[PATCH 13/13] drm/amdgpu: cleanup drm_mm and apply DRM buddy

[Arunpravin <Arunpravin.PaneerSelvam@amd.com>]

Remove drm_mm references and add DRM buddy
functions

Signed-off-by: Arunpravin <Arunpravin.PaneerSelvam@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h      |   4 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 233 +++++++++++--------
 2 files changed, 138 insertions(+), 99 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index 639c7b41e30b..a8ac9902ab29 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -26,6 +26,7 @@
 
 #include <linux/dma-direction.h>
 #include <drm/gpu_scheduler.h>
+#include <drm/drm_buddy.h>
 #include "amdgpu.h"
 
 #define AMDGPU_PL_GDS		(TTM_PL_PRIV + 0)
@@ -40,12 +41,13 @@
 
 struct amdgpu_vram_mgr {
 	struct ttm_resource_manager manager;
-	struct drm_mm mm;
+	struct drm_buddy_mm mm;
 	spinlock_t lock;
 	struct list_head reservations_pending;
 	struct list_head reserved_pages;
 	atomic64_t usage;
 	atomic64_t vis_usage;
+	uint64_t default_page_size;
 };
 
 struct amdgpu_gtt_mgr {
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index a9182c59907a..0c55a5ea1ed1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -180,10 +180,10 @@ const struct attribute_group amdgpu_vram_mgr_attr_group = {
  * Calculate how many bytes of the MM node are inside visible VRAM
  */
 static u64 amdgpu_vram_mgr_vis_size(struct amdgpu_device *adev,
-				    struct drm_mm_node *node)
+				    struct drm_buddy_block *block)
 {
-	uint64_t start = node->start << PAGE_SHIFT;
-	uint64_t end = (node->size + node->start) << PAGE_SHIFT;
+	uint64_t start = node_start(block);
+	uint64_t end = start + node_size(block);
 
 	if (start >= adev->gmc.visible_vram_size)
 		return 0;
@@ -204,9 +204,9 @@ u64 amdgpu_vram_mgr_bo_visible_size(struct amdgpu_bo *bo)
 {
 	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
 	struct ttm_resource *res = bo->tbo.resource;
-	unsigned pages = res->num_pages;
-	struct drm_mm_node *mm;
-	u64 usage;
+	struct amdgpu_vram_mgr_node *node = to_amdgpu_vram_mgr_node(res);
+	struct drm_buddy_block *block;
+	u64 usage = 0;
 
 	if (amdgpu_gmc_vram_full_visible(&adev->gmc))
 		return amdgpu_bo_size(bo);
@@ -214,9 +214,8 @@ u64 amdgpu_vram_mgr_bo_visible_size(struct amdgpu_bo *bo)
 	if (res->start >= adev->gmc.visible_vram_size >> PAGE_SHIFT)
 		return 0;
 
-	mm = &container_of(res, struct ttm_range_mgr_node, base)->mm_nodes[0];
-	for (usage = 0; pages; pages -= mm->size, mm++)
-		usage += amdgpu_vram_mgr_vis_size(adev, mm);
+	list_for_each_entry(block, &node->blocks, link)
+		usage += amdgpu_vram_mgr_vis_size(adev, block);
 
 	return usage;
 }
@@ -226,21 +225,30 @@ static void amdgpu_vram_mgr_do_reserve(struct ttm_resource_manager *man)
 {
 	struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
 	struct amdgpu_device *adev = to_amdgpu_device(mgr);
-	struct drm_mm *mm = &mgr->mm;
+	struct drm_buddy_mm *mm = &mgr->mm;
 	struct amdgpu_vram_reservation *rsv, *temp;
+	struct drm_buddy_block *block;
 	uint64_t vis_usage;
 
 	list_for_each_entry_safe(rsv, temp, &mgr->reservations_pending, node) {
-		if (drm_mm_reserve_node(mm, &rsv->mm_node))
+		if (drm_buddy_alloc(mm, rsv->start, rsv->start + rsv->size,
+					rsv->size, rsv->min_size, &rsv->block,
+					rsv->flags))
 			continue;
 
-		dev_dbg(adev->dev, "Reservation 0x%llx - %lld, Succeeded\n",
-			rsv->mm_node.start, rsv->mm_node.size);
+		block = list_first_entry_or_null(&rsv->block,
+						 struct drm_buddy_block,
+						 link);
 
