Clients like i915 need to segregate cache domains within the GTT which
can lead to small amounts of fragmentation. By allocating the uncached
buffers from the bottom and the cacheable buffers from the top, we can
reduce the amount of wasted space and also optimize allocation of the
mappable portion of the GTT to only those buffers that require CPU
access through the GTT.
For other drivers, allocating small bos from one end and large ones
from the other helps improve the quality of fragmentation.
Original patch by Chris Wilson.
v2 by Ben:
Update callers in i915_gem_object_bind_to_gtt()
Turn search flags and allocation flags into separate enums
Make checkpatch happy where logical/easy
v3 by Ben:
Rebased on top of the many drm_mm changes since the original patches
Remove ATOMIC from allocator flags (Chris)
Reverse order of TOPDOWN and BOTTOMUP
v4 by Lauri:
Remove i915 parts, they don't apply
Respin on top of drm-next
Signed-off-by: Lauri Kasanen <cand@xxxxxxx>
---
drivers/gpu/drm/drm_mm.c | 56 +++++++++++++++++++++++++++++++++++-------------
include/drm/drm_mm.h | 29 +++++++++++++++++++++----
2 files changed, 66 insertions(+), 19 deletions(-)
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index a2d45b74..1728bcc 100644
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -102,7 +102,8 @@ static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_
static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
struct drm_mm_node *node,
unsigned long size, unsigned alignment,
- unsigned long color)
+ unsigned long color,
+ enum drm_mm_allocator_flags flags)
{
struct drm_mm *mm = hole_node->mm;
unsigned long hole_start = drm_mm_hole_node_start(hole_node);
@@ -115,12 +116,22 @@ static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
if (mm->color_adjust)
mm->color_adjust(hole_node, color, &adj_start, &adj_end);
+ if (flags & DRM_MM_CREATE_TOP)
+ adj_start = adj_end - size;
+
if (alignment) {
unsigned tmp = adj_start % alignment;
- if (tmp)
- adj_start += alignment - tmp;
+ if (tmp) {
+ if (flags & DRM_MM_CREATE_TOP)
+ adj_start -= tmp;
+ else
+ adj_start += alignment - tmp;
+ }
}
+ BUG_ON(adj_start < hole_start);
+ BUG_ON(adj_end > hole_end);
+
if (adj_start == hole_start) {
hole_node->hole_follows = 0;
list_del(&hole_node->hole_stack);
@@ -215,16 +226,17 @@ EXPORT_SYMBOL(drm_mm_reserve_node);
int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node,
unsigned long size, unsigned alignment,
unsigned long color,
- enum drm_mm_search_flags flags)
+ enum drm_mm_search_flags sflags,
+ enum drm_mm_allocator_flags aflags)
{
struct drm_mm_node *hole_node;
hole_node = drm_mm_search_free_generic(mm, size, alignment,
- color, flags);
+ color, sflags);
if (!hole_node)
return -ENOSPC;
- drm_mm_insert_helper(hole_node, node, size, alignment, color);
+ drm_mm_insert_helper(hole_node, node, size, alignment, color, aflags);
return 0;
}
EXPORT_SYMBOL(drm_mm_insert_node_generic);
@@ -233,7 +245,8 @@ static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
struct drm_mm_node *node,
unsigned long size, unsigned alignment,
unsigned long color,
- unsigned long start, unsigned long end)
+ unsigned long start, unsigned long end,
+ enum drm_mm_allocator_flags flags)
{
struct drm_mm *mm = hole_node->mm;
unsigned long hole_start = drm_mm_hole_node_start(hole_node);
@@ -248,13 +261,20 @@ static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
if (adj_end > end)
adj_end = end;
+ if (flags & DRM_MM_CREATE_TOP)
+ adj_start = adj_end - size;
+
if (mm->color_adjust)
mm->color_adjust(hole_node, color, &adj_start, &adj_end);
if (alignment) {
unsigned tmp = adj_start % alignment;
- if (tmp)
- adj_start += alignment - tmp;
+ if (tmp) {
+ if (flags & DRM_MM_CREATE_TOP)
+ adj_start -= tmp;
+ else
+ adj_start += alignment - tmp;
+ }
}
if (adj_start == hole_start) {
@@ -271,6 +291,8 @@ static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
INIT_LIST_HEAD(&node->hole_stack);
list_add(&node->node_list, &hole_node->node_list);
+ BUG_ON(node->start < start);
+ BUG_ON(node->start < adj_start);
BUG_ON(node->start + node->size > adj_end);
BUG_ON(node->start + node->size > end);
@@ -298,21 +320,23 @@ static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
* 0 on success, -ENOSPC if there's no suitable hole.
