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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/gpu/drm/i915/gt/intel_timeline.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/gpu/drm/i915/gt/intel_timeline.c')
-rw-r--r--drivers/gpu/drm/i915/gt/intel_timeline.c493
1 files changed, 493 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 000000000..b9640212d
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_timeline.c
@@ -0,0 +1,493 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2016-2018 Intel Corporation
+ */
+
+#include <drm/drm_cache.h>
+
+#include "gem/i915_gem_internal.h"
+
+#include "i915_active.h"
+#include "i915_drv.h"
+#include "i915_syncmap.h"
+#include "intel_gt.h"
+#include "intel_ring.h"
+#include "intel_timeline.h"
+
+#define TIMELINE_SEQNO_BYTES 8
+
+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, &gt->ggtt->vm, NULL);
+ if (IS_ERR(vma))
+ i915_gem_object_put(obj);
+
+ return vma;
+}
+
+static void __timeline_retire(struct i915_active *active)
+{
+ struct intel_timeline *tl =
+ container_of(active, typeof(*tl), active);
+
+ i915_vma_unpin(tl->hwsp_ggtt);
+ intel_timeline_put(tl);
+}
+
+static int __timeline_active(struct i915_active *active)
+{
+ struct intel_timeline *tl =
+ container_of(active, typeof(*tl), active);
+
+ __i915_vma_pin(tl->hwsp_ggtt);
+ intel_timeline_get(tl);
+ return 0;
+}
+
+I915_SELFTEST_EXPORT int
+intel_timeline_pin_map(struct intel_timeline *timeline)
+{
+ struct drm_i915_gem_object *obj = timeline->hwsp_ggtt->obj;
+ u32 ofs = offset_in_page(timeline->hwsp_offset);
+ void *vaddr;
+
+ vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
+ if (IS_ERR(vaddr))
+ return PTR_ERR(vaddr);
+
+ timeline->hwsp_map = vaddr;
+ timeline->hwsp_seqno = memset(vaddr + ofs, 0, TIMELINE_SEQNO_BYTES);
+ drm_clflush_virt_range(vaddr + ofs, TIMELINE_SEQNO_BYTES);
+
+ return 0;
+}
+
+static int intel_timeline_init(struct intel_timeline *timeline,
+ struct intel_gt *gt,
+ struct i915_vma *hwsp,
+ unsigned int offset)
+{
+ kref_init(&timeline->kref);
+ atomic_set(&timeline->pin_count, 0);
+
+ timeline->gt = gt;
+
+ if (hwsp) {
+ timeline->hwsp_offset = offset;
+ timeline->hwsp_ggtt = i915_vma_get(hwsp);
+ } else {
+ timeline->has_initial_breadcrumb = true;
+ hwsp = hwsp_alloc(gt);
+ if (IS_ERR(hwsp))
+ return PTR_ERR(hwsp);
+ timeline->hwsp_ggtt = hwsp;
+ }
+
+ timeline->hwsp_map = NULL;
+ timeline->hwsp_seqno = (void *)(long)timeline->hwsp_offset;
+
+ 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);
+ i915_active_init(&timeline->active, __timeline_active,
+ __timeline_retire, 0);
+
+ return 0;
+}
+
+void intel_gt_init_timelines(struct intel_gt *gt)
+{
+ struct intel_gt_timelines *timelines = &gt->timelines;
+
+ spin_lock_init(&timelines->lock);
+ INIT_LIST_HEAD(&timelines->active_list);
+}
+
+static void intel_timeline_fini(struct rcu_head *rcu)
+{
+ struct intel_timeline *timeline =
+ container_of(rcu, struct intel_timeline, rcu);
+
+ if (timeline->hwsp_map)
+ i915_gem_object_unpin_map(timeline->hwsp_ggtt->obj);
+
+ i915_vma_put(timeline->hwsp_ggtt);
+ i915_active_fini(&timeline->active);
+
+ /*
+ * A small race exists between intel_gt_retire_requests_timeout and
+ * intel_timeline_exit which could result in the syncmap not getting
+ * free'd. Rather than work to hard to seal this race, simply cleanup
+ * the syncmap on fini.
