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>

drivers/gpu/drm/amd/amdgpu/Makefile

@@ -23,7 +23,8 @@ amdgpu-y += amdgpu_device.o amdgpu_kms.o \
 	amdgpu_pm.o atombios_dp.o amdgpu_afmt.o amdgpu_trace_points.o \
 	atombios_encoders.o amdgpu_sa.o atombios_i2c.o \
 	amdgpu_prime.o amdgpu_vm.o amdgpu_ib.o amdgpu_pll.o \
-	amdgpu_ucode.o amdgpu_bo_list.o amdgpu_ctx.o amdgpu_sync.o
+	amdgpu_ucode.o amdgpu_bo_list.o amdgpu_ctx.o amdgpu_sync.o \
+	amdgpu_gtt_mgr.o
 
 # add asic specific block
 amdgpu-$(CONFIG_DRM_AMDGPU_CIK)+= cik.o cik_ih.o kv_smc.o kv_dpm.o \

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c

@@ -648,7 +648,7 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
 	if (!r && p->uf_entry.robj) {
 		struct amdgpu_bo *uf = p->uf_entry.robj;
 
-		r = amdgpu_ttm_bind(uf->tbo.ttm, &uf->tbo.mem);
+		r = amdgpu_ttm_bind(&uf->tbo, &uf->tbo.mem);
 		p->job->uf_addr += amdgpu_bo_gpu_offset(uf);
 	}
 
@@ -1192,7 +1192,7 @@ int amdgpu_cs_sysvm_access_required(struct amdgpu_cs_parser *parser)
 	for (i = 0; i < parser->bo_list->num_entries; i++) {
 		struct amdgpu_bo *bo = parser->bo_list->array[i].robj;
 
-		r = amdgpu_ttm_bind(bo->tbo.ttm, &bo->tbo.mem);
+		r = amdgpu_ttm_bind(&bo->tbo, &bo->tbo.mem);
 		if (unlikely(r))
 			return r;
 	}

drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c

+/*
+ * 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
+};

drivers/gpu/drm/amd/amdgpu/amdgpu_object.c

@@ -673,7 +673,7 @@ int amdgpu_bo_pin_restricted(struct amdgpu_bo *bo, u32 domain,
 		dev_err(bo->adev->dev, "%p pin failed\n", bo);
 		goto error;
 	}
-	r = amdgpu_ttm_bind(bo->tbo.ttm, &bo->tbo.mem);
+	r = amdgpu_ttm_bind(&bo->tbo, &bo->tbo.mem);
 	if (unlikely(r)) {
 		dev_err(bo->adev->dev, "%p bind failed\n", bo);
 		goto error;

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

@@ -160,7 +160,7 @@ static int amdgpu_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
 		man->default_caching = TTM_PL_FLAG_CACHED;
 		break;
 	case TTM_PL_TT:
-		man->func = &ttm_bo_manager_func;
+		man->func = &amdgpu_gtt_mgr_func;
 		man->gpu_offset = adev->mc.gtt_start;
 		man->available_caching = TTM_PL_MASK_CACHING;
 		man->default_caching = TTM_PL_FLAG_CACHED;
@@ -277,7 +277,7 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo,
 
 	switch (old_mem->mem_type) {
 	case TTM_PL_TT:
-		r = amdgpu_ttm_bind(bo->ttm, old_mem);
+		r = amdgpu_ttm_bind(bo, old_mem);
 		if (r)
 			return r;
 
@@ -290,7 +290,7 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo,
 	}
 	switch (new_mem->mem_type) {
 	case TTM_PL_TT:
-		r = amdgpu_ttm_bind(bo->ttm, new_mem);
+		r = amdgpu_ttm_bind(bo, new_mem);
 		if (r)
 			return r;
 
@@ -675,7 +675,6 @@ static int amdgpu_ttm_backend_bind(struct ttm_tt *ttm,
 			return r;
 		}
 	}
-	gtt->offset = (u64)bo_mem->start << PAGE_SHIFT;
 	if (!ttm->num_pages) {
 		WARN(1, "nothing to bind %lu pages for mreg %p back %p!\n",
 		     ttm->num_pages, bo_mem, ttm);
@@ -696,16 +695,25 @@ bool amdgpu_ttm_is_bound(struct ttm_tt *ttm)
 	return gtt && !list_empty(&gtt->list);
 }
 
-int amdgpu_ttm_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
+int amdgpu_ttm_bind(struct ttm_buffer_object *bo, struct ttm_mem_reg *bo_mem)
 {
-	struct amdgpu_ttm_tt *gtt = (void *)ttm;
+	struct ttm_tt *ttm = bo->ttm;
+	struct amdgpu_ttm_tt *gtt = (void *)bo->ttm;
 	uint32_t flags;
 	int r;
 
 	if (!ttm || amdgpu_ttm_is_bound(ttm))
 		return 0;
 
+	r = amdgpu_gtt_mgr_alloc(&bo->bdev->man[TTM_PL_TT], bo,
+				 NULL, bo_mem);
+	if (r) {
+		DRM_ERROR("Failed to allocate GTT address space (%d)\n", r);
+		return r;
+	}
+
 	flags = amdgpu_ttm_tt_pte_flags(gtt->adev, ttm, bo_mem);
+	gtt->offset = (u64)bo_mem->start << PAGE_SHIFT;
 	r = amdgpu_gart_bind(gtt->adev, gtt->offset, ttm->num_pages,
 		ttm->pages, gtt->ttm.dma_address, flags);
 

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h

@@ -65,6 +65,13 @@ struct amdgpu_mman {
 	struct amdgpu_mman_lru			guard;
 };
 
+extern const struct ttm_mem_type_manager_func amdgpu_gtt_mgr_func;
+
+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);
+
 int amdgpu_copy_buffer(struct amdgpu_ring *ring,
 		       uint64_t src_offset,
 		       uint64_t dst_offset,
@@ -78,6 +85,6 @@ int amdgpu_fill_buffer(struct amdgpu_bo *bo,
 
 int amdgpu_mmap(struct file *filp, struct vm_area_struct *vma);
 bool amdgpu_ttm_is_bound(struct ttm_tt *ttm);
-int amdgpu_ttm_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);
+int amdgpu_ttm_bind(struct ttm_buffer_object *bo, struct ttm_mem_reg *bo_mem);
 
 #endif