*/
int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node,
- unsigned long size, unsigned alignment, unsigned long color,
+ unsigned long size, unsigned alignment,
+ unsigned long color,
unsigned long start, unsigned long end,
- enum drm_mm_search_flags flags)
+ enum drm_mm_search_flags sflags,
+ enum drm_mm_allocator_flags aflags)
{
struct drm_mm_node *hole_node;
hole_node = drm_mm_search_free_in_range_generic(mm,
size, alignment, color,
- start, end, flags);
+ start, end, sflags);
if (!hole_node)
return -ENOSPC;
drm_mm_insert_helper_range(hole_node, node,
size, alignment, color,
- start, end);
+ start, end, aflags);
return 0;
}
EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic);
@@ -391,7 +415,8 @@ static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
best = NULL;
best_size = ~0UL;
- drm_mm_for_each_hole(entry, mm, adj_start, adj_end) {
+ __drm_mm_for_each_hole(entry, mm, adj_start, adj_end,
+ flags & DRM_MM_SEARCH_BELOW) {
if (mm->color_adjust) {
mm->color_adjust(entry, color, &adj_start, &adj_end);
if (adj_end <= adj_start)
@@ -432,7 +457,8 @@ static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_
best = NULL;
best_size = ~0UL;
- drm_mm_for_each_hole(entry, mm, adj_start, adj_end) {
+ __drm_mm_for_each_hole(entry, mm, adj_start, adj_end,
+ flags & DRM_MM_SEARCH_BELOW) {
if (adj_start < start)
adj_start = start;
if (adj_end > end)
diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h
index 8b6981a..f2bc79b 100644
--- a/include/drm/drm_mm.h
+++ b/include/drm/drm_mm.h
@@ -47,8 +47,17 @@
enum drm_mm_search_flags {
DRM_MM_SEARCH_DEFAULT = 0,
DRM_MM_SEARCH_BEST = 1 << 0,
+ DRM_MM_SEARCH_BELOW = 1 << 1,
};
+enum drm_mm_allocator_flags {
+ DRM_MM_CREATE_DEFAULT = 0,
+ DRM_MM_CREATE_TOP = 1 << 0,
+};
+
+#define DRM_MM_BOTTOMUP DRM_MM_SEARCH_DEFAULT, DRM_MM_CREATE_DEFAULT
+#define DRM_MM_TOPDOWN DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP
+
struct drm_mm_node {
struct list_head node_list;
struct list_head hole_stack;
@@ -195,6 +204,14 @@ static inline unsigned long drm_mm_hole_node_end(struct drm_mm_node *hole_node)
1 : 0; \
entry = list_entry(entry->hole_stack.next, struct drm_mm_node, hole_stack))
+#define __drm_mm_for_each_hole(entry, mm, hole_start, hole_end, backwards) \
+ for (entry = list_entry((backwards) ? (mm)->hole_stack.prev : (mm)->hole_stack.next, struct drm_mm_node, hole_stack); \
+ &entry->hole_stack != &(mm)->hole_stack ? \
+ hole_start = drm_mm_hole_node_start(entry), \
+ hole_end = drm_mm_hole_node_end(entry), \
+ 1 : 0; \
+ entry = list_entry((backwards) ? entry->hole_stack.prev : entry->hole_stack.next, struct drm_mm_node, hole_stack))
+
/*
* Basic range manager support (drm_mm.c)
*/
@@ -205,7 +222,8 @@ int drm_mm_insert_node_generic(struct drm_mm *mm,
unsigned long size,
unsigned alignment,
unsigned long color,
- enum drm_mm_search_flags flags);
+ enum drm_mm_search_flags sflags,
+ enum drm_mm_allocator_flags aflags);
/**
* drm_mm_insert_node - search for space and insert @node
* @mm: drm_mm to allocate from
@@ -228,7 +246,8 @@ static inline int drm_mm_insert_node(struct drm_mm *mm,
unsigned alignment,
enum drm_mm_search_flags flags)
{
- return drm_mm_insert_node_generic(mm, node, size, alignment, 0, flags);
+ return drm_mm_insert_node_generic(mm, node, size, alignment, 0, flags,
+ DRM_MM_CREATE_DEFAULT);
}
int drm_mm_insert_node_in_range_generic(struct drm_mm *mm,
@@ -238,7 +257,8 @@ int drm_mm_insert_node_in_range_generic(struct drm_mm *mm,
unsigned long color,
unsigned long start,
unsigned long end,
- enum drm_mm_search_flags flags);
+ enum drm_mm_search_flags sflags,
+ enum drm_mm_allocator_flags aflags);
/**
* drm_mm_insert_node_in_range - ranged search for space and insert @node
* @mm: drm_mm to allocate from
@@ -266,7 +286,8 @@ static inline int drm_mm_insert_node_in_range(struct drm_mm *mm,
enum drm_mm_search_flags flags)
{
return drm_mm_insert_node_in_range_generic(mm, node, size, alignment,
- 0, start, end, flags);
+ 0, start, end, flags,
+ DRM_MM_CREATE_DEFAULT);
}
void drm_mm_remove_node(struct drm_mm_node *node);
--
1.8.3.1
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