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(context->ibucontext.device, page_addr,
  35                                  PAGE_SIZE, 0);
  36         if (IS_ERR(page->umem)) {
  37                 ret = PTR_ERR(page->umem);
  38                 kfree(page);
  39                 goto out;
  40         }
  41
  42         list_add(&page->list, &context->page_list);
  43
  44 found:
  45         offset = virt - page_addr;
  46         db->dma = sg_dma_address(page->umem->sg_head.sgl) + offset;
  47         db->virt_addr = sg_virt(page->umem->sg_head.sgl) + offset;
  48         db->u.user_page = page;
  49         refcount_inc(&page->refcount);
  50
  51 out:
  52         mutex_unlock(&context->page_mutex);
  53
  54         return ret;
  55 }
  56
  57 void hns_roce_db_unmap_user(struct hns_roce_ucontext *context,
  58                             struct hns_roce_db *db)
  59 {
  60         mutex_lock(&context->page_mutex);
  61
  62         refcount_dec(&db->u.user_page->refcount);
  63         if (refcount_dec_if_one(&db->u.user_page->refcount)) {
  64                 list_del(&db->u.user_page->list);
  65                 ib_umem_release(db->u.user_page->umem);
  66                 kfree(db->u.user_page);
  67         }
  68
  69         mutex_unlock(&context->page_mutex);
  70 }
  71
  72 static struct hns_roce_db_pgdir *hns_roce_alloc_db_pgdir(
  73                                         struct device *dma_device)
  74 {
  75         struct hns_roce_db_pgdir *pgdir;
  76
  77         pgdir = kzalloc(sizeof(*pgdir), GFP_KERNEL);
  78         if (!pgdir)
  79                 return NULL;
  80
  81         bitmap_fill(pgdir->order1,
  82                     HNS_ROCE_DB_PER_PAGE / HNS_ROCE_DB_TYPE_COUNT);
  83         pgdir->bits[0] = pgdir->order0;
  84         pgdir->bits[1] = pgdir->order1;
  85         pgdir->page = dma_alloc_coherent(dma_device, PAGE_SIZE,
  86                                          &pgdir->db_dma, GFP_KERNEL);
  87         if (!pgdir->page) {
  88                 kfree(pgdir);
  89                 return NULL;
  90         }
  91
  92         return pgdir;
  93 }
  94
  95 static int hns_roce_alloc_db_from_pgdir(struct hns_roce_db_pgdir *pgdir,
  96                                         struct hns_roce_db *db, int order)
  97 {
  98         int o;
  99         int i;
 100
 101         for (o = order; o <= 1; ++o) {
 102                 i = find_first_bit(pgdir->bits[o], HNS_ROCE_DB_PER_PAGE >> o);
 103                 if (i < HNS_ROCE_DB_PER_PAGE >> o)
 104                         goto found;
 105         }
 106
 107         return -ENOMEM;
 108
 109 found:
 110         clear_bit(i, pgdir->bits[o]);
 111
 112         i <<= o;
 113
 114         if (o > order)
 115                 set_bit(i ^ 1, pgdir->bits[order]);
 116
 117         db->u.pgdir     = pgdir;
 118         db->index       = i;
 119         db->db_record   = pgdir->page + db->index;
 120         db->dma         = pgdir->db_dma  + db->index * HNS_ROCE_DB_UNIT_SIZE;
 121         db->order       = order;
 122
 123         return 0;
 124 }
 125
 126 int hns_roce_alloc_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db,
 127                       int order)
 128 {
 129         struct hns_roce_db_pgdir *pgdir;
 130         int ret = 0;
 131
 132         mutex_lock(&hr_dev->pgdir_mutex);
 133
 134         list_for_each_entry(pgdir, &hr_dev->pgdir_list, list)
 135                 if (!hns_roce_alloc_db_from_pgdir(pgdir, db, order))
 136                         goto out;
 137
 138         pgdir = hns_roce_alloc_db_pgdir(hr_dev->dev);
 139         if (!pgdir) {
 140                 ret = -ENOMEM;
 141                 goto out;
 142         }
 143
 144         list_add(&pgdir->list, &hr_dev->pgdir_list);
 145
 146         /* This should never fail -- we just allocated an empty page: */
 147         WARN_ON(hns_roce_alloc_db_from_pgdir(pgdir, db, order));
 148
 149 out:
 150         mutex_unlock(&hr_dev->pgdir_mutex);
 151
 152         return ret;
 153 }
 154
 155 void hns_roce_free_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db)
 156 {
 157         int o;
 158         int i;
 159
 160         mutex_lock(&hr_dev->pgdir_mutex);
 161
 162         o = db->order;
 163         i = db->index;
 164
 165         if (db->order == 0 && test_bit(i ^ 1, db->u.pgdir->order0)) {
 166                 clear_bit(i ^ 1, db->u.pgdir->order0);
 167                 ++o;
 168         }
 169
 170         i >>= o;
 171         set_bit(i, db->u.pgdir->bits[o]);
 172
 173         if (bitmap_full(db->u.pgdir->order1,
 174                         HNS_ROCE_DB_PER_PAGE / HNS_ROCE_DB_TYPE_COUNT)) {
 175                 dma_free_coherent(hr_dev->dev, PAGE_SIZE, db->u.pgdir->page,
 176                                   db->u.pgdir->db_dma);
 177                 list_del(&db->u.pgdir->list);
 178                 kfree(db->u.pgdir);
 179         }
 180
 181         mutex_unlock(&hr_dev->pgdir_mutex);
 182 }