[Intel-gfx] [PATCH v6 01/64] drm/i915: Do not share hwsp across contexts any more, v6
Maarten Lankhorst
maarten.lankhorst at linux.intel.com
Tue Jan 5 15:34:55 UTC 2021
Instead of sharing pages with breadcrumbs, give each timeline a
single page. This allows unrelated timelines not to share locks
any more during command submission.
As an additional benefit, seqno wraparound no longer requires
i915_vma_pin, which means we no longer need to worry about a
potential -EDEADLK at a point where we are ready to submit.
Changes since v1:
- Fix erroneous i915_vma_acquire that should be a i915_vma_release (ickle).
- Extra check for completion in intel_read_hwsp().
Changes since v2:
- Fix inconsistent indent in hwsp_alloc() (kbuild)
- memset entire cacheline to 0.
Changes since v3:
- Do same in intel_timeline_reset_seqno(), and clflush for good measure.
Changes since v4:
- Use refcounting on timeline, instead of relying on i915_active.
- Fix waiting on kernel requests.
Changes since v5:
- Bump amount of slots to maximum (256), for best wraparounds.
- Add hwsp_offset to i915_request to fix potential wraparound hang.
- Ensure timeline wrap test works with the changes.
- Assign hwsp in intel_timeline_read_hwsp() within the rcu lock to
fix a hang.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom at intel.com> #v1
Reported-by: kernel test robot <lkp at intel.com>
---
drivers/gpu/drm/i915/gt/gen2_engine_cs.c | 2 +-
drivers/gpu/drm/i915/gt/gen6_engine_cs.c | 8 +-
drivers/gpu/drm/i915/gt/gen8_engine_cs.c | 12 +-
drivers/gpu/drm/i915/gt/intel_engine_cs.c | 1 +
drivers/gpu/drm/i915/gt/intel_gt_types.h | 4 -
drivers/gpu/drm/i915/gt/intel_timeline.c | 422 ++++--------------
.../gpu/drm/i915/gt/intel_timeline_types.h | 17 +-
drivers/gpu/drm/i915/gt/selftest_engine_cs.c | 5 +-
drivers/gpu/drm/i915/gt/selftest_timeline.c | 83 ++--
drivers/gpu/drm/i915/i915_request.c | 4 -
drivers/gpu/drm/i915/i915_request.h | 17 +-
11 files changed, 160 insertions(+), 415 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/gen2_engine_cs.c b/drivers/gpu/drm/i915/gt/gen2_engine_cs.c
index b491a64919c8..9646200d2792 100644
--- a/drivers/gpu/drm/i915/gt/gen2_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/gen2_engine_cs.c
@@ -143,7 +143,7 @@ static u32 *__gen2_emit_breadcrumb(struct i915_request *rq, u32 *cs,
int flush, int post)
{
GEM_BUG_ON(i915_request_active_timeline(rq)->hwsp_ggtt != rq->engine->status_page.vma);
- GEM_BUG_ON(offset_in_page(i915_request_active_timeline(rq)->hwsp_offset) != I915_GEM_HWS_SEQNO_ADDR);
+ GEM_BUG_ON(offset_in_page(rq->hwsp_seqno) != I915_GEM_HWS_SEQNO_ADDR);
*cs++ = MI_FLUSH;
diff --git a/drivers/gpu/drm/i915/gt/gen6_engine_cs.c b/drivers/gpu/drm/i915/gt/gen6_engine_cs.c
index ce38d1bcaba3..dd094e21bb51 100644
--- a/drivers/gpu/drm/i915/gt/gen6_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/gen6_engine_cs.c
@@ -161,7 +161,7 @@ u32 *gen6_emit_breadcrumb_rcs(struct i915_request *rq, u32 *cs)
PIPE_CONTROL_DC_FLUSH_ENABLE |
PIPE_CONTROL_QW_WRITE |
PIPE_CONTROL_CS_STALL);
- *cs++ = i915_request_active_timeline(rq)->hwsp_offset |
