drm/i915/execlists: Weak parallel submission support for execlists

A weak implementation of parallel submission (multi-bb execbuf IOCTL) for
execlists. Doing as little as possible to support this interface for
execlists - basically just passing submit fences between each request
generated and virtual engines are not allowed. This is on par with what
is there for the existing (hopefully soon deprecated) bonding interface.

We perma-pin these execlists contexts to align with GuC implementation.

v2:
 (John Harrison)
  - Drop siblings array as num_siblings must be 1
v3:
 (John Harrison)
  - Drop single submission
v4:
 (John Harrison)
  - Actually drop single submission
  - Use IS_ERR check on return value from intel_context_create
  - Set last request to NULL on unpin

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211222223532.28698-1-matthew.brost@intel.com

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 1f8d7bb32d3938e618141f3ebb822b30e6ebd68c..db4d03a357195b56f9b00e42b71ea63397dc8d1d 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -570,10 +570,6 @@ set_proto_ctx_engines_parallel_submit(struct i915_user_extension __user *base,
        struct intel_engine_cs **siblings = NULL;
        intel_engine_mask_t prev_mask;
 
-       /* FIXME: This is NIY for execlists */
-       if (!(intel_uc_uses_guc_submission(&to_gt(i915)->uc)))
-               return -ENODEV;
-
        if (get_user(slot, &ext->engine_index))
                return -EFAULT;
 
@@ -583,6 +579,13 @@ set_proto_ctx_engines_parallel_submit(struct i915_user_extension __user *base,
        if (get_user(num_siblings, &ext->num_siblings))
                return -EFAULT;
 
+       if (!intel_uc_uses_guc_submission(&to_gt(i915)->uc) &&
+           num_siblings != 1) {
+               drm_dbg(&i915->drm, "Only 1 sibling (%d) supported in non-GuC mode\n",
+                       num_siblings);
+               return -EINVAL;
+       }
+
        if (slot >= set->num_engines) {
                drm_dbg(&i915->drm, "Invalid placement value, %d >= %d\n",
                        slot, set->num_engines);

diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index ba083d800a0894f1b5faafd0c3acc341cbf24c8f..5d0ec7c49b6a5dbe358cf4ca593cf9e964ab1fd6 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -79,7 +79,8 @@ static int intel_context_active_acquire(struct intel_context *ce)
 
        __i915_active_acquire(&ce->active);
 
-       if (intel_context_is_barrier(ce) || intel_engine_uses_guc(ce->engine))
+       if (intel_context_is_barrier(ce) || intel_engine_uses_guc(ce->engine) ||
+           intel_context_is_parallel(ce))
                return 0;
 
        /* Preallocate tracking nodes */
@@ -563,7 +564,6 @@ void intel_context_bind_parent_child(struct intel_context *parent,
         * Callers responsibility to validate that this function is used
         * correctly but we use GEM_BUG_ON here ensure that they do.
         */
-       GEM_BUG_ON(!intel_engine_uses_guc(parent->engine));
        GEM_BUG_ON(intel_context_is_pinned(parent));
        GEM_BUG_ON(intel_context_is_child(parent));
        GEM_BUG_ON(intel_context_is_pinned(child));

diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index a69df5e9e77af6840d9a1afe71284d7bf476f7e5..be56d0b418928cdadb7e9be732c5c88b139d4e30 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -2599,6 +2599,43 @@ static void execlists_context_cancel_request(struct intel_context *ce,
                                      current->comm);
 }
 
+static struct intel_context *
+execlists_create_parallel(struct intel_engine_cs **engines,
+                         unsigned int num_siblings,
+                         unsigned int width)
+{
+       struct intel_context *parent = NULL, *ce, *err;
+       int i;
+
+       GEM_BUG_ON(num_siblings != 1);
+
+       for (i = 0; i < width; ++i) {
+               ce = intel_context_create(engines[i]);
+               if (IS_ERR(ce)) {
+                       err = ce;
+                       goto unwind;
+               }
+
+               if (i == 0)
+                       parent = ce;
+               else
+                       intel_context_bind_parent_child(parent, ce);
+       }
+
+       parent->parallel.fence_context = dma_fence_context_alloc(1);
+
+       intel_context_set_nopreempt(parent);
+       for_each_child(parent, ce)
+               intel_context_set_nopreempt(ce);
+
+       return parent;
+
+unwind:
+       if (parent)
+               intel_context_put(parent);
+       return err;
+}
+
 static const struct intel_context_ops execlists_context_ops = {
        .flags = COPS_HAS_INFLIGHT,
 
@@ -2617,6 +2654,7 @@ static const struct intel_context_ops execlists_context_ops = {
        .reset = lrc_reset,
        .destroy = lrc_destroy,
 
+       .create_parallel = execlists_create_parallel,
        .create_virtual = execlists_create_virtual,
 };
 

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index b3489599e4deb8bfba3eaa6a8e12aaa3f2e831de..84456ffeb4cdd0222b0b8a5362a96965990baa0c 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1065,6 +1065,10 @@ lrc_pin(struct intel_context *ce,
 
 void lrc_unpin(struct intel_context *ce)
 {
+       if (unlikely(ce->parallel.last_rq)) {
+               i915_request_put(ce->parallel.last_rq);
+               ce->parallel.last_rq = NULL;
+       }
        check_redzone((void *)ce->lrc_reg_state - LRC_STATE_OFFSET,
                      ce->engine);
 }

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index 0fbf24b8d5e19c46a79529eb3c9403449d9afe7d..06ebcea3c6a2cea4c16a2283ec24a9318fa93fdd 100644 (file)
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -3248,8 +3248,6 @@ static void guc_parent_context_unpin(struct intel_context *ce)
        GEM_BUG_ON(!intel_context_is_parent(ce));
        GEM_BUG_ON(!intel_engine_is_virtual(ce->engine));
 
-       if (ce->parallel.last_rq)
-               i915_request_put(ce->parallel.last_rq);
        unpin_guc_id(guc, ce);
        lrc_unpin(ce);
 }