Re: [PATCH 2/2] Add drm buddy manager support to amdgpu driver

Am 20.09.21 um 21:21 schrieb Arunpravin:

Replace drm_mm with drm buddy manager for VRAM memory management

Signed-off-by: Arunpravin Arunpravin.PaneerSelvam@amd.com

.../gpu/drm/amd/amdgpu/amdgpu_res_cursor.h | 78 +++++-- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 3 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 216 ++++++++++-------- 3 files changed, 189 insertions(+), 108 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h index acfa207cf970..ba24052e9062 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h @@ -30,12 +30,25 @@ #include <drm/ttm/ttm_resource.h> #include <drm/ttm/ttm_range_manager.h>

+struct amdgpu_vram_mgr_node {

• struct ttm_range_mgr_node tnode;

NAK, don't base this on ttm_range_mgr_node. Instead use ttm_resource.

And please name the member base instead.

• struct list_head blocks;

+};

+static inline struct amdgpu_vram_mgr_node * +to_amdgpu_vram_mgr_node(struct ttm_resource *res) +{

• return container_of(container_of(res, struct ttm_range_mgr_node, base),

• 	struct amdgpu_vram_mgr_node, tnode);
  

+}

Maybe stuff that in a separate amdgpu_vram_mgr.h file together with all the other defines for the vram manager.

/* 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; };

  /**

@@ -52,8 +65,6 @@ static inline void amdgpu_res_first(struct ttm_resource *res, uint64_t start, uint64_t size, struct amdgpu_res_cursor *cur) {

• struct drm_mm_node *node;
• if (!res || res->mem_type == TTM_PL_SYSTEM) { cur->start = start; cur->size = size;

@@ -65,14 +76,39 @@ static inline void amdgpu_res_first(struct ttm_resource *res,

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;
• if (cur->mem_type == TTM_PL_VRAM) {

Rather use a switch/case here.

• struct drm_buddy_block *block;
  

• struct list_head *head, *next;
  

• head = &to_amdgpu_vram_mgr_node(res)->blocks;
  

• block = list_first_entry_or_null(head, struct drm_buddy_block, link);
  

• while (start >= block->size << PAGE_SHIFT) {
  

• 	start -= block->size << PAGE_SHIFT;
  

• 	next = block->link.next;
  

• 	if (next != head)
  

• 		block = list_entry(next, struct drm_buddy_block, link);
  

• }
  
  

• cur->start = (node->start << PAGE_SHIFT) + start;
• cur->size = min((node->size << PAGE_SHIFT) - start, size);
• cur->remaining = size;
• cur->node = node;

• cur->start = (block->start << PAGE_SHIFT) + start;
  

• cur->size = min((block->size << PAGE_SHIFT) - start, size);
  

• cur->remaining = size;
  

• cur->node = block;
  

• } else if (cur->mem_type == TTM_PL_TT) {

• struct drm_mm_node *node;
  

• 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;
  

With a default handling for other placement types.

• } }

  /**

@@ -85,8 +121,6 @@ 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;

• BUG_ON(size > cur->remaining);

  cur->remaining -= size;

@@ -99,9 +133,23 @@ 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);

• if (cur->mem_type == TTM_PL_VRAM) {

• struct drm_buddy_block *block = cur->node;
  

• struct list_head *next;
  

• next = block->link.next;
  

• block = list_entry(next, struct drm_buddy_block, link);
  

• cur->node = block;
  

• cur->start = block->start << PAGE_SHIFT;
  

• cur->size = min(block->size << PAGE_SHIFT, cur->remaining);
  

• } else if (cur->mem_type == TTM_PL_TT) {

• struct drm_mm_node *node = cur->node;
  

• cur->node = ++node;
  

• cur->start = node->start << PAGE_SHIFT;
  

• cur->size = min(node->size << PAGE_SHIFT, cur->remaining);
  

• } }

  #endif

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h index e69f3e8e06e5..96c8e8aaa0ee 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) @@ -40,7 +41,7 @@

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;

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c index 7b2b0980ec41..de0c5f4cabaf 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c @@ -23,7 +23,9 @@ */

#include <linux/dma-mapping.h> +#include <linux/list_sort.h> #include <drm/ttm/ttm_range_manager.h> +#include <drm/drm_buddy.h>

#include "amdgpu.h" #include "amdgpu_vm.h" @@ -33,7 +35,7 @@

struct amdgpu_vram_reservation { struct list_head node;