+ *cs++ = i915_request_active_offset(rq) |
PIPE_CONTROL_GLOBAL_GTT;
*cs++ = rq->fence.seqno;
@@ -359,7 +359,7 @@ u32 *gen7_emit_breadcrumb_rcs(struct i915_request *rq, u32 *cs)
PIPE_CONTROL_QW_WRITE |
PIPE_CONTROL_GLOBAL_GTT_IVB |
PIPE_CONTROL_CS_STALL);
- *cs++ = i915_request_active_timeline(rq)->hwsp_offset;
+ *cs++ = i915_request_active_offset(rq);
*cs++ = rq->fence.seqno;
*cs++ = MI_USER_INTERRUPT;
@@ -374,7 +374,7 @@ u32 *gen7_emit_breadcrumb_rcs(struct i915_request *rq, u32 *cs)
u32 *gen6_emit_breadcrumb_xcs(struct i915_request *rq, u32 *cs)
{
GEM_BUG_ON(i915_request_active_timeline(rq)->hwsp_ggtt != rq->engine->status_page.vma);
- GEM_BUG_ON(offset_in_page(i915_request_active_timeline(rq)->hwsp_offset) != I915_GEM_HWS_SEQNO_ADDR);
+ GEM_BUG_ON(offset_in_page(rq->hwsp_seqno) != I915_GEM_HWS_SEQNO_ADDR);
*cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
*cs++ = I915_GEM_HWS_SEQNO_ADDR | MI_FLUSH_DW_USE_GTT;
@@ -394,7 +394,7 @@ u32 *gen7_emit_breadcrumb_xcs(struct i915_request *rq, u32 *cs)
int i;
GEM_BUG_ON(i915_request_active_timeline(rq)->hwsp_ggtt != rq->engine->status_page.vma);
- GEM_BUG_ON(offset_in_page(i915_request_active_timeline(rq)->hwsp_offset) != I915_GEM_HWS_SEQNO_ADDR);
+ GEM_BUG_ON(offset_in_page(rq->hwsp_seqno) != I915_GEM_HWS_SEQNO_ADDR);
*cs++ = MI_FLUSH_DW | MI_INVALIDATE_TLB |
MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
index 1972dd5dca00..33eaa0203b1d 100644
--- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
@@ -338,15 +338,13 @@ static inline u32 preempt_address(struct intel_engine_cs *engine)
static u32 hwsp_offset(const struct i915_request *rq)
{
- const struct intel_timeline_cacheline *cl;
+ const struct intel_timeline *tl;
- /* Before the request is executed, the timeline/cachline is fixed */
+ /* Before the request is executed, the timeline is fixed */
+ tl = rcu_dereference_protected(rq->timeline,
+ !i915_request_signaled(rq));
- cl = rcu_dereference_protected(rq->hwsp_cacheline, 1);
- if (cl)
- return cl->ggtt_offset;
-
- return rcu_dereference_protected(rq->timeline, 1)->hwsp_offset;
+ return page_mask_bits(tl->hwsp_offset) + offset_in_page(rq->hwsp_seqno);
}
int gen8_emit_init_breadcrumb(struct i915_request *rq)
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 1847d3c2ea99..1db608d1f26f 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -754,6 +754,7 @@ static int measure_breadcrumb_dw(struct intel_context *ce)
frame->rq.engine = engine;
frame->rq.context = ce;
rcu_assign_pointer(frame->rq.timeline, ce->timeline);
+ frame->rq.hwsp_seqno = ce->timeline->hwsp_seqno;
frame->ring.vaddr = frame->cs;
frame->ring.size = sizeof(frame->cs);
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_types.h b/drivers/gpu/drm/i915/gt/intel_gt_types.h
index a83d3e18254d..f7dab4fc926c 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_types.h
@@ -39,10 +39,6 @@ struct intel_gt {
struct intel_gt_timelines {
spinlock_t lock; /* protects active_list */
struct list_head active_list;
-
- /* Pack multiple timelines' seqnos into the same page */
