Re: [PATCH v11] drm/amdgpu: add drm buddy support to amdgpu

[Paul Menzel <pmenzel@xxxxxxxxxxxxx>]

Dear Arunprivin,


Thank you for your patch.

Am 23.03.22 um 07:25 schrieb Arunpravin Paneer Selvam:
> - Remove drm_mm references and replace with drm buddy functionalities

The commit message summary to me suggested, you can somehow use both 
allocators now. Two suggestions below:

1.  Switch to drm buddy allocator
2.  Use drm buddy alllocator

> - Add res cursor support for drm buddy

As an allocator switch sounds invasive, could you please extend the 
commit message, briefly describing the current situation, saying what 
the downsides are, and why the buddy allocator is “better”.

How did you test it? How can it be tested, that there are no regressions?

> v2(Matthew Auld):

Nit: I’d add a space before (.


Kind regards,

Paul


>    - replace spinlock with mutex as we call kmem_cache_zalloc
>      (..., GFP_KERNEL) in drm_buddy_alloc() function
>
>    - lock drm_buddy_block_trim() function as it calls
>      mark_free/mark_split are all globally visible
>
> v3(Matthew Auld):
>    - remove trim method error handling as we address the failure case
>      at drm_buddy_block_trim() function
>
> v4:
>    - fix warnings reported by kernel test robot <lkp@xxxxxxxxx>
>
> v5:
>    - fix merge conflict issue
>
> v6:
>    - fix warnings reported by kernel test robot <lkp@xxxxxxxxx>
>
> v7:
>    - remove DRM_BUDDY_RANGE_ALLOCATION flag usage
>
> v8:
>    - keep DRM_BUDDY_RANGE_ALLOCATION flag usage
>    - resolve conflicts created by drm/amdgpu: remove VRAM accounting v2
>
> v9(Christian):
>    - merged the below patch
>       - drm/amdgpu: move vram inline functions into a header
>    - rename label name as fallback
>    - move struct amdgpu_vram_mgr to amdgpu_vram_mgr.h
>    - remove unnecessary flags from struct amdgpu_vram_reservation
>    - rewrite block NULL check condition
>    - change else style as per coding standard
>    - rewrite the node max size
>    - add a helper function to fetch the first entry from the list
>
> v10(Christian):
>     - rename amdgpu_get_node() function name as amdgpu_vram_mgr_first_block
>
> v11:
>     - if size is not aligned with min_page_size, enable is_contiguous flag,
>       therefore, the size round up to the power of two and trimmed to the
>       original size.
>
> Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@xxxxxxx>
> ---
>   drivers/gpu/drm/Kconfig                       |   1 +
>   .../gpu/drm/amd/amdgpu/amdgpu_res_cursor.h    |  97 +++++--
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h       |  10 +-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c  | 263 ++++++++++--------
>   4 files changed, 234 insertions(+), 137 deletions(-)
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index f1422bee3dcc..5133c3f028ab 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -280,6 +280,7 @@ config DRM_AMDGPU
>   	select HWMON
>   	select BACKLIGHT_CLASS_DEVICE
>   	select INTERVAL_TREE
> +	select DRM_BUDDY
>   	help
>   	  Choose this option if you have a recent AMD Radeon graphics card.
>   
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h
> index acfa207cf970..864c609ba00b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h
> @@ -30,12 +30,15 @@
>   #include <drm/ttm/ttm_resource.h>
>   #include <drm/ttm/ttm_range_manager.h>
>   
> +#include "amdgpu_vram_mgr.h"
> +