-		vis_usage = amdgpu_vram_mgr_vis_size(adev, &rsv->mm_node);
-		atomic64_add(vis_usage, &mgr->vis_usage);
-		atomic64_add(rsv->mm_node.size << PAGE_SHIFT, &mgr->usage);
-		list_move(&rsv->node, &mgr->reserved_pages);
+		if (block) {
+			dev_dbg(adev->dev, "Reservation 0x%llx - %lld, Succeeded\n",
+				rsv->start, rsv->size);
+
+			vis_usage = amdgpu_vram_mgr_vis_size(adev, block);
+			atomic64_add(vis_usage, &mgr->vis_usage);
+			atomic64_add(rsv->size, &mgr->usage);
+			list_move(&rsv->node, &mgr->reserved_pages);
+		}
 	}
 }
 
@@ -264,11 +272,15 @@ int amdgpu_vram_mgr_reserve_range(struct ttm_resource_manager *man,
 		return -ENOMEM;
 
 	INIT_LIST_HEAD(&rsv->node);
-	rsv->mm_node.start = start >> PAGE_SHIFT;
-	rsv->mm_node.size = size >> PAGE_SHIFT;
+	INIT_LIST_HEAD(&rsv->block);
+
+	rsv->start = start;
+	rsv->size = size;
+	rsv->min_size = size;
+	rsv->flags |= DRM_BUDDY_RANGE_ALLOCATION;
 
 	spin_lock(&mgr->lock);
-	list_add_tail(&mgr->reservations_pending, &rsv->node);
+	list_add_tail(&rsv->node, &mgr->reservations_pending);
 	amdgpu_vram_mgr_do_reserve(man);
 	spin_unlock(&mgr->lock);
 
@@ -296,16 +308,16 @@ int amdgpu_vram_mgr_query_page_status(struct ttm_resource_manager *man,
 	spin_lock(&mgr->lock);
 
 	list_for_each_entry(rsv, &mgr->reservations_pending, node) {
-		if ((rsv->mm_node.start <= start) &&
-		    (start < (rsv->mm_node.start + rsv->mm_node.size))) {
+		if ((rsv->start <= start) &&
+		    (start < (rsv->start + rsv->size))) {
 			ret = -EBUSY;
 			goto out;
 		}
 	}
 
 	list_for_each_entry(rsv, &mgr->reserved_pages, node) {
-		if ((rsv->mm_node.start <= start) &&
-		    (start < (rsv->mm_node.start + rsv->mm_node.size))) {
+		if ((rsv->start <= start) &&
+		    (start < (rsv->start + rsv->size))) {
 			ret = 0;
 			goto out;
 		}
@@ -317,28 +329,6 @@ int amdgpu_vram_mgr_query_page_status(struct ttm_resource_manager *man,
 	return ret;
 }
 
-/**
- * amdgpu_vram_mgr_virt_start - update virtual start address
- *
- * @mem: ttm_resource to update
- * @node: just allocated node
- *
- * Calculate a virtual BO start address to easily check if everything is CPU
- * accessible.
- */
-static void amdgpu_vram_mgr_virt_start(struct ttm_resource *mem,
-				       struct drm_mm_node *node)
-{
-	unsigned long start;
-
-	start = node->start + node->size;
-	if (start > mem->num_pages)
-		start -= mem->num_pages;
-	else
-		start = 0;
-	mem->start = max(mem->start, start);
-}
-
 /**
  * amdgpu_vram_mgr_new - allocate new ranges
  *
@@ -354,13 +344,13 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 			       const struct ttm_place *place,
 			       struct ttm_resource **res)
 {
-	unsigned long lpfn, num_nodes, pages_per_node, pages_left, pages;
+	unsigned long lpfn, pages_per_node, pages_left, pages, n_pages;
+	uint64_t vis_usage = 0, mem_bytes, max_bytes, min_page_size;
 	struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
 	struct amdgpu_device *adev = to_amdgpu_device(mgr);
-	uint64_t vis_usage = 0, mem_bytes, max_bytes;
-	struct ttm_range_mgr_node *node;
-	struct drm_mm *mm = &mgr->mm;
-	enum drm_mm_insert_mode mode;
+	struct amdgpu_vram_mgr_node *node;
+	struct drm_buddy_mm *mm = &mgr->mm;
+	struct drm_buddy_block *block;
 	unsigned i;
 	int r;
 
@@ -379,10 +369,9 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 		goto error_sub;
 	}
 