- spinlock_t hwsp_lock;
- struct list_head hwsp_free_list;
} timelines;
struct intel_gt_requests {
diff --git a/drivers/gpu/drm/i915/gt/intel_timeline.c b/drivers/gpu/drm/i915/gt/intel_timeline.c
index 7fe05918a76e..3d43f15f34f3 100644
--- a/drivers/gpu/drm/i915/gt/intel_timeline.c
+++ b/drivers/gpu/drm/i915/gt/intel_timeline.c
@@ -12,21 +12,9 @@
#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 TIMELINE_SEQNO_BYTES 8
-#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)
+static struct i915_vma *hwsp_alloc(struct intel_gt *gt)
{
struct drm_i915_private *i915 = gt->i915;
struct drm_i915_gem_object *obj;
@@ -45,220 +33,59 @@ static struct i915_vma *__hwsp_alloc(struct intel_gt *gt)
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;
- }
-
- GT_TRACE(timeline->gt, "new HWSP allocated\n");
-
- 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 __rcu_cacheline_free(struct rcu_head *rcu)
-{
- struct intel_timeline_cacheline *cl =
- container_of(rcu, typeof(*cl), rcu);
-
- /* Must wait until after all *rq->hwsp are complete before removing */
- i915_gem_object_unpin_map(cl->hwsp->vma->obj);
- __idle_hwsp_free(cl->hwsp, ptr_unmask_bits(cl->vaddr, CACHELINE_BITS));
-
- i915_active_fini(&cl->active);
- kfree(cl);
-}
-
-static void __idle_cacheline_free(struct intel_timeline_cacheline *cl)
-{
- GEM_BUG_ON(!i915_active_is_idle(&cl->active));
- call_rcu(&cl->rcu, __rcu_cacheline_free);
-}
-
__i915_active_call
-static void __cacheline_retire(struct i915_active *active)
+static void __timeline_retire(struct i915_active *active)
{
- struct intel_timeline_cacheline *cl =
- container_of(active, typeof(*cl), active);
+ struct intel_timeline *tl =
+ container_of(active, typeof(*tl), active);
- i915_vma_unpin(cl->hwsp->vma);
- if (ptr_test_bit(cl->vaddr, CACHELINE_FREE))
- __idle_cacheline_free(cl);
+ i915_vma_unpin(tl->hwsp_ggtt);
+ intel_timeline_put(tl);
}
-static int __cacheline_active(struct i915_active *active)
+static int __timeline_active(struct i915_active *active)
{
- struct intel_timeline_cacheline *cl =
- container_of(active, typeof(*cl), active);
+ struct intel_timeline *tl =
+ container_of(active, typeof(*tl), active);
- __i915_vma_pin(cl->hwsp->vma);
+ __i915_vma_pin(tl->hwsp_ggtt);
+ intel_timeline_get(tl);
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);
- }
-
- 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,
- u32 ggtt_offset)
-{
- if (!cl)
- return;
-
- cl->ggtt_offset = ggtt_offset;
- 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)
-{
- if (!i915_active_acquire_if_busy(&cl->active)) {
- __idle_cacheline_free(cl);
- return;
- }
-
- GEM_BUG_ON(ptr_test_bit(cl->vaddr, CACHELINE_FREE));
- cl->vaddr = ptr_set_bit(cl->vaddr, CACHELINE_FREE);
-
- i915_active_release(&cl->active);
-}
-
static int intel_timeline_init(struct intel_timeline *timeline,
struct intel_gt *gt,
struct i915_vma *hwsp,
unsigned int offset)
{
void *vaddr;
+ u32 *seqno;
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 (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);
-
- 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 = offset;