+ */
+ i915_syncmap_free(&timeline->sync);
+
+ kfree(timeline);
+}
+
+struct intel_timeline *
+__intel_timeline_create(struct intel_gt *gt,
+ struct i915_vma *global_hwsp,
+ unsigned int offset)
+{
+ 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, offset);
+ if (err) {
+ kfree(timeline);
+ return ERR_PTR(err);
+ }
+
+ return timeline;
+}
+
+struct intel_timeline *
+intel_timeline_create_from_engine(struct intel_engine_cs *engine,
+ unsigned int offset)
+{
+ struct i915_vma *hwsp = engine->status_page.vma;
+ struct intel_timeline *tl;
+
+ tl = __intel_timeline_create(engine->gt, hwsp, offset);
+ if (IS_ERR(tl))
+ return tl;
+
+ /* Borrow a nearby lock; we only create these timelines during init */
+ mutex_lock(&hwsp->vm->mutex);
+ list_add_tail(&tl->engine_link, &engine->status_page.timelines);
+ mutex_unlock(&hwsp->vm->mutex);
+
+ return tl;
+}
+
+void __intel_timeline_pin(struct intel_timeline *tl)
+{
+ GEM_BUG_ON(!atomic_read(&tl->pin_count));
+ atomic_inc(&tl->pin_count);
+}
+
+int intel_timeline_pin(struct intel_timeline *tl, struct i915_gem_ww_ctx *ww)
+{
+ int err;
+
+ if (atomic_add_unless(&tl->pin_count, 1, 0))
+ return 0;
+
+ if (!tl->hwsp_map) {
+ err = intel_timeline_pin_map(tl);
+ if (err)
+ return err;
+ }
+
+ err = i915_ggtt_pin(tl->hwsp_ggtt, ww, 0, PIN_HIGH);
+ if (err)
+ return err;
+
+ tl->hwsp_offset =
+ i915_ggtt_offset(tl->hwsp_ggtt) +
+ offset_in_page(tl->hwsp_offset);
+ GT_TRACE(tl->gt, "timeline:%llx using HWSP offset:%x\n",
+ tl->fence_context, tl->hwsp_offset);
+
+ i915_active_acquire(&tl->active);
+ if (atomic_fetch_inc(&tl->pin_count)) {
+ i915_active_release(&tl->active);
+ __i915_vma_unpin(tl->hwsp_ggtt);
+ }
+
+ return 0;
+}
+
+void intel_timeline_reset_seqno(const struct intel_timeline *tl)
+{
+ u32 *hwsp_seqno = (u32 *)tl->hwsp_seqno;
+ /* Must be pinned to be writable, and no requests in flight. */
+ GEM_BUG_ON(!atomic_read(&tl->pin_count));
+
+ memset(hwsp_seqno + 1, 0, TIMELINE_SEQNO_BYTES - sizeof(*hwsp_seqno));
+ WRITE_ONCE(*hwsp_seqno, tl->seqno);
+ drm_clflush_virt_range(hwsp_seqno, TIMELINE_SEQNO_BYTES);
+}
+
+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)) {
+ /*
+ * The HWSP is volatile, and may have been lost while inactive,
+ * e.g. across suspend/resume. Be paranoid, and ensure that
+ * the HWSP value matches our seqno so we don't proclaim
+ * the next request as already complete.
+ */
+ intel_timeline_reset_seqno(tl);
+ 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 noinline int
+__intel_timeline_get_seqno(struct intel_timeline *tl,
+ u32 *seqno)
+{
+ u32 next_ofs = offset_in_page(tl->hwsp_offset + TIMELINE_SEQNO_BYTES);
+
+ /* w/a: bit 5 needs to be zero for MI_FLUSH_DW address. */
+ if (TIMELINE_SEQNO_BYTES <= BIT(5) && (next_ofs & BIT(5)))
+ next_ofs = offset_in_page(next_ofs + BIT(5));
+
+ tl->hwsp_offset = i915_ggtt_offset(tl->hwsp_ggtt) + next_ofs;
+ tl->hwsp_seqno = tl->hwsp_map + next_ofs;
+ intel_timeline_reset_seqno(tl);
+
+ *seqno = timeline_advance(tl);
+ GEM_BUG_ON(i915_seqno_passed(*tl->hwsp_seqno, *seqno));
+ return 0;
+}
+
+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->has_initial_breadcrumb))
+ return __intel_timeline_get_seqno(tl, seqno);
+
+ return 0;
+}
+
+int intel_timeline_read_hwsp(struct i915_request *from,
+ struct i915_request *to,
+ u32 *hwsp)
+{
+ struct intel_timeline *tl;
+ int err;
+
+ rcu_read_lock();
+ tl = rcu_dereference(from->timeline);
+ if (i915_request_signaled(from) ||
+ !i915_active_acquire_if_busy(&tl->active))
+ tl = NULL;
