[PATCH 6/7] drm/i915: Fail too long user submissions by default

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

...

10s default fence timeout

...

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/Kconfig.profile        |  8 ++++
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 46 +++++++++++++++++----
 2 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/Kconfig.profile b/drivers/gpu/drm/i915/Kconfig.profile
index 35bbe2b80596..55e157ffff73 100644
--- a/drivers/gpu/drm/i915/Kconfig.profile
+++ b/drivers/gpu/drm/i915/Kconfig.profile
@@ -1,3 +1,11 @@
+config DRM_I915_REQUEST_TIMEOUT
+	int "Default timeout for requests (ms)"
+	default 10000 # milliseconds
+	help
+	  ...
+
+	  May be 0 to disable the timeout.
+
 config DRM_I915_FENCE_TIMEOUT
 	int "Timeout for unsignaled foreign fences (ms, jiffy granularity)"
 	default 10000 # milliseconds
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index af69c27c7518..55fcc872b7c4 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -854,6 +854,25 @@ static void __assign_timeline(struct i915_gem_context *ctx,
 	context_apply_all(ctx, __apply_timeline, timeline);
 }
 
+static int
+__set_watchdog(struct i915_gem_context *ctx, unsigned long timeout_us);
+
+static void __set_default_fence_expiry(struct i915_gem_context *ctx)
+{
+	struct drm_i915_private *i915 = ctx->i915;
+	int ret;
+
+	if (!IS_ACTIVE(CONFIG_DRM_I915_REQUEST_TIMEOUT))
+		return;
+
+	/* Default expiry for user fences. */
+	ret = __set_watchdog(ctx, CONFIG_DRM_I915_REQUEST_TIMEOUT * 1000);
+	if (ret)
+		drm_notice(&i915->drm,
+			   "Failed to configure default fence expiry! (%d)",
+			   ret);
+}
+
 static struct i915_gem_context *
 i915_gem_create_context(struct drm_i915_private *i915, unsigned int flags)
 {
@@ -898,6 +917,8 @@ i915_gem_create_context(struct drm_i915_private *i915, unsigned int flags)
 		intel_timeline_put(timeline);
 	}
 
+	__set_default_fence_expiry(ctx);
+
 	trace_i915_context_create(ctx);
 
 	return ctx;
@@ -1404,20 +1425,31 @@ static int __apply_watchdog(struct intel_context *ce, void *timeout_us)
 	return intel_context_set_watchdog_us(ce, (u64)timeout_us);
 }
 
-static int set_watchdog(struct i915_gem_context *ctx,
-			struct drm_i915_gem_context_param *args)
+static int
+__set_watchdog(struct i915_gem_context *ctx, unsigned long timeout_us)
 {
 	int ret;
 
+	ret = context_apply_all(ctx, __apply_watchdog, (void *)timeout_us);
+	if (!ret)
+		ctx->watchdog.timeout_us = timeout_us;
+
+	return ret;
+}
+
+static int set_watchdog(struct i915_gem_context *ctx,
+			struct drm_i915_gem_context_param *args)
+{
 	if (args->size)
 		return -EINVAL;
 
-	ret = context_apply_all(ctx, __apply_watchdog, (void *)args->value);
-
-	if (!ret)
-		ctx->watchdog.timeout_us = args->value;
+	/* Disallow disabling or configuring longer watchdog than default. */
+	if (IS_ACTIVE(CONFIG_DRM_I915_REQUEST_TIMEOUT) &&
+	    (!args->value ||
+	     args->value > CONFIG_DRM_I915_REQUEST_TIMEOUT * 1000))
+		return -EPERM;
 
-	return ret;
+	return __set_watchdog(ctx, args->value);
 }
 
 static int __get_ringsize(struct intel_context *ce, void *arg)
-- 
2.27.0