- vaddr = i915_gem_object_pin_map(hwsp->obj, I915_MAP_WB);
- if (IS_ERR(vaddr))
- return PTR_ERR(vaddr);
+ timeline->hwsp_ggtt = hwsp;
}
- timeline->hwsp_seqno =
- memset(vaddr + timeline->hwsp_offset, 0, CACHELINE_BYTES);
+ vaddr = i915_gem_object_pin_map(hwsp->obj, I915_MAP_WB);
+ if (IS_ERR(vaddr))
+ return PTR_ERR(vaddr);
+
+ timeline->hwsp_map = vaddr;
+ seqno = vaddr + timeline->hwsp_offset;
+ WRITE_ONCE(*seqno, 0);
+ timeline->hwsp_seqno = seqno;
- timeline->hwsp_ggtt = i915_vma_get(hwsp);
GEM_BUG_ON(timeline->hwsp_offset >= hwsp->size);
timeline->fence_context = dma_fence_context_alloc(1);
@@ -269,6 +96,7 @@ static int intel_timeline_init(struct intel_timeline *timeline,
INIT_LIST_HEAD(&timeline->requests);
i915_syncmap_init(&timeline->sync);
+ i915_active_init(&timeline->active, __timeline_active, __timeline_retire);
return 0;
}
@@ -279,23 +107,18 @@ void intel_gt_init_timelines(struct intel_gt *gt)
spin_lock_init(&timelines->lock);
INIT_LIST_HEAD(&timelines->active_list);
-
- spin_lock_init(&timelines->hwsp_lock);
- INIT_LIST_HEAD(&timelines->hwsp_free_list);
}
-static void intel_timeline_fini(struct intel_timeline *timeline)
+static void intel_timeline_fini(struct rcu_head *rcu)
{
- GEM_BUG_ON(atomic_read(&timeline->pin_count));
- GEM_BUG_ON(!list_empty(&timeline->requests));
- GEM_BUG_ON(timeline->retire);
+ struct intel_timeline *timeline =
+ container_of(rcu, struct intel_timeline, rcu);
- if (timeline->hwsp_cacheline)
- cacheline_free(timeline->hwsp_cacheline);
- else
- i915_gem_object_unpin_map(timeline->hwsp_ggtt->obj);
+ i915_gem_object_unpin_map(timeline->hwsp_ggtt->obj);
i915_vma_put(timeline->hwsp_ggtt);
+ i915_active_fini(&timeline->active);
+ kfree(timeline);
}
struct intel_timeline *
@@ -361,9 +184,9 @@ int intel_timeline_pin(struct intel_timeline *tl, struct i915_gem_ww_ctx *ww)
GT_TRACE(tl->gt, "timeline:%llx using HWSP offset:%x\n",
tl->fence_context, tl->hwsp_offset);
- cacheline_acquire(tl->hwsp_cacheline, tl->hwsp_offset);
+ i915_active_acquire(&tl->active);
if (atomic_fetch_inc(&tl->pin_count)) {
- cacheline_release(tl->hwsp_cacheline);
+ i915_active_release(&tl->active);
__i915_vma_unpin(tl->hwsp_ggtt);
}
@@ -372,9 +195,13 @@ int intel_timeline_pin(struct intel_timeline *tl, struct i915_gem_ww_ctx *ww)
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));
- WRITE_ONCE(*(u32 *)tl->hwsp_seqno, tl->seqno);
+
+ memset(hwsp_seqno + 1, 0, TIMELINE_SEQNO_BYTES - sizeof(*hwsp_seqno));
+ WRITE_ONCE(*hwsp_seqno, tl->seqno);
+ clflush(hwsp_seqno);
}
void intel_timeline_enter(struct intel_timeline *tl)
@@ -450,106 +277,23 @@ static u32 timeline_advance(struct intel_timeline *tl)
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;
-
- might_lock(&tl->gt->ggtt->vm.mutex);
- GT_TRACE(tl->gt, "timeline:%llx wrapped\n", tl->fence_context);
-
- /*
- * 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_ggtt_pin(vma, NULL, 0, PIN_HIGH);
- if (err) {
- __idle_hwsp_free(vma->private, cacheline);
- goto err_rollback;
- }
+ u32 next_ofs = offset_in_page(tl->hwsp_offset + TIMELINE_SEQNO_BYTES);