+
+ if (tl) {
+ /* hwsp_offset may wraparound, so use from->hwsp_seqno */
+ *hwsp = i915_ggtt_offset(tl->hwsp_ggtt) +
+ offset_in_page(from->hwsp_seqno);
+ }
+
+ /* ensure we wait on the right request, if not, we completed */
+ if (tl && __i915_request_is_complete(from)) {
+ i915_active_release(&tl->active);
+ tl = NULL;
+ }
+ rcu_read_unlock();
+
+ if (!tl)
+ return 1;
+
+ /* Can't do semaphore waits on kernel context */
+ if (!tl->has_initial_breadcrumb) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ err = i915_active_add_request(&tl->active, to);
+
+out:
+ i915_active_release(&tl->active);
+ return err;
+}
+
+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;
+
+ i915_active_release(&tl->active);
+ __i915_vma_unpin(tl->hwsp_ggtt);
+}
+
+void __intel_timeline_free(struct kref *kref)
+{
+ struct intel_timeline *timeline =
+ container_of(kref, typeof(*timeline), kref);
+
+ GEM_BUG_ON(atomic_read(&timeline->pin_count));
+ GEM_BUG_ON(!list_empty(&timeline->requests));
+ GEM_BUG_ON(timeline->retire);
+
+ call_rcu(&timeline->rcu, intel_timeline_fini);
+}
+
+void intel_gt_fini_timelines(struct intel_gt *gt)
+{
+ struct intel_gt_timelines *timelines = &gt->timelines;
+
+ GEM_BUG_ON(!list_empty(&timelines->active_list));
+}
+
+void intel_gt_show_timelines(struct intel_gt *gt,
+ struct drm_printer *m,
+ void (*show_request)(struct drm_printer *m,
+ const struct i915_request *rq,
+ const char *prefix,
+ int indent))
+{
+ struct intel_gt_timelines *timelines = &gt->timelines;
+ struct intel_timeline *tl, *tn;
+ LIST_HEAD(free);
+
+ spin_lock(&timelines->lock);
+ list_for_each_entry_safe(tl, tn, &timelines->active_list, link) {
+ unsigned long count, ready, inflight;
+ struct i915_request *rq, *rn;
+ struct dma_fence *fence;
+
+ if (!mutex_trylock(&tl->mutex)) {
+ drm_printf(m, "Timeline %llx: busy; skipping\n",
+ tl->fence_context);
+ continue;
+ }
+
+ intel_timeline_get(tl);
+ GEM_BUG_ON(!atomic_read(&tl->active_count));
+ atomic_inc(&tl->active_count); /* pin the list element */
+ spin_unlock(&timelines->lock);
+
+ count = 0;
+ ready = 0;
+ inflight = 0;
+ list_for_each_entry_safe(rq, rn, &tl->requests, link) {
+ if (i915_request_completed(rq))
+ continue;
+
+ count++;
+ if (i915_request_is_ready(rq))
+ ready++;
+ if (i915_request_is_active(rq))
+ inflight++;
+ }
+
+ drm_printf(m, "Timeline %llx: { ", tl->fence_context);
+ drm_printf(m, "count: %lu, ready: %lu, inflight: %lu",
+ count, ready, inflight);
+ drm_printf(m, ", seqno: { current: %d, last: %d }",
+ *tl->hwsp_seqno, tl->seqno);
+ fence = i915_active_fence_get(&tl->last_request);
+ if (fence) {
+ drm_printf(m, ", engine: %s",
+ to_request(fence)->engine->name);
+ dma_fence_put(fence);
+ }
+ drm_printf(m, " }\n");
+
+ if (show_request) {
+ list_for_each_entry_safe(rq, rn, &tl->requests, link)
+ show_request(m, rq, "", 2);
+ }
+
+ mutex_unlock(&tl->mutex);
+ spin_lock(&timelines->lock);
+
+ /* Resume list iteration after reacquiring spinlock */
+ list_safe_reset_next(tl, tn, link);
+ if (atomic_dec_and_test(&tl->active_count))
+ list_del(&tl->link);
+
+ /* Defer the final release to after the spinlock */
+ if (refcount_dec_and_test(&tl->kref.refcount)) {
+ GEM_BUG_ON(atomic_read(&tl->active_count));
+ list_add(&tl->link, &free);
+ }
+ }
+ spin_unlock(&timelines->lock);
+
+ list_for_each_entry_safe(tl, tn, &free, link)
+ __intel_timeline_free(&tl->kref);
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "gt/selftests/mock_timeline.c"
+#include "gt/selftest_timeline.c"
+#endif