[PATCH 07/21] drm/i915/gem: Set the watchdog timeout as part of intel_context creation

[Jason Ekstrand]

Instead of handling it like a context param, we add a little wrapper for
intel_context_create() whenever it's used to create a user context.
This wrapper always sets the timeout for us.  This fixes a bug where a
client could get around the timeout by swapping out the set of engines
using SETPARAM.

Signed-off-by: Jason Ekstrand <jason at jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c   | 58 ++++++-------------
 drivers/gpu/drm/i915/gt/intel_context_param.h |  3 +-
 2 files changed, 20 insertions(+), 41 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 0b35ab9509cb2..857a60469d510 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -287,6 +287,23 @@ engines_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 	return NOTIFY_DONE;
 }
 
+static struct intel_context *
+intel_user_context_create(struct drm_i915_private *i915,
+			  struct intel_engine_cs *engine)
+{
+	struct intel_context *ce = intel_context_create(engine);
+	if (IS_ERR(ce))
+		return ce;
+
+	if (IS_ACTIVE(CONFIG_DRM_I915_REQUEST_TIMEOUT) &&
+	    i915->params.request_timeout_ms) {
+		unsigned long timeout_us = i915->params.request_timeout_ms * 1000;
+		intel_context_set_watchdog_us(ce, (uintptr_t)timeout_us);
+	}
+
+	return ce;
+}
+
 static struct i915_gem_engines *alloc_engines(unsigned int count)
 {
 	struct i915_gem_engines *e;
@@ -319,7 +336,7 @@ static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx)
 		GEM_BUG_ON(engine->legacy_idx >= I915_NUM_ENGINES);
 		GEM_BUG_ON(e->engines[engine->legacy_idx]);
 
-		ce = intel_context_create(engine);
+		ce = intel_user_context_create(ctx->i915, engine);
 		if (IS_ERR(ce)) {
 			__free_engines(e, e->num_engines + 1);
 			return ERR_CAST(ce);
@@ -759,41 +776,6 @@ static void __assign_ppgtt(struct i915_gem_context *ctx,
 		i915_vm_close(vm);
 }
 
-static int __apply_watchdog(struct intel_context *ce, void *timeout_us)
-{
-	return intel_context_set_watchdog_us(ce, (uintptr_t)timeout_us);
-}
-
-static int
-__set_watchdog(struct i915_gem_context *ctx, unsigned long timeout_us)
-{
-	int ret;
-
-	ret = context_apply_all(ctx, __apply_watchdog,
-				(void *)(uintptr_t)timeout_us);
-	if (!ret)
-		ctx->watchdog.timeout_us = timeout_us;
-
-	return ret;
-}
-
-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) ||
-	    !i915->params.request_timeout_ms)
-		return;
-
-	/* Default expiry for user fences. */
-	ret = __set_watchdog(ctx, i915->params.request_timeout_ms * 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)
 {
@@ -836,8 +818,6 @@ i915_gem_create_context(struct drm_i915_private *i915, unsigned int flags)
 		}
 	}
 
-	__set_default_fence_expiry(ctx);
-
 	trace_i915_context_create(ctx);
 
 	return ctx;
@@ -1715,7 +1695,7 @@ set_engines(struct i915_gem_context *ctx,
 			return -ENOENT;
 		}
 
-		ce = intel_context_create(engine);
+		ce = intel_user_context_create(i915, engine);
 		if (IS_ERR(ce)) {
 			__free_engines(set.engines, n);
 			return PTR_ERR(ce);
diff --git a/drivers/gpu/drm/i915/gt/intel_context_param.h b/drivers/gpu/drm/i915/gt/intel_context_param.h
index dffedd983693d..0c69cb42d075c 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_param.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_param.h
@@ -10,11 +10,10 @@
 
 #include "intel_context.h"
 
-static inline int
+static inline void
 intel_context_set_watchdog_us(struct intel_context *ce, u64 timeout_us)
 {
 	ce->watchdog.timeout_us = timeout_us;
-	return 0;
 }
 
 #endif /* INTEL_CONTEXT_PARAM_H */
-- 
2.31.1