>   /* state back for walking over vram_mgr and gtt_mgr allocations */
>   struct amdgpu_res_cursor {
>   	uint64_t		start;
>   	uint64_t		size;
>   	uint64_t		remaining;
> -	struct drm_mm_node	*node;
> +	void			*node;
> +	uint32_t		mem_type;
>   };
>   
>   /**
> @@ -52,27 +55,63 @@ static inline void amdgpu_res_first(struct ttm_resource *res,
>   				    uint64_t start, uint64_t size,
>   				    struct amdgpu_res_cursor *cur)
>   {
> +	struct drm_buddy_block *block;
> +	struct list_head *head, *next;
>   	struct drm_mm_node *node;
>   
> -	if (!res || res->mem_type == TTM_PL_SYSTEM) {
> -		cur->start = start;
> -		cur->size = size;
> -		cur->remaining = size;
> -		cur->node = NULL;
> -		WARN_ON(res && start + size > res->num_pages << PAGE_SHIFT);
> -		return;
> -	}
> +	if (!res)
> +		goto fallback;
>   
>   	BUG_ON(start + size > res->num_pages << PAGE_SHIFT);
>   
> -	node = to_ttm_range_mgr_node(res)->mm_nodes;
> -	while (start >= node->size << PAGE_SHIFT)
> -		start -= node++->size << PAGE_SHIFT;
> +	cur->mem_type = res->mem_type;
> +
> +	switch (cur->mem_type) {
> +	case TTM_PL_VRAM:
> +		head = &to_amdgpu_vram_mgr_node(res)->blocks;
> +
> +		block = list_first_entry_or_null(head,
> +						 struct drm_buddy_block,
> +						 link);
> +		if (!block)
> +			goto fallback;
> +
> +		while (start >= amdgpu_node_size(block)) {
> +			start -= amdgpu_node_size(block);
> +
> +			next = block->link.next;
> +			if (next != head)
> +				block = list_entry(next, struct drm_buddy_block, link);
> +		}
> +
> +		cur->start = amdgpu_node_start(block) + start;
> +		cur->size = min(amdgpu_node_size(block) - start, size);
> +		cur->remaining = size;
> +		cur->node = block;
> +		break;
> +	case TTM_PL_TT:
> +		node = to_ttm_range_mgr_node(res)->mm_nodes;
> +		while (start >= node->size << PAGE_SHIFT)
> +			start -= node++->size << PAGE_SHIFT;
> +
> +		cur->start = (node->start << PAGE_SHIFT) + start;
> +		cur->size = min((node->size << PAGE_SHIFT) - start, size);
> +		cur->remaining = size;
> +		cur->node = node;
> +		break;
> +	default:
> +		goto fallback;
> +	}
>   
> -	cur->start = (node->start << PAGE_SHIFT) + start;
> -	cur->size = min((node->size << PAGE_SHIFT) - start, size);
> +	return;
> +
> +fallback:
> +	cur->start = start;
> +	cur->size = size;
>   	cur->remaining = size;
> -	cur->node = node;
> +	cur->node = NULL;
> +	WARN_ON(res && start + size > res->num_pages << PAGE_SHIFT);
> +	return;
>   }
>   
>   /**
> @@ -85,7 +124,9 @@ static inline void amdgpu_res_first(struct ttm_resource *res,
>    */
>   static inline void amdgpu_res_next(struct amdgpu_res_cursor *cur, uint64_t size)
>   {
> -	struct drm_mm_node *node = cur->node;
> +	struct drm_buddy_block *block;
> +	struct drm_mm_node *node;
> +	struct list_head *next;
>   
>   	BUG_ON(size > cur->remaining);
>   
> @@ -99,9 +140,27 @@ static inline void amdgpu_res_next(struct amdgpu_res_cursor *cur, uint64_t size)
>   		return;
>   	}
>   
> -	cur->node = ++node;
> -	cur->start = node->start << PAGE_SHIFT;
> -	cur->size = min(node->size << PAGE_SHIFT, cur->remaining);
> +	switch (cur->mem_type) {
> +	case TTM_PL_VRAM:
> +		block = cur->node;
> +
> +		next = block->link.next;
> +		block = list_entry(next, struct drm_buddy_block, link);
> +
> +		cur->node = block;
> +		cur->start = amdgpu_node_start(block);
> +		cur->size = min(amdgpu_node_size(block), cur->remaining);
> +		break;
> +	case TTM_PL_TT:
> +		node = cur->node;
> +
> +		cur->node = ++node;
> +		cur->start = node->start << PAGE_SHIFT;
> +		cur->size = min(node->size << PAGE_SHIFT, cur->remaining);
> +		break;
> +	default:
> +		return;
> +	}
>   }
>   
>   #endif
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> index 9120ae80ef52..6a70818039dd 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 "amdgpu_vram_mgr.h"
>   #include "amdgpu.h"
>   
>   #define AMDGPU_PL_GDS		(TTM_PL_PRIV + 0)
> @@ -38,15 +39,6 @@
>   
>   #define AMDGPU_POISON	0xd0bed0be
>   
> -struct amdgpu_vram_mgr {
> -	struct ttm_resource_manager manager;
> -	struct drm_mm mm;
> -	spinlock_t lock;
> -	struct list_head reservations_pending;
> -	struct list_head reserved_pages;
> -	atomic64_t vis_usage;
> -};
> -
>   struct amdgpu_gtt_mgr {
>   	struct ttm_resource_manager manager;
>   	struct drm_mm mm;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index 0a7611648573..41fb7e6a104b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -32,10 +32,18 @@
>   #include "atom.h"
>   
>   struct amdgpu_vram_reservation {
> +	u64 start;
> +	u64 size;
> +	struct list_head block;
>   	struct list_head node;
> -	struct drm_mm_node mm_node;
>   };
>   
> +static inline struct drm_buddy_block *
> +amdgpu_vram_mgr_first_block(struct list_head *list)
> +{
> +	return list_first_entry_or_null(list, struct drm_buddy_block, link);
> +}
> +
>   static inline struct amdgpu_vram_mgr *
>   to_vram_mgr(struct ttm_resource_manager *man)
>   {
> @@ -194,10 +202,10 @@ 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;
> +	u64 start = amdgpu_node_start(block);
> +	u64 end = start + amdgpu_node_size(block);
>   
>   	if (start >= adev->gmc.visible_vram_size)
>   		return 0;
> @@ -218,9 +226,9 @@ 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);
> @@ -228,9 +236,8 @@ 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;
>   }
> @@ -240,21 +247,28 @@ 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 = &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_blocks(mm, rsv->start, rsv->start + rsv->size,
> +					   rsv->size, mm->chunk_size, &rsv->block,
> +					   DRM_BUDDY_RANGE_ALLOCATION))
> +			continue;
> +
> +		block = amdgpu_vram_mgr_first_block(&rsv->block);
> +		if (!block)
>   			continue;
>   
>   		dev_dbg(adev->dev, "Reservation 0x%llx - %lld, Succeeded\n",
> -			rsv->mm_node.start, rsv->mm_node.size);
> +			rsv->start, rsv->size);
>   
> -		vis_usage = amdgpu_vram_mgr_vis_size(adev, &rsv->mm_node);
> +		vis_usage = amdgpu_vram_mgr_vis_size(adev, block);
>   		atomic64_add(vis_usage, &mgr->vis_usage);
>   		spin_lock(&man->bdev->lru_lock);
> -		man->usage += rsv->mm_node.size << PAGE_SHIFT;
> +		man->usage += rsv->size;
>   		spin_unlock(&man->bdev->lru_lock);
>   		list_move(&rsv->node, &mgr->reserved_pages);
>   	}
> @@ -279,13 +293,15 @@ int amdgpu_vram_mgr_reserve_range(struct amdgpu_vram_mgr *mgr,
>   		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);
>   
> -	spin_lock(&mgr->lock);
> +	rsv->start = start;
> +	rsv->size = size;
> +
> +	mutex_lock(&mgr->lock);
>   	list_add_tail(&rsv->node, &mgr->reservations_pending);
>   	amdgpu_vram_mgr_do_reserve(&mgr->manager);
> -	spin_unlock(&mgr->lock);
> +	mutex_unlock(&mgr->lock);
>   
>   	return 0;
>   }
> @@ -307,19 +323,19 @@ int amdgpu_vram_mgr_query_page_status(struct amdgpu_vram_mgr *mgr,
>   	struct amdgpu_vram_reservation *rsv;
>   	int ret;
>   
