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 }
183