drivers/infiniband/hw/ehca/ipz_pt_fn.c

   1 /*
   2  *  IBM eServer eHCA Infiniband device driver for Linux on POWER
   3  *
   4  *  internal queue handling
   5  *
   6  *  Authors: Waleri Fomin <fomin@de.ibm.com>
   7  *           Reinhard Ernst <rernst@de.ibm.com>
   8  *           Christoph Raisch <raisch@de.ibm.com>
   9  *
  10  *  Copyright (c) 2005 IBM Corporation
  11  *
  12  *  This source code is distributed under a dual license of GPL v2.0 and OpenIB
  13  *  BSD.
  14  *
  15  * OpenIB BSD License
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions are met:
  19  *
  20  * Redistributions of source code must retain the above copyright notice, this
  21  * list of conditions and the following disclaimer.
  22  *
  23  * Redistributions in binary form must reproduce the above copyright notice,
  24  * this list of conditions and the following disclaimer in the documentation
  25  * and/or other materials
  26  * provided with the distribution.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  29  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  32  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  33  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  34  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  35  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  36  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  37  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  38  * POSSIBILITY OF SUCH DAMAGE.
  39  */
  40
  41 #include <linux/slab.h>
  42
  43 #include "ehca_tools.h"
  44 #include "ipz_pt_fn.h"
  45 #include "ehca_classes.h"
  46
  47 #define PAGES_PER_KPAGE (PAGE_SIZE >> EHCA_PAGESHIFT)
  48
  49 struct kmem_cache *small_qp_cache;
  50
  51 void *ipz_qpageit_get_inc(struct ipz_queue *queue)
  52 {
  53         void *ret = ipz_qeit_get(queue);
  54         queue->current_q_offset += queue->pagesize;
  55         if (queue->current_q_offset > queue->queue_length) {
  56                 queue->current_q_offset -= queue->pagesize;
  57                 ret = NULL;
  58         }
  59         if (((u64)ret) % queue->pagesize) {
  60                 ehca_gen_err("ERROR!! not at PAGE-Boundary");
  61                 return NULL;
  62         }
  63         return ret;
  64 }
  65
  66 void *ipz_qeit_eq_get_inc(struct ipz_queue *queue)
  67 {
  68         void *ret = ipz_qeit_get(queue);
  69         u64 last_entry_in_q = queue->queue_length - queue->qe_size;
  70
  71         queue->current_q_offset += queue->qe_size;
  72         if (queue->current_q_offset > last_entry_in_q) {
  73                 queue->current_q_offset = 0;
  74                 queue->toggle_state = (~queue->toggle_state) & 1;
  75         }
  76
  77         return ret;
  78 }
  79
  80 int ipz_queue_abs_to_offset(struct ipz_queue *queue, u64 addr, u64 *q_offset)
  81 {
  82         int i;
  83         for (i = 0; i < queue->queue_length / queue->pagesize; i++) {
  84                 u64 page = __pa(queue->queue_pages[i]);
  85                 if (addr >= page && addr < page + queue->pagesize) {
  86                         *q_offset = addr - page + i * queue->pagesize;
  87                         return 0;
  88                 }
  89         }
  90         return -EINVAL;
  91 }
  92
  93 #if PAGE_SHIFT < EHCA_PAGESHIFT
  94 #error Kernel pages must be at least as large than eHCA pages (4K) !
  95 #endif
  96
  97 /*
  98  * allocate pages for queue:
  99  * outer loop allocates whole kernel pages (page aligned) and
 100  * inner loop divides a kernel page into smaller hca queue pages
 101  */
 102 static int alloc_queue_pages(struct ipz_queue *queue, const u32 nr_of_pages)
 103 {
 104         int k, f = 0;
 105         u8 *kpage;
 106
 107         while (f < nr_of_pages) {
 108                 kpage = (u8 *)get_zeroed_page(GFP_KERNEL);
 109                 if (!kpage)
 110                         goto out;
 111
 112                 for (k = 0; k < PAGES_PER_KPAGE && f < nr_of_pages; k++) {
 113                         queue->queue_pages[f] = (struct ipz_page *)kpage;
 114                         kpage += EHCA_PAGESIZE;
 115                         f++;
 116                 }
 117         }
 118         return 1;
 119
 120 out:
 121         for (f = 0; f < nr_of_pages && queue->queue_pages[f];
 122              f += PAGES_PER_KPAGE)
 123                 free_page((unsigned long)(queue->queue_pages)[f]);
 124         return 0;
 125 }
 126
 127 static int alloc_small_queue_page(struct ipz_queue *queue, struct ehca_pd *pd)
 128 {
 129         int order = ilog2(queue->pagesize) - 9;
 130         struct ipz_small_queue_page *page;
 131         unsigned long bit;
 132
 133         mutex_lock(&pd->lock);
 134
 135         if (!list_empty(&pd->free[order]))
 136                 page = list_entry(pd->free[order].next,
 137                                   struct ipz_small_queue_page, list);
 138         else {
 139                 page = kmem_cache_zalloc(small_qp_cache, GFP_KERNEL);
 140                 if (!page)
 141                         goto out;
 142
 143                 page->page = get_zeroed_page(GFP_KERNEL);
 144                 if (!page->page) {
 145                         kmem_cache_free(small_qp_cache, page);
 146                         goto out;
