drivers/net/ethernet/chelsio/libcxgb/libcxgb_ppm.c

   1 /*
   2  * libcxgb_ppm.c: Chelsio common library for T3/T4/T5 iSCSI PagePod Manager
   3  *
   4  * Copyright (c) 2016 Chelsio Communications, Inc. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the
  10  * OpenIB.org BSD license below:
  11  *
  12  *     Redistribution and use in source and binary forms, with or
  13  *     without modification, are permitted provided that the following
  14  *     conditions are met:
  15  *
  16  *      - Redistributions of source code must retain the above
  17  *        copyright notice, this list of conditions and the following
  18  *        disclaimer.
  19  *
  20  *      - Redistributions in binary form must reproduce the above
  21  *        copyright notice, this list of conditions and the following
  22  *        disclaimer in the documentation and/or other materials
  23  *        provided with the distribution.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  32  * SOFTWARE.
  33  *
  34  * Written by: Karen Xie (kxie@chelsio.com)
  35  */
  36
  37 #define DRV_NAME "libcxgb"
  38 #define DRV_VERSION "1.0.0-ko"
  39 #define pr_fmt(fmt) DRV_NAME ": " fmt
  40
  41 #include <linux/kernel.h>
  42 #include <linux/module.h>
  43 #include <linux/errno.h>
  44 #include <linux/types.h>
  45 #include <linux/debugfs.h>
  46 #include <linux/export.h>
  47 #include <linux/list.h>
  48 #include <linux/skbuff.h>
  49 #include <linux/pci.h>
  50 #include <linux/scatterlist.h>
  51
  52 #include "libcxgb_ppm.h"
  53
  54 /* Direct Data Placement -
  55  * Directly place the iSCSI Data-In or Data-Out PDU's payload into
  56  * pre-posted final destination host-memory buffers based on the
  57  * Initiator Task Tag (ITT) in Data-In or Target Task Tag (TTT)
  58  * in Data-Out PDUs. The host memory address is programmed into
  59  * h/w in the format of pagepod entries. The location of the
  60  * pagepod entry is encoded into ddp tag which is used as the base
  61  * for ITT/TTT.
  62  */
  63
  64 /* Direct-Data Placement page size adjustment
  65  */
  66 int cxgbi_ppm_find_page_index(struct cxgbi_ppm *ppm, unsigned long pgsz)
  67 {
  68         struct cxgbi_tag_format *tformat = &ppm->tformat;
  69         int i;
  70
  71         for (i = 0; i < DDP_PGIDX_MAX; i++) {
  72                 if (pgsz == 1UL << (DDP_PGSZ_BASE_SHIFT +
  73                                          tformat->pgsz_order[i])) {
  74                         pr_debug("%s: %s ppm, pgsz %lu -> idx %d.\n",
  75                                  __func__, ppm->ndev->name, pgsz, i);
  76                         return i;
  77                 }
  78         }
  79         pr_info("ippm: ddp page size %lu not supported.\n", pgsz);
  80         return DDP_PGIDX_MAX;
  81 }
  82
  83 /* DDP setup & teardown
  84  */
  85 static int ppm_find_unused_entries(unsigned long *bmap,
  86                                    unsigned int max_ppods,
  87                                    unsigned int start,
  88                                    unsigned int nr,
  89                                    unsigned int align_mask)
  90 {
  91         unsigned long i;
  92
  93         i = bitmap_find_next_zero_area(bmap, max_ppods, start, nr, align_mask);
  94
  95         if (unlikely(i >= max_ppods) && (start > nr))
  96                 i = bitmap_find_next_zero_area(bmap, max_ppods, 0, start - 1,
  97                                                align_mask);