• struct drm_mm_node mm_node;

• struct drm_buddy_block mm_node; };

  static inline struct amdgpu_vram_mgr *

@@ -196,10 +198,10 @@ 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 = block->start << PAGE_SHIFT;

• uint64_t end = (block->size + block->start) << PAGE_SHIFT;

  if (start >= adev->gmc.visible_vram_size) return 0;

@@ -220,8 +222,8 @@ 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;

• struct amdgpu_vram_mgr_node *vnode = to_amdgpu_vram_mgr_node(res);

• struct drm_buddy_block *block; u64 usage;

  if (amdgpu_gmc_vram_full_visible(&adev->gmc))

@@ -230,9 +232,8 @@ 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, &vnode->blocks, link)

• usage += amdgpu_vram_mgr_vis_size(adev, block);
  
  

  return usage; }

@@ -242,12 +243,15 @@ 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; uint64_t vis_usage;

• int r = 0;

  list_for_each_entry_safe(rsv, temp, &mgr->reservations_pending, node) {

• if (drm_mm_reserve_node(mm, &rsv->mm_node))
  

• r = drm_buddy_alloc_range(mm, &rsv->node, rsv->mm_node.start, rsv->mm_node.size);
  

• if (unlikely(r))
  continue;
  
  

  dev_dbg(adev->dev, "Reservation 0x%llx - %lld, Succeeded\n",

@@ -333,26 +337,16 @@ 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)
  

+static int sort_blocks(void *priv, const struct list_head *A,

• 			const struct list_head *B)
  

Please prefix all function with amdgpu_vram_mgr_.

{

• unsigned long start;

• struct drm_buddy_block *a = list_entry(A, typeof(*a), link);
• struct drm_buddy_block *b = list_entry(B, typeof(*b), link);

• start = node->start + node->size;
• if (start > mem->num_pages)

• start -= mem->num_pages;
  

• if (a->start < b->start)

• return -1;
  

  else

• start = 0;
  

• mem->start = max(mem->start, start);

• return 1;
  

  }

  /**

@@ -370,15 +364,20 @@ 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 amdgpu_vram_mgr_node *vnode;
• struct drm_buddy_mm *mm = &mgr->mm; struct ttm_range_mgr_node *node;

• struct drm_mm *mm = &mgr->mm;
• enum drm_mm_insert_mode mode;

• enum drm_buddy_alloc_mode mode;
• struct drm_buddy_block *block;
• unsigned int visible_pfn;
• bool bar_limit_enabled;
• unsigned long n_pages; unsigned i;

• int r;

• int r = 0;

Please don't initialize the return type here. That's considered bad coding style.

lpfn = place->lpfn; if (!lpfn) @@ -395,10 +394,9 @@ 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

@@ -407,57 +405,97 @@ 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);
  

• if (!node) {

• vnode = kzalloc(sizeof(*vnode), GFP_KERNEL);

• if (!vnode) { r = -ENOMEM; goto error_sub; }

• node = &vnode->tnode;

• ttm_resource_init(tbo, place, &node->base);

• mode = DRM_MM_INSERT_BEST;
• if (place->flags & TTM_PL_FLAG_TOPDOWN)

• mode = DRM_MM_INSERT_HIGH;
  

• bar_limit_enabled = !(amdgpu_gmc_vram_full_visible(&adev->gmc));

• visible_pfn = adev->gmc.visible_vram_size >> PAGE_SHIFT;

• mode = DRM_BUDDY_BOTTOM_UP;

• if (!place->fpfn && lpfn == man->size &&

• 			(place->flags & TTM_PL_FLAG_TOPDOWN))
  

• /* Allocate blocks from CPU non-mappable (TOP-DOWN) region */
  

• mode = DRM_BUDDY_TOP_DOWN;
  

• else if (place->fpfn || (lpfn != man->size && lpfn != visible_pfn))

• /* Allocate blocks in desired range */
  

• mode = DRM_BUDDY_ALLOC_RANGE;
  
  

  pages_left = node->base.num_pages;

  /* Limit maximum size to 2GB due to SG table limitations */ pages = min(pages_left, 2UL << (30 - PAGE_SHIFT));

• INIT_LIST_HEAD(&vnode->blocks);

• 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;
  

• }
  

• if (mode == DRM_BUDDY_ALLOC_RANGE) {

• r = drm_buddy_alloc_range(mm, &vnode->blocks,
  

• 		(uint64_t)place->fpfn << PAGE_SHIFT, pages << PAGE_SHIFT);
  

That handling won't work. It's possible that you need contiguous memory in a specific range.