> -	spin_lock(&mgr->lock);
> +	mutex_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;
>   		}
> @@ -327,32 +343,10 @@ int amdgpu_vram_mgr_query_page_status(struct amdgpu_vram_mgr *mgr,
>   
>   	ret = -ENOENT;
>   out:
> -	spin_unlock(&mgr->lock);
> +	mutex_unlock(&mgr->lock);
>   	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
>    *
> @@ -368,13 +362,14 @@ 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;
>   	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;
> +	u64 vis_usage = 0, max_bytes, min_page_size;
> +	struct amdgpu_vram_mgr_node *node;
> +	struct drm_buddy *mm = &mgr->mm;
> +	struct drm_buddy_block *block;
> +	bool is_contiguous = 0;
>   	unsigned i;
>   	int r;
>   
> @@ -382,14 +377,15 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>   	if (!lpfn)
>   		lpfn = man->size >> PAGE_SHIFT;
>   
> +	if (place->flags & TTM_PL_FLAG_CONTIGUOUS)
> +		is_contiguous = 1;
> +
>   	max_bytes = adev->gmc.mc_vram_size;
>   	if (tbo->type != ttm_bo_type_kernel)
>   		max_bytes -= AMDGPU_VM_RESERVED_VRAM;
>   
> -	mem_bytes = tbo->base.size;
>   	if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
>   		pages_per_node = ~0ul;
> -		num_nodes = 1;
>   	} else {
>   #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>   		pages_per_node = HPAGE_PMD_NR;
> @@ -399,11 +395,9 @@ 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)
>   		return -ENOMEM;
>   
> @@ -415,48 +409,86 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>   		goto error_fini;
>   	}
>   
> -	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;
>   
> -	pages_left = node->base.num_pages;
> +	if (place->fpfn || lpfn != man->size >> PAGE_SHIFT)
> +		/* Allocate blocks in desired range */
> +		node->flags |= DRM_BUDDY_RANGE_ALLOCATION;
>   
> -	/* Limit maximum size to 2GB due to SG table limitations */
> -	pages = min(pages_left, 2UL << (30 - PAGE_SHIFT));
> +	BUG_ON(!node->base.num_pages);
> +	pages_left = node->base.num_pages;
>   
>   	i = 0;
> -	spin_lock(&mgr->lock);
>   	while (pages_left) {
> -		uint32_t alignment = tbo->page_alignment;
> +		if (tbo->page_alignment)
> +			min_page_size = tbo->page_alignment << PAGE_SHIFT;
> +		else
> +			min_page_size = mgr->default_page_size;
> +
> +		/* Limit maximum size to 2GB due to SG table limitations */
> +		pages = min(pages_left, 2UL << (30 - PAGE_SHIFT));
>   
>   		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;
> +			min_page_size = pages_per_node << PAGE_SHIFT;
> +
> +		if (!is_contiguous && !IS_ALIGNED(pages, min_page_size >> PAGE_SHIFT))
> +			is_contiguous = 1;
> +
> +		if (is_contiguous) {
> +			pages = roundup_pow_of_two(pages);
> +			min_page_size = pages << PAGE_SHIFT;
> +
> +			if (pages > lpfn)
> +				lpfn = pages;
>   		}
>   
> -		vis_usage += amdgpu_vram_mgr_vis_size(adev, &node->mm_nodes[i]);
> -		amdgpu_vram_mgr_virt_start(&node->base, &node->mm_nodes[i]);
> -		pages_left -= pages;
> +		BUG_ON(min_page_size < mm->chunk_size);
> +
> +		mutex_lock(&mgr->lock);
> +		r = drm_buddy_alloc_blocks(mm, (u64)place->fpfn << PAGE_SHIFT,
> +					   (u64)lpfn << PAGE_SHIFT,
> +					   (u64)pages << PAGE_SHIFT,
> +					   min_page_size,
> +					   &node->blocks,
> +					   node->flags);
> +		mutex_unlock(&mgr->lock);
> +		if (unlikely(r))
> +			goto error_free_blocks;
> +
>   		++i;
>   
>   		if (pages > pages_left)
> -			pages = pages_left;
> +			pages_left = 0;
> +		else