  98         if (unlikely(i >= max_ppods))
  99                 return -ENOSPC;
 100
 101         bitmap_set(bmap, i, nr);
 102         return (int)i;
 103 }
 104
 105 static void ppm_mark_entries(struct cxgbi_ppm *ppm, int i, int count,
 106                              unsigned long caller_data)
 107 {
 108         struct cxgbi_ppod_data *pdata = ppm->ppod_data + i;
 109
 110         pdata->caller_data = caller_data;
 111         pdata->npods = count;
 112
 113         if (pdata->color == ((1 << PPOD_IDX_SHIFT) - 1))
 114                 pdata->color = 0;
 115         else
 116                 pdata->color++;
 117 }
 118
 119 static int ppm_get_cpu_entries(struct cxgbi_ppm *ppm, unsigned int count,
 120                                unsigned long caller_data)
 121 {
 122         struct cxgbi_ppm_pool *pool;
 123         unsigned int cpu;
 124         int i;
 125
 126         cpu = get_cpu();
 127         pool = per_cpu_ptr(ppm->pool, cpu);
 128         spin_lock_bh(&pool->lock);
 129         put_cpu();
 130
 131         i = ppm_find_unused_entries(pool->bmap, ppm->pool_index_max,
 132                                     pool->next, count, 0);
 133         if (i < 0) {
 134                 pool->next = 0;
 135                 spin_unlock_bh(&pool->lock);
 136                 return -ENOSPC;
 137         }
 138
 139         pool->next = i + count;
 140         if (pool->next >= ppm->pool_index_max)
 141                 pool->next = 0;
 142
 143         spin_unlock_bh(&pool->lock);
 144
 145         pr_debug("%s: cpu %u, idx %d + %d (%d), next %u.\n",
 146                  __func__, cpu, i, count, i + cpu * ppm->pool_index_max,
 147                 pool->next);
 148
 149         i += cpu * ppm->pool_index_max;
 150         ppm_mark_entries(ppm, i, count, caller_data);
 151
 152         return i;
 153 }
 154
 155 static int ppm_get_entries(struct cxgbi_ppm *ppm, unsigned int count,
 156                            unsigned long caller_data)
 157 {
 158         int i;
 159
 160         spin_lock_bh(&ppm->map_lock);
 161         i = ppm_find_unused_entries(ppm->ppod_bmap, ppm->bmap_index_max,
 162                                     ppm->next, count, 0);
 163         if (i < 0) {
 164                 ppm->next = 0;
 165                 spin_unlock_bh(&ppm->map_lock);
 166                 pr_debug("ippm: NO suitable entries %u available.\n",
 167                          count);
 168                 return -ENOSPC;
 169         }
 170
 171         ppm->next = i + count;
 172         if (ppm->next >= ppm->bmap_index_max)
 173                 ppm->next = 0;
 174
 175         spin_unlock_bh(&ppm->map_lock);
 176
 177         pr_debug("%s: idx %d + %d (%d), next %u, caller_data 0x%lx.\n",
 178                  __func__, i, count, i + ppm->pool_rsvd, ppm->next,
 179                  caller_data);
 180
 181         i += ppm->pool_rsvd;
 182         ppm_mark_entries(ppm, i, count, caller_data);
 183
 184         return i;
 185 }
 186
 187 static void ppm_unmark_entries(struct cxgbi_ppm *ppm, int i, int count)
 188 {
 189         pr_debug("%s: idx %d + %d.\n", __func__, i, count);
 190
 191         if (i < ppm->pool_rsvd) {
 192                 unsigned int cpu;
 193                 struct cxgbi_ppm_pool *pool;
 194
 195                 cpu = i / ppm->pool_index_max;
 196                 i %= ppm->pool_index_max;
 197
 198                 pool = per_cpu_ptr(ppm->pool, cpu);
 199                 spin_lock_bh(&pool->lock);
