diff options
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem_context.c | 2 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/intel_lrc.c | 50 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/selftests/intel_lrc.c | 180 |
3 files changed, 217 insertions, 15 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index fe7ddb1f59e1..f8c94405670b 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -562,7 +562,7 @@ static void init_contexts(struct drm_i915_private *i915) static bool needs_preempt_context(struct drm_i915_private *i915) { - return HAS_LOGICAL_RING_PREEMPTION(i915); + return HAS_EXECLISTS(i915); } int i915_gem_contexts_init(struct drm_i915_private *dev_priv) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index bec232acc8d7..b662a054f228 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -233,7 +233,7 @@ static inline bool need_preempt(const struct intel_engine_cs *engine, { int last_prio; - if (!intel_engine_has_preemption(engine)) + if (!engine->preempt_context) return false; if (i915_request_completed(rq)) @@ -2035,7 +2035,7 @@ static int gen8_emit_bb_start(struct i915_request *rq, { u32 *cs; - cs = intel_ring_begin(rq, 6); + cs = intel_ring_begin(rq, 4); if (IS_ERR(cs)) return PTR_ERR(cs); @@ -2046,19 +2046,37 @@ static int gen8_emit_bb_start(struct i915_request *rq, * particular all the gen that do not need the w/a at all!), if we * took care to make sure that on every switch into this context * (both ordinary and for preemption) that arbitrartion was enabled - * we would be fine. However, there doesn't seem to be a downside to - * being paranoid and making sure it is set before each batch and - * every context-switch. - * - * Note that if we fail to enable arbitration before the request - * is complete, then we do not see the context-switch interrupt and - * the engine hangs (with RING_HEAD == RING_TAIL). - * - * That satisfies both the GPGPU w/a and our heavy-handed paranoia. + * we would be fine. However, for gen8 there is another w/a that + * requires us to not preempt inside GPGPU execution, so we keep + * arbitration disabled for gen8 batches. Arbitration will be + * re-enabled before we close the request + * (engine->emit_fini_breadcrumb). */ + *cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE; + + /* FIXME(BDW+): Address space and security selectors. */ + *cs++ = MI_BATCH_BUFFER_START_GEN8 | + (flags & I915_DISPATCH_SECURE ? 0 : BIT(8)); + *cs++ = lower_32_bits(offset); + *cs++ = upper_32_bits(offset); + + intel_ring_advance(rq, cs); + + return 0; +} + +static int gen9_emit_bb_start(struct i915_request *rq, + u64 offset, u32 len, + const unsigned int flags) +{ + u32 *cs; + + cs = intel_ring_begin(rq, 6); + if (IS_ERR(cs)) + return PTR_ERR(cs); + *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; - /* FIXME(BDW): Address space and security selectors. */ *cs++ = MI_BATCH_BUFFER_START_GEN8 | (flags & I915_DISPATCH_SECURE ? 0 : BIT(8)); *cs++ = lower_32_bits(offset); @@ -2316,7 +2334,8 @@ void intel_execlists_set_default_submission(struct intel_engine_cs *engine) engine->flags |= I915_ENGINE_SUPPORTS_STATS; if (!intel_vgpu_active(engine->i915)) engine->flags |= I915_ENGINE_HAS_SEMAPHORES; - if (engine->preempt_context) + if (engine->preempt_context && + HAS_LOGICAL_RING_PREEMPTION(engine->i915)) engine->flags |= I915_ENGINE_HAS_PREEMPTION; } @@ -2350,7 +2369,10 @@ logical_ring_default_vfuncs(struct intel_engine_cs *engine) * until a more refined solution exists. */ } - engine->emit_bb_start = gen8_emit_bb_start; + if (IS_GEN(engine->i915, 8)) + engine->emit_bb_start = gen8_emit_bb_start; + else + engine->emit_bb_start = gen9_emit_bb_start; } static inline void diff --git a/drivers/gpu/drm/i915/selftests/intel_lrc.c b/drivers/gpu/drm/i915/selftests/intel_lrc.c index 0d3cae564db8..8bcd4e1d58ee 100644 --- a/drivers/gpu/drm/i915/selftests/intel_lrc.c +++ b/drivers/gpu/drm/i915/selftests/intel_lrc.c @@ -76,6 +76,185 @@ err_unlock: return err; } +static int live_busywait_preempt(void *arg) +{ + struct drm_i915_private *i915 = arg; + struct i915_gem_context *ctx_hi, *ctx_lo; + struct intel_engine_cs *engine; + struct drm_i915_gem_object *obj; + struct i915_vma *vma; + enum intel_engine_id id; + intel_wakeref_t wakeref; + int err = -ENOMEM; + u32 *map; + + /* + * Verify that even without HAS_LOGICAL_RING_PREEMPTION, we can + * preempt the busywaits used to synchronise between rings. + */ + + mutex_lock(&i915->drm.struct_mutex); + wakeref = intel_runtime_pm_get(i915); + + ctx_hi = kernel_context(i915); + if (!ctx_hi) + goto err_unlock; + ctx_hi->sched.priority = INT_MAX; + + ctx_lo = kernel_context(i915); + if (!ctx_lo) + goto err_ctx_hi; + ctx_lo->sched.priority = INT_MIN; + + obj = i915_gem_object_create_internal(i915, PAGE_SIZE); + if (IS_ERR(obj)) { + err = PTR_ERR(obj); + goto err_ctx_lo; + } + + map = i915_gem_object_pin_map(obj, I915_MAP_WC); + if (IS_ERR(map)) { + err = PTR_ERR(map); + goto err_obj; + } + + vma = i915_vma_instance(obj, &i915->ggtt.vm, 0); + if (IS_ERR(vma)) { + err = PTR_ERR(vma); + goto err_map; + } + + err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL); + if (err) + goto err_map; + + for_each_engine(engine, i915, id) { + struct i915_request *lo, *hi; + struct igt_live_test t; + u32 *cs; + + if (!intel_engine_can_store_dword(engine)) + continue; + + if (igt_live_test_begin(&t, i915, __func__, engine->name)) { + err = -EIO; + goto err_vma; + } + + /* + * We create two requests. The low priority request + * busywaits on a semaphore (inside the ringbuffer where + * is should be preemptible) and the high priority requests + * uses a MI_STORE_DWORD_IMM to update the semaphore value + * allowing the first request to complete. If preemption + * fails, we hang instead. + */ + + lo = i915_request_alloc(engine, ctx_lo); + if (IS_ERR(lo)) { + err = PTR_ERR(lo); + goto err_vma; + } + + cs = intel_ring_begin(lo, 8); + if (IS_ERR(cs)) { + err = PTR_ERR(cs); + i915_request_add(lo); + goto err_vma; + } + + *cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT; + *cs++ = i915_ggtt_offset(vma); + *cs++ = 0; + *cs++ = 1; + + /* XXX Do we need a flush + invalidate here? */ + + *cs++ = MI_SEMAPHORE_WAIT | + MI_SEMAPHORE_GLOBAL_GTT | + MI_SEMAPHORE_POLL | + MI_SEMAPHORE_SAD_EQ_SDD; + *cs++ = 0; + *cs++ = i915_ggtt_offset(vma); + *cs++ = 0; + + intel_ring_advance(lo, cs); + i915_request_add(lo); + + if (wait_for(READ_ONCE(*map), 10)) { + err = -ETIMEDOUT; + goto err_vma; + } + + /* Low priority request should be busywaiting now */ + if (i915_request_wait(lo, I915_WAIT_LOCKED, 1) != -ETIME) { + pr_err("%s: Busywaiting request did not!\n", + engine->name); + err = -EIO; + goto err_vma; + } + + hi = i915_request_alloc(engine, ctx_hi); + if (IS_ERR(hi)) { + err = PTR_ERR(hi); + goto err_vma; + } + + cs = intel_ring_begin(hi, 4); + if (IS_ERR(cs)) { + err = PTR_ERR(cs); + i915_request_add(hi); + goto err_vma; + } + + *cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT; + *cs++ = i915_ggtt_offset(vma); + *cs++ = 0; + *cs++ = 0; + + intel_ring_advance(hi, cs); + i915_request_add(hi); + + if (i915_request_wait(lo, I915_WAIT_LOCKED, HZ / 5) < 0) { + struct drm_printer p = drm_info_printer(i915->drm.dev); + + pr_err("%s: Failed to preempt semaphore busywait!\n", + engine->name); + + intel_engine_dump(engine, &p, "%s\n", engine->name); + GEM_TRACE_DUMP(); + + i915_gem_set_wedged(i915); + err = -EIO; + goto err_vma; + } + GEM_BUG_ON(READ_ONCE(*map)); + + if (igt_live_test_end(&t)) { + err = -EIO; + goto err_vma; + } + } + + err = 0; +err_vma: + i915_vma_unpin(vma); +err_map: + i915_gem_object_unpin_map(obj); +err_obj: + i915_gem_object_put(obj); +err_ctx_lo: + kernel_context_close(ctx_lo); +err_ctx_hi: + kernel_context_close(ctx_hi); +err_unlock: + if (igt_flush_test(i915, I915_WAIT_LOCKED)) + err = -EIO; + intel_runtime_pm_put(i915, wakeref); + mutex_unlock(&i915->drm.struct_mutex); + return err; +} + static int live_preempt(void *arg) { struct drm_i915_private *i915 = arg; @@ -1127,6 +1306,7 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915) { static const struct i915_subtest tests[] = { SUBTEST(live_sanitycheck), + SUBTEST(live_busywait_preempt), SUBTEST(live_preempt), SUBTEST(live_late_preempt), SUBTEST(live_suppress_self_preempt), |