diff options
Diffstat (limited to 'drivers/gpu/drm/i915/gt/intel_timeline.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/intel_timeline.c | 591 |
1 files changed, 591 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_timeline.c b/drivers/gpu/drm/i915/gt/intel_timeline.c new file mode 100644 index 000000000000..1a3f04458730 --- /dev/null +++ b/drivers/gpu/drm/i915/gt/intel_timeline.c @@ -0,0 +1,591 @@ +/* + * SPDX-License-Identifier: MIT + * + * Copyright © 2016-2018 Intel Corporation + */ + +#include "gt/intel_gt_types.h" + +#include "i915_drv.h" + +#include "i915_active.h" +#include "i915_syncmap.h" +#include "gt/intel_timeline.h" + +#define ptr_set_bit(ptr, bit) ((typeof(ptr))((unsigned long)(ptr) | BIT(bit))) +#define ptr_test_bit(ptr, bit) ((unsigned long)(ptr) & BIT(bit)) + +struct intel_timeline_hwsp { + struct intel_gt *gt; + struct i915_gt_timelines *gt_timelines; + struct list_head free_link; + struct i915_vma *vma; + u64 free_bitmap; +}; + +struct intel_timeline_cacheline { + struct i915_active active; + struct intel_timeline_hwsp *hwsp; + void *vaddr; +#define CACHELINE_BITS 6 +#define CACHELINE_FREE CACHELINE_BITS +}; + +static struct i915_vma *__hwsp_alloc(struct intel_gt *gt) +{ + struct drm_i915_private *i915 = gt->i915; + struct drm_i915_gem_object *obj; + struct i915_vma *vma; + + obj = i915_gem_object_create_internal(i915, PAGE_SIZE); + if (IS_ERR(obj)) + return ERR_CAST(obj); + + i915_gem_object_set_cache_coherency(obj, I915_CACHE_LLC); + + vma = i915_vma_instance(obj, >->ggtt->vm, NULL); + if (IS_ERR(vma)) + i915_gem_object_put(obj); + + return vma; +} + +static struct i915_vma * +hwsp_alloc(struct intel_timeline *timeline, unsigned int *cacheline) +{ + struct i915_gt_timelines *gt = &timeline->gt->timelines; + struct intel_timeline_hwsp *hwsp; + + BUILD_BUG_ON(BITS_PER_TYPE(u64) * CACHELINE_BYTES > PAGE_SIZE); + + spin_lock_irq(>->hwsp_lock); + + /* hwsp_free_list only contains HWSP that have available cachelines */ + hwsp = list_first_entry_or_null(>->hwsp_free_list, + typeof(*hwsp), free_link); + if (!hwsp) { + struct i915_vma *vma; + + spin_unlock_irq(>->hwsp_lock); + + hwsp = kmalloc(sizeof(*hwsp), GFP_KERNEL); + if (!hwsp) + return ERR_PTR(-ENOMEM); + + vma = __hwsp_alloc(timeline->gt); + if (IS_ERR(vma)) { + kfree(hwsp); + return vma; + } + + vma->private = hwsp; + hwsp->gt = timeline->gt; + hwsp->vma = vma; + hwsp->free_bitmap = ~0ull; + hwsp->gt_timelines = gt; + + spin_lock_irq(>->hwsp_lock); + list_add(&hwsp->free_link, >->hwsp_free_list); + } + + GEM_BUG_ON(!hwsp->free_bitmap); + *cacheline = __ffs64(hwsp->free_bitmap); + hwsp->free_bitmap &= ~BIT_ULL(*cacheline); + if (!hwsp->free_bitmap) + list_del(&hwsp->free_link); + + spin_unlock_irq(>->hwsp_lock); + + GEM_BUG_ON(hwsp->vma->private != hwsp); + return hwsp->vma; +} + +static void __idle_hwsp_free(struct intel_timeline_hwsp *hwsp, int cacheline) +{ + struct i915_gt_timelines *gt = hwsp->gt_timelines; + unsigned long flags; + + spin_lock_irqsave(>->hwsp_lock, flags); + + /* As a cacheline becomes available, publish the HWSP on the freelist */ + if (!hwsp->free_bitmap) + list_add_tail(&hwsp->free_link, >->hwsp_free_list); + + GEM_BUG_ON(cacheline >= BITS_PER_TYPE(hwsp->free_bitmap)); + hwsp->free_bitmap |= BIT_ULL(cacheline); + + /* And if no one is left using it, give the page back to the system */ + if (hwsp->free_bitmap == ~0ull) { + i915_vma_put(hwsp->vma); + list_del(&hwsp->free_link); + kfree(hwsp); + } + + spin_unlock_irqrestore(>->hwsp_lock, flags); +} + +static void __idle_cacheline_free(struct intel_timeline_cacheline *cl) +{ + GEM_BUG_ON(!i915_active_is_idle(&cl->active)); + + i915_gem_object_unpin_map(cl->hwsp->vma->obj); + i915_vma_put(cl->hwsp->vma); + __idle_hwsp_free(cl->hwsp, ptr_unmask_bits(cl->vaddr, CACHELINE_BITS)); + + i915_active_fini(&cl->active); + kfree(cl); +} + +static