- 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->fence);
- if (err)
- goto err_cacheline;
+ /* 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));
- 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);
- GT_TRACE(tl->gt, "timeline:%llx using HWSP offset:%x\n",
- tl->fence_context, tl->hwsp_offset);
-
- cacheline_acquire(cl, tl->hwsp_offset);
- tl->hwsp_cacheline = cl;
+ 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;
-
-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,
@@ -559,51 +303,52 @@ int intel_timeline_get_seqno(struct intel_timeline *tl,
*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);
+ if (unlikely(!*seqno && tl->has_initial_breadcrumb))
+ return __intel_timeline_get_seqno(tl, 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;
+ struct intel_timeline *tl;
int err;
- GEM_BUG_ON(!rcu_access_pointer(from->hwsp_cacheline));
-
rcu_read_lock();
- cl = rcu_dereference(from->hwsp_cacheline);
- if (i915_request_completed(from)) /* confirm cacheline is valid */
- goto unlock;
- if (unlikely(!i915_active_acquire_if_busy(&cl->active)))
- goto unlock; /* seqno wrapped and completed! */
- if (unlikely(i915_request_completed(from)))
- goto release;
+ tl = rcu_dereference(from->timeline);
+ if (i915_request_completed(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_completed(from)) {
+ i915_active_release(&tl->active);
+ tl = NULL;
+ }
rcu_read_unlock();
- err = cacheline_ref(cl, to);
- if (err)
+ 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);
- *hwsp = cl->ggtt_offset;
out:
- i915_active_release(&cl->active);
+ i915_active_release(&tl->active);
return err;
-
-release:
- i915_active_release(&cl->active);
-unlock:
- rcu_read_unlock();
- return 1;
}
void intel_timeline_unpin(struct intel_timeline *tl)
@@ -612,8 +357,7 @@ void intel_timeline_unpin(struct intel_timeline *tl)
if (!atomic_dec_and_test(&tl->pin_count))
return;
- cacheline_release(tl->hwsp_cacheline);
-
+ i915_active_release(&tl->active);
__i915_vma_unpin(tl->hwsp_ggtt);
}
@@ -622,8 +366,11 @@ 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);
+ 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)
@@ -631,7 +378,6 @@ 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));
}
void intel_gt_show_timelines(struct intel_gt *gt,
diff --git a/drivers/gpu/drm/i915/gt/intel_timeline_types.h b/drivers/gpu/drm/i915/gt/intel_timeline_types.h
index e360f50706bf..9c1d767a867f 100644
--- a/drivers/gpu/drm/i915/gt/intel_timeline_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_timeline_types.h
@@ -18,7 +18,6 @@
struct i915_vma;
struct i915_syncmap;
struct intel_gt;
-struct intel_timeline_hwsp;
struct intel_timeline {
u64 fence_context;
@@ -45,12 +44,11 @@ struct intel_timeline {
atomic_t pin_count;
atomic_t active_count;
+ void *hwsp_map;
const u32 *hwsp_seqno;
struct i915_vma *hwsp_ggtt;
u32 hwsp_offset;
- struct intel_timeline_cacheline *hwsp_cacheline;
-
bool has_initial_breadcrumb;
/**
@@ -67,6 +65,8 @@ struct intel_timeline {
*/
struct i915_active_fence last_request;
+ struct i915_active active;