-	if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
+	if (place->flags & TTM_PL_FLAG_CONTIGUOUS)
 		pages_per_node = ~0ul;
-		num_nodes = 1;
-	} else {
+	else {
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 		pages_per_node = HPAGE_PMD_NR;
 #else
@@ -391,11 +380,10 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 #endif
 		pages_per_node = max_t(uint32_t, pages_per_node,
 				       tbo->page_alignment);
-		num_nodes = DIV_ROUND_UP_ULL(PFN_UP(mem_bytes), pages_per_node);
 	}
 
-	node = kvmalloc(struct_size(node, mm_nodes, num_nodes),
-			GFP_KERNEL | __GFP_ZERO);
+	node = kzalloc(sizeof(*node), GFP_KERNEL);
+
 	if (!node) {
 		r = -ENOMEM;
 		goto error_sub;
@@ -403,9 +391,17 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 
 	ttm_resource_init(tbo, place, &node->base);
 
-	mode = DRM_MM_INSERT_BEST;
+	INIT_LIST_HEAD(&node->blocks);
+
 	if (place->flags & TTM_PL_FLAG_TOPDOWN)
-		mode = DRM_MM_INSERT_HIGH;
+		node->flags |= DRM_BUDDY_TOPDOWN_ALLOCATION;
+
+	if (place->fpfn || lpfn != man->size)
+		/* Allocate blocks in desired range */
+		node->flags |= DRM_BUDDY_RANGE_ALLOCATION;
+
+	min_page_size = mgr->default_page_size;
+	BUG_ON(min_page_size < mm->chunk_size);
 
 	pages_left = node->base.num_pages;
 
@@ -413,36 +409,63 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 	pages = min(pages_left, 2UL << (30 - PAGE_SHIFT));
 
 	i = 0;
-	spin_lock(&mgr->lock);
 	while (pages_left) {
-		uint32_t alignment = tbo->page_alignment;
-
 		if (pages >= pages_per_node)
-			alignment = pages_per_node;
-
-		r = drm_mm_insert_node_in_range(mm, &node->mm_nodes[i], pages,
-						alignment, 0, place->fpfn,
-						lpfn, mode);
-		if (unlikely(r)) {
-			if (pages > pages_per_node) {
-				if (is_power_of_2(pages))
-					pages = pages / 2;
-				else
-					pages = rounddown_pow_of_two(pages);
-				continue;
-			}
-			goto error_free;
+			pages = pages_per_node;
+
+		n_pages = pages;
+
+		if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
+			n_pages = roundup_pow_of_two(n_pages);
+			min_page_size = (uint64_t)n_pages << PAGE_SHIFT;
+
+			if (n_pages > lpfn)
+				lpfn = n_pages;
 		}
 
-		vis_usage += amdgpu_vram_mgr_vis_size(adev, &node->mm_nodes[i]);
-		amdgpu_vram_mgr_virt_start(&node->base, &node->mm_nodes[i]);
+		spin_lock(&mgr->lock);
+		r = drm_buddy_alloc(mm, (uint64_t)place->fpfn << PAGE_SHIFT,
+					(uint64_t)lpfn << PAGE_SHIFT,
+					(uint64_t)n_pages << PAGE_SHIFT,
+					 min_page_size, &node->blocks,
+					 node->flags);
+		spin_unlock(&mgr->lock);
+
+		if (unlikely(r))
+			goto error_free_blocks;
+
 		pages_left -= pages;
 		++i;
 
 		if (pages > pages_left)
 			pages = pages_left;
 	}
-	spin_unlock(&mgr->lock);
+
+	/* Free unused pages for contiguous allocation */
+	if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
+		uint64_t actual_size = (uint64_t)node->base.num_pages << PAGE_SHIFT;
+
+		r = drm_buddy_free_unused_pages(mm,
+						actual_size,
+						&node->blocks);
+
+		if (unlikely(r))
+			goto error_free_blocks;
+	}
+
+	list_for_each_entry(block, &node->blocks, link)
+		vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
+
+	block = list_first_entry_or_null(&node->blocks,
+					 struct drm_buddy_block,
+					 link);
+
+	if (!block) {
+		r = -ENOSPC;
+		goto error_free_res;
+	}
+
+	node->base.start = node_start(block) >> PAGE_SHIFT;
 
 	if (i == 1)
 		node->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
@@ -456,12 +479,12 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 	*res = &node->base;
 	return 0;
 
