xref: /openbmc/linux/drivers/infiniband/hw/mthca/mthca_allocator.c (revision 12d1e2f3c5762df4ad72c75b2464a5b538f12aa9)
1 /*
2  * Copyright (c) 2004 Topspin Communications.  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/bitmap.h>
36 
37 #include "mthca_dev.h"
38 
39 /* Trivial bitmap-based allocator */
40 u32 mthca_alloc(struct mthca_alloc *alloc)
41 {
42 	unsigned long flags;
43 	u32 obj;
44 
45 	spin_lock_irqsave(&alloc->lock, flags);
46 
47 	obj = find_next_zero_bit(alloc->table, alloc->max, alloc->last);
48 	if (obj >= alloc->max) {
49 		alloc->top = (alloc->top + alloc->max) & alloc->mask;
50 		obj = find_first_zero_bit(alloc->table, alloc->max);
51 	}
52 
53 	if (obj < alloc->max) {
54 		set_bit(obj, alloc->table);
55 		obj |= alloc->top;
56 	} else
57 		obj = -1;
58 
59 	spin_unlock_irqrestore(&alloc->lock, flags);
60 
61 	return obj;
62 }
63 
64 void mthca_free(struct mthca_alloc *alloc, u32 obj)
65 {
66 	unsigned long flags;
67 
68 	obj &= alloc->max - 1;
69 
70 	spin_lock_irqsave(&alloc->lock, flags);
71 
72 	clear_bit(obj, alloc->table);
73 	alloc->last = min(alloc->last, obj);
74 	alloc->top = (alloc->top + alloc->max) & alloc->mask;
75 
76 	spin_unlock_irqrestore(&alloc->lock, flags);
77 }
78 
79 int mthca_alloc_init(struct mthca_alloc *alloc, u32 num, u32 mask,
80 		     u32 reserved)
81 {
82 	int i;
83 
84 	/* num must be a power of 2 */
85 	if (num != 1 << (ffs(num) - 1))
86 		return -EINVAL;
87 
88 	alloc->last = 0;
89 	alloc->top  = 0;
90 	alloc->max  = num;
91 	alloc->mask = mask;
92 	spin_lock_init(&alloc->lock);
93 	alloc->table = bitmap_zalloc(num, GFP_KERNEL);
94 	if (!alloc->table)
95 		return -ENOMEM;
96 
97 	for (i = 0; i < reserved; ++i)
98 		set_bit(i, alloc->table);
99 
100 	return 0;
101 }
102 
103 void mthca_alloc_cleanup(struct mthca_alloc *alloc)
104 {
105 	bitmap_free(alloc->table);
106 }
107 
108 /*
109  * Array of pointers with lazy allocation of leaf pages.  Callers of
110  * _get, _set and _clear methods must use a lock or otherwise
111  * serialize access to the array.
112  */
113 
114 #define MTHCA_ARRAY_MASK (PAGE_SIZE / sizeof (void *) - 1)
115 
116 void *mthca_array_get(struct mthca_array *array, int index)
117 {
118 	int p = (index * sizeof (void *)) >> PAGE_SHIFT;
119 
120 	if (array->page_list[p].page)
121 		return array->page_list[p].page[index & MTHCA_ARRAY_MASK];
122 	else
123 		return NULL;
124 }
125 
126 int mthca_array_set(struct mthca_array *array, int index, void *value)
127 {
128 	int p = (index * sizeof (void *)) >> PAGE_SHIFT;
129 
130 	/* Allocate with GFP_ATOMIC because we'll be called with locks held. */
131 	if (!array->page_list[p].page)
132 		array->page_list[p].page = (void **) get_zeroed_page(GFP_ATOMIC);
133 
134 	if (!array->page_list[p].page)
135 		return -ENOMEM;
136 
137 	array->page_list[p].page[index & MTHCA_ARRAY_MASK] = value;
138 	++array->page_list[p].used;
139 
140 	return 0;
141 }
142 
143 void mthca_array_clear(struct mthca_array *array, int index)
144 {
145 	int p = (index * sizeof (void *)) >> PAGE_SHIFT;
146 
147 	if (--array->page_list[p].used == 0) {
148 		free_page((unsigned long) array->page_list[p].page);
149 		array->page_list[p].page = NULL;
150 	} else
151 		array->page_list[p].page[index & MTHCA_ARRAY_MASK] = NULL;
152 
153 	if (array->page_list[p].used < 0)
154 		pr_debug("Array %p index %d page %d with ref count %d < 0\n",
155 			 array, index, p, array->page_list[p].used);
156 }
157 
158 int mthca_array_init(struct mthca_array *array, int nent)
159 {
160 	int npage = (nent * sizeof (void *) + PAGE_SIZE - 1) / PAGE_SIZE;
161 	int i;
162 
163 	array->page_list = kmalloc_array(npage, sizeof(*array->page_list),
164 					 GFP_KERNEL);
165 	if (!array->page_list)
166 		return -ENOMEM;
167 
168 	for (i = 0; i < npage; ++i) {
169 		array->page_list[i].page = NULL;
170 		array->page_list[i].used = 0;
171 	}
172 
173 	return 0;
174 }
175 
176 void mthca_array_cleanup(struct mthca_array *array, int nent)
177 {
178 	int i;
179 
180 	for (i = 0; i < (nent * sizeof (void *) + PAGE_SIZE - 1) / PAGE_SIZE; ++i)
181 		free_page((unsigned long) array->page_list[i].page);
182 
183 	kfree(array->page_list);
184 }
185 
186 /*
187  * Handling for queue buffers -- we allocate a bunch of memory and
188  * register it in a memory region at HCA virtual address 0.  If the
189  * requested size is > max_direct, we split the allocation into
190  * multiple pages, so we don't require too much contiguous memory.
