| /* |
| * SPDX-License-Identifier: MIT |
| * |
| * Copyright © 2016-2018 Intel Corporation |
| */ |
| |
| #include "i915_drv.h" |
| |
| #include "i915_active.h" |
| #include "i915_syncmap.h" |
| #include "intel_gt.h" |
| #include "intel_ring.h" |
| #include "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)) |
| |
| #define CACHELINE_BITS 6 |
| #define CACHELINE_FREE CACHELINE_BITS |
| |
| struct intel_timeline_hwsp { |
| struct intel_gt *gt; |
| struct intel_gt_timelines *gt_timelines; |
| struct list_head free_link; |
| struct i915_vma *vma; |
| u64 free_bitmap; |
| }; |
| |
| 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 intel_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 intel_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_rcu(cl, rcu); |
| } |
| |
| __i915_active_call |
| 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 int __cacheline_active(struct i915_active *active) |
| { |
| struct intel_timeline_cacheline *cl = |
| container_of(active, typeof(*cl), active); |
| |
| __i915_vma_pin(cl->hwsp->vma); |
| return 0; |
| } |
| |
| 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(&cl->active, __cacheline_active, __cacheline_retire); |
| |
| return cl; |
| } |
| |
| static void cacheline_acquire(struct intel_timeline_cacheline *cl) |
| { |
| if (cl) |
| i915_active_acquire(&cl->active); |
| } |
| |
| 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; |
| |
| kref_init(&timeline->kref); |
| atomic_set(&timeline->pin_count, 0); |
| |
| timeline->gt = gt; |
| |
| 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_FENCE(&timeline->last_request); |
| INIT_LIST_HEAD(&timeline->requests); |
| |
| i915_syncmap_init(&timeline->sync); |
| |
| return 0; |
| } |
| |
| void intel_gt_init_timelines(struct intel_gt *gt) |
| { |
| struct intel_gt_timelines *timelines = >->timelines; |
| |
| spin_lock_init(&timelines->lock); |
| INIT_LIST_HEAD(&timelines->active_list); |
| |
| spin_lock_init(&timelines->hwsp_lock); |
| INIT_LIST_HEAD(&timelines->hwsp_free_list); |
| } |
| |
| void intel_timeline_fini(struct intel_timeline *timeline) |
| { |
| GEM_BUG_ON(atomic_read(&timeline->pin_count)); |
| GEM_BUG_ON(!list_empty(&timeline->requests)); |
| GEM_BUG_ON(timeline->retire); |
| |
| 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); |
| } |
| |
| return timeline; |
| } |
| |
| int intel_timeline_pin(struct intel_timeline *tl) |
| { |
| int err; |
| |
| if (atomic_add_unless(&tl->pin_count, 1, 0)) |
| return 0; |
| |
| err = i915_vma_pin(tl->hwsp_ggtt, 0, 0, PIN_GLOBAL | PIN_HIGH); |
| if (err) |
| return err; |
| |
| tl->hwsp_offset = |
| i915_ggtt_offset(tl->hwsp_ggtt) + |
| offset_in_page(tl->hwsp_offset); |
| |
| cacheline_acquire(tl->hwsp_cacheline); |
| if (atomic_fetch_inc(&tl->pin_count)) { |
| cacheline_release(tl->hwsp_cacheline); |
| __i915_vma_unpin(tl->hwsp_ggtt); |
| } |
| |
| return 0; |
| } |
| |
| void intel_timeline_enter(struct intel_timeline *tl) |
| { |
| struct intel_gt_timelines *timelines = &tl->gt->timelines; |
| |
| /* |
| * Pretend we are serialised by the timeline->mutex. |
| * |
| * While generally true, there are a few exceptions to the rule |
| * for the engine->kernel_context being used to manage power |
| * transitions. As the engine_park may be called from under any |
| * timeline, it uses the power mutex as a global serialisation |
| * lock to prevent any other request entering its timeline. |
| * |
| * The rule is generally tl->mutex, otherwise engine->wakeref.mutex. |
| * |
| * However, intel_gt_retire_request() does not know which engine |
| * it is retiring along and so cannot partake in the engine-pm |
| * barrier, and there we use the tl->active_count as a means to |
| * pin the timeline in the active_list while the locks are dropped. |
| * Ergo, as that is outside of the engine-pm barrier, we need to |
| * use atomic to manipulate tl->active_count. |
| */ |
| lockdep_assert_held(&tl->mutex); |
| |
| if (atomic_add_unless(&tl->active_count, 1, 0)) |
| return; |
| |
| spin_lock(&timelines->lock); |
| if (!atomic_fetch_inc(&tl->active_count)) |
| list_add_tail(&tl->link, &timelines->active_list); |
| spin_unlock(&timelines->lock); |
| } |
| |
| void intel_timeline_exit(struct intel_timeline *tl) |
| { |
| struct intel_gt_timelines *timelines = &tl->gt->timelines; |
| |
| /* See intel_timeline_enter() */ |
| lockdep_assert_held(&tl->mutex); |
| |
| GEM_BUG_ON(!atomic_read(&tl->active_count)); |
| if (atomic_add_unless(&tl->active_count, -1, 1)) |
| return; |
| |
| spin_lock(&timelines->lock); |
| if (atomic_dec_and_test(&tl->active_count)) |
| list_del(&tl->link); |
| spin_unlock(&timelines->lock); |
| |
| /* |
| * 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); |
| } |
| |
| static u32 timeline_advance(struct intel_timeline *tl) |
| { |
| GEM_BUG_ON(!atomic_read(&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, &rq->fence); |
| 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_add_request(&cl->active, rq); |
| } |
| |
| int intel_timeline_read_hwsp(struct i915_request *from, |
| struct i915_request *to, |
| u32 *hwsp) |
| { |
| struct intel_timeline_cacheline *cl; |
| int err; |
| |
| GEM_BUG_ON(!rcu_access_pointer(from->hwsp_cacheline)); |
| |
| rcu_read_lock(); |
| cl = rcu_dereference(from->hwsp_cacheline); |
| if (unlikely(!i915_active_acquire_if_busy(&cl->active))) |
| goto unlock; /* seqno wrapped and completed! */ |
| if (unlikely(i915_request_completed(from))) |
| goto release; |
| rcu_read_unlock(); |
| |
| err = cacheline_ref(cl, to); |
| if (err) |
| goto out; |
| |
| *hwsp = i915_ggtt_offset(cl->hwsp->vma) + |
| ptr_unmask_bits(cl->vaddr, CACHELINE_BITS) * CACHELINE_BYTES; |
| |
| out: |
| i915_active_release(&cl->active); |
| return err; |
| |
| release: |
| i915_active_release(&cl->active); |
| unlock: |
| rcu_read_unlock(); |
| return 1; |
| } |
| |
| void intel_timeline_unpin(struct intel_timeline *tl) |
| { |
| GEM_BUG_ON(!atomic_read(&tl->pin_count)); |
| if (!atomic_dec_and_test(&tl->pin_count)) |
| return; |
| |
| cacheline_release(tl->hwsp_cacheline); |
| |
| __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_rcu(timeline, rcu); |
| } |
| |
| void intel_gt_fini_timelines(struct intel_gt *gt) |
| { |
| struct intel_gt_timelines *timelines = >->timelines; |
| |
| GEM_BUG_ON(!list_empty(&timelines->active_list)); |
| GEM_BUG_ON(!list_empty(&timelines->hwsp_free_list)); |
| } |
| |
| #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) |
| #include "gt/selftests/mock_timeline.c" |
| #include "gt/selftest_timeline.c" |
| #endif |