 147                 }
 148
 149                 list_add(&page->list, &pd->free[order]);
 150         }
 151
 152         bit = find_first_zero_bit(page->bitmap, IPZ_SPAGE_PER_KPAGE >> order);
 153         __set_bit(bit, page->bitmap);
 154         page->fill++;
 155
 156         if (page->fill == IPZ_SPAGE_PER_KPAGE >> order)
 157                 list_move(&page->list, &pd->full[order]);
 158
 159         mutex_unlock(&pd->lock);
 160
 161         queue->queue_pages[0] = (void *)(page->page | (bit << (order + 9)));
 162         queue->small_page = page;
 163         queue->offset = bit << (order + 9);
 164         return 1;
 165
 166 out:
 167         ehca_err(pd->ib_pd.device, "failed to allocate small queue page");
 168         mutex_unlock(&pd->lock);
 169         return 0;
 170 }
 171
 172 static void free_small_queue_page(struct ipz_queue *queue, struct ehca_pd *pd)
 173 {
 174         int order = ilog2(queue->pagesize) - 9;
 175         struct ipz_small_queue_page *page = queue->small_page;
 176         unsigned long bit;
 177         int free_page = 0;
 178
 179         bit = ((unsigned long)queue->queue_pages[0] & ~PAGE_MASK)
 180                 >> (order + 9);
 181
 182         mutex_lock(&pd->lock);
 183
 184         __clear_bit(bit, page->bitmap);
 185         page->fill--;
 186
 187         if (page->fill == 0) {
 188                 list_del(&page->list);
 189                 free_page = 1;
 190         }
 191
 192         if (page->fill == (IPZ_SPAGE_PER_KPAGE >> order) - 1)
 193                 /* the page was full until we freed the chunk */
 194                 list_move_tail(&page->list, &pd->free[order]);
 195
 196         mutex_unlock(&pd->lock);
 197
 198         if (free_page) {
 199                 free_page(page->page);
 200                 kmem_cache_free(small_qp_cache, page);
 201         }
 202 }
 203
 204 int ipz_queue_ctor(struct ehca_pd *pd, struct ipz_queue *queue,
 205                    const u32 nr_of_pages, const u32 pagesize,
 206                    const u32 qe_size, const u32 nr_of_sg,
 207                    int is_small)
 208 {
 209         if (pagesize > PAGE_SIZE) {
 210                 ehca_gen_err("FATAL ERROR: pagesize=%x "
 211                              "is greater than kernel page size", pagesize);
 212                 return 0;
 213         }
 214
 215         /* init queue fields */
 216         queue->queue_length = nr_of_pages * pagesize;
 217         queue->pagesize = pagesize;
 218         queue->qe_size = qe_size;
 219         queue->act_nr_of_sg = nr_of_sg;
 220         queue->current_q_offset = 0;
 221         queue->toggle_state = 1;
 222         queue->small_page = NULL;
 223
 224         /* allocate queue page pointers */
 225         queue->queue_pages = kzalloc(nr_of_pages * sizeof(void *),
 226                                      GFP_KERNEL | __GFP_NOWARN);
 227         if (!queue->queue_pages) {
 228                 queue->queue_pages = vzalloc(nr_of_pages * sizeof(void *));
 229                 if (!queue->queue_pages) {
 230                         ehca_gen_err("Couldn't allocate queue page list");
 231                         return 0;
 232                 }
 233         }
 234
 235         /* allocate actual queue pages */
 236         if (is_small) {
 237                 if (!alloc_small_queue_page(queue, pd))
 238                         goto ipz_queue_ctor_exit0;
 239         } else
 240                 if (!alloc_queue_pages(queue, nr_of_pages))
 241                         goto ipz_queue_ctor_exit0;
 242
 243         return 1;
 244
 245 ipz_queue_ctor_exit0:
 246         ehca_gen_err("Couldn't alloc pages queue=%p "
 247                  "nr_of_pages=%x",  queue, nr_of_pages);
 248         if (is_vmalloc_addr(queue->queue_pages))
 249                 vfree(queue->queue_pages);
 250         else
 251                 kfree(queue->queue_pages);
 252
 253         return 0;
 254 }
 255
 256 int ipz_queue_dtor(struct ehca_pd *pd, struct ipz_queue *queue)
 257 {
 258         int i, nr_pages;
 259
 260         if (!queue || !queue->queue_pages) {
 261                 ehca_gen_dbg("queue or queue_pages is NULL");
 262                 return 0;
 263         }
 264
 265         if (queue->small_page)
 266                 free_small_queue_page(queue, pd);
 267         else {
 268                 nr_pages = queue->queue_length / queue->pagesize;
 269                 for (i = 0; i < nr_pages; i += PAGES_PER_KPAGE)
 270                         free_page((unsigned long)queue->queue_pages[i]);
 271         }
 272
 273         if (is_vmalloc_addr(queue->queue_pages))
 274                 vfree(queue->queue_pages);
 275         else
 276                 kfree(queue->queue_pages);
 277
 278         return 1;
 279 }
 280
 281 int ehca_init_small_qp_cache(void)
 282 {
 283         small_qp_cache = kmem_cache_create("ehca_cache_small_qp",
 284                                            sizeof(struct ipz_small_queue_page),
 285                                            0, SLAB_HWCACHE_ALIGN, NULL);
 286         if (!small_qp_cache)
 287                 return -ENOMEM;
 288
 289         return 0;
 290 }
 291
 292 void ehca_cleanup_small_qp_cache(void)
 293 {
 294         kmem_cache_destroy(small_qp_cache);
 295 }