drm/msm: Remove struct_mutex usage

The remaining struct_mutex usage is just to serialize various gpu
related things (submit/retire/recover/fault/etc), so replace
struct_mutex with gpu->lock.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20211109181117.591148-4-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/adreno/a5xx_debugfs.c

@@ -107,7 +107,7 @@ reset_set(void *data, u64 val)
 	 * try to reset an active GPU.
 	 */
 
-	mutex_lock(&dev->struct_mutex);
+	mutex_lock(&gpu->lock);
 
 	release_firmware(adreno_gpu->fw[ADRENO_FW_PM4]);
 	adreno_gpu->fw[ADRENO_FW_PM4] = NULL;
@@ -133,7 +133,7 @@ reset_set(void *data, u64 val)
 	gpu->funcs->recover(gpu);
 
 	pm_runtime_put_sync(&gpu->pdev->dev);
-	mutex_unlock(&dev->struct_mutex);
+	mutex_unlock(&gpu->lock);
 
 	return 0;
 }

drivers/gpu/drm/msm/adreno/adreno_device.c

@@ -408,9 +408,9 @@ struct msm_gpu *adreno_load_gpu(struct drm_device *dev)
 		return NULL;
 	}
 
-	mutex_lock(&dev->struct_mutex);
+	mutex_lock(&gpu->lock);
 	ret = msm_gpu_hw_init(gpu);
-	mutex_unlock(&dev->struct_mutex);
+	mutex_unlock(&gpu->lock);
 	pm_runtime_put_autosuspend(&pdev->dev);
 	if (ret) {
 		DRM_DEV_ERROR(dev->dev, "gpu hw init failed: %d\n", ret);

drivers/gpu/drm/msm/msm_debugfs.c

@@ -29,14 +29,14 @@ static int msm_gpu_show(struct seq_file *m, void *arg)
 	struct msm_gpu *gpu = priv->gpu;
 	int ret;
 
-	ret = mutex_lock_interruptible(&show_priv->dev->struct_mutex);
+	ret = mutex_lock_interruptible(&gpu->lock);
 	if (ret)
 		return ret;
 
 	drm_printf(&p, "%s Status:\n", gpu->name);
 	gpu->funcs->show(gpu, show_priv->state, &p);
 
-	mutex_unlock(&show_priv->dev->struct_mutex);
+	mutex_unlock(&gpu->lock);
 
 	return 0;
 }
@@ -48,9 +48,9 @@ static int msm_gpu_release(struct inode *inode, struct file *file)
 	struct msm_drm_private *priv = show_priv->dev->dev_private;
 	struct msm_gpu *gpu = priv->gpu;
 
-	mutex_lock(&show_priv->dev->struct_mutex);
+	mutex_lock(&gpu->lock);
 	gpu->funcs->gpu_state_put(show_priv->state);
-	mutex_unlock(&show_priv->dev->struct_mutex);
+	mutex_unlock(&gpu->lock);
 
 	kfree(show_priv);
 
@@ -72,7 +72,7 @@ static int msm_gpu_open(struct inode *inode, struct file *file)
 	if (!show_priv)
 		return -ENOMEM;
 
-	ret = mutex_lock_interruptible(&dev->struct_mutex);
+	ret = mutex_lock_interruptible(&gpu->lock);
 	if (ret)
 		goto free_priv;
 
@@ -81,7 +81,7 @@ static int msm_gpu_open(struct inode *inode, struct file *file)
 	show_priv->state = gpu->funcs->gpu_state_get(gpu);
 	pm_runtime_put_sync(&gpu->pdev->dev);
 
-	mutex_unlock(&dev->struct_mutex);
+	mutex_unlock(&gpu->lock);
 
 	if (IS_ERR(show_priv->state)) {
 		ret = PTR_ERR(show_priv->state);

drivers/gpu/drm/msm/msm_gpu.c

@@ -150,7 +150,7 @@ int msm_gpu_hw_init(struct msm_gpu *gpu)
 {
 	int ret;
 
