On Mon, Sep 20, 2021 at 3:21 PM Arunpravin Arunpravin.PaneerSelvam@amd.com wrote:

Replace drm_mm with drm buddy manager for VRAM memory management

Would be good to document why we are doing this and what advantages it brings over the old drm_mm code.

Alex

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;
  

•   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);
  

+}

/* 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) {
  

•           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;
  

•   }
  

}

/** @@ -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)
  

{

•   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;
  
    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);
  

•           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);
  

•                   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);
  

•                           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);
  

•   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);
  

-- 2.25.1