Why sleep when you can busywait for an interrupt? Throw out the old irq handlers, and use irq_poll instead. References: https://bugs.freedesktop.org/show_bug.cgi?id=111880 Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/Kconfig | 1 + drivers/gpu/drm/i915/Kconfig.debug | 5 +++ drivers/gpu/drm/i915/gt/intel_engine_types.h | 3 ++ drivers/gpu/drm/i915/gt/intel_gt_irq.c | 13 ++++-- drivers/gpu/drm/i915/gt/intel_lrc.c | 42 ++++++++++++++++++++ drivers/gpu/drm/i915/i915_drv.h | 3 ++ drivers/gpu/drm/i915/i915_irq.c | 14 ++++++- drivers/gpu/drm/i915/i915_pci.c | 1 - include/linux/irq_poll.h | 15 ++++++- lib/irq_poll.c | 13 +++--- 10 files changed, 95 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig index 0d21402945ab..bf2b27b6ebf2 100644 --- a/drivers/gpu/drm/i915/Kconfig +++ b/drivers/gpu/drm/i915/Kconfig @@ -13,6 +13,7 @@ config DRM_I915 select DRM_PANEL select DRM_MIPI_DSI select RELAY + select IRQ_POLL select IRQ_WORK # i915 depends on ACPI_VIDEO when ACPI is enabled # but for select to work, need to select ACPI_VIDEO's dependencies, ick diff --git a/drivers/gpu/drm/i915/Kconfig.debug b/drivers/gpu/drm/i915/Kconfig.debug index 4a800faa275c..4d23a84ac2c4 100644 --- a/drivers/gpu/drm/i915/Kconfig.debug +++ b/drivers/gpu/drm/i915/Kconfig.debug @@ -44,6 +44,7 @@ config DRM_I915_DEBUG select DRM_I915_SELFTEST select DRM_I915_DEBUG_RUNTIME_PM select DRM_I915_DEBUG_MMIO + select TIGERLAKE_DEBUG_IRQ default n help Choose this option to turn on extra driver debugging that may affect @@ -220,3 +221,7 @@ config DRM_I915_DEBUG_RUNTIME_PM driver loading, suspend and resume operations. If in doubt, say "N" + +config TIGERLAKE_DEBUG_IRQ + bool "[TGL] Reduce IRQ functionality for stability" + default n diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h index 943f0663837e..53265add81ec 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h @@ -8,6 +8,7 @@ #define __INTEL_ENGINE_TYPES__ #include <linux/hashtable.h> +#include <linux/irq_poll.h> #include <linux/irq_work.h> #include <linux/kref.h> #include <linux/list.h> @@ -330,6 +331,8 @@ struct intel_engine_cs { struct drm_i915_gem_object *default_state; void *pinned_default_state; + struct irq_poll irq_poll; + struct { struct intel_ring *ring; struct intel_timeline *timeline; diff --git a/drivers/gpu/drm/i915/gt/intel_gt_irq.c b/drivers/gpu/drm/i915/gt/intel_gt_irq.c index 34a4fb624bf7..7d4c2f18576e 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_irq.c +++ b/drivers/gpu/drm/i915/gt/intel_gt_irq.c @@ -45,6 +45,9 @@ gen11_gt_engine_identity(struct intel_gt *gt, lockdep_assert_held(>->irq_lock); + if (WARN_ON(TIGERLAKE_NO_IRQ(gt->i915))) + return 0; + raw_reg_write(regs, GEN11_IIR_REG_SELECTOR(bank), BIT(bit)); /* @@ -209,12 +212,14 @@ void gen11_gt_irq_reset(struct intel_gt *gt) void gen11_gt_irq_postinstall(struct intel_gt *gt) { - const u32 irqs = GT_RENDER_USER_INTERRUPT | GT_CONTEXT_SWITCH_INTERRUPT; struct intel_uncore *uncore = gt->uncore; - const u32 dmask = irqs << 16 | irqs; - const u32 smask = irqs << 16; + u32 irqs, dmask, smask; - BUILD_BUG_ON(irqs & 0xffff0000); + irqs = GT_RENDER_USER_INTERRUPT | GT_CONTEXT_SWITCH_INTERRUPT; + if (TIGERLAKE_NO_IRQ(gt->i915)) + irqs = 0; /* XXX lalalala */ + smask = irqs << 16; + dmask = smask | irqs; /* Enable RCS, BCS, VCS and VECS class interrupts. */ intel_uncore_write(uncore, GEN11_RENDER_COPY_INTR_ENABLE, dmask); diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 431d3b8c3371..de4c494d775e 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -989,6 +989,9 @@ __execlists_schedule_in(struct i915_request *rq) execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_IN); intel_engine_context_in(engine); + if (TIGERLAKE_NO_IRQ(engine->i915)) + irq_poll_activate(&engine->irq_poll); + return engine; } @@ -1028,6 +1031,9 @@ __execlists_schedule_out(struct i915_request *rq, { struct intel_context * const ce = rq->hw_context; + if (TIGERLAKE_NO_IRQ(engine->i915)) + irq_poll_deactivate(&engine->irq_poll); + intel_engine_context_out(engine); execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_OUT); intel_gt_pm_put(engine->gt); @@ -1196,6 +1202,8 @@ static void execlists_submit_ports(struct intel_engine_cs *engine) /* we need to manually load the submit queue */ if (execlists->ctrl_reg) writel(EL_CTRL_LOAD, execlists->ctrl_reg); + + irq_poll_sched(&engine->irq_poll); } static bool ctx_single_port_submission(const struct intel_context *ce) @@ -1838,6 +1846,11 @@ gen8_csb_parse(const struct intel_engine_execlists *execlists, const u32 *csb) return *csb & (GEN8_CTX_STATUS_IDLE_ACTIVE | GEN8_CTX_STATUS_PREEMPTED); } +static inline bool has_breadcrumbs(struct i915_request *rq) +{ + return !list_empty(&rq->hw_context->signals); +} + static void process_csb(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; @@ -1940,6 +1953,10 @@ static void process_csb(struct intel_engine_cs *engine) */ GEM_BUG_ON(!i915_request_completed(*execlists->active) && !reset_in_progress(execlists)); + + if (has_breadcrumbs(*execlists->active)) + intel_engine_queue_breadcrumbs(engine); + execlists_schedule_out(*execlists->active++); GEM_BUG_ON(execlists->active - execlists->inflight > @@ -1987,6 +2004,27 @@ static void execlists_submission_tasklet(unsigned long data) } } +static int iop_handler(struct irq_poll *iop, int budget) +{ + struct intel_engine_cs *engine = + container_of(iop, typeof(*engine), irq_poll); + struct intel_engine_execlists *execlists = &engine->execlists; + struct tasklet_struct *t = &execlists->tasklet; + + if (execlists->csb_head == READ_ONCE(*execlists->csb_write)) + return 0; + + if (!tasklet_trylock(t)) + return 0; + + /* Must wait for any GPU reset in progress. */ + if (__tasklet_is_enabled(t)) + t->func(t->data); + + tasklet_unlock(t); + return 0; +} + static void execlists_submission_timer(struct timer_list *timer) { struct intel_engine_cs *engine = @@ -3446,6 +3484,7 @@ void intel_execlists_set_default_submission(struct intel_engine_cs *engine) static void execlists_destroy(struct intel_engine_cs *engine) { + irq_poll_disable(&engine->irq_poll); intel_engine_cleanup_common(engine); lrc_destroy_wa_ctx(engine); kfree(engine); @@ -3532,6 +3571,9 @@ static void rcs_submission_override(struct intel_engine_cs *engine) int intel_execlists_submission_setup(struct intel_engine_cs *engine) { + irq_poll_init(&engine->irq_poll, -1, iop_handler); + irq_poll_disable(&engine->irq_poll); + tasklet_init(&engine->execlists.tasklet, execlists_submission_tasklet, (unsigned long)engine); timer_setup(&engine->execlists.timer, execlists_submission_timer, 0); diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 337d8306416a..c505d9e38e98 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2069,6 +2069,9 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915, #define IS_GEN9_LP(dev_priv) (IS_GEN(dev_priv, 9) && IS_LP(dev_priv)) #define IS_GEN9_BC(dev_priv) (IS_GEN(dev_priv, 9) && !IS_LP(dev_priv)) +#define TIGERLAKE_NO_IRQ(i915) \ + IS_ENABLED(CONFIG_TIGERLAKE_DEBUG_IRQ) && IS_TIGERLAKE(i915) + #define HAS_ENGINE(dev_priv, id) (INTEL_INFO(dev_priv)->engine_mask & BIT(id)) #define ENGINE_INSTANCES_MASK(dev_priv, first, count) ({ \ diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index bc83f094065a..05060f829981 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -360,6 +360,9 @@ void gen6_enable_rps_interrupts(struct drm_i915_private *dev_priv) if (READ_ONCE(rps->interrupts_enabled)) return; + if (!dev_priv->pm_rps_events) + return; + spin_lock_irq(>->irq_lock); WARN_ON_ONCE(rps->pm_iir); @@ -376,7 +379,12 @@ void