drm/i915: Extend I915_CONTEXT_PARAM_SSEU to support local ctx->engine[]

Allow the user to specify a local engine index (as opposed to
class:index) that they can use to refer to a preset engine inside the
ctx->engine[] array defined by an earlier I915_CONTEXT_PARAM_ENGINES.
This will be useful for setting SSEU parameters on virtual engines that
are local to the context and do not have a valid global class:instance
lookup.

Note that due to the ambiguity in using class:instance with
ctx->engines[], if a user supplied engine map is active the user must
specify the engine to alter by its index into the ctx->engines[].

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190521211134.16117-3-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index c501e2848ca056d996a9490df2edfd1434aa4dbc..d38d8a45a5cfb0f53093775c059396696d5f40bb 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -1363,6 +1363,7 @@ static int set_sseu(struct i915_gem_context *ctx,
        struct drm_i915_gem_context_param_sseu user_sseu;
        struct intel_context *ce;
        struct intel_sseu sseu;
+       unsigned long lookup;
        int ret;
 
        if (args->size < sizeof(user_sseu))
@@ -1375,10 +1376,17 @@ static int set_sseu(struct i915_gem_context *ctx,
                           sizeof(user_sseu)))
                return -EFAULT;
 
-       if (user_sseu.flags || user_sseu.rsvd)
+       if (user_sseu.rsvd)
                return -EINVAL;
 
-       ce = lookup_user_engine(ctx, 0, &user_sseu.engine);
+       if (user_sseu.flags & ~(I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX))
+               return -EINVAL;
+
+       lookup = 0;
+       if (user_sseu.flags & I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX)
+               lookup |= LOOKUP_USER_INDEX;
+
+       ce = lookup_user_engine(ctx, lookup, &user_sseu.engine);
        if (IS_ERR(ce))
                return PTR_ERR(ce);
 
@@ -1821,6 +1829,7 @@ static int get_sseu(struct i915_gem_context *ctx,
 {
        struct drm_i915_gem_context_param_sseu user_sseu;
        struct intel_context *ce;
+       unsigned long lookup;
        int err;
 
        if (args->size == 0)
@@ -1832,10 +1841,17 @@ static int get_sseu(struct i915_gem_context *ctx,
                           sizeof(user_sseu)))
                return -EFAULT;
 
-       if (user_sseu.flags || user_sseu.rsvd)
+       if (user_sseu.rsvd)
                return -EINVAL;
 
-       ce = lookup_user_engine(ctx, 0, &user_sseu.engine);
+       if (user_sseu.flags & ~(I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX))
+               return -EINVAL;
+
+       lookup = 0;
+       if (user_sseu.flags & I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX)
+               lookup |= LOOKUP_USER_INDEX;
+
+       ce = lookup_user_engine(ctx, lookup, &user_sseu.engine);
        if (IS_ERR(ce))
                return PTR_ERR(ce);
 

diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 8e1bb22926e48efe401ba40b64941bacc1a4d76f..82bd488ed0d1a4c9e860f921ea6adb9b26f7fa02 100644 (file)
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -1576,9 +1576,10 @@ struct drm_i915_gem_context_param_sseu {
        struct i915_engine_class_instance engine;
 
        /*
-        * Unused for now. Must be cleared to zero.
+        * Unknown flags must be cleared to zero.
         */
        __u32 flags;
+#define I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX (1u << 0)
 
        /*
         * Mask of slices to enable for the context. Valid values are a subset