drm: Improve drm_mm search (and fix topdown allocation) with rbtrees

The drm_mm range manager claimed to support top-down insertion, but it
was neither searching for the top-most hole that could fit the
allocation request nor fitting the request to the hole correctly.

In order to search the range efficiently, we create a secondary index
for the holes using either their size or their address. This index
allows us to find the smallest hole or the hole at the bottom or top of
the range efficiently, whilst keeping the hole stack to rapidly service
evictions.

v2: Search for holes both high and low. Rename flags to mode.
v3: Discover rb_entry_safe() and use it!
v4: Kerneldoc for enum drm_mm_insert_mode.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Sinclair Yeh <syeh@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com> # vmwgfx
Reviewed-by: Lucas Stach <l.stach@pengutronix.de> #etnaviv
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170202210438.28702-1-chris@chris-wilson.co.uk

1 files changed, 26 insertions, 32 deletions

diff --git a/drivers/gpu/drm/selftests/test-drm_mm.c b/drivers/gpu/drm/selftests/test-drm_mm.c
index 6df53e6c1308..bb5b7480e0b4 100644
--- a/drivers/gpu/drm/selftests/test-drm_mm.c
+++ b/drivers/gpu/drm/selftests/test-drm_mm.c
@@ -22,23 +22,24 @@ static unsigned int max_iterations = 8192;
 static unsigned int max_prime = 128;
 
 enum {
-	DEFAULT,
-	TOPDOWN,
 	BEST,
+	BOTTOMUP,
+	TOPDOWN,
+	EVICT,
 };
 
 static const struct insert_mode {
 	const char *name;
-	unsigned int search_flags;
-	unsigned int create_flags;
+	enum drm_mm_insert_mode mode;
 } insert_modes[] = {
-	[DEFAULT] = { "default", DRM_MM_SEARCH_DEFAULT, DRM_MM_CREATE_DEFAULT },
-	[TOPDOWN] = { "top-down", DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP },
-	[BEST] = { "best", DRM_MM_SEARCH_BEST, DRM_MM_CREATE_DEFAULT },
+	[BEST] = { "best", DRM_MM_INSERT_BEST },
+	[BOTTOMUP] = { "bottom-up", DRM_MM_INSERT_LOW },
+	[TOPDOWN] = { "top-down", DRM_MM_INSERT_HIGH },
+	[EVICT] = { "evict", DRM_MM_INSERT_EVICT },
 	{}
 }, evict_modes[] = {
-	{ "default", DRM_MM_SEARCH_DEFAULT, DRM_MM_CREATE_DEFAULT },
-	{ "top-down", DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP },
+	{ "bottom-up", DRM_MM_INSERT_LOW },
+	{ "top-down", DRM_MM_INSERT_HIGH },
 	{}
 };
 
@@ -526,8 +527,7 @@ static bool expect_insert(struct drm_mm *mm, struct drm_mm_node *node,
 
 	err = drm_mm_insert_node_generic(mm, node,
 					 size, alignment, color,
-					 mode->search_flags,
-					 mode->create_flags);
+					 mode->mode);
 	if (err) {
 		pr_err("insert (size=%llu, alignment=%llu, color=%lu, mode=%s) failed with err=%d\n",
 		       size, alignment, color, mode->name, err);
@@ -547,7 +547,7 @@ static bool expect_insert_fail(struct drm_mm *mm, u64 size)
 	struct drm_mm_node tmp = {};
 	int err;
 
-	err = drm_mm_insert_node(mm, &tmp, size, 0, DRM_MM_SEARCH_DEFAULT);
+	err = drm_mm_insert_node(mm, &tmp, size);
 	if (likely(err == -ENOSPC))
 		return true;
 
@@ -753,11 +753,10 @@ static bool expect_insert_in_range(struct drm_mm *mm, struct drm_mm_node *node,
 {
 	int err;
 