void __cacheline_retire(struct i915_active *active) +{ + struct intel_timeline_cacheline *cl = + container_of(active, typeof(*cl), active); + + i915_vma_unpin(cl->hwsp->vma); + if (ptr_test_bit(cl->vaddr, CACHELINE_FREE)) + __idle_cacheline_free(cl); +} + +static struct intel_timeline_cacheline * +cacheline_alloc(struct intel_timeline_hwsp *hwsp, unsigned int cacheline) +{ + struct intel_timeline_cacheline *cl; + void *vaddr; + + GEM_BUG_ON(cacheline >= BIT(CACHELINE_BITS)); + + cl = kmalloc(sizeof(*cl), GFP_KERNEL); + if (!cl) + return ERR_PTR(-ENOMEM); + + vaddr = i915_gem_object_pin_map(hwsp->vma->obj, I915_MAP_WB); + if (IS_ERR(vaddr)) { + kfree(cl); + return ERR_CAST(vaddr); + } + + i915_vma_get(hwsp->vma); + cl->hwsp = hwsp; + cl->vaddr = page_pack_bits(vaddr, cacheline); + + i915_active_init(hwsp->gt->i915, &cl->active, __cacheline_retire); + + return cl; +} + +static void cacheline_acquire(struct intel_timeline_cacheline *cl) +{ + if (cl && i915_active_acquire(&cl->active)) + __i915_vma_pin(cl->hwsp->vma); +} + +static void cacheline_release(struct intel_timeline_cacheline *cl) +{ + if (cl) + i915_active_release(&cl->active); +} + +static void cacheline_free(struct intel_timeline_cacheline *cl) +{ + GEM_BUG_ON(ptr_test_bit(cl->vaddr, CACHELINE_FREE)); + cl->vaddr = ptr_set_bit(cl->vaddr, CACHELINE_FREE); + + if (i915_active_is_idle(&cl->active)) + __idle_cacheline_free(cl); +} + +int intel_timeline_init(struct intel_timeline *timeline, + struct intel_gt *gt, + struct i915_vma *hwsp) +{ + void *vaddr; + + /* + * Ideally we want a set of engines on a single leaf as we expect + * to mostly be tracking synchronisation between engines. It is not + * a huge issue if this is not the case, but we may want to mitigate + * any page crossing penalties if they become an issue. + * + * Called during early_init before we know how many engines there are. + */ + BUILD_BUG_ON(KSYNCMAP < I915_NUM_ENGINES); + + timeline->gt = gt; + timeline->pin_count = 0; + timeline->has_initial_breadcrumb = !hwsp; + timeline->hwsp_cacheline = NULL; + + if (!hwsp) { + struct intel_timeline_cacheline *cl; + unsigned int cacheline; + + hwsp = hwsp_alloc(timeline, &cacheline); + if (IS_ERR(hwsp)) + return PTR_ERR(hwsp); + + cl = cacheline_alloc(hwsp->private, cacheline); + if (IS_ERR(cl)) { + __idle_hwsp_free(hwsp->private, cacheline); + return PTR_ERR(cl); + } + + timeline->hwsp_cacheline = cl; + timeline->hwsp_offset = cacheline * CACHELINE_BYTES; + + vaddr = page_mask_bits(cl->vaddr); + } else { + timeline->hwsp_offset = I915_GEM_HWS_SEQNO_ADDR; + + vaddr = i915_gem_object_pin_map(hwsp->obj, I915_MAP_WB); + if (IS_ERR(vaddr)) + return PTR_ERR(vaddr); + } + + timeline->hwsp_seqno = + memset(vaddr + timeline->hwsp_offset, 0, CACHELINE_BYTES); + + timeline->hwsp_ggtt = i915_vma_get(hwsp); + GEM_BUG_ON(timeline->hwsp_offset >= hwsp->size); + + timeline->fence_context = dma_fence_context_alloc(1); + + mutex_init(&timeline->mutex); + + INIT_ACTIVE_REQUEST(&timeline->last_request); + INIT_LIST_HEAD(&timeline->requests); + + i915_syncmap_init(&timeline->sync); + + return 0; +} + +static void timelines_init(struct intel_gt *gt) +{ + struct i915_gt_timelines *timelines = >->timelines; + + mutex_init(&timelines->mutex); + INIT_LIST_HEAD(&timelines->active_list); + + spin_lock_init(&timelines->hwsp_lock); + INIT_LIST_HEAD(&timelines->hwsp_free_list); + + /* via i915_gem_wait_for_idle() */ + i915_gem_shrinker_taints_mutex(gt->i915, &timelines->mutex); +} + +void intel_timelines_init(struct drm_i915_private *i915) +{ + timelines_init(&i915->gt); +} + +static void timeline_add_to_active(struct intel_timeline *tl) +{ + struct i915_gt_timelines *gt = &tl->gt->timelines; + + mutex_lock(>->mutex); + list_add(&tl->link, >->active_list); + mutex_unlock(>->mutex); +} + +static void timeline_remove_from_active(struct