From 73377dbcc754f1e673b60f238c237c5e909f92b1 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 16 May 2018 19:33:53 +0100 Subject: [PATCH] drm/i915/execlists: Split out CSB processing MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Pull the CSB event processing into its own routine so that we can reuse it during reset to flush any missed interrupts/events. Signed-off-by: Chris Wilson Cc: Michał Winiarski CC: Michel Thierry Cc: Jeff McGee Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20180516183355.10553-6-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/intel_lrc.c | 91 +++++++++++++++++++++++----------------- 1 file changed, 52 insertions(+), 39 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index acbdf36..f38391e 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -958,34 +958,14 @@ static void execlists_cancel_requests(struct intel_engine_cs *engine) local_irq_restore(flags); } -/* - * Check the unread Context Status Buffers and manage the submission of new - * contexts to the ELSP accordingly. - */ -static void execlists_submission_tasklet(unsigned long data) +static void process_csb(struct intel_engine_cs *engine) { - struct intel_engine_cs * const engine = (struct intel_engine_cs *)data; struct intel_engine_execlists * const execlists = &engine->execlists; struct execlist_port *port = execlists->port; - struct drm_i915_private *dev_priv = engine->i915; + struct drm_i915_private *i915 = engine->i915; bool fw = false; - /* - * We can skip acquiring intel_runtime_pm_get() here as it was taken - * on our behalf by the request (see i915_gem_mark_busy()) and it will - * not be relinquished until the device is idle (see - * i915_gem_idle_work_handler()). As a precaution, we make sure - * that all ELSP are drained i.e. we have processed the CSB, - * before allowing ourselves to idle and calling intel_runtime_pm_put(). - */ - GEM_BUG_ON(!dev_priv->gt.awake); - - /* - * Prefer doing test_and_clear_bit() as a two stage operation to avoid - * imposing the cost of a locked atomic transaction when submitting a - * new request (outside of the context-switch interrupt). - */ - while (test_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted)) { + do { /* The HWSP contains a (cacheable) mirror of the CSB */ const u32 *buf = &engine->status_page.page_addr[I915_HWS_CSB_BUF0_INDEX]; @@ -993,28 +973,27 @@ static void execlists_submission_tasklet(unsigned long data) if (unlikely(execlists->csb_use_mmio)) { buf = (u32 * __force) - (dev_priv->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_BUF_LO(engine, 0))); - execlists->csb_head = -1; /* force mmio read of CSB ptrs */ + (i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_BUF_LO(engine, 0))); + execlists->csb_head = -1; /* force mmio read of CSB */ } /* Clear before reading to catch new interrupts */ clear_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted); smp_mb__after_atomic(); - if (unlikely(execlists->csb_head == -1)) { /* following a reset */ + if (unlikely(execlists->csb_head == -1)) { /* after a reset */ if (!fw) { - intel_uncore_forcewake_get(dev_priv, - execlists->fw_domains); + intel_uncore_forcewake_get(i915, execlists->fw_domains); fw = true; } - head = readl(dev_priv->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine))); + head = readl(i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine))); tail = GEN8_CSB_WRITE_PTR(head); head = GEN8_CSB_READ_PTR(head); execlists->csb_head = head; } else { const int write_idx = - intel_hws_csb_write_index(dev_priv) - + intel_hws_csb_write_index(i915) - I915_HWS_CSB_BUF0_INDEX; head = execlists->csb_head; @@ -1023,8 +1002,8 @@ static void execlists_submission_tasklet(unsigned long data) } GEM_TRACE("%s cs-irq head=%d [%d%s], tail=%d [%d%s]\n", engine->name, - head, GEN8_CSB_READ_PTR(readl(dev_priv->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)))), fw ? "" : "?", - tail, GEN8_CSB_WRITE_PTR(readl(dev_priv->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)))), fw ? "" : "?"); + head, GEN8_CSB_READ_PTR(readl(i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)))), fw ? "" : "?", + tail, GEN8_CSB_WRITE_PTR(readl(i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)))), fw ? "" : "?"); while (head != tail) { struct i915_request *rq; @@ -1034,7 +1013,8 @@ static void execlists_submission_tasklet(unsigned long data) if (++head == GEN8_CSB_ENTRIES) head = 0; - /* We are flying near dragons again. + /* + * We are flying near dragons again. * * We hold a reference to the request in execlist_port[] * but no more than that. We are operating in softirq @@ -1143,15 +1123,48 @@ static void execlists_submission_tasklet(unsigned long data) if (head != execlists->csb_head) { execlists->csb_head = head; writel(_MASKED_FIELD(GEN8_CSB_READ_PTR_MASK, head << 8), - dev_priv->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine))); + i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine))); } - } + } while (test_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted)); - if (!execlists_is_active(execlists, EXECLISTS_ACTIVE_PREEMPT)) - execlists_dequeue(engine); + if (unlikely(fw)) + intel_uncore_forcewake_put(i915, execlists->fw_domains); +} - if (fw) - intel_uncore_forcewake_put(dev_priv, execlists->fw_domains); +/* + * Check the unread Context Status Buffers and manage the submission of new + * contexts to the ELSP accordingly. + */ +static void execlists_submission_tasklet(unsigned long data) +{ + struct intel_engine_cs * const engine = (struct intel_engine_cs *)data; + + GEM_TRACE("%s awake?=%d, active=%x, irq-posted?=%d\n", + engine->name, + engine->i915->gt.awake, + engine->execlists.active, + test_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted)); + + /* + * We can skip acquiring intel_runtime_pm_get() here as it was taken + * on our behalf by the request (see i915_gem_mark_busy()) and it will + * not be relinquished until the device is idle (see + * i915_gem_idle_work_handler()). As a precaution, we make sure + * that all ELSP are drained i.e. we have processed the CSB, + * before allowing ourselves to idle and calling intel_runtime_pm_put(). + */ + GEM_BUG_ON(!engine->i915->gt.awake); + + /* + * Prefer doing test_and_clear_bit() as a two stage operation to avoid + * imposing the cost of a locked atomic transaction when submitting a + * new request (outside of the context-switch interrupt). + */ + if (test_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted)) + process_csb(engine); + + if (!execlists_is_active(&engine->execlists, EXECLISTS_ACTIVE_PREEMPT)) + execlists_dequeue(engine); /* If the engine is now idle, so should be the flag; and vice versa. */ GEM_BUG_ON(execlists_is_active(&engine->execlists, -- 2.7.4