From af8e087157ef5034fa12d93202037f87da61355d Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Tue, 20 May 2008 14:03:27 -0700 Subject: [gem] Use a separate sequence number field from classic/ttm This lets us get some qualities we desire, such as using the full 32-bit range (except zero), avoiding DRM_WAIT_ON, and a 1:1 mapping of active sequence numbers to request structs, which will be used soon for throttling and interrupt-driven list cleanup. --- linux-core/i915_gem.c | 123 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 120 insertions(+), 3 deletions(-) (limited to 'linux-core') diff --git a/linux-core/i915_gem.c b/linux-core/i915_gem.c index ee8f1023..3535fae1 100644 --- a/linux-core/i915_gem.c +++ b/linux-core/i915_gem.c @@ -115,6 +115,123 @@ i915_gem_object_move_to_inactive(struct drm_gem_object *obj) } } +/** + * Creates a new sequence number, emitting a write of it to the status page + * plus an interrupt, which will trigger i915_user_interrupt_handler. + * + * Must be called with struct_lock held. + * + * Returned sequence numbers are nonzero on success. + */ +static uint32_t +i915_add_request(struct drm_device *dev) +{ + drm_i915_private_t *dev_priv = dev->dev_private; + struct drm_i915_gem_request *request; + uint32_t seqno; + RING_LOCALS; + + request = drm_calloc(1, sizeof(*request), DRM_MEM_DRIVER); + if (request == NULL) + return 0; + + /* Grab the seqno we're going to make this request be, and bump the + * next (skipping 0 so it can be the reserved no-seqno value). + */ + seqno = dev_priv->mm.next_gem_seqno; + dev_priv->mm.next_gem_seqno++; + if (dev_priv->mm.next_gem_seqno == 0) + dev_priv->mm.next_gem_seqno++; + + BEGIN_LP_RING(4); + OUT_RING(CMD_STORE_DWORD_IDX); + OUT_RING(I915_GEM_HWS_INDEX << STORE_DWORD_INDEX_SHIFT); + OUT_RING(seqno); + + OUT_RING(GFX_OP_USER_INTERRUPT); + ADVANCE_LP_RING(); + + DRM_DEBUG("%d\n", seqno); + + request->seqno = seqno; + list_add_tail(&request->list, &dev_priv->mm.request_list); + + return seqno; +} + +/** + * Returns true if seq1 is later than seq2. + */ +static int +i915_seqno_passed(uint32_t seq1, uint32_t seq2) +{ + return (int32_t)(seq1 - seq2) >= 0; +} + +static uint32_t +i915_get_gem_seqno(struct drm_device *dev) +{ + drm_i915_private_t *dev_priv = dev->dev_private; + + return READ_HWSP(dev_priv, I915_GEM_HWS_INDEX); +} + +/** + * This function clears the request list as sequence numbers are passed. + */ +void +i915_gem_retire_requests(struct drm_device *dev) +{ + drm_i915_private_t *dev_priv = dev->dev_private; + uint32_t seqno; + + seqno = i915_get_gem_seqno(dev); + + while (!list_empty(&dev_priv->mm.request_list)) { + struct drm_i915_gem_request *request; + uint32_t retiring_seqno; + + request = list_first_entry(&dev_priv->mm.request_list, + struct drm_i915_gem_request, + list); + retiring_seqno = request->seqno; + + if (i915_seqno_passed(seqno, retiring_seqno)) { + list_del(&request->list); + drm_free(request, sizeof(*request), DRM_MEM_DRIVER); + } else + break; + } +} + +/** + * Waits for a sequence number to be signaled, and cleans up the + * request and object lists appropriately for that event. + */ +int +i915_wait_request(struct drm_device *dev, uint32_t seqno) +{ + drm_i915_private_t *dev_priv = dev->dev_private; + int ret = 0; + + BUG_ON(seqno == 0); + + i915_user_irq_on(dev_priv); + ret = wait_event_interruptible(dev_priv->irq_queue, + i915_seqno_passed(i915_get_gem_seqno(dev), + seqno)); + i915_user_irq_off(dev_priv); + + /* Directly dispatch request retiring. While we have the work queue + * to handle this, the waiter on a request often wants an associated + * buffer to have made it to the inactive list, and we would need + * a separate wait queue to handle that. + */ + if (ret == 0) + i915_gem_retire_requests(dev); + + return ret; +} static void i915_gem_flush(struct drm_device *dev, @@ -207,7 +324,7 @@ i915_gem_object_wait_rendering(struct drm_gem_object *obj) obj->write_domain = 0; i915_gem_object_move_to_active(obj); - obj_priv->last_rendering_seqno = i915_emit_irq(dev); + obj_priv->last_rendering_seqno = i915_add_request(dev); BUG_ON(obj_priv->last_rendering_seqno == 0); #if WATCH_LRU DRM_INFO("%s: flush moves to exec list %p\n", __func__, obj); @@ -221,7 +338,7 @@ i915_gem_object_wait_rendering(struct drm_gem_object *obj) DRM_INFO("%s: object %p wait for seqno %08x\n", __func__, obj, obj_priv->last_rendering_seqno); #endif - ret = i915_wait_irq(dev, obj_priv->last_rendering_seqno); + ret = i915_wait_request(dev, obj_priv->last_rendering_seqno); if (ret != 0) return ret; @@ -995,7 +1112,7 @@ i915_gem_execbuffer(struct drm_device *dev, void *data, * *some* interrupts representing completion of buffers that we can * wait on when trying to clear up gtt space). */ - seqno = i915_emit_irq(dev); + seqno = i915_add_request(dev); BUG_ON(seqno == 0); for (i = 0; i < args->buffer_count; i++) { struct drm_gem_object *obj = object_list[i]; -- cgit v1.2.3