From 0a3cd8d8f8a261ae75d1668df363df455f5e69c4 Mon Sep 17 00:00:00 2001
From: Jason Ekstrand <jason@jlekstrand.net>
Date: Thu, 8 Jul 2021 10:48:27 -0500
Subject: drm/i915/gem: Return an error ptr from context_lookup
Git-commit: 046d1660daee31e49b20df538ca9e2c22bd2bfb3
Patch-mainline: v5.15-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

We're about to start doing lazy context creation which means contexts
get created in i915_gem_context_lookup and we may start having more
errors than -ENOENT.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210708154835.528166-23-jason@jlekstrand.net
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c    | 12 ++++++------
 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c |  4 ++--
 drivers/gpu/drm/i915/i915_drv.h                |  2 +-
 drivers/gpu/drm/i915/i915_perf.c               |  4 ++--
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 4972b8c91d94..7045e3afa711 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -2636,8 +2636,8 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
 	int ret = 0;
 
 	ctx = i915_gem_context_lookup(file_priv, args->ctx_id);
-	if (!ctx)
-		return -ENOENT;
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
 
 	switch (args->param) {
 	case I915_CONTEXT_PARAM_GTT_SIZE:
@@ -2705,8 +2705,8 @@ int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data,
 	int ret;
 
 	ctx = i915_gem_context_lookup(file_priv, args->ctx_id);
-	if (!ctx)
-		return -ENOENT;
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
 
 	ret = ctx_setparam(file_priv, ctx, args);
 
@@ -2725,8 +2725,8 @@ int i915_gem_context_reset_stats_ioctl(struct drm_device *dev,
 		return -EINVAL;
 
 	ctx = i915_gem_context_lookup(file->driver_priv, args->ctx_id);
-	if (!ctx)
-		return -ENOENT;
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
 
 	/*
 	 * We opt for unserialised reads here. This may result in tearing
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index c6c3a05fa36f..80642c2a7b48 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -737,8 +737,8 @@ static int eb_select_context(struct i915_execbuffer *eb)
 	struct i915_gem_context *ctx;
 
 	ctx = i915_gem_context_lookup(eb->file->driver_priv, eb->args->rsvd1);
-	if (unlikely(!ctx))
-		return -ENOENT;
+	if (unlikely(IS_ERR(ctx)))
+		return PTR_ERR(ctx);
 
 	eb->gem_context = ctx;
 	if (rcu_access_pointer(ctx->vm))
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 98609f16e8ef..5fa7a08ce3a7 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1849,7 +1849,7 @@ i915_gem_context_lookup(struct drm_i915_file_private *file_priv, u32 id)
 		ctx = NULL;
 	rcu_read_unlock();
 
-	return ctx;
+	return ctx ? ctx : ERR_PTR(-ENOENT);
 }
 
 static inline struct i915_address_space *
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 9f94914958c3..b4ec114a4698 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -3414,10 +3414,10 @@ i915_perf_open_ioctl_locked(struct i915_perf *perf,
 		struct drm_i915_file_private *file_priv = file->driver_priv;
 
 		specific_ctx = i915_gem_context_lookup(file_priv, ctx_handle);
-		if (!specific_ctx) {
+		if (IS_ERR(specific_ctx)) {
 			DRM_DEBUG("Failed to look up context with ID %u for opening perf stream\n",
 				  ctx_handle);
-			ret = -ENOENT;
+			ret = PTR_ERR(specific_ctx);
 			goto err;
 		}
 	}
-- 
2.38.1