• if (unlikely(r))
  

• 	goto error_free_res;
  

• } else {

• while (pages_left) {
  

• 	if (pages >= pages_per_node)
  

• 		pages = pages_per_node;
  

• 	n_pages = pages;
  

• 	if (place->flags & TTM_PL_FLAG_CONTIGUOUS)
  

• 		n_pages = roundup_pow_of_two(n_pages);
  

That approach won't work either. For contiguous allocation you need to allocate one big chunk and then free up what you don't need at the end.

• 	do {
  

• 		unsigned int order;
  

• 		order = fls(n_pages) - 1;
  

• 		BUG_ON(order > mm->max_order);
  

• 		spin_lock(&mgr->lock);
  

• 		block = drm_buddy_alloc(mm, order, bar_limit_enabled,
  

• 							visible_pfn, mode);
  

That doesn't seem to make much sense either. The backend allocator should not care about the BAR size nor the visible_pfn.

• 		spin_unlock(&mgr->lock);
  
  

• 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;
  

• ++i;
  

• 		if (IS_ERR(block)) {
  

• 			r = -ENOSPC;
  

• 			goto error_free_blocks;
  

• 		}
  
  

• if (pages > pages_left)
  

• 	pages = pages_left;
  

• 		n_pages -= BIT(order);
  

• 		list_add_tail(&block->link, &vnode->blocks);
  

• 		if (!n_pages)
  

• 			break;
  

• 	} while (1);
  

• 	pages_left -= pages;
  

• 	++i;
  

• 	if (pages > pages_left)
  

• 		pages = pages_left;
  

• }
  

  }
• spin_lock(&mgr->lock);
• list_sort(NULL, &vnode->blocks, sort_blocks);

Why do you sort the list here?

Regards, Christian.

• list_for_each_entry(block, &vnode->blocks, link)

• vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
  

• block = list_first_entry_or_null(&vnode->blocks,

• 	struct drm_buddy_block, link);
  

• node->base.start = block->start; spin_unlock(&mgr->lock);

  if (i == 1)

@@ -472,12 +510,12 @@ 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, &vnode->blocks); spin_unlock(&mgr->lock);

• kvfree(node);

+error_free_res:

• kfree(vnode); error_sub: atomic64_sub(mem_bytes, &mgr->usage); return r;

@@ -494,28 +532,28 @@ 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 *vnode = 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, &vnode->blocks, link) {

• usage += block->size << PAGE_SHIFT;
  

• vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
  

  }

• amdgpu_vram_mgr_do_reserve(man);

• drm_buddy_free_list(mm, &vnode->blocks); spin_unlock(&mgr->lock);

  atomic64_sub(usage, &mgr->usage); atomic64_sub(vis_usage, &mgr->vis_usage);

• kvfree(node);

• kfree(vnode); }

  /**

@@ -668,12 +706,6 @@ uint64_t amdgpu_vram_mgr_vis_usage(struct ttm_resource_manager *man) static void amdgpu_vram_mgr_debug(struct ttm_resource_manager *man, struct drm_printer *printer) {

• struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
• spin_lock(&mgr->lock);
• drm_mm_print(&mgr->mm, printer);
• spin_unlock(&mgr->lock);
• drm_printf(printer, "man size:%llu pages, ram usage:%lluMB, vis usage:%lluMB\n", man->size, amdgpu_vram_mgr_usage(man) >> 20, amdgpu_vram_mgr_vis_usage(man) >> 20);

@@ -701,7 +733,7 @@ int amdgpu_vram_mgr_init(struct amdgpu_device *adev)

man->func = &amdgpu_vram_mgr_func;

• drm_mm_init(&mgr->mm, 0, man->size);

• drm_buddy_init(&mgr->mm, man->size << PAGE_SHIFT, PAGE_SIZE); spin_lock_init(&mgr->lock); INIT_LIST_HEAD(&mgr->reservations_pending); INIT_LIST_HEAD(&mgr->reserved_pages);

@@ -737,10 +769,10 @@ 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(&mgr->mm, &rsv->mm_node);
  

  kfree(rsv); }

• drm_mm_takedown(&mgr->mm);

• drm_buddy_fini(&mgr->mm); spin_unlock(&mgr->lock);

  ttm_resource_manager_cleanup(man);