gen6_enable_rps_interrupts(struct drm_i915_private *dev_priv) u32 gen6_sanitize_rps_pm_mask(const struct drm_i915_private *i915, u32 mask) { - return mask & ~i915->gt_pm.rps.pm_intrmsk_mbz; + const struct intel_rps *rps = &i915->gt_pm.rps; + + if (!rps->interrupts_enabled) + return ~0u; + + return mask & ~rps->pm_intrmsk_mbz; } void gen6_disable_rps_interrupts(struct drm_i915_private *dev_priv) @@ -4314,7 +4322,9 @@ void intel_irq_init(struct drm_i915_private *dev_priv) dev_priv->gt.pm_guc_events = GUC_INTR_GUC2HOST << 16; /* Let's track the enabled rps events */ - if (IS_VALLEYVIEW(dev_priv)) + if (TIGERLAKE_NO_IRQ(dev_priv)) + dev_priv->pm_rps_events = 0; + else if (IS_VALLEYVIEW(dev_priv)) /* WaGsvRC0ResidencyMethod:vlv */ dev_priv->pm_rps_events = GEN6_PM_RP_UP_EI_EXPIRED; else diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c index 1cbf3998b361..86be10cc6a70 100644 --- a/drivers/gpu/drm/i915/i915_pci.c +++ b/drivers/gpu/drm/i915/i915_pci.c @@ -806,7 +806,6 @@ static const struct intel_device_info intel_tigerlake_12_info = { .display.has_modular_fia = 1, .engine_mask = BIT(RCS0) | BIT(BCS0) | BIT(VECS0) | BIT(VCS0) | BIT(VCS2), - .has_rps = false, /* XXX disabled for debugging */ }; #undef GEN diff --git a/include/linux/irq_poll.h b/include/linux/irq_poll.h index 16aaeccb65cb..d66d0e0e9379 100644 --- a/include/linux/irq_poll.h +++ b/include/linux/irq_poll.h @@ -2,19 +2,22 @@ #ifndef IRQ_POLL_H #define IRQ_POLL_H +#include <linux/atomic.h> +#include <linux/list.h> + struct irq_poll; typedef int (irq_poll_fn)(struct irq_poll *, int); struct irq_poll { struct list_head list; unsigned long state; + atomic_t count; int weight; irq_poll_fn *poll; }; enum { IRQ_POLL_F_SCHED = 0, - IRQ_POLL_F_DISABLE = 1, }; extern void irq_poll_sched(struct irq_poll *); @@ -23,4 +26,14 @@ extern void irq_poll_complete(struct irq_poll *); extern void irq_poll_enable(struct irq_poll *); extern void irq_poll_disable(struct irq_poll *); +static inline void irq_poll_activate(struct irq_poll *iop) +{ + atomic_inc(&iop->count); +} + +static inline void irq_poll_deactivate(struct irq_poll *iop) +{ + atomic_dec(&iop->count); +} + #endif diff --git a/lib/irq_poll.c b/lib/irq_poll.c index 2f17b488d58e..59408fa75fa6 100644 --- a/lib/irq_poll.c +++ b/lib/irq_poll.c @@ -28,8 +28,9 @@ void irq_poll_sched(struct irq_poll *iop) { unsigned long flags; - if (test_bit(IRQ_POLL_F_DISABLE, &iop->state)) + if (!atomic_read(&iop->count)) return; + if (test_and_set_bit(IRQ_POLL_F_SCHED, &iop->state)) return; @@ -122,7 +123,7 @@ static void __latent_entropy irq_poll_softirq(struct softirq_action *h) * move the instance around on the list at-will. */ if (work >= weight) { - if (test_bit(IRQ_POLL_F_DISABLE, &iop->state)) + if (!atomic_read(&iop->count)) __irq_poll_complete(iop); else list_move_tail(&iop->list, list); @@ -144,10 +145,9 @@ static void __latent_entropy irq_poll_softirq(struct softirq_action *h) **/ void irq_poll_disable(struct irq_poll *iop) { - set_bit(IRQ_POLL_F_DISABLE, &iop->state); + atomic_set_release(&iop->count, 0); while (test_and_set_bit(IRQ_POLL_F_SCHED, &iop->state)) msleep(1); - clear_bit(IRQ_POLL_F_DISABLE, &iop->state); } EXPORT_SYMBOL(irq_poll_disable); @@ -161,9 +161,7 @@ EXPORT_SYMBOL(irq_poll_disable); **/ void irq_poll_enable(struct irq_poll *iop) { - BUG_ON(!test_bit(IRQ_POLL_F_SCHED, &iop->state)); - smp_mb__before_atomic(); - clear_bit_unlock(IRQ_POLL_F_SCHED, &iop->state); + irq_poll_activate(iop); } EXPORT_SYMBOL(irq_poll_enable); @@ -182,6 +180,7 @@ void irq_poll_init(struct irq_poll *iop, int weight, irq_poll_fn *poll_fn) INIT_LIST_HEAD(&iop->list); iop->weight = weight; iop->poll = poll_fn; + atomic_set(&iop->count, 1); } EXPORT_SYMBOL(irq_poll_init); -- 2.23.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
