linux-kernel - [PATCH] accel/amdxdna: Refactor hardware context destroy routine

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Message-ID: <20250124173536.148676-1-lizhi.hou@amd.com>
Date: Fri, 24 Jan 2025 09:35:36 -0800
From: Lizhi Hou <lizhi.hou@....com>
To: <ogabbay@...nel.org>, <quic_jhugo@...cinc.com>,
	<dri-devel@...ts.freedesktop.org>
CC: Lizhi Hou <lizhi.hou@....com>, <linux-kernel@...r.kernel.org>,
	<min.ma@....com>, <max.zhen@....com>, <sonal.santan@....com>,
	<king.tam@....com>, <mario.limonciello@....com>
Subject: [PATCH] accel/amdxdna: Refactor hardware context destroy routine

It is required by firmware to wait up to 2 seconds for pending commands
before sending the destroy hardware context command. After 2 seconds
wait, if there are still pending commands, driver needs to cancel them.

So the context destroy steps need to be:
  1. Stop drm scheduler. (drm_sched_entity_destroy)
  2. Wait up to 2 seconds for pending commands.
  3. Destroy hardware context and cancel the rest pending requests.
  4. Wait all jobs associated with the hwctx are freed.
  5. Free job resources.

Signed-off-by: Lizhi Hou <lizhi.hou@....com>
---
 drivers/accel/amdxdna/aie2_ctx.c    | 29 ++++++++++++++++-------------
 drivers/accel/amdxdna/amdxdna_ctx.c |  2 ++
 drivers/accel/amdxdna/amdxdna_ctx.h |  3 +++
 3 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/drivers/accel/amdxdna/aie2_ctx.c b/drivers/accel/amdxdna/aie2_ctx.c
index 2799729801f6..88c428fa4ad1 100644
--- a/drivers/accel/amdxdna/aie2_ctx.c
+++ b/drivers/accel/amdxdna/aie2_ctx.c
@@ -34,6 +34,8 @@ static void aie2_job_release(struct kref *ref)
 
 	job = container_of(ref, struct amdxdna_sched_job, refcnt);
 	amdxdna_sched_job_cleanup(job);
+	atomic64_inc(&job->hwctx->job_free_cnt);
+	wake_up(&job->hwctx->priv->job_free_wq);
 	if (job->out_fence)
 		dma_fence_put(job->out_fence);
 	kfree(job);
@@ -134,7 +136,8 @@ static void aie2_hwctx_wait_for_idle(struct amdxdna_hwctx *hwctx)
 	if (!fence)
 		return;
 
-	dma_fence_wait(fence, false);
+	/* Wait up to 2 seconds for fw to finish all pending requests */
+	dma_fence_wait_timeout(fence, false, msecs_to_jiffies(2000));
 	dma_fence_put(fence);
 }
 
@@ -616,6 +619,7 @@ int aie2_hwctx_init(struct amdxdna_hwctx *hwctx)
 	hwctx->status = HWCTX_STAT_INIT;
 	ndev = xdna->dev_handle;
 	ndev->hwctx_num++;
+	init_waitqueue_head(&priv->job_free_wq);
 
 	XDNA_DBG(xdna, "hwctx %s init completed", hwctx->name);
 
@@ -652,25 +656,23 @@ void aie2_hwctx_fini(struct amdxdna_hwctx *hwctx)
 	xdna = hwctx->client->xdna;
 	ndev = xdna->dev_handle;
 	ndev->hwctx_num--;
-	drm_sched_wqueue_stop(&hwctx->priv->sched);
 
-	/* Now, scheduler will not send command to device. */
+	XDNA_DBG(xdna, "%s sequence number %lld", hwctx->name, hwctx->priv->seq);
+	drm_sched_entity_destroy(&hwctx->priv->entity);
+
+	aie2_hwctx_wait_for_idle(hwctx);
+
+	/* Request fw to destroy hwctx and cancel the rest pending requests */
 	aie2_release_resource(hwctx);
 
-	/*
-	 * All submitted commands are aborted.
-	 * Restart scheduler queues to cleanup jobs. The amdxdna_sched_job_run()
-	 * will return NODEV if it is called.
-	 */
-	drm_sched_wqueue_start(&hwctx->priv->sched);
+	/* Wait for all submitted jobs to be completed or canceled */
+	wait_event(hwctx->priv->job_free_wq,
+		   atomic64_read(&hwctx->job_submit_cnt) ==
+		   atomic64_read(&hwctx->job_free_cnt));
 
-	aie2_hwctx_wait_for_idle(hwctx);
-	drm_sched_entity_destroy(&hwctx->priv->entity);
 	drm_sched_fini(&hwctx->priv->sched);
 	aie2_ctx_syncobj_destroy(hwctx);
 
-	XDNA_DBG(xdna, "%s sequence number %lld", hwctx->name, hwctx->priv->seq);
-
 	for (idx = 0; idx < ARRAY_SIZE(hwctx->priv->cmd_buf); idx++)
 		drm_gem_object_put(to_gobj(hwctx->priv->cmd_buf[idx]));
 	amdxdna_gem_unpin(hwctx->priv->heap);
@@ -879,6 +881,7 @@ int aie2_cmd_submit(struct amdxdna_hwctx *hwctx, struct amdxdna_sched_job *job,
 	drm_gem_unlock_reservations(job->bos, job->bo_cnt, &acquire_ctx);
 
 	aie2_job_put(job);
+	atomic64_inc(&hwctx->job_submit_cnt);
 
 	return 0;
 
diff --git a/drivers/accel/amdxdna/amdxdna_ctx.c b/drivers/accel/amdxdna/amdxdna_ctx.c
index d11b1c83d9c3..43442b9e273b 100644
--- a/drivers/accel/amdxdna/amdxdna_ctx.c
+++ b/drivers/accel/amdxdna/amdxdna_ctx.c
@@ -220,6 +220,8 @@ int amdxdna_drm_create_hwctx_ioctl(struct drm_device *dev, void *data, struct dr
 	args->syncobj_handle = hwctx->syncobj_hdl;
 	mutex_unlock(&xdna->dev_lock);
 
+	atomic64_set(&hwctx->job_submit_cnt, 0);
+	atomic64_set(&hwctx->job_free_cnt, 0);
 	XDNA_DBG(xdna, "PID %d create HW context %d, ret %d", client->pid, args->handle, ret);
 	drm_dev_exit(idx);
 	return 0;
diff --git a/drivers/accel/amdxdna/amdxdna_ctx.h b/drivers/accel/amdxdna/amdxdna_ctx.h
index 80b0304193ec..f0a4a8586d85 100644
--- a/drivers/accel/amdxdna/amdxdna_ctx.h
+++ b/drivers/accel/amdxdna/amdxdna_ctx.h
@@ -87,6 +87,9 @@ struct amdxdna_hwctx {
 	struct amdxdna_qos_info		     qos;
 	struct amdxdna_hwctx_param_config_cu *cus;
 	u32				syncobj_hdl;
+
+	atomic64_t			job_submit_cnt;
+	atomic64_t			job_free_cnt ____cacheline_aligned_in_smp;
 };
 
 #define drm_job_to_xdna_job(j) \
-- 
2.34.1