 200                 bitmap_clear(pool->bmap, i, count);
 201
 202                 if (i < pool->next)
 203                         pool->next = i;
 204                 spin_unlock_bh(&pool->lock);
 205
 206                 pr_debug("%s: cpu %u, idx %d, next %u.\n",
 207                          __func__, cpu, i, pool->next);
 208         } else {
 209                 spin_lock_bh(&ppm->map_lock);
 210
 211                 i -= ppm->pool_rsvd;
 212                 bitmap_clear(ppm->ppod_bmap, i, count);
 213
 214                 if (i < ppm->next)
 215                         ppm->next = i;
 216                 spin_unlock_bh(&ppm->map_lock);
 217
 218                 pr_debug("%s: idx %d, next %u.\n", __func__, i, ppm->next);
 219         }
 220 }
 221
 222 void cxgbi_ppm_ppod_release(struct cxgbi_ppm *ppm, u32 idx)
 223 {
 224         struct cxgbi_ppod_data *pdata;
 225
 226         if (idx >= ppm->ppmax) {
 227                 pr_warn("ippm: idx too big %u > %u.\n", idx, ppm->ppmax);
 228                 return;
 229         }
 230
 231         pdata = ppm->ppod_data + idx;
 232         if (!pdata->npods) {
 233                 pr_warn("ippm: idx %u, npods 0.\n", idx);
 234                 return;
 235         }
 236
 237         pr_debug("release idx %u, npods %u.\n", idx, pdata->npods);
 238         ppm_unmark_entries(ppm, idx, pdata->npods);
 239 }
 240 EXPORT_SYMBOL(cxgbi_ppm_ppod_release);
 241
 242 int cxgbi_ppm_ppods_reserve(struct cxgbi_ppm *ppm, unsigned short nr_pages,
 243                             u32 per_tag_pg_idx, u32 *ppod_idx,
 244                             u32 *ddp_tag, unsigned long caller_data)
 245 {
 246         struct cxgbi_ppod_data *pdata;
 247         unsigned int npods;
 248         int idx = -1;
 249         unsigned int hwidx;
 250         u32 tag;
 251
 252         npods = (nr_pages + PPOD_PAGES_MAX - 1) >> PPOD_PAGES_SHIFT;
 253         if (!npods) {
 254                 pr_warn("%s: pages %u -> npods %u, full.\n",
 255                         __func__, nr_pages, npods);
 256                 return -EINVAL;
 257         }
 258
 259         /* grab from cpu pool first */
 260         idx = ppm_get_cpu_entries(ppm, npods, caller_data);
 261         /* try the general pool */
 262         if (idx < 0)
 263                 idx = ppm_get_entries(ppm, npods, caller_data);
 264         if (idx < 0) {
 265                 pr_debug("ippm: pages %u, nospc %u, nxt %u, 0x%lx.\n",
 266                          nr_pages, npods, ppm->next, caller_data);
 267                 return idx;
 268         }
 269
 270         pdata = ppm->ppod_data + idx;
 271         hwidx = ppm->base_idx + idx;
 272
 273         tag = cxgbi_ppm_make_ddp_tag(hwidx, pdata->color);
 274
 275         if (per_tag_pg_idx)
 276                 tag |= (per_tag_pg_idx << 30) & 0xC0000000;
 277
 278         *ppod_idx = idx;
 279         *ddp_tag = tag;
 280
 281         pr_debug("ippm: sg %u, tag 0x%x(%u,%u), data 0x%lx.\n",
 282                  nr_pages, tag, idx, npods, caller_data);
 283
 284         return npods;
 285 }
 286 EXPORT_SYMBOL(cxgbi_ppm_ppods_reserve);
 287
 288 void cxgbi_ppm_make_ppod_hdr(struct cxgbi_ppm *ppm, u32 tag,
 289                              unsigned int tid, unsigned int offset,
 290                              unsigned int length,
 291                              struct cxgbi_pagepod_hdr *hdr)
 292 {
 293         /* The ddp tag in pagepod should be with bit 31:30 set to 0.