intel_timeline *tl) +{ + struct i915_gt_timelines *gt = &tl->gt->timelines; + + mutex_lock(>->mutex); + list_del(&tl->link); + mutex_unlock(>->mutex); +} + +static void timelines_park(struct intel_gt *gt) +{ + struct i915_gt_timelines *timelines = >->timelines; + struct intel_timeline *timeline; + + mutex_lock(&timelines->mutex); + list_for_each_entry(timeline, &timelines->active_list, link) { + /* + * All known fences are completed so we can scrap + * the current sync point tracking and start afresh, + * any attempt to wait upon a previous sync point + * will be skipped as the fence was signaled. + */ + i915_syncmap_free(&timeline->sync); + } + mutex_unlock(&timelines->mutex); +} + +/** + * intel_timelines_park - called when the driver idles + * @i915: the drm_i915_private device + * + * When the driver is completely idle, we know that all of our sync points + * have been signaled and our tracking is then entirely redundant. Any request + * to wait upon an older sync point will be completed instantly as we know + * the fence is signaled and therefore we will not even look them up in the + * sync point map. + */ +void intel_timelines_park(struct drm_i915_private *i915) +{ + timelines_park(&i915->gt); +} + +void intel_timeline_fini(struct intel_timeline *timeline) +{ + GEM_BUG_ON(timeline->pin_count); + GEM_BUG_ON(!list_empty(&timeline->requests)); + + i915_syncmap_free(&timeline->sync); + + if (timeline->hwsp_cacheline) + cacheline_free(timeline->hwsp_cacheline); + else + i915_gem_object_unpin_map(timeline->hwsp_ggtt->obj); + + i915_vma_put(timeline->hwsp_ggtt); +} + +struct intel_timeline * +intel_timeline_create(struct intel_gt *gt, struct i915_vma *global_hwsp) +{ + struct intel_timeline *timeline; + int err; + + timeline = kzalloc(sizeof(*timeline), GFP_KERNEL); + if (!timeline) + return ERR_PTR(-ENOMEM); + + err = intel_timeline_init(timeline, gt, global_hwsp); + if (err) { + kfree(timeline); + return ERR_PTR(err); + } + + kref_init(&timeline->kref); + + return timeline; +} + +int intel_timeline_pin(struct intel_timeline *tl) +{ + int err; + + if (tl->pin_count++) + return 0; + GEM_BUG_ON(!tl->pin_count); + + err = i915_vma_pin(tl->hwsp_ggtt, 0, 0, PIN_GLOBAL | PIN_HIGH); + if (err) + goto unpin; + + tl->hwsp_offset = + i915_ggtt_offset(tl->hwsp_ggtt) + + offset_in_page(tl->hwsp_offset); + + cacheline_acquire(tl->hwsp_cacheline); + timeline_add_to_active(tl); + + return 0; + +unpin: + tl->pin_count = 0; + return err; +} + +static u32 timeline_advance(struct intel_timeline *tl) +{ + GEM_BUG_ON(!tl->pin_count); + GEM_BUG_ON(tl->seqno & tl->has_initial_breadcrumb); + + return tl->seqno += 1 + tl->has_initial_breadcrumb; +} + +static void timeline_rollback(struct intel_timeline *tl) +{ + tl->seqno -= 1 + tl->has_initial_breadcrumb; +} + +static noinline int +__intel_timeline_get_seqno(struct intel_timeline *tl, + struct i915_request *rq, + u32 *seqno) +{ + struct intel_timeline_cacheline *cl; + unsigned int cacheline; + struct i915_vma *vma; + void *vaddr; + int err; + + /* + * If there is an outstanding GPU reference to this cacheline, + * such as it being sampled by a HW semaphore on another timeline, + * we cannot wraparound our seqno value (the HW semaphore does + * a strict greater-than-or-equals compare, not i915_seqno_passed). + * So if the cacheline is still busy, we must detach ourselves + * from it and leave it inflight alongside its users. + * + * However, if nobody is watching and we can guarantee that nobody + * will, we could simply reuse the same cacheline. + * + * if (i915_active_request_is_signaled(&tl->last_request) && + * i915_active_is_signaled(&tl->hwsp_cacheline->active)) + * return 0; + * + * That seems unlikely for a busy timeline that needed to wrap in + * the first place, so just replace the cacheline. + */ + + vma = hwsp_alloc(tl, &cacheline); + if (IS_ERR(vma)) { + err = PTR_ERR(vma); + goto err_rollback; + } + + err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH); + if (err) { + __idle_hwsp_free(vma->private, cacheline); + goto err_rollback; + } + + cl = cacheline_alloc(vma->private, cacheline); + if (IS_ERR(cl)) { + err = PTR_ERR(cl); + __idle_hwsp_free(vma->private, cacheline); + goto err_unpin; + } + GEM_BUG_ON(cl->hwsp->vma != vma); + + /* + * Attach the old cacheline to the current request, so that we only + * free it after the current request is retired, which ensures that + * all writes into the cacheline from previous requests are complete. + */ + err = i915_active_ref(&tl->hwsp_cacheline->active, + tl->fence_context, rq); + if (err) + goto err_cacheline; + + cacheline_release(tl->hwsp_cacheline); /* ownership now xfered to rq */ + cacheline_free(tl->hwsp_cacheline); + + i915_vma_unpin(tl->hwsp_ggtt); /* binding kept alive by old cacheline */ + i915_vma_put(tl->hwsp_ggtt); + + tl->hwsp_ggtt = i915_vma_get(vma); + + vaddr = page_mask_bits(cl->vaddr); + tl->hwsp_offset = cacheline * CACHELINE_BYTES; + tl->hwsp_seqno = + memset(vaddr + tl->hwsp_offset, 0, CACHELINE_BYTES); + + tl->hwsp_offset += i915_ggtt_offset(vma); + + cacheline_acquire(cl); + tl->hwsp_cacheline = cl; + + *seqno = timeline_advance(tl); + GEM_BUG_ON(i915_seqno_passed(*tl->hwsp_seqno, *seqno)); + return 0; + +err_cacheline: + cacheline_free(cl); +err_unpin: + i915_vma_unpin(vma); +err_rollback: + timeline_rollback(tl); + return err; +} + +int intel_timeline_get_seqno(struct intel_timeline *tl, + struct i915_request *rq, + u32 *seqno) +{ + *seqno = timeline_advance(tl); + + /* Replace the HWSP on wraparound for HW semaphores */ + if (unlikely(!*seqno && tl->hwsp_cacheline)) + return __intel_timeline_get_seqno(tl, rq, seqno); + + return 0; +} + +static int cacheline_ref(struct intel_timeline_cacheline *cl, + struct i915_request *rq) +{ + return i915_active_ref(&cl->active, rq->fence.context, rq); +} + +int intel_timeline_read_hwsp(struct i915_request *from, + struct i915_request *to, + u32 *hwsp) +{ + struct intel_timeline_cacheline *cl = from->hwsp_cacheline; + struct intel_timeline *tl = from->timeline; + int err; + + GEM_BUG_ON(to->timeline == tl); + + mutex_lock_nested(&tl->mutex, SINGLE_DEPTH_NESTING); + err = i915_request_completed(from); + if (!err) + err = cacheline_ref(cl, to); + if (!err) { + if (likely(cl == tl->hwsp_cacheline)) { + *hwsp = tl->hwsp_offset; + } else { /* across a seqno wrap, recover the original offset */ + *hwsp = i915_ggtt_offset(cl->hwsp->vma) + + ptr_unmask_bits(cl->vaddr, CACHELINE_BITS) * + CACHELINE_BYTES; + } + } + mutex_unlock(&tl->mutex); + + return err; +} + +void intel_timeline_unpin(struct intel_timeline *tl) +{ + GEM_BUG_ON(!tl->pin_count); + if (--tl->pin_count) + return; + + timeline_remove_from_active(tl); + cacheline_release(tl->hwsp_cacheline); + + /* + * Since this timeline is idle, all bariers upon which we were waiting + * must also be complete and so we can discard the last used barriers + * without loss of information. + */ + i915_syncmap_free(&tl->sync); + + __i915_vma_unpin(tl->hwsp_ggtt); +} + +void __intel_timeline_free(struct kref *kref) +{ + struct intel_timeline *timeline = + container_of(kref, typeof(*timeline), kref); + + intel_timeline_fini(timeline); + kfree(timeline); +} + +static void timelines_fini(struct intel_gt *gt) +{ + struct i915_gt_timelines *timelines = >->timelines; + + GEM_BUG_ON(!list_empty(&timelines->active_list)); + GEM_BUG_ON(!list_empty(&timelines->hwsp_free_list)); + + mutex_destroy(&timelines->mutex); +} + +void intel_timelines_fini(struct drm_i915_private *i915) +{ + timelines_fini(&i915->gt); +} + +#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) +#include "gt/selftests/mock_timeline.c" +#include "gt/selftest_timeline.c" +#endif |