-	WARN_ON(!mutex_is_locked(&gpu->dev->struct_mutex));
+	WARN_ON(!mutex_is_locked(&gpu->lock));
 
 	if (!gpu->needs_hw_init)
 		return 0;
@@ -361,7 +361,7 @@ static void recover_worker(struct kthread_work *work)
 	char *comm = NULL, *cmd = NULL;
 	int i;
 
-	mutex_lock(&dev->struct_mutex);
+	mutex_lock(&gpu->lock);
 
 	DRM_DEV_ERROR(dev->dev, "%s: hangcheck recover!\n", gpu->name);
 
@@ -442,7 +442,7 @@ static void recover_worker(struct kthread_work *work)
 		}
 	}
 
-	mutex_unlock(&dev->struct_mutex);
+	mutex_unlock(&gpu->lock);
 
 	msm_gpu_retire(gpu);
 }
@@ -450,12 +450,11 @@ static void recover_worker(struct kthread_work *work)
 static void fault_worker(struct kthread_work *work)
 {
 	struct msm_gpu *gpu = container_of(work, struct msm_gpu, fault_work);
-	struct drm_device *dev = gpu->dev;
 	struct msm_gem_submit *submit;
 	struct msm_ringbuffer *cur_ring = gpu->funcs->active_ring(gpu);
 	char *comm = NULL, *cmd = NULL;
 
-	mutex_lock(&dev->struct_mutex);
+	mutex_lock(&gpu->lock);
 
 	submit = find_submit(cur_ring, cur_ring->memptrs->fence + 1);
 	if (submit && submit->fault_dumped)
@@ -490,7 +489,7 @@ static void fault_worker(struct kthread_work *work)
 	memset(&gpu->fault_info, 0, sizeof(gpu->fault_info));
 	gpu->aspace->mmu->funcs->resume_translation(gpu->aspace->mmu);
 
-	mutex_unlock(&dev->struct_mutex);
+	mutex_unlock(&gpu->lock);
 }
 
 static void hangcheck_timer_reset(struct msm_gpu *gpu)
@@ -733,7 +732,7 @@ void msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
 	struct msm_ringbuffer *ring = submit->ring;
 	unsigned long flags;
 
-	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+	WARN_ON(!mutex_is_locked(&gpu->lock));
 
 	pm_runtime_get_sync(&gpu->pdev->dev);
 
@@ -848,6 +847,7 @@ int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev,
 
 	INIT_LIST_HEAD(&gpu->active_list);
 	mutex_init(&gpu->active_lock);
+	mutex_init(&gpu->lock);
 	kthread_init_work(&gpu->retire_work, retire_worker);
 	kthread_init_work(&gpu->recover_work, recover_worker);
 	kthread_init_work(&gpu->fault_work, fault_worker);

drivers/gpu/drm/msm/msm_gpu.h

@@ -161,13 +161,23 @@ struct msm_gpu {
 	 */
 	struct list_head active_list;
 
+	/**
+	 * lock:
+	 *
+	 * General lock for serializing all the gpu things.
+	 *
+	 * TODO move to per-ring locking where feasible (ie. submit/retire
+	 * path, etc)
+	 */
+	struct mutex lock;
+
 	/**
 	 * active_submits:
 	 *
 	 * The number of submitted but not yet retired submits, used to
 	 * determine transitions between active and idle.
 	 *
-	 * Protected by lock
+	 * Protected by active_lock
 	 */
 	int active_submits;
 
@@ -548,28 +558,28 @@ static inline struct msm_gpu_state *msm_gpu_crashstate_get(struct msm_gpu *gpu)
 {
 	struct msm_gpu_state *state = NULL;
 
-	mutex_lock(&gpu->dev->struct_mutex);
+	mutex_lock(&gpu->lock);
 
 	if (gpu->crashstate) {
 		kref_get(&gpu->crashstate->ref);
 		state = gpu->crashstate;
 	}
 