 294          * The ddp Tag on the wire should be with non-zero 31:30 to the peer
 295          */
 296         tag &= 0x3FFFFFFF;
 297
 298         hdr->vld_tid = htonl(PPOD_VALID_FLAG | PPOD_TID(tid));
 299
 300         hdr->rsvd = 0;
 301         hdr->pgsz_tag_clr = htonl(tag & ppm->tformat.idx_clr_mask);
 302         hdr->max_offset = htonl(length);
 303         hdr->page_offset = htonl(offset);
 304
 305         pr_debug("ippm: tag 0x%x, tid 0x%x, xfer %u, off %u.\n",
 306                  tag, tid, length, offset);
 307 }
 308 EXPORT_SYMBOL(cxgbi_ppm_make_ppod_hdr);
 309
 310 static void ppm_free(struct cxgbi_ppm *ppm)
 311 {
 312         vfree(ppm);
 313 }
 314
 315 static void ppm_destroy(struct kref *kref)
 316 {
 317         struct cxgbi_ppm *ppm = container_of(kref,
 318                                              struct cxgbi_ppm,
 319                                              refcnt);
 320         pr_info("ippm: kref 0, destroy %s ppm 0x%p.\n",
 321                 ppm->ndev->name, ppm);
 322
 323         *ppm->ppm_pp = NULL;
 324
 325         free_percpu(ppm->pool);
 326         ppm_free(ppm);
 327 }
 328
 329 int cxgbi_ppm_release(struct cxgbi_ppm *ppm)
 330 {
 331         if (ppm) {
 332                 int rv;
 333
 334                 rv = kref_put(&ppm->refcnt, ppm_destroy);
 335                 return rv;
 336         }
 337         return 1;
 338 }
 339 EXPORT_SYMBOL(cxgbi_ppm_release);
 340
 341 static struct cxgbi_ppm_pool *ppm_alloc_cpu_pool(unsigned int *total,
 342                                                  unsigned int *pcpu_ppmax)
 343 {
 344         struct cxgbi_ppm_pool *pools;
 345         unsigned int ppmax = (*total) / num_possible_cpus();
 346         unsigned int max = (PCPU_MIN_UNIT_SIZE - sizeof(*pools)) << 3;
 347         unsigned int bmap;
 348         unsigned int alloc_sz;
 349         unsigned int count = 0;
 350         unsigned int cpu;
 351
 352         /* make sure per cpu pool fits into PCPU_MIN_UNIT_SIZE */
 353         if (ppmax > max)
 354                 ppmax = max;
 355
 356         /* pool size must be multiple of unsigned long */
 357         bmap = BITS_TO_LONGS(ppmax);
 358         ppmax = (bmap * sizeof(unsigned long)) << 3;
 359
 360         alloc_sz = sizeof(*pools) + sizeof(unsigned long) * bmap;
 361         pools = __alloc_percpu(alloc_sz, __alignof__(struct cxgbi_ppm_pool));
 362
 363         if (!pools)
 364                 return NULL;
 365
 366         for_each_possible_cpu(cpu) {
 367                 struct cxgbi_ppm_pool *ppool = per_cpu_ptr(pools, cpu);
 368
 369                 memset(ppool, 0, alloc_sz);
 370                 spin_lock_init(&ppool->lock);
 371                 count += ppmax;
 372         }
 373
 374         *total = count;
 375         *pcpu_ppmax = ppmax;
 376
 377         return pools;
 378 }
 379
 380 int cxgbi_ppm_init(void **ppm_pp, struct net_device *ndev,
 381                    struct pci_dev *pdev, void *lldev,
 382                    struct cxgbi_tag_format *tformat,
 383                    unsigned int ppmax,
 384                    unsigned int llimit,
 385                    unsigned int start,
 386                    unsigned int reserve_factor)
 387 {
 388         struct cxgbi_ppm *ppm = (struct cxgbi_ppm *)(*ppm_pp);
 389         struct cxgbi_ppm_pool *pool = NULL;
 390         unsigned int ppmax_pool = 0;
 391         unsigned int pool_index_max = 0;
 392         unsigned int alloc_sz;
 393         unsigned int ppod_bmap_size;
 394
 395         if (ppm) {
 396                 pr_info("ippm: %s, ppm 0x%p,0x%p already initialized, %u/%u.\n",
 397                         ndev->name, ppm_pp, ppm, ppm->ppmax, ppmax);
 398                 kref_get(&ppm->refcnt);