-error_free:
-	while (i--)
-		drm_mm_remove_node(&node->mm_nodes[i]);
+error_free_blocks:
+	spin_lock(&mgr->lock);
+	drm_buddy_free_list(mm, &node->blocks);
 	spin_unlock(&mgr->lock);
-	kvfree(node);
-
+error_free_res:
+	kfree(node);
 error_sub:
 	atomic64_sub(mem_bytes, &mgr->usage);
 	return r;
@@ -478,28 +501,28 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 static void amdgpu_vram_mgr_del(struct ttm_resource_manager *man,
 				struct ttm_resource *res)
 {
-	struct ttm_range_mgr_node *node = to_ttm_range_mgr_node(res);
+	struct amdgpu_vram_mgr_node *node = to_amdgpu_vram_mgr_node(res);
 	struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
 	struct amdgpu_device *adev = to_amdgpu_device(mgr);
+	struct drm_buddy_mm *mm = &mgr->mm;
+	struct drm_buddy_block *block;
 	uint64_t usage = 0, vis_usage = 0;
-	unsigned i, pages;
 
 	spin_lock(&mgr->lock);
-	for (i = 0, pages = res->num_pages; pages;
-	     pages -= node->mm_nodes[i].size, ++i) {
-		struct drm_mm_node *mm = &node->mm_nodes[i];
-
-		drm_mm_remove_node(mm);
-		usage += mm->size << PAGE_SHIFT;
-		vis_usage += amdgpu_vram_mgr_vis_size(adev, mm);
+	list_for_each_entry(block, &node->blocks, link) {
+		usage += node_size(block);
+		vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
 	}
+
 	amdgpu_vram_mgr_do_reserve(man);
+
+	drm_buddy_free_list(mm, &node->blocks);
 	spin_unlock(&mgr->lock);
 
 	atomic64_sub(usage, &mgr->usage);
 	atomic64_sub(vis_usage, &mgr->vis_usage);
 
-	kvfree(node);
+	kfree(node);
 }
 
 /**
@@ -653,9 +676,18 @@ static void amdgpu_vram_mgr_debug(struct ttm_resource_manager *man,
 				  struct drm_printer *printer)
 {
 	struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
+	struct drm_buddy_mm *mm = &mgr->mm;
+	struct drm_buddy_block *block;
 
 	spin_lock(&mgr->lock);
-	drm_mm_print(&mgr->mm, printer);
+	drm_printf(printer, "default_page_size: %lluKiB\n",
+		   mgr->default_page_size >> 10);
+
+	drm_buddy_print(mm, printer);
+
+	drm_printf(printer, "reserved:\n");
+	list_for_each_entry(block, &mgr->reserved_pages, link)
+		drm_buddy_block_print(mm, block, printer);
 	spin_unlock(&mgr->lock);
 
 	drm_printf(printer, "man size:%llu pages, ram usage:%lluMB, vis usage:%lluMB\n",
@@ -680,15 +712,20 @@ int amdgpu_vram_mgr_init(struct amdgpu_device *adev)
 {
 	struct amdgpu_vram_mgr *mgr = &adev->mman.vram_mgr;
 	struct ttm_resource_manager *man = &mgr->manager;
+	int err;
 
 	ttm_resource_manager_init(man, adev->gmc.real_vram_size >> PAGE_SHIFT);
 
 	man->func = &amdgpu_vram_mgr_func;
 
-	drm_mm_init(&mgr->mm, 0, man->size);
+	err = drm_buddy_init(&mgr->mm, man->size << PAGE_SHIFT, PAGE_SIZE);
+	if (err)
+		return err;
+
 	spin_lock_init(&mgr->lock);
 	INIT_LIST_HEAD(&mgr->reservations_pending);
 	INIT_LIST_HEAD(&mgr->reserved_pages);
+	mgr->default_page_size = PAGE_SIZE;
 
 	ttm_set_driver_manager(&adev->mman.bdev, TTM_PL_VRAM, &mgr->manager);
 	ttm_resource_manager_set_used(man, true);
@@ -721,10 +758,10 @@ void amdgpu_vram_mgr_fini(struct amdgpu_device *adev)
 		kfree(rsv);
 
 	list_for_each_entry_safe(rsv, temp, &mgr->reserved_pages, node) {
-		drm_mm_remove_node(&rsv->mm_node);
+		drm_buddy_free_list(&mgr->mm, &rsv->block);
 		kfree(rsv);
 	}
-	drm_mm_takedown(&mgr->mm);
+	drm_buddy_fini(&mgr->mm);
 	spin_unlock(&mgr->lock);
 
 	ttm_resource_manager_cleanup(man);
-- 
2.25.1