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 "ehca_tools.h"
  42 #include "ipz_pt_fn.h"
  43 #include "ehca_classes.h"
  44
  45 #define PAGES_PER_KPAGE (PAGE_SIZE >> EHCA_PAGESHIFT)
  46
  47 struct kmem_cache *small_qp_cache;
  48
  49 void *ipz_qpageit_get_inc(struct ipz_queue *queue)
  50 {
  51         void *ret = ipz_qeit_get(queue);
  52         queue->current_q_offset += queue->pagesize;
  53         if (queue->current_q_offset > queue->queue_length) {
  54                 queue->current_q_offset -= queue->pagesize;
  55                 ret = NULL;
  56         }
  57         if (((u64)ret) % queue->pagesize) {
  58                 ehca_gen_err("ERROR!! not at PAGE-Boundary");
  59                 return NULL;
  60         }
  61         return ret;
  62 }
  63
  64 void *ipz_qeit_eq_get_inc(struct ipz_queue *queue)
  65 {
  66         void *ret = ipz_qeit_get(queue);
  67         u64 last_entry_in_q = queue->queue_length - queue->qe_size;
  68
  69         queue->current_q_offset += queue->qe_size;
  70         if (queue->current_q_offset > last_entry_in_q) {
  71                 queue->current_q_offset = 0;
  72                 queue->toggle_state = (~queue->toggle_state) & 1;
  73         }
  74
  75         return ret;
  76 }
  77
  78 int ipz_queue_abs_to_offset(struct ipz_queue *queue, u64 addr, u64 *q_offset)
  79 {
  80         int i;
  81         for (i = 0; i < queue->queue_length / queue->pagesize; i++) {
  82                 u64 page = (u64)virt_to_abs(queue->queue_pages[i]);
  83                 if (addr >= page && addr < page + queue->pagesize) {
  84                         *q_offset = addr - page + i * queue->pagesize;
  85                         return 0;
  86                 }
  87         }
  88         return -EINVAL;
  89 }
  90
  91 #if PAGE_SHIFT < EHCA_PAGESHIFT
  92 #error Kernel pages must be at least as large than eHCA pages (4K) !
  93 #endif
  94
  95 /*
  96  * allocate pages for queue:
  97  * outer loop allocates whole kernel pages (page aligned) and
  98  * inner loop divides a kernel page into smaller hca queue pages
  99  */
 100 static int alloc_queue_pages(struct ipz_queue *queue, const u32 nr_of_pages)
 101 {
 102         int k, f = 0;
 103         u8 *kpage;
 104
 105         while (f < nr_of_pages) {
 106                 kpage = (u8 *)get_zeroed_page(GFP_KERNEL);
 107                 if (!kpage)
 108                         goto out;
 109
 110                 for (k = 0; k < PAGES_PER_KPAGE && f < nr_of_pages; k++) {
 111                         queue->queue_pages[f] = (struct ipz_page *)kpage;
 112                         kpage += EHCA_PAGESIZE;
 113                         f++;
 114                 }
 115         }
 116         return 1;
 117
 118 out:
 119         for (f = 0; f < nr_of_pages && queue->queue_pages[f];
 120              f += PAGES_PER_KPAGE)
 121                 free_page((unsigned long)(queue->queue_pages)[f]);
 122         return 0;
 123 }
 124
 125 static int alloc_small_queue_page(struct ipz_queue *queue, struct ehca_pd *pd)
 126 {
 127         int order = ilog2(queue->pagesize) - 9;
 128         struct ipz_small_queue_page *page;
 129         unsigned long bit;
 130
 131         mutex_lock(&pd->lock);
 132
 133         if (!list_empty(&pd->free[order]))
 134                 page = list_entry(pd->free[order].next,
 135                                   struct ipz_small_queue_page, list);
 136         else {
 137                 page = kmem_cache_zalloc(small_qp_cache, GFP_KERNEL);
 138                 if (!page)
 139                         goto out;
 140
 141                 page->page = get_zeroed_page(GFP_KERNEL);
 142                 if (!page->page) {
 143                         kmem_cache_free(small_qp_cache, page);
 144                         goto out;
 145                 }
 146
 147                 list_add(&page->list, &pd->free[order]);
 148         }
 149
 150         bit = find_first_zero_bit(page->bitmap, IPZ_SPAGE_PER_KPAGE >> order);
 151         __set_bit(bit, page->bitmap);
 152         page->fill++;
 153
 154         if (page->fill == IPZ_SPAGE_PER_KPAGE >> order)
 155                 list_move(&page->list, &pd->full[order]);
 156
 157         mutex_unlock(&pd->lock);
 158
 159         queue->queue_pages[0] = (void *)(page->page | (bit << (order + 9)));