-	mutex_unlock(&gpu->dev->struct_mutex);
+	mutex_unlock(&gpu->lock);
 
 	return state;
 }
 
 static inline void msm_gpu_crashstate_put(struct msm_gpu *gpu)
 {
-	mutex_lock(&gpu->dev->struct_mutex);
+	mutex_lock(&gpu->lock);
 
 	if (gpu->crashstate) {
 		if (gpu->funcs->gpu_state_put(gpu->crashstate))
 			gpu->crashstate = NULL;
 	}
 
-	mutex_unlock(&gpu->dev->struct_mutex);
+	mutex_unlock(&gpu->lock);
 }
 
 /*

drivers/gpu/drm/msm/msm_perf.c

@@ -155,9 +155,12 @@ static int perf_open(struct inode *inode, struct file *file)
 	struct msm_gpu *gpu = priv->gpu;
 	int ret = 0;
 
-	mutex_lock(&dev->struct_mutex);
+	if (!gpu)
+		return -ENODEV;
 
-	if (perf->open || !gpu) {
+	mutex_lock(&gpu->lock);
+
+	if (perf->open) {
 		ret = -EBUSY;
 		goto out;
 	}
@@ -171,7 +174,7 @@ static int perf_open(struct inode *inode, struct file *file)
 	perf->next_jiffies = jiffies + SAMPLE_TIME;
 
 out:
-	mutex_unlock(&dev->struct_mutex);
+	mutex_unlock(&gpu->lock);
 	return ret;
 }
 

drivers/gpu/drm/msm/msm_rd.c

@@ -86,7 +86,7 @@ struct msm_rd_state {
 	struct msm_gem_submit *submit;
 
 	/* fifo access is synchronized on the producer side by
-	 * struct_mutex held by submit code (otherwise we could
+	 * gpu->lock held by submit code (otherwise we could
 	 * end up w/ cmds logged in different order than they
 	 * were executed).  And read_lock synchronizes the reads
 	 */
@@ -181,9 +181,12 @@ static int rd_open(struct inode *inode, struct file *file)
 	uint32_t gpu_id;
 	int ret = 0;
 
-	mutex_lock(&dev->struct_mutex);
+	if (!gpu)
+		return -ENODEV;
 
-	if (rd->open || !gpu) {
+	mutex_lock(&gpu->lock);
+
+	if (rd->open) {
 		ret = -EBUSY;
 		goto out;
 	}
@@ -200,7 +203,7 @@ static int rd_open(struct inode *inode, struct file *file)
 	rd_write_section(rd, RD_GPU_ID, &gpu_id, sizeof(gpu_id));
 
 out:
-	mutex_unlock(&dev->struct_mutex);
+	mutex_unlock(&gpu->lock);
 	return ret;
 }
 
@@ -340,11 +343,10 @@ static void snapshot_buf(struct msm_rd_state *rd,
 	msm_gem_unlock(&obj->base);
 }
 
-/* called under struct_mutex */
+/* called under gpu->lock */
 void msm_rd_dump_submit(struct msm_rd_state *rd, struct msm_gem_submit *submit,
 		const char *fmt, ...)
 {
-	struct drm_device *dev = submit->dev;
 	struct task_struct *task;
 	char msg[256];
 	int i, n;
@@ -355,7 +357,7 @@ void msm_rd_dump_submit(struct msm_rd_state *rd, struct msm_gem_submit *submit,
 	/* writing into fifo is serialized by caller, and
 	 * rd->read_lock is used to serialize the reads
 	 */
-	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+	WARN_ON(!mutex_is_locked(&submit->gpu->lock));
 
 	if (fmt) {
 		va_list args;

drivers/gpu/drm/msm/msm_ringbuffer.c

@@ -21,11 +21,11 @@ static struct dma_fence *msm_job_run(struct drm_sched_job *job)
 	pm_runtime_get_sync(&gpu->pdev->dev);
 
 	/* TODO move submit path over to using a per-ring lock.. */
-	mutex_lock(&gpu->dev->struct_mutex);
+	mutex_lock(&gpu->lock);
 
 	msm_gpu_submit(gpu, submit);
 
-	mutex_unlock(&gpu->dev->struct_mutex);
+	mutex_unlock(&gpu->lock);
 
 	pm_runtime_put(&gpu->pdev->dev);