1/*
2 * Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses.  You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 *     Redistribution and use in source and binary forms, with or
11 *     without modification, are permitted provided that the following
12 *     conditions are met:
13 *
14 *      - Redistributions of source code must retain the above
15 *        copyright notice, this list of conditions and the following
16 *        disclaimer.
17 *
18 *      - Redistributions in binary form must reproduce the above
19 *        copyright notice, this list of conditions and the following
20 *        disclaimer in the documentation and/or other materials
21 *        provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32
33#include <linux/errno.h>
34#include <linux/slab.h>
35#include <linux/mm.h>
36#include <linux/export.h>
37#include <linux/bitmap.h>
38#include <linux/dma-mapping.h>
39#include <linux/vmalloc.h>
40#include <linux/mlx5/driver.h>
41
42#include "mlx5_core.h"
43
44/* Handling for queue buffers -- we allocate a bunch of memory and
45 * register it in a memory region at HCA virtual address 0.  If the
46 * requested size is > max_direct, we split the allocation into
47 * multiple pages, so we don't require too much contiguous memory.
48 */
49
50int mlx5_buf_alloc(struct mlx5_core_dev *dev, int size, int max_direct,
51		   struct mlx5_buf *buf)
52{
53	dma_addr_t t;
54
55	buf->size = size;
56	if (size <= max_direct) {
57		buf->nbufs        = 1;
58		buf->npages       = 1;
59		buf->page_shift   = (u8)get_order(size) + PAGE_SHIFT;
60		buf->direct.buf   = dma_zalloc_coherent(&dev->pdev->dev,
61							size, &t, GFP_KERNEL);
62		if (!buf->direct.buf)
63			return -ENOMEM;
64
65		buf->direct.map = t;
66
67		while (t & ((1 << buf->page_shift) - 1)) {
68			--buf->page_shift;
69			buf->npages *= 2;
70		}
71	} else {
72		int i;
73
74		buf->direct.buf  = NULL;
75		buf->nbufs       = (size + PAGE_SIZE - 1) / PAGE_SIZE;
76		buf->npages      = buf->nbufs;
77		buf->page_shift  = PAGE_SHIFT;
78		buf->page_list   = kcalloc(buf->nbufs, sizeof(*buf->page_list),
79					   GFP_KERNEL);
80		if (!buf->page_list)
81			return -ENOMEM;
82
83		for (i = 0; i < buf->nbufs; i++) {
84			buf->page_list[i].buf =
85				dma_zalloc_coherent(&dev->pdev->dev, PAGE_SIZE,
86						    &t, GFP_KERNEL);
87			if (!buf->page_list[i].buf)
88				goto err_free;
89
90			buf->page_list[i].map = t;
91		}
92
93		if (BITS_PER_LONG == 64) {
94			struct page **pages;
95			pages = kmalloc(sizeof(*pages) * buf->nbufs, GFP_KERNEL);
96			if (!pages)
97				goto err_free;
98			for (i = 0; i < buf->nbufs; i++)
99				pages[i] = virt_to_page(buf->page_list[i].buf);
100			buf->direct.buf = vmap(pages, buf->nbufs, VM_MAP, PAGE_KERNEL);
101			kfree(pages);
102			if (!buf->direct.buf)
103				goto err_free;
104		}
105	}
106
107	return 0;
108
109err_free:
110	mlx5_buf_free(dev, buf);
111
112	return -ENOMEM;
113}
114EXPORT_SYMBOL_GPL(mlx5_buf_alloc);
115
116void mlx5_buf_free(struct mlx5_core_dev *dev, struct mlx5_buf *buf)
117{
118	int i;
119
