This adds a bunch of complexity which the media driver has never actually used. The media driver does technically bond a balanced engine to another engine but the balanced engine only has one engine in the sibling set. This doesn't actually result in a virtual engine.
This functionality was originally added to handle cases where we may have more than two video engines and media might want to load-balance their bonded submits by, for instance, submitting to a balanced vcs0-1 as the primary and then vcs2-3 as the secondary. However, no such hardware has shipped thus far and, if we ever want to enable such use-cases in the future, we'll use the up-and-coming parallel submit API which targets GuC submission.
This makes I915_CONTEXT_ENGINES_EXT_BOND a total no-op. We leave the validation code in place in case we ever decide we want to do something interesting with the bonding information.
v2 (Jason Ekstrand): - Don't delete quite as much code.
v3 (Tvrtko Ursulin): - Add some history to the commit message
Signed-off-by: Jason Ekstrand jason@jlekstrand.net --- drivers/gpu/drm/i915/gem/i915_gem_context.c | 18 +- .../drm/i915/gt/intel_execlists_submission.c | 69 ------ .../drm/i915/gt/intel_execlists_submission.h | 4 - drivers/gpu/drm/i915/gt/selftest_execlists.c | 229 ------------------ 4 files changed, 6 insertions(+), 314 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c index 92e55441a7621..be42dc918ef6f 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c @@ -1553,6 +1553,12 @@ set_engines__bond(struct i915_user_extension __user *base, void *data) } virtual = set->engines->engines[idx]->engine;
+ if (intel_engine_is_virtual(virtual)) { + drm_dbg(&i915->drm, + "Bonding with virtual engines not allowed\n"); + return -EINVAL; + } + err = check_user_mbz(&ext->flags); if (err) return err; @@ -1593,18 +1599,6 @@ set_engines__bond(struct i915_user_extension __user *base, void *data) n, ci.engine_class, ci.engine_instance); return -EINVAL; } - - /* - * A non-virtual engine has no siblings to choose between; and - * a submit fence will always be directed to the one engine. - */ - if (intel_engine_is_virtual(virtual)) { - err = intel_virtual_engine_attach_bond(virtual, - master, - bond); - if (err) - return err; - } }
return 0; diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c index 0e8c320927d15..14378b28169b7 100644 --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c @@ -181,18 +181,6 @@ struct virtual_engine { int prio; } nodes[I915_NUM_ENGINES];
- /* - * Keep track of bonded pairs -- restrictions upon on our selection - * of physical engines any particular request may be submitted to. - * If we receive a submit-fence from a master engine, we will only - * use one of sibling_mask physical engines. - */ - struct ve_bond { - const struct intel_engine_cs *master; - intel_engine_mask_t sibling_mask; - } *bonds; - unsigned int num_bonds; - /* And finally, which physical engines this virtual engine maps onto. */ unsigned int num_siblings; struct intel_engine_cs *siblings[]; @@ -3307,7 +3295,6 @@ static void rcu_virtual_context_destroy(struct work_struct *wrk) intel_breadcrumbs_free(ve->base.breadcrumbs); intel_engine_free_request_pool(&ve->base);
- kfree(ve->bonds); kfree(ve); }
@@ -3560,33 +3547,13 @@ static void virtual_submit_request(struct i915_request *rq) spin_unlock_irqrestore(&ve->base.active.lock, flags); }
-static struct ve_bond * -virtual_find_bond(struct virtual_engine *ve, - const struct intel_engine_cs *master) -{ - int i; - - for (i = 0; i < ve->num_bonds; i++) { - if (ve->bonds[i].master == master) - return &ve->bonds[i]; - } - - return NULL; -} - static void virtual_bond_execute(struct i915_request *rq, struct dma_fence *signal) { - struct virtual_engine *ve = to_virtual_engine(rq->engine); intel_engine_mask_t allowed, exec; - struct ve_bond *bond;
allowed = ~to_request(signal)->engine->mask;
- bond = virtual_find_bond(ve, to_request(signal)->engine); - if (bond) - allowed &= bond->sibling_mask; - /* Restrict the bonded request to run on only the available engines */ exec = READ_ONCE(rq->execution_mask); while (!try_cmpxchg(&rq->execution_mask, &exec, exec & allowed)) @@ -3736,42 +3703,6 @@ intel_execlists_create_virtual(struct intel_engine_cs **siblings, return ERR_PTR(err); }
