Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  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  * $Id: mthca_allocator.c 1349 2004-12-16 21:09:43Z roland $
 33  */
 34 
 35 #include <linux/errno.h>
 36 #include <linux/slab.h>
 37 #include <linux/bitmap.h>
 38 
 39 #include "mthca_dev.h"
 40 
 41 /* Trivial bitmap-based allocator */
 42 u32 mthca_alloc(struct mthca_alloc *alloc)
 43 {
 44         unsigned long flags;
 45         u32 obj;
 46 
 47         spin_lock_irqsave(&alloc->lock, flags);
 48 
 49         obj = find_next_zero_bit(alloc->table, alloc->max, alloc->last);
 50         if (obj >= alloc->max) {
 51                 alloc->top = (alloc->top + alloc->max) & alloc->mask;
 52                 obj = find_first_zero_bit(alloc->table, alloc->max);
 53         }
 54 
 55         if (obj < alloc->max) {
 56                 set_bit(obj, alloc->table);
 57                 obj |= alloc->top;
 58         } else
 59                 obj = -1;
 60 
 61         spin_unlock_irqrestore(&alloc->lock, flags);
 62 
 63         return obj;
 64 }
 65 
 66 void mthca_free(struct mthca_alloc *alloc, u32 obj)
 67 {
 68         unsigned long flags;
 69 
 70         obj &= alloc->max - 1;
 71 
 72         spin_lock_irqsave(&alloc->lock, flags);
 73 
 74         clear_bit(obj, alloc->table);
 75         alloc->last = min(alloc->last, obj);
 76         alloc->top = (alloc->top + alloc->max) & alloc->mask;
 77 
 78         spin_unlock_irqrestore(&alloc->lock, flags);
 79 }
 80 
 81 int mthca_alloc_init(struct mthca_alloc *alloc, u32 num, u32 mask,
 82                      u32 reserved)
 83 {
 84         int i;
 85 
 86         /* num must be a power of 2 */
 87         if (num != 1 << (ffs(num) - 1))
 88                 return -EINVAL;
 89 
 90         alloc->last = 0;
 91         alloc->top  = 0;
 92         alloc->max  = num;
 93         alloc->mask = mask;
 94         spin_lock_init(&alloc->lock);
 95         alloc->table = kmalloc(BITS_TO_LONGS(num) * sizeof (long),
 96                                GFP_KERNEL);
 97         if (!alloc->table)
 98                 return -ENOMEM;
 99 
100         bitmap_zero(alloc->table, num);
101         for (i = 0; i < reserved; ++i)
102                 set_bit(i, alloc->table);
103 
104         return 0;
105 }
106 
107 void mthca_alloc_cleanup(struct mthca_alloc *alloc)
108 {
109         kfree(alloc->table);
110 }
111 
112 /*
113  * Array of pointers with lazy allocation of leaf pages.  Callers of
114  * _get, _set and _clear methods must use a lock or otherwise
115  * serialize access to the array.
116  */
117 
118 #define MTHCA_ARRAY_MASK (PAGE_SIZE / sizeof (void *) - 1)
119 
120 void *mthca_array_get(struct mthca_array *array, int index)
121 {
122         int p = (index * sizeof (void *)) >> PAGE_SHIFT;
123 
124         if (array->page_list[p].page)
125                 return array->page_list[p].page[index & MTHCA_ARRAY_MASK];
126         else
127                 return NULL;
128 }
129 
130 int mthca_array_set(struct mthca_array *array, int index, void *value)
131 {
132         int p = (index * sizeof (void *)) >> PAGE_SHIFT;
133 
134         /* Allocate with GFP_ATOMIC because we'll be called with locks held. */
135         if (!array->page_list[p].page)
136                 array->page_list[p].page = (void **) get_zeroed_page(GFP_ATOMIC);
137 
138         if (!array->page_list[p].page)
139                 return -ENOMEM;
140 
141         array->page_list[p].page[index & MTHCA_ARRAY_MASK] = value;
142         ++array->page_list[p].used;
143 
144         return 0;
145 }
146 
147 void mthca_array_clear(struct mthca_array *array, int index)
148 {
149         int p = (index * sizeof (void *)) >> PAGE_SHIFT;
150 
151         if (--array->page_list[p].used == 0) {
152                 free_page((unsigned long) array->page_list[p].page);
153                 array->page_list[p].page = NULL;
154         } else
155                 array->page_list[p].page[index & MTHCA_ARRAY_MASK] = NULL;
156 
157         if (array->page_list[p].used < 0)
158                 pr_debug("Array %p index %d page %d with ref count %d < 0\n",
159                          array, index, p, array->page_list[p].used);
160 }
161 
162 int mthca_array_init(struct mthca_array *array, int nent)
163 {
164         int npage = (nent * sizeof (void *) + PAGE_SIZE - 1) / PAGE_SIZE;
165         int i;
166 
167         array->page_list = kmalloc(npage * sizeof *array->page_list, GFP_KERNEL);
168         if (!array->page_list)
169                 return -ENOMEM;
170 
171         for (i = 0; i < npage; ++i) {
172                 array->page_list[i].page = NULL;
173                 array->page_list[i].used = 0;
174         }
175 
176         return 0;
177 }
178 
179 void mthca_array_cleanup(struct mthca_array *array, int nent)
180 {
181         int i;
182 
183         for (i = 0; i < (nent * sizeof (void *) + PAGE_SIZE - 1) / PAGE_SIZE; ++i)
184                 free_page((unsigned long) array->page_list[i].page);
185 
186         kfree(array->page_list);
187 }
188 
189 /*
190  * Handling for queue buffers -- we allocate a bunch of memory and
191  * register it in a memory region at HCA virtual address 0.  If the
192  * requested size is > max_direct, we split the allocation into
193  * multiple pages, so we don't require too much contiguous memory.
