From: Chris Wilson Date: Mon, 13 Dec 2010 16:54:50 +0000 (+0000) Subject: drm/i915/ringbuffer: Make IRQ refcnting atomic X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b13c2b96bf15b9dd0f1a45fd788f3a3025c5aec6;p=linux-beck.git drm/i915/ringbuffer: Make IRQ refcnting atomic In order to enforce the correct memory barriers for irq get/put, we need to perform the actual counting using atomic operations. Signed-off-by: Chris Wilson --- diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 27fa2a1b26a5..726c2ccd674c 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2000,17 +2000,19 @@ i915_do_wait_request(struct drm_device *dev, uint32_t seqno, trace_i915_gem_request_wait_begin(dev, seqno); ring->waiting_seqno = seqno; - ring->irq_get(ring); - if (interruptible) - ret = wait_event_interruptible(ring->irq_queue, - i915_seqno_passed(ring->get_seqno(ring), seqno) - || atomic_read(&dev_priv->mm.wedged)); - else - wait_event(ring->irq_queue, - i915_seqno_passed(ring->get_seqno(ring), seqno) - || atomic_read(&dev_priv->mm.wedged)); + ret = -ENODEV; + if (ring->irq_get(ring)) { + if (interruptible) + ret = wait_event_interruptible(ring->irq_queue, + i915_seqno_passed(ring->get_seqno(ring), seqno) + || atomic_read(&dev_priv->mm.wedged)); + else + wait_event(ring->irq_queue, + i915_seqno_passed(ring->get_seqno(ring), seqno) + || atomic_read(&dev_priv->mm.wedged)); - ring->irq_put(ring); + ring->irq_put(ring); + } ring->waiting_seqno = 0; trace_i915_gem_request_wait_end(dev, seqno); @@ -3157,14 +3159,15 @@ i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file) * generation is designed to be run atomically and so is * lockless. */ - ring->irq_get(ring); - ret = wait_event_interruptible(ring->irq_queue, - i915_seqno_passed(ring->get_seqno(ring), seqno) - || atomic_read(&dev_priv->mm.wedged)); - ring->irq_put(ring); + if (ring->irq_get(ring)) { + ret = wait_event_interruptible(ring->irq_queue, + i915_seqno_passed(ring->get_seqno(ring), seqno) + || atomic_read(&dev_priv->mm.wedged)); + ring->irq_put(ring); - if (ret == 0 && atomic_read(&dev_priv->mm.wedged)) - ret = -EIO; + if (ret == 0 && atomic_read(&dev_priv->mm.wedged)) + ret = -EIO; + } } if (ret == 0) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 02e4dd82f754..2ddb98b5c90f 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1186,10 +1186,9 @@ void i915_trace_irq_get(struct drm_device *dev, u32 seqno) drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private; struct intel_ring_buffer *ring = LP_RING(dev_priv); - if (dev_priv->trace_irq_seqno == 0) - ring->irq_get(ring); - - dev_priv->trace_irq_seqno = seqno; + if (dev_priv->trace_irq_seqno == 0 && + ring->irq_get(ring)) + dev_priv->trace_irq_seqno = seqno; } static int i915_wait_irq(struct drm_device * dev, int irq_nr) @@ -1211,10 +1210,12 @@ static int i915_wait_irq(struct drm_device * dev, int irq_nr) if (master_priv->sarea_priv) master_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT; - ring->irq_get(ring); - DRM_WAIT_ON(ret, ring->irq_queue, 3 * DRM_HZ, - READ_BREADCRUMB(dev_priv) >= irq_nr); - ring->irq_put(ring); + ret = -ENODEV; + if (ring->irq_get(ring)) { + DRM_WAIT_ON(ret, ring->irq_queue, 3 * DRM_HZ, + READ_BREADCRUMB(dev_priv) >= irq_nr); + ring->irq_put(ring); + } if (ret == -EBUSY) { DRM_ERROR("EBUSY -- rec: %d emitted: %d\n", diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 74b99718a1fb..a3fd993e0de0 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -327,25 +327,28 @@ ring_get_seqno(struct intel_ring_buffer *ring) return intel_read_status_page(ring, I915_GEM_HWS_INDEX); } -static void +static bool render_ring_get_irq(struct intel_ring_buffer *ring) { struct drm_device *dev = ring->dev; - if (dev->irq_enabled && ++ring->irq_refcount == 1) { + if (!dev->irq_enabled) + return false; + + if (atomic_inc_return(&ring->irq_refcount) == 1) { drm_i915_private_t *dev_priv = dev->dev_private; unsigned long irqflags; spin_lock_irqsave(&dev_priv->irq_lock, irqflags); - if (HAS_PCH_SPLIT(dev)) ironlake_enable_graphics_irq(dev_priv, GT_USER_INTERRUPT); else i915_enable_irq(dev_priv, I915_USER_INTERRUPT); - spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags); } + + return true; } static void @@ -353,8 +356,7 @@ render_ring_put_irq(struct intel_ring_buffer *ring) { struct drm_device *dev = ring->dev; - BUG_ON(dev->irq_enabled && ring->irq_refcount == 0); - if (dev->irq_enabled && --ring->irq_refcount == 0) { + if (atomic_dec_and_test(&ring->irq_refcount)) { drm_i915_private_t *dev_priv = dev->dev_private; unsigned long irqflags; @@ -417,12 +419,15 @@ ring_add_request(struct intel_ring_buffer *ring, return 0; } -static void +static bool ring_get_irq(struct intel_ring_buffer *ring, u32 flag) { struct drm_device *dev = ring->dev; - if (dev->irq_enabled && ++ring->irq_refcount == 1) { + if (!dev->irq_enabled) + return false; + + if (atomic_inc_return(&ring->irq_refcount) == 1) { drm_i915_private_t *dev_priv = dev->dev_private; unsigned long irqflags; @@ -430,6 +435,8 @@ ring_get_irq(struct intel_ring_buffer *ring, u32 flag) ironlake_enable_graphics_irq(dev_priv, flag); spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags); } + + return true; } static void @@ -437,7 +444,7 @@ ring_put_irq(struct intel_ring_buffer *ring, u32 flag) { struct drm_device *dev = ring->dev; - if (dev->irq_enabled && --ring->irq_refcount == 0) { + if (atomic_dec_and_test(&ring->irq_refcount)) { drm_i915_private_t *dev_priv = dev->dev_private; unsigned long irqflags; @@ -447,16 +454,15 @@ ring_put_irq(struct intel_ring_buffer *ring, u32 flag) } } - -static void +static bool bsd_ring_get_irq(struct intel_ring_buffer *ring) { - ring_get_irq(ring, GT_BSD_USER_INTERRUPT); + return ring_get_irq(ring, GT_BSD_USER_INTERRUPT); } static void bsd_ring_put_irq(struct intel_ring_buffer *ring) { - ring_put_irq(ring, GT_BSD_USER_INTERRUPT); + ring_put_irq(ring, GT_BSD_USER_INTERRUPT); } static int @@ -846,16 +852,16 @@ gen6_ring_dispatch_execbuffer(struct intel_ring_buffer *ring, return 0; } -static void +static bool gen6_bsd_ring_get_irq(struct intel_ring_buffer *ring) { - ring_get_irq(ring, GT_GEN6_BSD_USER_INTERRUPT); + return ring_get_irq(ring, GT_GEN6_BSD_USER_INTERRUPT); } static void gen6_bsd_ring_put_irq(struct intel_ring_buffer *ring) { - ring_put_irq(ring, GT_GEN6_BSD_USER_INTERRUPT); + ring_put_irq(ring, GT_GEN6_BSD_USER_INTERRUPT); } /* ring buffer for Video Codec for Gen6+ */ @@ -876,16 +882,16 @@ static const struct intel_ring_buffer gen6_bsd_ring = { /* Blitter support (SandyBridge+) */ -static void +static bool blt_ring_get_irq(struct intel_ring_buffer *ring) { - ring_get_irq(ring, GT_BLT_USER_INTERRUPT); + return ring_get_irq(ring, GT_BLT_USER_INTERRUPT); } static void blt_ring_put_irq(struct intel_ring_buffer *ring) { - ring_put_irq(ring, GT_BLT_USER_INTERRUPT); + ring_put_irq(ring, GT_BLT_USER_INTERRUPT); } diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 9652e4600b5e..8e2e357ad6ee 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -54,8 +54,8 @@ struct intel_ring_buffer { u32 irq_seqno; /* last seq seem at irq time */ u32 waiting_seqno; u32 sync_seqno[I915_NUM_RINGS-1]; - u32 irq_refcount; - void (*irq_get)(struct intel_ring_buffer *ring); + atomic_t irq_refcount; + bool __must_check (*irq_get)(struct intel_ring_buffer *ring); void (*irq_put)(struct intel_ring_buffer *ring); int (*init)(struct intel_ring_buffer *ring);