-int intel_virtual_engine_attach_bond(struct intel_engine_cs *engine, - const struct intel_engine_cs *master, - const struct intel_engine_cs *sibling) -{ - struct virtual_engine *ve = to_virtual_engine(engine); - struct ve_bond *bond; - int n; - - /* Sanity check the sibling is part of the virtual engine */ - for (n = 0; n < ve->num_siblings; n++) - if (sibling == ve->siblings[n]) - break; - if (n == ve->num_siblings) - return -EINVAL; - - bond = virtual_find_bond(ve, master); - if (bond) { - bond->sibling_mask |= sibling->mask; - return 0; - } - - bond = krealloc(ve->bonds, - sizeof(*bond) * (ve->num_bonds + 1), - GFP_KERNEL); - if (!bond) - return -ENOMEM; - - bond[ve->num_bonds].master = master; - bond[ve->num_bonds].sibling_mask = sibling->mask; - - ve->bonds = bond; - ve->num_bonds++; - - return 0; -} - void intel_execlists_show_requests(struct intel_engine_cs *engine, struct drm_printer *m, void (*show_request)(struct drm_printer *m, diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.h b/drivers/gpu/drm/i915/gt/intel_execlists_submission.h index bab3d37cf3f98..ad4f3e1a0fded 100644 --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.h +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.h @@ -36,10 +36,6 @@ struct intel_context * intel_execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count);
-int intel_virtual_engine_attach_bond(struct intel_engine_cs *engine, - const struct intel_engine_cs *master, - const struct intel_engine_cs *sibling); - bool intel_engine_in_execlists_submission_mode(const struct intel_engine_cs *engine);
diff --git a/drivers/gpu/drm/i915/gt/selftest_execlists.c b/drivers/gpu/drm/i915/gt/selftest_execlists.c index 01d9896dd4844..a0e75b71a3374 100644 --- a/drivers/gpu/drm/i915/gt/selftest_execlists.c +++ b/drivers/gpu/drm/i915/gt/selftest_execlists.c @@ -4311,234 +4311,6 @@ static int live_virtual_preserved(void *arg) return 0; }
-static int bond_virtual_engine(struct intel_gt *gt, - unsigned int class, - struct intel_engine_cs **siblings, - unsigned int nsibling, - unsigned int flags) -#define BOND_SCHEDULE BIT(0) -{ - struct intel_engine_cs *master; - struct i915_request *rq[16]; - enum intel_engine_id id; - struct igt_spinner spin; - unsigned long n; - int err; - - /* - * A set of bonded requests is intended to be run concurrently - * across a number of engines. We use one request per-engine - * and a magic fence to schedule each of the bonded requests - * at the same time. A consequence of our current scheduler is that - * we only move requests to the HW ready queue when the request - * becomes ready, that is when all of its prerequisite fences have - * been signaled. As one of those fences is the master submit fence, - * there is a delay on all secondary fences as the HW may be - * currently busy. Equally, as all the requests are independent, - * they may have other fences that delay individual request - * submission to HW. Ergo, we do not guarantee that all requests are - * immediately submitted to HW at the same time, just that if the - * rules are abided by, they are ready at the same time as the - * first is submitted. Userspace can embed semaphores in its batch - * to ensure parallel execution of its phases as it requires. - * Though naturally it gets requested that perhaps the scheduler should - * take care of parallel execution, even across preemption events on - * different HW. (The proper answer is of course "lalalala".) - * - * With the submit-fence, we have identified three possible phases - * of synchronisation depending on the master fence: queued (not - * ready), executing, and signaled. The first two are quite simple - * and checked below. However, the signaled master fence handling is - * contentious. Currently we do not distinguish between a signaled - * fence and an expired fence, as once signaled it does not convey - * any information about the previous execution. It may even be freed - * and hence checking later it may not exist at all. Ergo we currently - * do not apply the bonding constraint for an already signaled fence, - * as our expectation is that it should not constrain the secondaries - * and is outside of the scope of the bonded