+
/** A chain of completed timelines ready for early retirement. */
struct intel_timeline *retire;
@@ -90,15 +90,4 @@ struct intel_timeline {
struct rcu_head rcu;
};
-struct intel_timeline_cacheline {
- struct i915_active active;
-
- struct intel_timeline_hwsp *hwsp;
- void *vaddr;
-
- u32 ggtt_offset;
-
- struct rcu_head rcu;
-};
-
#endif /* __I915_TIMELINE_TYPES_H__ */
diff --git a/drivers/gpu/drm/i915/gt/selftest_engine_cs.c b/drivers/gpu/drm/i915/gt/selftest_engine_cs.c
index 439c8984f5fa..fd9414b0d1bd 100644
--- a/drivers/gpu/drm/i915/gt/selftest_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/selftest_engine_cs.c
@@ -42,6 +42,9 @@ static int perf_end(struct intel_gt *gt)
static int write_timestamp(struct i915_request *rq, int slot)
{
+ struct intel_timeline *tl =
+ rcu_dereference_protected(rq->timeline,
+ !i915_request_signaled(rq));
u32 cmd;
u32 *cs;
@@ -54,7 +57,7 @@ static int write_timestamp(struct i915_request *rq, int slot)
cmd++;
*cs++ = cmd;
*cs++ = i915_mmio_reg_offset(RING_TIMESTAMP(rq->engine->mmio_base));
- *cs++ = i915_request_timeline(rq)->hwsp_offset + slot * sizeof(u32);
+ *cs++ = tl->hwsp_offset + slot * sizeof(u32);
*cs++ = 0;
intel_ring_advance(rq, cs);
diff --git a/drivers/gpu/drm/i915/gt/selftest_timeline.c b/drivers/gpu/drm/i915/gt/selftest_timeline.c
index 6f3a3687ef0f..6e32e91cdab4 100644
--- a/drivers/gpu/drm/i915/gt/selftest_timeline.c
+++ b/drivers/gpu/drm/i915/gt/selftest_timeline.c
@@ -666,7 +666,7 @@ static int live_hwsp_wrap(void *arg)
if (IS_ERR(tl))
return PTR_ERR(tl);
- if (!tl->has_initial_breadcrumb || !tl->hwsp_cacheline)
+ if (!tl->has_initial_breadcrumb)
goto out_free;
err = intel_timeline_pin(tl, NULL);
@@ -833,12 +833,26 @@ static int setup_watcher(struct hwsp_watcher *w, struct intel_gt *gt)
return 0;
}
+static void switch_tl_lock(struct i915_request *from, struct i915_request *to)
+{
+ /* some light mutex juggling required; think co-routines */
+
+ if (from) {
+ lockdep_unpin_lock(&from->context->timeline->mutex, from->cookie);
+ mutex_unlock(&from->context->timeline->mutex);
+ }
+
+ if (to) {
+ mutex_lock(&to->context->timeline->mutex);
+ to->cookie = lockdep_pin_lock(&to->context->timeline->mutex);
+ }
+}
+
static int create_watcher(struct hwsp_watcher *w,
struct intel_engine_cs *engine,
int ringsz)
{
struct intel_context *ce;
- struct intel_timeline *tl;
ce = intel_context_create(engine);
if (IS_ERR(ce))
@@ -851,11 +865,8 @@ static int create_watcher(struct hwsp_watcher *w,
return PTR_ERR(w->rq);
w->addr = i915_ggtt_offset(w->vma);
- tl = w->rq->context->timeline;
- /* some light mutex juggling required; think co-routines */
- lockdep_unpin_lock(&tl->mutex, w->rq->cookie);
- mutex_unlock(&tl->mutex);
+ switch_tl_lock(w->rq, NULL);
return 0;
}
@@ -864,15 +875,13 @@ static int check_watcher(struct hwsp_watcher *w, const char *name,
bool (*op)(u32 hwsp, u32 seqno))
{
struct i915_request *rq = fetch_and_zero(&w->rq);
- struct intel_timeline *tl = rq->context->timeline;
u32 offset, end;
int err;
GEM_BUG_ON(w->addr - i915_ggtt_offset(w->vma) > w->vma->size);