 160         queue->small_page = page;
 161         queue->offset = bit << (order + 9);
 162         return 1;
 163
 164 out:
 165         ehca_err(pd->ib_pd.device, "failed to allocate small queue page");
 166         mutex_unlock(&pd->lock);
 167         return 0;
 168 }
 169
 170 static void free_small_queue_page(struct ipz_queue *queue, struct ehca_pd *pd)
 171 {
 172         int order = ilog2(queue->pagesize) - 9;
 173         struct ipz_small_queue_page *page = queue->small_page;
 174         unsigned long bit;
 175         int free_page = 0;
 176
 177         bit = ((unsigned long)queue->queue_pages[0] & ~PAGE_MASK)
 178                 >> (order + 9);
 179
 180         mutex_lock(&pd->lock);
 181
 182         __clear_bit(bit, page->bitmap);
 183         page->fill--;
 184
 185         if (page->fill == 0) {
 186                 list_del(&page->list);
 187                 free_page = 1;
 188         }
 189
 190         if (page->fill == (IPZ_SPAGE_PER_KPAGE >> order) - 1)
 191                 /* the page was full until we freed the chunk */
 192                 list_move_tail(&page->list, &pd->free[order]);
 193
 194         mutex_unlock(&pd->lock);
 195
 196         if (free_page) {
 197                 free_page(page->page);
 198                 kmem_cache_free(small_qp_cache, page);
 199         }
 200 }
 201
 202 int ipz_queue_ctor(struct ehca_pd *pd, struct ipz_queue *queue,
 203                    const u32 nr_of_pages, const u32 pagesize,
 204                    const u32 qe_size, const u32 nr_of_sg,
 205                    int is_small)
 206 {
 207         if (pagesize > PAGE_SIZE) {
 208                 ehca_gen_err("FATAL ERROR: pagesize=%x "
 209                              "is greater than kernel page size", pagesize);
 210                 return 0;
 211         }
 212
 213         /* init queue fields */
 214         queue->queue_length = nr_of_pages * pagesize;
 215         queue->pagesize = pagesize;
 216         queue->qe_size = qe_size;
 217         queue->act_nr_of_sg = nr_of_sg;
 218         queue->current_q_offset = 0;
 219         queue->toggle_state = 1;
 220         queue->small_page = NULL;
 221
 222         /* allocate queue page pointers */
 223         queue->queue_pages = vmalloc(nr_of_pages * sizeof(void *));
 224         if (!queue->queue_pages) {
 225                 ehca_gen_err("Couldn't allocate queue page list");
 226                 return 0;
 227         }
 228         memset(queue->queue_pages, 0, nr_of_pages * sizeof(void *));
 229
 230         /* allocate actual queue pages */
 231         if (is_small) {
 232                 if (!alloc_small_queue_page(queue, pd))
 233                         goto ipz_queue_ctor_exit0;
 234         } else
 235                 if (!alloc_queue_pages(queue, nr_of_pages))
 236                         goto ipz_queue_ctor_exit0;
 237
 238         return 1;
 239
 240 ipz_queue_ctor_exit0:
 241         ehca_gen_err("Couldn't alloc pages queue=%p "
 242                  "nr_of_pages=%x",  queue, nr_of_pages);
 243         vfree(queue->queue_pages);
 244
 245         return 0;
 246 }
 247
 248 int ipz_queue_dtor(struct ehca_pd *pd, struct ipz_queue *queue)
 249 {
 250         int i, nr_pages;
 251
 252         if (!queue || !queue->queue_pages) {
 253                 ehca_gen_dbg("queue or queue_pages is NULL");
 254                 return 0;
 255         }
 256
 257         if (queue->small_page)
 258                 free_small_queue_page(queue, pd);
 259         else {
 260                 nr_pages = queue->queue_length / queue->pagesize;
 261                 for (i = 0; i < nr_pages; i += PAGES_PER_KPAGE)
 262                         free_page((unsigned long)queue->queue_pages[i]);
 263         }
 264
 265         vfree(queue->queue_pages);
 266
 267         return 1;
 268 }
 269
 270 int ehca_init_small_qp_cache(void)
 271 {
 272         small_qp_cache = kmem_cache_create("ehca_cache_small_qp",
 273                                            sizeof(struct ipz_small_queue_page),
 274                                            0, SLAB_HWCACHE_ALIGN, NULL);
 275         if (!small_qp_cache)
 276                 return -ENOMEM;
 277
 278         return 0;
 279 }
 280
 281 void ehca_cleanup_small_qp_cache(void)
 282 {
 283         kmem_cache_destroy(small_qp_cache);
 284 }