194  */
195 
196 int mthca_buf_alloc(struct mthca_dev *dev, int size, int max_direct,
197                     union mthca_buf *buf, int *is_direct, struct mthca_pd *pd,
198                     int hca_write, struct mthca_mr *mr)
199 {
200         int err = -ENOMEM;
201         int npages, shift;
202         u64 *dma_list = NULL;
203         dma_addr_t t;
204         int i;
205 
206         if (size <= max_direct) {
207                 *is_direct = 1;
208                 npages     = 1;
209                 shift      = get_order(size) + PAGE_SHIFT;
210 
211                 buf->direct.buf = dma_alloc_coherent(&dev->pdev->dev,
212                                                      size, &t, GFP_KERNEL);
213                 if (!buf->direct.buf)
214                         return -ENOMEM;
215 
216                 pci_unmap_addr_set(&buf->direct, mapping, t);
217 
218                 memset(buf->direct.buf, 0, size);
219 
220                 while (t & ((1 << shift) - 1)) {
221                         --shift;
222                         npages *= 2;
223                 }
224 
225                 dma_list = kmalloc(npages * sizeof *dma_list, GFP_KERNEL);
226                 if (!dma_list)
227                         goto err_free;
228 
229                 for (i = 0; i < npages; ++i)
230                         dma_list[i] = t + i * (1 << shift);
231         } else {
232                 *is_direct = 0;
233                 npages     = (size + PAGE_SIZE - 1) / PAGE_SIZE;
234                 shift      = PAGE_SHIFT;
235 
236                 dma_list = kmalloc(npages * sizeof *dma_list, GFP_KERNEL);
237                 if (!dma_list)
238                         return -ENOMEM;
239 
240                 buf->page_list = kmalloc(npages * sizeof *buf->page_list,
241                                          GFP_KERNEL);
242                 if (!buf->page_list)
243                         goto err_out;
244 
245                 for (i = 0; i < npages; ++i)
246                         buf->page_list[i].buf = NULL;
247 
248                 for (i = 0; i < npages; ++i) {
249                         buf->page_list[i].buf =
250                                 dma_alloc_coherent(&dev->pdev->dev, PAGE_SIZE,
251                                                    &t, GFP_KERNEL);
252                         if (!buf->page_list[i].buf)
253                                 goto err_free;
254 
255                         dma_list[i] = t;
256                         pci_unmap_addr_set(&buf->page_list[i], mapping, t);
257 
258                         clear_page(buf->page_list[i].buf);
259                 }
260         }
261 
262         err = mthca_mr_alloc_phys(dev, pd->pd_num,
263                                   dma_list, shift, npages,
264                                   0, size,
265                                   MTHCA_MPT_FLAG_LOCAL_READ |
266                                   (hca_write ? MTHCA_MPT_FLAG_LOCAL_WRITE : 0),
267                                   mr);
268         if (err)
269                 goto err_free;
270 
271         kfree(dma_list);
272 
273         return 0;
274 
275 err_free:
276         mthca_buf_free(dev, size, buf, *is_direct, NULL);
277 
278 err_out:
279         kfree(dma_list);
280 
281         return err;
282 }
283 
284 void mthca_buf_free(struct mthca_dev *dev, int size, union mthca_buf *buf,
285                     int is_direct, struct mthca_mr *mr)
286 {
287         int i;
288 
289         if (mr)
290                 mthca_free_mr(dev, mr);
291 
292         if (is_direct)
293                 dma_free_coherent(&dev->pdev->dev, size, buf->direct.buf,
294                                   pci_unmap_addr(&buf->direct, mapping));
295         else {
296                 for (i = 0; i < (size + PAGE_SIZE - 1) / PAGE_SIZE; ++i)
297                         dma_free_coherent(&dev->pdev->dev, PAGE_SIZE,
298                                           buf->page_list[i].buf,
299                                           pci_unmap_addr(&buf->page_list[i],
300                                                          mapping));
301                 kfree(buf->page_list);
302         }
303 }
304 
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