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
hns_roce_db_map_user(struct hns_roce_ucontext * context,unsigned long virt,struct hns_roce_db * db)11 int hns_roce_db_map_user(struct hns_roce_ucontext *context, unsigned long virt,
12 struct hns_roce_db *db)
13 {
14 unsigned long page_addr = virt & PAGE_MASK;
15 struct hns_roce_user_db_page *page;
16 unsigned int offset;
17 int ret = 0;
18
19 mutex_lock(&context->page_mutex);
20
21 list_for_each_entry(page, &context->page_list, list)
22 if (page->user_virt == page_addr)
23 goto found;
24
25 page = kmalloc(sizeof(*page), GFP_KERNEL);
26 if (!page) {
27 ret = -ENOMEM;
28 goto out;
29 }
30
31 refcount_set(&page->refcount, 1);
32 page->user_virt = page_addr;
33 page->umem = ib_umem_get(context->ibucontext.device, page_addr,
34 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->sgt_append.sgt.sgl) + offset;
46 db->virt_addr = sg_virt(page->umem->sgt_append.sgt.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
hns_roce_db_unmap_user(struct hns_roce_ucontext * context,struct hns_roce_db * db)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
hns_roce_alloc_db_pgdir(struct device * dma_device)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
hns_roce_alloc_db_from_pgdir(struct hns_roce_db_pgdir * pgdir,struct hns_roce_db * db,int order)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 unsigned long o;
98 unsigned long 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
hns_roce_alloc_db(struct hns_roce_dev * hr_dev,struct hns_roce_db * db,int order)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
hns_roce_free_db(struct hns_roce_dev * hr_dev,struct hns_roce_db * db)154 void hns_roce_free_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db)
155 {
156 unsigned long o;
157 unsigned long 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 }
182