linux/drivers/infiniband/hw/hns/hns_roce_db.c
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   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
  11int 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
  44found:
  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
  51out:
  52        mutex_unlock(&context->page_mutex);
  53
  54        return ret;
  55}
  56
  57void 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
  72static 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
  95static 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
 109found:
 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
 126int 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
 149out:
 150        mutex_unlock(&hr_dev->pgdir_mutex);
 151
 152        return ret;
 153}
 154
 155void 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}
 183