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/*
* 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 intel_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 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(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 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(hwsp->gt->i915, &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_REQUEST(&timeline->last_request, &timeline->mutex);
INIT_LIST_HEAD(&timeline->requests);
i915_syncmap_init(&timeline->sync);
return 0;
}
static void timelines_init(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_timelines_init(struct drm_i915_private *i915)
{
timelines_init(&i915->gt);
}
void intel_timeline_fini(struct intel_timeline *timeline)
{
GEM_BUG_ON(atomic_read(&timeline->pin_count));
GEM_BUG_ON(!list_empty(&timeline->requests));
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;
unsigned long flags;
lockdep_assert_held(&tl->mutex);
GEM_BUG_ON(!atomic_read(&tl->pin_count));
if (tl->active_count++)
return;
GEM_BUG_ON(!tl->active_count); /* overflow? */
spin_lock_irqsave(&timelines->lock, flags);
list_add(&tl->link, &timelines->active_list);
spin_unlock_irqrestore(&timelines->lock, flags);
}
void intel_timeline_exit(struct intel_timeline *tl)
{
struct intel_gt_timelines *timelines = &tl->gt->timelines;
unsigned long flags;
lockdep_assert_held(&tl->mutex);
GEM_BUG_ON(!tl->active_count);
if (--tl->active_count)
return;
spin_lock_irqsave(&timelines->lock, flags);
list_del(&tl->link);
spin_unlock_irqrestore(&timelines->lock, flags);
/*
* 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);
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->timeline, 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(!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(timeline);
}
static void timelines_fini(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_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
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