drivers/infiniband/hw/hns/hns_roce_db.c

   1 /* SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) */
   2 /*
   3  * Copyright (c) 2017 Hisilicon Limited.
   4  * Copyright (c) 2007, 2008 Mellanox Technologies. All rights reserved.
   5  */
   6
   7 #include <linux/platform_device.h>
   8 #include <rdma/ib_umem.h>
   9 #include "hns_roce_device.h"
  10
  11 int hns_roce_db_map_user(struct hns_roce_ucontext *context,
  12                          struct ib_udata *udata, unsigned long virt,
  13                          struct hns_roce_db *db)
  14 {
  15         unsigned long page_addr = virt & PAGE_MASK;
  16         struct hns_roce_user_db_page *page;
  17         unsigned int offset;
  18         int ret = 0;
  19
  20         mutex_lock(&context->page_mutex);
  21
  22         list_for_each_entry(page, &context->page_list, list)
  23                 if (page->user_virt == page_addr)
  24                         goto found;
  25
  26         page = kmalloc(sizeof(*page), GFP_KERNEL);
  27         if (!page) {
  28                 ret = -ENOMEM;
  29                 goto out;
  30         }
  31
  32         refcount_set(&page->refcount, 1);
  33         page->user_virt = page_addr;
  34         page->umem = ib_umem_get(udata, page_addr, PAGE_SIZE, 0);
  35         if (IS_ERR(page->umem)) {
  36                 ret = PTR_ERR(page->umem);
  37                 kfree(page);
  38                 goto out;
  39         }
  40
  41         list_add(&page->list, &context->page_list);
  42
  43 found:
  44         offset = virt - page_addr;
  45         db->dma = sg_dma_address(page->umem->sg_head.sgl) + offset;
  46         db->virt_addr = sg_virt(page->umem->sg_head.sgl) + offset;
  47         db->u.user_page = page;
  48         refcount_inc(&page->refcount);
  49
  50 out:
  51         mutex_unlock(&context->page_mutex);
  52
  53         return ret;
  54 }
  55
  56 void hns_roce_db_unmap_user(struct hns_roce_ucontext *context,
  57                             struct hns_roce_db *db)
  58 {
  59         mutex_lock(&context->page_mutex);
  60
  61         refcount_dec(&db->u.user_page->refcount);
  62         if (refcount_dec_if_one(&db->u.user_page->refcount)) {
  63                 list_del(&db->u.user_page->list);
  64                 ib_umem_release(db->u.user_page->umem);
  65                 kfree(db->u.user_page);
  66         }
  67
  68         mutex_unlock(&context->page_mutex);
  69 }
  70
  71 static struct hns_roce_db_pgdir *hns_roce_alloc_db_pgdir(
  72                                         struct device *dma_device)
  73 {
  74         struct hns_roce_db_pgdir *pgdir;
  75
  76         pgdir = kzalloc(sizeof(*pgdir), GFP_KERNEL);
  77         if (!pgdir)
  78                 return NULL;
  79
  80         bitmap_fill(pgdir->order1,
  81                     HNS_ROCE_DB_PER_PAGE / HNS_ROCE_DB_TYPE_COUNT);
  82         pgdir->bits[0] = pgdir->order0;
  83         pgdir->bits[1] = pgdir->order1;
  84         pgdir->page = dma_alloc_coherent(dma_device, PAGE_SIZE,
  85                                          &pgdir->db_dma, GFP_KERNEL);
  86         if (!pgdir->page) {
  87                 kfree(pgdir);
  88                 return NULL;
  89         }
  90
  91         return pgdir;
  92 }
  93
  94 static int hns_roce_alloc_db_from_pgdir(struct hns_roce_db_pgdir *pgdir,
  95                                         struct hns_roce_db *db, int order)
  96 {
  97         int o;
  98         int i;
  99
 100         for (o = order; o <= 1; ++o) {
 101                 i = find_first_bit(pgdir->bits[o], HNS_ROCE_DB_PER_PAGE >> o);
 102                 if (i < HNS_ROCE_DB_PER_PAGE >> o)
 103                         goto found;
 104         }
 105
 106         return -ENOMEM;
 107
 108 found:
 109         clear_bit(i, pgdir->bits[o]);
 110
 111         i <<= o;
 112
 113         if (o > order)
 114                 set_bit(i ^ 1, pgdir->bits[order]);
 115
 116         db->u.pgdir     = pgdir;
 117         db->index       = i;
 118         db->db_record   = pgdir->page + db->index;
 119         db->dma         = pgdir->db_dma  + db->index * HNS_ROCE_DB_UNIT_SIZE;
 120         db->order       = order;
 121
 122         return 0;
 123 }
 124
 125 int hns_roce_alloc_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db,
 126                       int order)
 127 {
 128         struct hns_roce_db_pgdir *pgdir;
 129         int ret = 0;
 130
 131         mutex_lock(&hr_dev->pgdir_mutex);
 132
 133         list_for_each_entry(pgdir, &hr_dev->pgdir_list, list)
 134                 if (!hns_roce_alloc_db_from_pgdir(pgdir, db, order))
 135                         goto out;
 136
 137         pgdir = hns_roce_alloc_db_pgdir(hr_dev->dev);
 138         if (!pgdir) {
 139                 ret = -ENOMEM;
 140                 goto out;
 141         }
 142
 143         list_add(&pgdir->list, &hr_dev->pgdir_list);
 144
 145         /* This should never fail -- we just allocated an empty page: */
 146         WARN_ON(hns_roce_alloc_db_from_pgdir(pgdir, db, order));
 147
 148 out:
 149         mutex_unlock(&hr_dev->pgdir_mutex);
 150
 151         return ret;
 152 }
 153
 154 void hns_roce_free_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db)
 155 {
 156         int o;
 157         int i;
 158
 159         mutex_lock(&hr_dev->pgdir_mutex);
 160
 161         o = db->order;
 162         i = db->index;
 163
 164         if (db->order == 0 && test_bit(i ^ 1, db->u.pgdir->order0)) {
 165                 clear_bit(i ^ 1, db->u.pgdir->order0);
 166                 ++o;
 167         }
 168
 169         i >>= o;
 170         set_bit(i, db->u.pgdir->bits[o]);
 171
 172         if (bitmap_full(db->u.pgdir->order1,
 173                         HNS_ROCE_DB_PER_PAGE / HNS_ROCE_DB_TYPE_COUNT)) {
 174                 dma_free_coherent(hr_dev->dev, PAGE_SIZE, db->u.pgdir->page,
 175                                   db->u.pgdir->db_dma);
 176                 list_del(&db->u.pgdir->list);
 177                 kfree(db->u.pgdir);
 178         }
 179
 180         mutex_unlock(&hr_dev->pgdir_mutex);
 181 }