 399                 return 1;
 400         }
 401
 402         if (reserve_factor) {
 403                 ppmax_pool = ppmax / reserve_factor;
 404                 pool = ppm_alloc_cpu_pool(&ppmax_pool, &pool_index_max);
 405
 406                 pr_debug("%s: ppmax %u, cpu total %u, per cpu %u.\n",
 407                          ndev->name, ppmax, ppmax_pool, pool_index_max);
 408         }
 409
 410         ppod_bmap_size = BITS_TO_LONGS(ppmax - ppmax_pool);
 411         alloc_sz = sizeof(struct cxgbi_ppm) +
 412                         ppmax * (sizeof(struct cxgbi_ppod_data)) +
 413                         ppod_bmap_size * sizeof(unsigned long);
 414
 415         ppm = vmalloc(alloc_sz);
 416         if (!ppm)
 417                 goto release_ppm_pool;
 418
 419         memset(ppm, 0, alloc_sz);
 420
 421         ppm->ppod_bmap = (unsigned long *)(&ppm->ppod_data[ppmax]);
 422
 423         if ((ppod_bmap_size >> 3) > (ppmax - ppmax_pool)) {
 424                 unsigned int start = ppmax - ppmax_pool;
 425                 unsigned int end = ppod_bmap_size >> 3;
 426
 427                 bitmap_set(ppm->ppod_bmap, ppmax, end - start);
 428                 pr_info("%s: %u - %u < %u * 8, mask extra bits %u, %u.\n",
 429                         __func__, ppmax, ppmax_pool, ppod_bmap_size, start,
 430                         end);
 431         }
 432
 433         spin_lock_init(&ppm->map_lock);
 434         kref_init(&ppm->refcnt);
 435
 436         memcpy(&ppm->tformat, tformat, sizeof(struct cxgbi_tag_format));
 437
 438         ppm->ppm_pp = ppm_pp;
 439         ppm->ndev = ndev;
 440         ppm->pdev = pdev;
 441         ppm->lldev = lldev;
 442         ppm->ppmax = ppmax;
 443         ppm->next = 0;
 444         ppm->llimit = llimit;
 445         ppm->base_idx = start > llimit ?
 446                         (start - llimit + 1) >> PPOD_SIZE_SHIFT : 0;
 447         ppm->bmap_index_max = ppmax - ppmax_pool;
 448
 449         ppm->pool = pool;
 450         ppm->pool_rsvd = ppmax_pool;
 451         ppm->pool_index_max = pool_index_max;
 452
 453         /* check one more time */
 454         if (*ppm_pp) {
 455                 ppm_free(ppm);
 456                 ppm = (struct cxgbi_ppm *)(*ppm_pp);
 457
 458                 pr_info("ippm: %s, ppm 0x%p,0x%p already initialized, %u/%u.\n",
 459                         ndev->name, ppm_pp, *ppm_pp, ppm->ppmax, ppmax);
 460
 461                 kref_get(&ppm->refcnt);
 462                 return 1;
 463         }
 464         *ppm_pp = ppm;
 465
 466         ppm->tformat.pgsz_idx_dflt = cxgbi_ppm_find_page_index(ppm, PAGE_SIZE);
 467
 468         pr_info("ippm %s: ppm 0x%p, 0x%p, base %u/%u, pg %lu,%u, rsvd %u,%u.\n",
 469                 ndev->name, ppm_pp, ppm, ppm->base_idx, ppm->ppmax, PAGE_SIZE,
 470                 ppm->tformat.pgsz_idx_dflt, ppm->pool_rsvd,
 471                 ppm->pool_index_max);
 472
 473         return 0;
 474
 475 release_ppm_pool:
 476         free_percpu(pool);
 477         return -ENOMEM;
 478 }
 479 EXPORT_SYMBOL(cxgbi_ppm_init);
 480
 481 unsigned int cxgbi_tagmask_set(unsigned int ppmax)
 482 {
 483         unsigned int bits = fls(ppmax);
 484
 485         if (bits > PPOD_IDX_MAX_SIZE)
 486                 bits = PPOD_IDX_MAX_SIZE;
 487
 488         pr_info("ippm: ppmax %u/0x%x -> bits %u, tagmask 0x%x.\n",
 489                 ppmax, ppmax, bits, 1 << (bits + PPOD_IDX_SHIFT));
 490
 491         return 1 << (bits + PPOD_IDX_SHIFT);
 492 }
 493 EXPORT_SYMBOL(cxgbi_tagmask_set);
 494
 495 MODULE_AUTHOR("Chelsio Communications");
 496 MODULE_DESCRIPTION("Chelsio common library");
 497 MODULE_VERSION(DRV_VERSION);
 498 MODULE_LICENSE("Dual BSD/GPL");