-	err = drm_mm_insert_node_in_range_generic(mm, node,
-						  size, alignment, color,
-						  range_start, range_end,
-						  mode->search_flags,
-						  mode->create_flags);
+	err = drm_mm_insert_node_in_range(mm, node,
+					  size, alignment, color,
+					  range_start, range_end,
+					  mode->mode);
 	if (err) {
 		pr_err("insert (size=%llu, alignment=%llu, color=%lu, mode=%s) nto range [%llx, %llx] failed with err=%d\n",
 		       size, alignment, color, mode->name,
@@ -781,11 +780,10 @@ static bool expect_insert_in_range_fail(struct drm_mm *mm,
 	struct drm_mm_node tmp = {};
 	int err;
 
-	err = drm_mm_insert_node_in_range_generic(mm, &tmp,
-						  size, 0, 0,
-						  range_start, range_end,
-						  DRM_MM_SEARCH_DEFAULT,
-						  DRM_MM_CREATE_DEFAULT);
+	err = drm_mm_insert_node_in_range(mm, &tmp,
+					  size, 0, 0,
+					  range_start, range_end,
+					  0);
 	if (likely(err == -ENOSPC))
 		return true;
 
@@ -1324,7 +1322,7 @@ static int evict_something(struct drm_mm *mm,
 	drm_mm_scan_init_with_range(&scan, mm,
 				    size, alignment, 0,
 				    range_start, range_end,
-				    mode->create_flags);
+				    mode->mode);
 	if (!evict_nodes(&scan,
 			 nodes, order, count, false,
 			 &evict_list))
@@ -1332,8 +1330,7 @@ static int evict_something(struct drm_mm *mm,
 
 	memset(&tmp, 0, sizeof(tmp));
 	err = drm_mm_insert_node_generic(mm, &tmp, size, alignment, 0,
-					 mode->search_flags,
-					 mode->create_flags);
+					 DRM_MM_INSERT_EVICT);
 	if (err) {
 		pr_err("Failed to insert into eviction hole: size=%d, align=%d\n",
 		       size, alignment);
@@ -1408,8 +1405,7 @@ static int igt_evict(void *ignored)
 	ret = -EINVAL;
 	drm_mm_init(&mm, 0, size);
 	for (n = 0; n < size; n++) {
-		err = drm_mm_insert_node(&mm, &nodes[n].node, 1, 0,
-					 DRM_MM_SEARCH_DEFAULT);
+		err = drm_mm_insert_node(&mm, &nodes[n].node, 1);
 		if (err) {
 			pr_err("insert failed, step %d\n", n);
 			ret = err;
@@ -1517,8 +1513,7 @@ static int igt_evict_range(void *ignored)
 	ret = -EINVAL;
 	drm_mm_init(&mm, 0, size);
 	for (n = 0; n < size; n++) {
-		err = drm_mm_insert_node(&mm, &nodes[n].node, 1, 0,
-					 DRM_MM_SEARCH_DEFAULT);
+		err = drm_mm_insert_node(&mm, &nodes[n].node, 1);
 		if (err) {
 			pr_err("insert failed, step %d\n", n);
 			ret = err;
@@ -1904,7 +1899,7 @@ static int evict_color(struct drm_mm *mm,
 	drm_mm_scan_init_with_range(&scan, mm,
 				    size, alignment, color,
 				    range_start, range_end,
-				    mode->create_flags);
+				    mode->mode);
 	if (!evict_nodes(&scan,
 			 nodes, order, count, true,
 			 &evict_list))
@@ -1912,8 +1907,7 @@ static int evict_color(struct drm_mm *mm,
 
 	memset(&tmp, 0, sizeof(tmp));
 	err = drm_mm_insert_node_generic(mm, &tmp, size, alignment, color,
-					 mode->search_flags,
-					 mode->create_flags);
+					 DRM_MM_INSERT_EVICT);
 	if (err) {
 		pr_err("Failed to insert into eviction hole: size=%d, align=%d, color=%lu, err=%d\n",
 		       size, alignment, color, err);