191  */
192 
193 int mthca_buf_alloc(struct mthca_dev *dev, int size, int max_direct,
194 		    union mthca_buf *buf, int *is_direct, struct mthca_pd *pd,
195 		    int hca_write, struct mthca_mr *mr)
196 {
197 	int err = -ENOMEM;
198 	int npages, shift;
199 	u64 *dma_list = NULL;
200 	dma_addr_t t;
201 	int i;
202 
203 	if (size <= max_direct) {
204 		*is_direct = 1;
205 		npages     = 1;
206 		shift      = get_order(size) + PAGE_SHIFT;
207 
208 		buf->direct.buf = dma_alloc_coherent(&dev->pdev->dev,
209 						     size, &t, GFP_KERNEL);
210 		if (!buf->direct.buf)
211 			return -ENOMEM;
212 
213 		dma_unmap_addr_set(&buf->direct, mapping, t);
214 
215 		while (t & ((1 << shift) - 1)) {
216 			--shift;
217 			npages *= 2;
218 		}
219 
220 		dma_list = kmalloc_array(npages, sizeof(*dma_list),
221 					 GFP_KERNEL);
222 		if (!dma_list)
223 			goto err_free;
224 
225 		for (i = 0; i < npages; ++i)
226 			dma_list[i] = t + i * (1 << shift);
227 	} else {
228 		*is_direct = 0;
229 		npages     = (size + PAGE_SIZE - 1) / PAGE_SIZE;
230 		shift      = PAGE_SHIFT;
231 
232 		dma_list = kmalloc_array(npages, sizeof(*dma_list),
233 					 GFP_KERNEL);
234 		if (!dma_list)
235 			return -ENOMEM;
236 
237 		buf->page_list = kmalloc_array(npages,
238 					       sizeof(*buf->page_list),
239 					       GFP_KERNEL);
240 		if (!buf->page_list)
241 			goto err_out;
242 
243 		for (i = 0; i < npages; ++i)
244 			buf->page_list[i].buf = NULL;
245 
246 		for (i = 0; i < npages; ++i) {
247 			buf->page_list[i].buf =
248 				dma_alloc_coherent(&dev->pdev->dev, PAGE_SIZE,
249 						   &t, GFP_KERNEL);
250 			if (!buf->page_list[i].buf)
251 				goto err_free;
252 
253 			dma_list[i] = t;
254 			dma_unmap_addr_set(&buf->page_list[i], mapping, t);
255 
256 			clear_page(buf->page_list[i].buf);
257 		}
258 	}
259 
260 	err = mthca_mr_alloc_phys(dev, pd->pd_num,
261 				  dma_list, shift, npages,
262 				  0, size,
263 				  MTHCA_MPT_FLAG_LOCAL_READ |
264 				  (hca_write ? MTHCA_MPT_FLAG_LOCAL_WRITE : 0),
265 				  mr);
266 	if (err)
267 		goto err_free;
268 
269 	kfree(dma_list);
270 
271 	return 0;
272 
273 err_free:
274 	mthca_buf_free(dev, size, buf, *is_direct, NULL);
275 
276 err_out:
277 	kfree(dma_list);
278 
279 	return err;
280 }
281 
282 void mthca_buf_free(struct mthca_dev *dev, int size, union mthca_buf *buf,
283 		    int is_direct, struct mthca_mr *mr)
284 {
285 	int i;
286 
287 	if (mr)
288 		mthca_free_mr(dev, mr);
289 
290 	if (is_direct)
291 		dma_free_coherent(&dev->pdev->dev, size, buf->direct.buf,
292 				  dma_unmap_addr(&buf->direct, mapping));
293 	else {
294 		for (i = 0; i < (size + PAGE_SIZE - 1) / PAGE_SIZE; ++i)
295 			dma_free_coherent(&dev->pdev->dev, PAGE_SIZE,
296 					  buf->page_list[i].buf,
297 					  dma_unmap_addr(&buf->page_list[i],
298 							 mapping));
299 		kfree(buf->page_list);
300 	}
301 }
302