drm/i915: Stop storing ctx->user_handle

The user_handle need only be known by userspace for it to lookup the
context via the idr; internally we have no use for it.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190321140711.11190-3-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_debugfs.c

@@ -409,9 +409,8 @@ static void print_context_stats(struct seq_file *m,
 
 			rcu_read_lock();
 			task = pid_task(ctx->pid ?: file->pid, PIDTYPE_PID);
-			snprintf(name, sizeof(name), "%s/%d",
-				 task ? task->comm : "<unknown>",
-				 ctx->user_handle);
+			snprintf(name, sizeof(name), "%s",
+				 task ? task->comm : "<unknown>");
 			rcu_read_unlock();
 
 			print_file_stats(m, name, stats);

drivers/gpu/drm/i915/i915_gem_context.c

@@ -602,20 +602,15 @@ static int gem_context_register(struct i915_gem_context *ctx,
 
 	/* And finally expose ourselves to userspace via the idr */
 	mutex_lock(&fpriv->context_idr_lock);
-	ret = idr_alloc(&fpriv->context_idr, ctx,
-			DEFAULT_CONTEXT_HANDLE, 0, GFP_KERNEL);
-	if (ret >= 0)
-		ctx->user_handle = ret;
+	ret = idr_alloc(&fpriv->context_idr, ctx, 0, 0, GFP_KERNEL);
 	mutex_unlock(&fpriv->context_idr_lock);
-	if (ret < 0)
-		goto err_name;
+	if (ret >= 0)
+		goto out;
 
-	return 0;
-
-err_name:
 	kfree(fetch_and_zero(&ctx->name));
 err_pid:
 	put_pid(fetch_and_zero(&ctx->pid));
+out:
 	return ret;
 }
 
@@ -638,11 +633,11 @@ int i915_gem_context_open(struct drm_i915_private *i915,
 	}
 
 	err = gem_context_register(ctx, file_priv);
-	if (err)
+	if (err < 0)
 		goto err_ctx;
 
-	GEM_BUG_ON(ctx->user_handle != DEFAULT_CONTEXT_HANDLE);
 	GEM_BUG_ON(i915_gem_context_is_kernel(ctx));
+	GEM_BUG_ON(err > 0);
 
 	return 0;
 
@@ -852,10 +847,10 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
 		return PTR_ERR(ctx);
 
 	ret = gem_context_register(ctx, file_priv);
-	if (ret)
+	if (ret < 0)
 		goto err_ctx;
 
-	args->ctx_id = ctx->user_handle;
+	args->ctx_id = ret;
 	DRM_DEBUG("HW context %d created\n", args->ctx_id);
 
 	return 0;
@@ -877,7 +872,7 @@ int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
 	if (args->pad != 0)
 		return -EINVAL;
 
-	if (args->ctx_id == DEFAULT_CONTEXT_HANDLE)
+	if (!args->ctx_id)
 		return -ENOENT;
 
 	if (mutex_lock_interruptible(&file_priv->context_idr_lock))

drivers/gpu/drm/i915/i915_gem_context.h

@@ -126,11 +126,6 @@ static inline void i915_gem_context_unpin_hw_id(struct i915_gem_context *ctx)
 	atomic_dec(&ctx->hw_id_pin_count);
 }
 
-static inline bool i915_gem_context_is_default(const struct i915_gem_context *c)
-{
-	return c->user_handle == DEFAULT_CONTEXT_HANDLE;
-}
-
 static inline bool i915_gem_context_is_kernel(struct i915_gem_context *ctx)
 {
 	return !ctx->file_priv;

drivers/gpu/drm/i915/i915_gem_context_types.h

@@ -129,15 +129,6 @@ struct i915_gem_context {
 	struct list_head active_engines;
 	struct mutex mutex;
 
-	/**
-	 * @user_handle: userspace identifier
-	 *
-	 * A unique per-file identifier is generated from
-	 * &drm_i915_file_private.contexts.
-	 */
-	u32 user_handle;
-#define DEFAULT_CONTEXT_HANDLE 0
-
 	struct i915_sched_attr sched;
 
 	/** hw_contexts: per-engine logical HW state */

drivers/gpu/drm/i915/i915_gpu_error.c

@@ -454,8 +454,8 @@ static void error_print_context(struct drm_i915_error_state_buf *m,
 				const char *header,
 				const struct drm_i915_error_context *ctx)
 {
-	err_printf(m, "%s%s[%d] user_handle %d hw_id %d, prio %d, guilty %d active %d\n",
-		   header, ctx->comm, ctx->pid, ctx->handle, ctx->hw_id,
+	err_printf(m, "%s%s[%d] hw_id %d, prio %d, guilty %d active %d\n",
+		   header, ctx->comm, ctx->pid, ctx->hw_id,
 		   ctx->sched_attr.priority, ctx->guilty, ctx->active);
 }
 
@@ -758,11 +758,9 @@ static void __err_print_to_sgl(struct drm_i915_error_state_buf *m,
 		if (obj) {
 			err_puts(m, m->i915->engine[i]->name);
 			if (ee->context.pid)
-				err_printf(m, " (submitted by %s [%d], ctx %d [%d])",
+				err_printf(m, " (submitted by %s [%d])",
 					   ee->context.comm,
-					   ee->context.pid,
-					   ee->context.handle,
-					   ee->context.hw_id);
+					   ee->context.pid);
 			err_printf(m, " --- gtt_offset = 0x%08x %08x\n",
 				   upper_32_bits(obj->gtt_offset),
 				   lower_32_bits(obj->gtt_offset));
@@ -1330,7 +1328,6 @@ static void record_context(struct drm_i915_error_context *e,
 		rcu_read_unlock();
 	}
 
-	e->handle = ctx->user_handle;
 	e->hw_id = ctx->hw_id;
 	e->sched_attr = ctx->sched;
 	e->guilty = atomic_read(&ctx->guilty_count);

drivers/gpu/drm/i915/i915_gpu_error.h

@@ -116,7 +116,6 @@ struct i915_gpu_state {
 		struct drm_i915_error_context {
 			char comm[TASK_COMM_LEN];
 			pid_t pid;
-			u32 handle;
 			u32 hw_id;
 			int active;
 			int guilty;

drivers/gpu/drm/i915/selftests/mock_context.c

@@ -98,7 +98,7 @@ live_context(struct drm_i915_private *i915, struct drm_file *file)
 		return ctx;
 
 	err = gem_context_register(ctx, file->driver_priv);
-	if (err)
+	if (err < 0)
 		goto err_ctx;
 
 	return ctx;