i915_request_get(rq);
- mutex_lock(&tl->mutex);
- rq->cookie = lockdep_pin_lock(&tl->mutex);
+ switch_tl_lock(NULL, rq);
i915_request_add(rq);
if (i915_request_wait(rq, 0, HZ) < 0) {
@@ -901,10 +910,7 @@ static int check_watcher(struct hwsp_watcher *w, const char *name,
static void cleanup_watcher(struct hwsp_watcher *w)
{
if (w->rq) {
- struct intel_timeline *tl = w->rq->context->timeline;
-
- mutex_lock(&tl->mutex);
- w->rq->cookie = lockdep_pin_lock(&tl->mutex);
+ switch_tl_lock(NULL, w->rq);
i915_request_add(w->rq);
}
@@ -942,7 +948,7 @@ static struct i915_request *wrap_timeline(struct i915_request *rq)
}
i915_request_put(rq);
- rq = intel_context_create_request(ce);
+ rq = i915_request_create(ce);
if (IS_ERR(rq))
return rq;
@@ -977,7 +983,7 @@ static int live_hwsp_read(void *arg)
if (IS_ERR(tl))
return PTR_ERR(tl);
- if (!tl->hwsp_cacheline)
+ if (!tl->has_initial_breadcrumb)
goto out_free;
for (i = 0; i < ARRAY_SIZE(watcher); i++) {
@@ -999,7 +1005,7 @@ static int live_hwsp_read(void *arg)
do {
struct i915_sw_fence *submit;
struct i915_request *rq;
- u32 hwsp;
+ u32 hwsp, dummy;
submit = heap_fence_create(GFP_KERNEL);
if (!submit) {
@@ -1017,14 +1023,26 @@ static int live_hwsp_read(void *arg)
goto out;
}
- /* Skip to the end, saving 30 minutes of nops */
- tl->seqno = -10u + 2 * (count & 3);
- WRITE_ONCE(*(u32 *)tl->hwsp_seqno, tl->seqno);
ce->timeline = intel_timeline_get(tl);
- rq = intel_context_create_request(ce);
+ /* Ensure timeline is mapped, done during first pin */
+ err = intel_context_pin(ce);
+ if (err) {
+ intel_context_put(ce);
+ goto out;
+ }
+
+ /*
+ * Start at a new wrap, and set seqno right before another wrap,
+ * saving 30 minutes of nops
+ */
+ tl->seqno = -12u + 2 * (count & 3);
+ __intel_timeline_get_seqno(tl, &dummy);
+
+ rq = i915_request_create(ce);
if (IS_ERR(rq)) {
err = PTR_ERR(rq);
+ intel_context_unpin(ce);
intel_context_put(ce);
goto out;
}
@@ -1034,32 +1052,35 @@ static int live_hwsp_read(void *arg)
GFP_KERNEL);
if (err < 0) {
i915_request_add(rq);
+ intel_context_unpin(ce);
intel_context_put(ce);
goto out;
}
- mutex_lock(&watcher[0].rq->context->timeline->mutex);
+ switch_tl_lock(rq, watcher[0].rq);
err = intel_timeline_read_hwsp(rq, watcher[0].rq, &hwsp);
if (err == 0)
err = emit_read_hwsp(watcher[0].rq, /* before */
rq->fence.seqno, hwsp,
&watcher[0].addr);
- mutex_unlock(&watcher[0].rq->context->timeline->mutex);
+ switch_tl_lock(watcher[0].rq, rq);
if (err) {
i915_request_add(rq);
+ intel_context_unpin(ce);
intel_context_put(ce);
goto out;
}
- mutex_lock(&watcher[1].rq->context->timeline->mutex);
+ switch_tl_lock(rq, watcher[1].rq);
err = intel_timeline_read_hwsp(rq, watcher[1].rq, &hwsp);
if (err == 0)
err = emit_read_hwsp(watcher[1].rq, /* after */
rq->fence.seqno, hwsp,
&watcher[1].addr);
- mutex_unlock(&watcher[1].rq->context->timeline->mutex);
+ switch_tl_lock(watcher[1].rq, rq);
if (err) {
i915_request_add(rq);
+ intel_context_unpin(ce);
intel_context_put(ce);
goto out;
}
@@ -1068,6 +1089,7 @@ static int live_hwsp_read(void *arg)
i915_request_add(rq);
