {
+		ret = -EINVAL;
+		goto err_put_job;
+	}
+
 	ret = drm_sched_job_init(&job->base,
 				 &job->group->queues[job->queue_idx]->entity,
-				 1, job->group);
+				 credits, job->group);
 	if (ret)
 		goto err_put_job;
 
-- 
2.46.0

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