[PATCH 05/15] drm/i915: Use vma->exec_entry as our double-entry placeholder

Chris Wilson
2017-02-23T16:18:40Z

This has the benefit of not requiring us to manipulate the
vma->exec_link list when tearing down the execbuffer, and is a
marginally cheaper test to detect the user error.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_gem_evict.c | 17 ++-----
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 77 ++++++++++++++++--------------
drivers/gpu/drm/i915/i915_vma.c | 1 -
3 files changed, 44 insertions(+), 51 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
index a0de5734f7d0..4753c3f46f7e 100644
--- a/drivers/gpu/drm/i915/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
@@ -59,9 +59,6 @@ mark_free(struct drm_mm_scan *scan,
if (i915_vma_is_pinned(vma))
return false;

- if (WARN_ON(!list_empty(&vma->exec_list)))
- return false;
-
if (flags & PIN_NONFAULT && !list_empty(&vma->obj->userfault_link))
return false;

@@ -160,8 +157,6 @@ i915_gem_evict_something(struct i915_address_space *vm,
list_for_each_entry_safe(vma, next, &eviction_list, exec_list) {
ret = drm_mm_scan_remove_block(&scan, &vma->node);
BUG_ON(ret);
-
- INIT_LIST_HEAD(&vma->exec_list);
}

/* Can we unpin some objects such as idle hw contents,
@@ -210,17 +205,12 @@ i915_gem_evict_something(struct i915_address_space *vm,
if (drm_mm_scan_remove_block(&scan, &vma->node))
__i915_vma_pin(vma);
else
- list_del_init(&vma->exec_list);
+ list_del(&vma->exec_list);
}

/* Unbinding will emit any required flushes */
ret = 0;
- while (!list_empty(&eviction_list)) {
- vma = list_first_entry(&eviction_list,
- struct i915_vma,
- exec_list);
-
- list_del_init(&vma->exec_list);
+ list_for_each_entry_safe(vma, next, &eviction_list, exec_list) {
__i915_vma_unpin(vma);
if (ret == 0)
ret = i915_vma_unbind(vma);
@@ -316,7 +306,7 @@ int i915_gem_evict_for_node(struct i915_address_space *vm,
}

/* Overlap of objects in the same batch? */
- if (i915_vma_is_pinned(vma) || !list_empty(&vma->exec_list)) {
+ if (i915_vma_is_pinned(vma)) {
ret = -ENOSPC;
if (vma->exec_entry &&
vma->exec_entry->flags & EXEC_OBJECT_PINNED)
@@ -337,7 +327,6 @@ int i915_gem_evict_for_node(struct i915_address_space *vm,
}

list_for_each_entry_safe(vma, next, &eviction_list, exec_list) {
- list_del_init(&vma->exec_list);
__i915_vma_unpin(vma);
if (ret == 0)
ret = i915_vma_unbind(vma);
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 0f6c7acbc063..9c1dacabe7ef 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -106,13 +106,40 @@ eb_create(struct i915_execbuffer *eb)
} else
eb->and = -eb->args->buffer_count;

- INIT_LIST_HEAD(&eb->vmas);
return 0;
}

+static inline void
+__eb_unreserve_vma(struct i915_vma *vma,
+ const struct drm_i915_gem_exec_object2 *entry)
+{
+ if (unlikely(entry->flags & __EXEC_OBJECT_HAS_FENCE))
+ i915_vma_unpin_fence(vma);
+
+ if (entry->flags & __EXEC_OBJECT_HAS_PIN)
+ __i915_vma_unpin(vma);
+}
+
+static void
+eb_unreserve_vma(struct i915_vma *vma)
+{
+ struct drm_i915_gem_exec_object2 *entry = vma->exec_entry;
+
+ __eb_unreserve_vma(vma, entry);
+ entry->flags &= ~(__EXEC_OBJECT_HAS_FENCE | __EXEC_OBJECT_HAS_PIN);
+}
+
static void
eb_reset(struct i915_execbuffer *eb)
{
+ struct i915_vma *vma;
+
+ list_for_each_entry(vma, &eb->vmas, exec_list) {
+ eb_unreserve_vma(vma);
+ i915_vma_put(vma);
+ vma->exec_entry = NULL;
+ }
+
if (eb->and >= 0)
memset(eb->buckets, 0, (eb->and+1)*sizeof(struct hlist_head));
}
@@ -144,6 +171,8 @@ eb_lookup_vmas(struct i915_execbuffer *eb)
struct list_head objects;
int i, ret;

+ INIT_LIST_HEAD(&eb->vmas);
+
INIT_LIST_HEAD(&objects);
spin_lock(&eb->file->table_lock);
/* Grab a reference to the object and release the lock so we can lookup
@@ -250,40 +279,23 @@ static struct i915_vma *eb_get_vma(struct i915_execbuffer *eb, unsigned long han
}
}

-static void
-eb_unreserve_vma(struct i915_vma *vma)
-{
- struct drm_i915_gem_exec_object2 *entry;
-
- if (!drm_mm_node_allocated(&vma->node))
- return;
-
- entry = vma->exec_entry;
-
- if (entry->flags & __EXEC_OBJECT_HAS_FENCE)
- i915_vma_unpin_fence(vma);
-
- if (entry->flags & __EXEC_OBJECT_HAS_PIN)
- __i915_vma_unpin(vma);
-
- entry->flags &= ~(__EXEC_OBJECT_HAS_FENCE | __EXEC_OBJECT_HAS_PIN);
-}
-
static void eb_destroy(struct i915_execbuffer *eb)
{
- i915_gem_context_put(eb->ctx);
+ struct i915_vma *vma;

- while (!list_empty(&eb->vmas)) {
- struct i915_vma *vma;
+ list_for_each_entry(vma, &eb->vmas, exec_list) {
+ if (!vma->exec_entry)
+ continue;

- vma = list_first_entry(&eb->vmas,
- struct i915_vma,
- exec_list);
- list_del_init(&vma->exec_list);
- eb_unreserve_vma(vma);
+ __eb_unreserve_vma(vma, vma->exec_entry);
vma->exec_entry = NULL;
i915_vma_put(vma);
}
+
+ i915_gem_context_put(eb->ctx);
+
+ if (eb->buckets)
+ kfree(eb->buckets);
}

static inline int use_cpu_reloc(struct drm_i915_gem_object *obj)
@@ -980,13 +992,7 @@ eb_relocate_slow(struct i915_execbuffer *eb)
int i, total, ret;

/* We may process another execbuffer during the unlock... */
- while (!list_empty(&eb->vmas)) {
- vma = list_first_entry(&eb->vmas, struct i915_vma, exec_list);
- list_del_init(&vma->exec_list);
- eb_unreserve_vma(vma);
- i915_vma_put(vma);
- }
-
+ eb_reset(eb);
mutex_unlock(&dev->struct_mutex);

total = 0;
@@ -1047,7 +1053,6 @@ eb_relocate_slow(struct i915_execbuffer *eb)
}

/* reacquire the objects */
- eb_reset(eb);
ret = eb_lookup_vmas(eb);
if (ret)
goto err;
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index c1abfe7b48ea..fab3fa2062c5 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -85,7 +85,6 @@ vma_create(struct drm_i915_gem_object *obj,
if (vma == NULL)
return ERR_PTR(-ENOMEM);

- INIT_LIST_HEAD(&vma->exec_list);
for (i = 0; i < ARRAY_SIZE(vma->last_read); i++)
init_request_active(&vma->last_read[i], i915_vma_retire);
init_request_active(&vma->last_fence, NULL);