drm/amdgpu: add a custom GTT memory manager v2

Only allocate address space when we really need it.

v2: fix a typo, add correct function description,
    stop leaking the node in the error case.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 238 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
new file mode 100644
index 000000000000..262e872bea0e
--- /dev/null
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
@@ -0,0 +1,238 @@
+/*
+ * Copyright 2016 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Christian König
+ */
+
+#include <drm/drmP.h>
+#include "amdgpu.h"
+
+struct amdgpu_gtt_mgr {
+	struct drm_mm mm;
+	spinlock_t lock;
+	uint64_t available;
+};
+
+/**
+ * amdgpu_gtt_mgr_init - init GTT manager and DRM MM
+ *
+ * @man: TTM memory type manager
+ * @p_size: maximum size of GTT
+ *
+ * Allocate and initialize the GTT manager.
+ */
+static int amdgpu_gtt_mgr_init(struct ttm_mem_type_manager *man,
+			       unsigned long p_size)
+{
+	struct amdgpu_gtt_mgr *mgr;
+
+	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
+	if (!mgr)
+		return -ENOMEM;
+
+	drm_mm_init(&mgr->mm, 0, p_size);
+	spin_lock_init(&mgr->lock);
+	mgr->available = p_size;
+	man->priv = mgr;
+	return 0;
+}
+
+/**
+ * amdgpu_gtt_mgr_fini - free and destroy GTT manager
+ *
+ * @man: TTM memory type manager
+ *
+ * Destroy and free the GTT manager, returns -EBUSY if ranges are still
+ * allocated inside it.
+ */
+static int amdgpu_gtt_mgr_fini(struct ttm_mem_type_manager *man)
+{
+	struct amdgpu_gtt_mgr *mgr = man->priv;
+
+	spin_lock(&mgr->lock);
+	if (!drm_mm_clean(&mgr->mm)) {
+		spin_unlock(&mgr->lock);
+		return -EBUSY;
+	}
+
+	drm_mm_takedown(&mgr->mm);
+	spin_unlock(&mgr->lock);
+	kfree(mgr);
+	man->priv = NULL;
+	return 0;
+}
+
+/**
+ * amdgpu_gtt_mgr_alloc - allocate new ranges
+ *
+ * @man: TTM memory type manager
+ * @tbo: TTM BO we need this range for
+ * @place: placement flags and restrictions
+ * @mem: the resulting mem object
+ *
+ * Allocate the address space for a node.
+ */
+int amdgpu_gtt_mgr_alloc(struct ttm_mem_type_manager *man,
+			 struct ttm_buffer_object *tbo,
+			 const struct ttm_place *place,
+			 struct ttm_mem_reg *mem)
+{
+	struct amdgpu_gtt_mgr *mgr = man->priv;
+	struct drm_mm_node *node = mem->mm_node;
+	enum drm_mm_search_flags sflags = DRM_MM_SEARCH_BEST;
+	enum drm_mm_allocator_flags aflags = DRM_MM_CREATE_DEFAULT;
+	unsigned long fpfn, lpfn;
+	int r;
+
+	if (node->start != AMDGPU_BO_INVALID_OFFSET)
+		return 0;
+
+	if (place)
+		fpfn = place->fpfn;
+	else
+		fpfn = 0;
+
+	if (place && place->lpfn)
+		lpfn = place->lpfn;
+	else
+		lpfn = man->size;
+
+	if (place && place->flags & TTM_PL_FLAG_TOPDOWN) {
+		sflags = DRM_MM_SEARCH_BELOW;
+		aflags = DRM_MM_CREATE_TOP;
+	}
+
+	spin_lock(&mgr->lock);
+	r = drm_mm_insert_node_in_range_generic(&mgr->mm, node, mem->num_pages,
+						mem->page_alignment, 0,
+						fpfn, lpfn, sflags, aflags);
+	spin_unlock(&mgr->lock);
+
+	if (!r) {
+		mem->start = node->start;
+		tbo->offset = (tbo->mem.start << PAGE_SHIFT) +
+		    tbo->bdev->man[tbo->mem.mem_type].gpu_offset;
+	}
+
+	return r;
+}
+
+/**
+ * amdgpu_gtt_mgr_new - allocate a new node
+ *
+ * @man: TTM memory type manager
+ * @tbo: TTM BO we need this range for
+ * @place: placement flags and restrictions
+ * @mem: the resulting mem object
+ *
+ * Dummy, allocate the node but no space for it yet.
+ */
+static int amdgpu_gtt_mgr_new(struct ttm_mem_type_manager *man,
+			      struct ttm_buffer_object *tbo,
+			      const struct ttm_place *place,
+			      struct ttm_mem_reg *mem)
+{
+	struct amdgpu_gtt_mgr *mgr = man->priv;
+	struct drm_mm_node *node;
+	int r;
+
+	spin_lock(&mgr->lock);
+	if (mgr->available < mem->num_pages) {
+		spin_unlock(&mgr->lock);
+		return 0;
+	}
+	mgr->available -= mem->num_pages;
+	spin_unlock(&mgr->lock);
+
+	node = kzalloc(sizeof(*node), GFP_KERNEL);
+	if (!node)
+		return -ENOMEM;
+
+	node->start = AMDGPU_BO_INVALID_OFFSET;
+	mem->mm_node = node;
+
+	if (place->fpfn || place->lpfn || place->flags & TTM_PL_FLAG_TOPDOWN) {
+		r = amdgpu_gtt_mgr_alloc(man, tbo, place, mem);
+		if (unlikely(r)) {
+			kfree(node);
+			mem->mm_node = NULL;
+		}
+	} else {
+		mem->start = node->start;
+	}
+
+	return 0;
+}
+
+/**
+ * amdgpu_gtt_mgr_del - free ranges
+ *
+ * @man: TTM memory type manager
+ * @tbo: TTM BO we need this range for
+ * @place: placement flags and restrictions
+ * @mem: TTM memory object
+ *
+ * Free the allocated GTT again.
+ */
+static void amdgpu_gtt_mgr_del(struct ttm_mem_type_manager *man,
+			       struct ttm_mem_reg *mem)
+{
+	struct amdgpu_gtt_mgr *mgr = man->priv;
+	struct drm_mm_node *node = mem->mm_node;
+
+	if (!node)
+		return;
+
+	spin_lock(&mgr->lock);
+	if (node->start != AMDGPU_BO_INVALID_OFFSET)
+		drm_mm_remove_node(node);
+	mgr->available += mem->num_pages;
+	spin_unlock(&mgr->lock);
+
+	kfree(node);
+	mem->mm_node = NULL;
+}
+
+/**
+ * amdgpu_gtt_mgr_debug - dump VRAM table
+ *
+ * @man: TTM memory type manager
+ * @prefix: text prefix
+ *
+ * Dump the table content using printk.
+ */
+static void amdgpu_gtt_mgr_debug(struct ttm_mem_type_manager *man,
+				  const char *prefix)
+{
+	struct amdgpu_gtt_mgr *mgr = man->priv;
+
+	spin_lock(&mgr->lock);
+	drm_mm_debug_table(&mgr->mm, prefix);
+	spin_unlock(&mgr->lock);
+}
+
+const struct ttm_mem_type_manager_func amdgpu_gtt_mgr_func = {
+	amdgpu_gtt_mgr_init,
+	amdgpu_gtt_mgr_fini,
+	amdgpu_gtt_mgr_new,
+	amdgpu_gtt_mgr_del,
+	amdgpu_gtt_mgr_debug
+};