rq = wrap_timeline(rq);
+ intel_context_unpin(ce);
intel_context_put(ce);
if (IS_ERR(rq)) {
err = PTR_ERR(rq);
@@ -1107,8 +1129,8 @@ static int live_hwsp_read(void *arg)
3 * watcher[1].rq->ring->size)
break;
- } while (!__igt_timeout(end_time, NULL));
- WRITE_ONCE(*(u32 *)tl->hwsp_seqno, 0xdeadbeef);
+ } while (!__igt_timeout(end_time, NULL) &&
+ count < (PAGE_SIZE / TIMELINE_SEQNO_BYTES - 1) / 2);
pr_info("%s: simulated %lu wraps\n", engine->name, count);
err = check_watcher(&watcher[1], "after", cmp_gte);
@@ -1153,9 +1175,7 @@ static int live_hwsp_rollover_kernel(void *arg)
}
GEM_BUG_ON(i915_active_fence_isset(&tl->last_request));
- tl->seqno = 0;
- timeline_rollback(tl);
- timeline_rollback(tl);
+ tl->seqno = -2u;
WRITE_ONCE(*(u32 *)tl->hwsp_seqno, tl->seqno);
for (i = 0; i < ARRAY_SIZE(rq); i++) {
@@ -1235,11 +1255,10 @@ static int live_hwsp_rollover_user(void *arg)
goto out;
tl = ce->timeline;
- if (!tl->has_initial_breadcrumb || !tl->hwsp_cacheline)
+ if (!tl->has_initial_breadcrumb)
goto out;
- timeline_rollback(tl);
- timeline_rollback(tl);
+ tl->seqno = -4u;
WRITE_ONCE(*(u32 *)tl->hwsp_seqno, tl->seqno);
for (i = 0; i < ARRAY_SIZE(rq); i++) {
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index bfd82d8259f4..b661b3b5992e 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -851,7 +851,6 @@ __i915_request_create(struct intel_context *ce, gfp_t gfp)
rq->fence.seqno = seqno;
RCU_INIT_POINTER(rq->timeline, tl);
- RCU_INIT_POINTER(rq->hwsp_cacheline, tl->hwsp_cacheline);
rq->hwsp_seqno = tl->hwsp_seqno;
GEM_BUG_ON(i915_request_completed(rq));
@@ -1090,9 +1089,6 @@ emit_semaphore_wait(struct i915_request *to,
if (i915_request_has_initial_breadcrumb(to))
goto await_fence;
- if (!rcu_access_pointer(from->hwsp_cacheline))
- goto await_fence;
-
/*
* If this or its dependents are waiting on an external fence
* that may fail catastrophically, then we want to avoid using
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index a8c413203f72..c25b0afcc225 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -237,16 +237,6 @@ struct i915_request {
*/
const u32 *hwsp_seqno;
- /*
- * If we need to access the timeline's seqno for this request in
- * another request, we need to keep a read reference to this associated
- * cacheline, so that we do not free and recycle it before the foreign
- * observers have completed. Hence, we keep a pointer to the cacheline
- * inside the timeline's HWSP vma, but it is only valid while this
- * request has not completed and guarded by the timeline mutex.
- */
- struct intel_timeline_cacheline __rcu *hwsp_cacheline;
-
/** Position in the ring of the start of the request */
u32 head;
@@ -615,4 +605,11 @@ i915_request_active_timeline(const struct i915_request *rq)
lockdep_is_held(&rq->engine->active.lock));
}
+static inline u32
+i915_request_active_offset(const struct i915_request *rq)
+{
+ return page_mask_bits(i915_request_active_timeline(rq)->hwsp_offset) +
+ offset_in_page(rq->hwsp_seqno);
+}
+
#endif /* I915_REQUEST_H */
--
2.30.0.rc1
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