linux/drivers/gpu/drm/vmwgfx/vmwgfx_thp.c
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   1// SPDX-License-Identifier: GPL-2.0 OR MIT
   2/*
   3 * Huge page-table-entry support for IO memory.
   4 *
   5 * Copyright (C) 2007-2019 Vmware, Inc. All rights reservedd.
   6 */
   7#include "vmwgfx_drv.h"
   8#include <drm/ttm/ttm_module.h>
   9#include <drm/ttm/ttm_bo_driver.h>
  10#include <drm/ttm/ttm_placement.h>
  11
  12/**
  13 * struct vmw_thp_manager - Range manager implementing huge page alignment
  14 *
  15 * @mm: The underlying range manager. Protected by @lock.
  16 * @lock: Manager lock.
  17 */
  18struct vmw_thp_manager {
  19        struct drm_mm mm;
  20        spinlock_t lock;
  21};
  22
  23static int vmw_thp_insert_aligned(struct drm_mm *mm, struct drm_mm_node *node,
  24                                  unsigned long align_pages,
  25                                  const struct ttm_place *place,
  26                                  struct ttm_mem_reg *mem,
  27                                  unsigned long lpfn,
  28                                  enum drm_mm_insert_mode mode)
  29{
  30        if (align_pages >= mem->page_alignment &&
  31            (!mem->page_alignment || align_pages % mem->page_alignment == 0)) {
  32                return drm_mm_insert_node_in_range(mm, node,
  33                                                   mem->num_pages,
  34                                                   align_pages, 0,
  35                                                   place->fpfn, lpfn, mode);
  36        }
  37
  38        return -ENOSPC;
  39}
  40
  41static int vmw_thp_get_node(struct ttm_mem_type_manager *man,
  42                            struct ttm_buffer_object *bo,
  43                            const struct ttm_place *place,
  44                            struct ttm_mem_reg *mem)
  45{
  46        struct vmw_thp_manager *rman = (struct vmw_thp_manager *) man->priv;
  47        struct drm_mm *mm = &rman->mm;
  48        struct drm_mm_node *node;
  49        unsigned long align_pages;
  50        unsigned long lpfn;
  51        enum drm_mm_insert_mode mode = DRM_MM_INSERT_BEST;
  52        int ret;
  53
  54        node = kzalloc(sizeof(*node), GFP_KERNEL);
  55        if (!node)
  56                return -ENOMEM;
  57
  58        lpfn = place->lpfn;
  59        if (!lpfn)
  60                lpfn = man->size;
  61
  62        mode = DRM_MM_INSERT_BEST;
  63        if (place->flags & TTM_PL_FLAG_TOPDOWN)
  64                mode = DRM_MM_INSERT_HIGH;
  65
  66        spin_lock(&rman->lock);
  67        if (IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)) {
  68                align_pages = (HPAGE_PUD_SIZE >> PAGE_SHIFT);
  69                if (mem->num_pages >= align_pages) {
  70                        ret = vmw_thp_insert_aligned(mm, node, align_pages,
  71                                                     place, mem, lpfn, mode);
  72                        if (!ret)
  73                                goto found_unlock;
  74                }
  75        }
  76
  77        align_pages = (HPAGE_PMD_SIZE >> PAGE_SHIFT);
  78        if (mem->num_pages >= align_pages) {
  79                ret = vmw_thp_insert_aligned(mm, node, align_pages, place, mem,
  80                                             lpfn, mode);
  81                if (!ret)
  82                        goto found_unlock;
  83        }
  84
  85        ret = drm_mm_insert_node_in_range(mm, node, mem->num_pages,
  86                                          mem->page_alignment, 0,
  87                                          place->fpfn, lpfn, mode);
  88found_unlock:
  89        spin_unlock(&rman->lock);
  90
  91        if (unlikely(ret)) {
  92                kfree(node);
  93        } else {
  94                mem->mm_node = node;
  95                mem->start = node->start;
  96        }
  97
  98        return ret;
  99}
 100
 101
 102
 103static void vmw_thp_put_node(struct ttm_mem_type_manager *man,
 104                             struct ttm_mem_reg *mem)
 105{
 106        struct vmw_thp_manager *rman = (struct vmw_thp_manager *) man->priv;
 107
 108        if (mem->mm_node) {
 109                spin_lock(&rman->lock);
 110                drm_mm_remove_node(mem->mm_node);
 111                spin_unlock(&rman->lock);
 112
 113                kfree(mem->mm_node);
 114                mem->mm_node = NULL;
 115        }
 116}
 117
 118static int vmw_thp_init(struct ttm_mem_type_manager *man,
 119                        unsigned long p_size)
 120{
 121        struct vmw_thp_manager *rman;
 122
 123        rman = kzalloc(sizeof(*rman), GFP_KERNEL);
 124        if (!rman)
 125                return -ENOMEM;
 126
 127        drm_mm_init(&rman->mm, 0, p_size);
 128        spin_lock_init(&rman->lock);
 129        man->priv = rman;
 130        return 0;
 131}
 132
 133static int vmw_thp_takedown(struct ttm_mem_type_manager *man)
 134{
 135        struct vmw_thp_manager *rman = (struct vmw_thp_manager *) man->priv;
 136        struct drm_mm *mm = &rman->mm;
 137
 138        spin_lock(&rman->lock);
 139        if (drm_mm_clean(mm)) {
 140                drm_mm_takedown(mm);
 141                spin_unlock(&rman->lock);
 142                kfree(rman);
 143                man->priv = NULL;
 144                return 0;
 145        }
 146        spin_unlock(&rman->lock);
 147        return -EBUSY;
 148}
 149
 150static void vmw_thp_debug(struct ttm_mem_type_manager *man,
 151                          struct drm_printer *printer)
 152{
 153        struct vmw_thp_manager *rman = (struct vmw_thp_manager *) man->priv;
 154
 155        spin_lock(&rman->lock);
 156        drm_mm_print(&rman->mm, printer);
 157        spin_unlock(&rman->lock);
 158}
 159
 160const struct ttm_mem_type_manager_func vmw_thp_func = {
 161        .init = vmw_thp_init,
 162        .takedown = vmw_thp_takedown,
 163        .get_node = vmw_thp_get_node,
 164        .put_node = vmw_thp_put_node,
 165        .debug = vmw_thp_debug
 166};
 167