request API (i.e. all - * userspace requests are meant to be running in parallel). As - * it imposes no constraint, and is effectively a no-op, we do not - * check below as normal execution flows are checked extensively above. - * - * XXX Is the degenerate handling of signaled submit fences the - * expected behaviour for userpace? - */ - - GEM_BUG_ON(nsibling >= ARRAY_SIZE(rq) - 1); - - if (igt_spinner_init(&spin, gt)) - return -ENOMEM; - - err = 0; - rq[0] = ERR_PTR(-ENOMEM); - for_each_engine(master, gt, id) { - struct i915_sw_fence fence = {}; - struct intel_context *ce; - - if (master->class == class) - continue; - - ce = intel_context_create(master); - if (IS_ERR(ce)) { - err = PTR_ERR(ce); - goto out; - } - - memset_p((void *)rq, ERR_PTR(-EINVAL), ARRAY_SIZE(rq)); - - rq[0] = igt_spinner_create_request(&spin, ce, MI_NOOP); - intel_context_put(ce); - if (IS_ERR(rq[0])) { - err = PTR_ERR(rq[0]); - goto out; - } - i915_request_get(rq[0]); - - if (flags & BOND_SCHEDULE) { - onstack_fence_init(&fence); - err = i915_sw_fence_await_sw_fence_gfp(&rq[0]->submit, - &fence, - GFP_KERNEL); - } - - i915_request_add(rq[0]); - if (err < 0) - goto out; - - if (!(flags & BOND_SCHEDULE) && - !igt_wait_for_spinner(&spin, rq[0])) { - err = -EIO; - goto out; - } - - for (n = 0; n < nsibling; n++) { - struct intel_context *ve; - - ve = intel_execlists_create_virtual(siblings, nsibling); - if (IS_ERR(ve)) { - err = PTR_ERR(ve); - onstack_fence_fini(&fence); - goto out; - } - - err = intel_virtual_engine_attach_bond(ve->engine, - master, - siblings[n]); - if (err) { - intel_context_put(ve); - onstack_fence_fini(&fence); - goto out; - } - - err = intel_context_pin(ve); - intel_context_put(ve); - if (err) { - onstack_fence_fini(&fence); - goto out; - } - - rq[n + 1] = i915_request_create(ve); - intel_context_unpin(ve); - if (IS_ERR(rq[n + 1])) { - err = PTR_ERR(rq[n + 1]); - onstack_fence_fini(&fence); - goto out; - } - i915_request_get(rq[n + 1]); - - err = i915_request_await_execution(rq[n + 1], - &rq[0]->fence, - ve->engine->bond_execute); - i915_request_add(rq[n + 1]); - if (err < 0) { - onstack_fence_fini(&fence); - goto out; - } - } - onstack_fence_fini(&fence); - intel_engine_flush_submission(master); - igt_spinner_end(&spin); - - if (i915_request_wait(rq[0], 0, HZ / 10) < 0) { - pr_err("Master request did not execute (on %s)!\n", - rq[0]->engine->name); - err = -EIO; - goto out; - } - - for (n = 0; n < nsibling; n++) { - if (i915_request_wait(rq[n + 1], 0, - MAX_SCHEDULE_TIMEOUT) < 0) { - err = -EIO; - goto out; - } - - if (rq[n + 1]->engine != siblings[n]) { - pr_err("Bonded request did not execute on target engine: expected %s, used %s; master was %s\n", - siblings[n]->name, - rq[n + 1]->engine->name, - rq[0]->engine->name); - err = -EINVAL; - goto out; - } - } - - for (n = 0; !IS_ERR(rq[n]); n++) - i915_request_put(rq[n]); - rq[0] = ERR_PTR(-ENOMEM); - } - -out: - for (n = 0; !IS_ERR(rq[n]); n++) - i915_request_put(rq[n]); - if (igt_flush_test(gt->i915)) - err = -EIO; - - igt_spinner_fini(&spin); - return err; -} - -static int live_virtual_bond(void *arg) -{ - static const struct phase { - const char *name; - unsigned int flags; - } phases[] = { - { "", 0 }, - { "schedule", BOND_SCHEDULE }, - { }, - }; - struct intel_gt *gt = arg; - struct intel_engine_cs *siblings[MAX_ENGINE_INSTANCE + 1]; - unsigned int class; - int err; - - if (intel_uc_uses_guc_submission(>->uc)) - return 0; - - for (class = 0; class <= MAX_ENGINE_CLASS; class++) { - const struct phase *p; - int nsibling; - - nsibling = select_siblings(gt, class, siblings); - if (nsibling < 2) - continue; - - for (p = phases; p->name; p++) { - err = bond_virtual_engine(gt, - class, siblings, nsibling, - p->flags); - if (err) { - pr_err("%s(%s): failed class=%d, nsibling=%d, err=%d\n", - __func__, p->name, class, nsibling, err); - return err; - } - } - } - - return 0; -} - static int reset_virtual_engine(struct intel_gt *gt, struct intel_engine_cs **siblings, unsigned int nsibling) @@ -4712,7 +4484,6 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915) SUBTEST(live_virtual_mask), SUBTEST(live_virtual_preserved), SUBTEST(live_virtual_slice), - SUBTEST(live_virtual_bond), SUBTEST(live_virtual_reset), };