> +			pages_left -= pages;
>   	}
> -	spin_unlock(&mgr->lock);
>   
> -	if (i == 1)
> +	/* Free unused pages for contiguous allocation */
> +	if (is_contiguous) {
> +		u64 actual_size = (u64)node->base.num_pages << PAGE_SHIFT;
> +
> +		mutex_lock(&mgr->lock);
> +		drm_buddy_block_trim(mm,
> +				     actual_size,
> +				     &node->blocks);
> +		mutex_unlock(&mgr->lock);
> +	}
> +
> +	list_for_each_entry(block, &node->blocks, link)
> +		vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
> +
> +	block = amdgpu_vram_mgr_first_block(&node->blocks);
> +	if (!block) {
> +		r = -EINVAL;
> +		goto error_fini;
> +	}
> +
> +	node->base.start = amdgpu_node_start(block) >> PAGE_SHIFT;
> +
> +	if (i == 1 && is_contiguous)
>   		node->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
>   
>   	if (adev->gmc.xgmi.connected_to_cpu)
> @@ -468,13 +500,13 @@ 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]);
> -	spin_unlock(&mgr->lock);
> +error_free_blocks:
> +	mutex_lock(&mgr->lock);
> +	drm_buddy_free_list(mm, &node->blocks);
> +	mutex_unlock(&mgr->lock);
>   error_fini:
>   	ttm_resource_fini(man, &node->base);
> -	kvfree(node);
> +	kfree(node);
>   
>   	return r;
>   }
> @@ -490,27 +522,26 @@ 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 = &mgr->mm;
> +	struct drm_buddy_block *block;
>   	uint64_t 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];
> +	mutex_lock(&mgr->lock);
> +	list_for_each_entry(block, &node->blocks, link)
> +		vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
>   
> -		drm_mm_remove_node(mm);
> -		vis_usage += amdgpu_vram_mgr_vis_size(adev, mm);
> -	}
>   	amdgpu_vram_mgr_do_reserve(man);
> -	spin_unlock(&mgr->lock);
> +
> +	drm_buddy_free_list(mm, &node->blocks);
> +	mutex_unlock(&mgr->lock);
>   
>   	atomic64_sub(vis_usage, &mgr->vis_usage);
>   
>   	ttm_resource_fini(man, res);
> -	kvfree(node);
> +	kfree(node);
>   }
>   
>   /**
> @@ -648,13 +679,22 @@ 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 = &mgr->mm;
> +	struct drm_buddy_block *block;
>   
>   	drm_printf(printer, "  vis usage:%llu\n",
>   		   amdgpu_vram_mgr_vis_usage(mgr));
>   
> -	spin_lock(&mgr->lock);
> -	drm_mm_print(&mgr->mm, printer);
> -	spin_unlock(&mgr->lock);
> +	mutex_lock(&mgr->lock);
> +	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);
> +	mutex_unlock(&mgr->lock);
>   }
>   
>   static const struct ttm_resource_manager_func amdgpu_vram_mgr_func = {
> @@ -674,16 +714,21 @@ 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->mman.bdev,
>   				  adev->gmc.real_vram_size);
>   
>   	man->func = &amdgpu_vram_mgr_func;
>   
> -	drm_mm_init(&mgr->mm, 0, man->size >> PAGE_SHIFT);
> -	spin_lock_init(&mgr->lock);
> +	err = drm_buddy_init(&mgr->mm, man->size, PAGE_SIZE);
> +	if (err)
> +		return err;
> +
> +	mutex_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);
> @@ -711,16 +756,16 @@ void amdgpu_vram_mgr_fini(struct amdgpu_device *adev)
>   	if (ret)
>   		return;
>   
> -	spin_lock(&mgr->lock);
> +	mutex_lock(&mgr->lock);
>   	list_for_each_entry_safe(rsv, temp, &mgr->reservations_pending, node)
>   		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);
> -	spin_unlock(&mgr->lock);
> +	drm_buddy_fini(&mgr->mm);
> +	mutex_unlock(&mgr->lock);
>   
>   	ttm_resource_manager_cleanup(man);
>   	ttm_set_driver_manager(&adev->mman.bdev, TTM_PL_VRAM, NULL);
>
> base-commit: a678f97326454b60ffbbde6abf52d23997d71a27