120	if (buf->nbufs == 1)
121		dma_free_coherent(&dev->pdev->dev, buf->size, buf->direct.buf,
122				  buf->direct.map);
123	else {
124		if (BITS_PER_LONG == 64)
125			vunmap(buf->direct.buf);
126
127		for (i = 0; i < buf->nbufs; i++)
128			if (buf->page_list[i].buf)
129				dma_free_coherent(&dev->pdev->dev, PAGE_SIZE,
130						  buf->page_list[i].buf,
131						  buf->page_list[i].map);
132		kfree(buf->page_list);
133	}
134}
135EXPORT_SYMBOL_GPL(mlx5_buf_free);
136
137static struct mlx5_db_pgdir *mlx5_alloc_db_pgdir(struct device *dma_device)
138{
139	struct mlx5_db_pgdir *pgdir;
140
141	pgdir = kzalloc(sizeof(*pgdir), GFP_KERNEL);
142	if (!pgdir)
143		return NULL;
144
145	bitmap_fill(pgdir->bitmap, MLX5_DB_PER_PAGE);
146	pgdir->db_page = dma_alloc_coherent(dma_device, PAGE_SIZE,
147					    &pgdir->db_dma, GFP_KERNEL);
148	if (!pgdir->db_page) {
149		kfree(pgdir);
150		return NULL;
151	}
152
153	return pgdir;
154}
155
156static int mlx5_alloc_db_from_pgdir(struct mlx5_db_pgdir *pgdir,
157				    struct mlx5_db *db)
158{
159	int offset;
160	int i;
161
162	i = find_first_bit(pgdir->bitmap, MLX5_DB_PER_PAGE);
163	if (i >= MLX5_DB_PER_PAGE)
164		return -ENOMEM;
165
166	__clear_bit(i, pgdir->bitmap);
167
168	db->u.pgdir = pgdir;
169	db->index   = i;
170	offset = db->index * L1_CACHE_BYTES;
171	db->db      = pgdir->db_page + offset / sizeof(*pgdir->db_page);
172	db->dma     = pgdir->db_dma  + offset;
173
174	db->db[0] = 0;
175	db->db[1] = 0;
176
177	return 0;
178}
179
180int mlx5_db_alloc(struct mlx5_core_dev *dev, struct mlx5_db *db)
181{
182	struct mlx5_db_pgdir *pgdir;
183	int ret = 0;
184
185	mutex_lock(&dev->priv.pgdir_mutex);
186
187	list_for_each_entry(pgdir, &dev->priv.pgdir_list, list)
188		if (!mlx5_alloc_db_from_pgdir(pgdir, db))
189			goto out;
190
191	pgdir = mlx5_alloc_db_pgdir(&(dev->pdev->dev));
192	if (!pgdir) {
193		ret = -ENOMEM;
194		goto out;
195	}
196
197	list_add(&pgdir->list, &dev->priv.pgdir_list);
198
199	/* This should never fail -- we just allocated an empty page: */
200	WARN_ON(mlx5_alloc_db_from_pgdir(pgdir, db));
201
202out:
203	mutex_unlock(&dev->priv.pgdir_mutex);
204
205	return ret;
206}
207EXPORT_SYMBOL_GPL(mlx5_db_alloc);
208
209void mlx5_db_free(struct mlx5_core_dev *dev, struct mlx5_db *db)
210{
211	mutex_lock(&dev->priv.pgdir_mutex);
212
213	__set_bit(db->index, db->u.pgdir->bitmap);
214
215	if (bitmap_full(db->u.pgdir->bitmap, MLX5_DB_PER_PAGE)) {
216		dma_free_coherent(&(dev->pdev->dev), PAGE_SIZE,
217				  db->u.pgdir->db_page, db->u.pgdir->db_dma);
218		list_del(&db->u.pgdir->list);
219		kfree(db->u.pgdir);
220	}
221
222	mutex_unlock(&dev->priv.pgdir_mutex);
223}
224EXPORT_SYMBOL_GPL(mlx5_db_free);
225
226
227void mlx5_fill_page_array(struct mlx5_buf *buf, __be64 *pas)
228{
229	u64 addr;
230	int i;
231
232	for (i = 0; i < buf->npages; i++) {
233		if (buf->nbufs == 1)
234			addr = buf->direct.map + (i << buf->page_shift);
235		else
236			addr = buf->page_list[i].map;
237
238		pas[i] = cpu_to_be64(addr);
239	}
240}
241EXPORT_SYMBOL_GPL(mlx5_fill_page_array);
242