drivers/ntb/test/ntb_msi_test.c

   1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
   2
   3 #include <linux/module.h>
   4 #include <linux/debugfs.h>
   5 #include <linux/ntb.h>
   6 #include <linux/pci.h>
   7 #include <linux/radix-tree.h>
   8 #include <linux/workqueue.h>
   9
  10 MODULE_LICENSE("Dual BSD/GPL");
  11 MODULE_VERSION("0.1");
  12 MODULE_AUTHOR("Logan Gunthorpe <logang@deltatee.com>");
  13 MODULE_DESCRIPTION("Test for sending MSI interrupts over an NTB memory window");
  14
  15 static int num_irqs = 4;
  16 module_param(num_irqs, int, 0644);
  17 MODULE_PARM_DESC(num_irqs, "number of irqs to use");
  18
  19 struct ntb_msit_ctx {
  20         struct ntb_dev *ntb;
  21         struct dentry *dbgfs_dir;
  22         struct work_struct setup_work;
  23
  24         struct ntb_msit_isr_ctx {
  25                 int irq_idx;
  26                 int irq_num;
  27                 int occurrences;
  28                 struct ntb_msit_ctx *nm;
  29                 struct ntb_msi_desc desc;
  30         } *isr_ctx;
  31
  32         struct ntb_msit_peer {
  33                 struct ntb_msit_ctx *nm;
  34                 int pidx;
  35                 int num_irqs;
  36                 struct completion init_comp;
  37                 struct ntb_msi_desc *msi_desc;
  38         } peers[];
  39 };
  40
  41 static struct dentry *ntb_msit_dbgfs_topdir;
  42
  43 static irqreturn_t ntb_msit_isr(int irq, void *dev)
  44 {
  45         struct ntb_msit_isr_ctx *isr_ctx = dev;
  46         struct ntb_msit_ctx *nm = isr_ctx->nm;
  47
  48         dev_dbg(&nm->ntb->dev, "Interrupt Occurred: %d",
  49                 isr_ctx->irq_idx);
  50
  51         isr_ctx->occurrences++;
  52
  53         return IRQ_HANDLED;
  54 }
  55
  56 static void ntb_msit_setup_work(struct work_struct *work)
  57 {
  58         struct ntb_msit_ctx *nm = container_of(work, struct ntb_msit_ctx,
  59                                                setup_work);
  60         int irq_count = 0;
  61         int irq;
  62         int ret;
  63         uintptr_t i;
  64
  65         ret = ntb_msi_setup_mws(nm->ntb);
  66         if (ret) {
  67                 dev_err(&nm->ntb->dev, "Unable to setup MSI windows: %d\n",
  68                         ret);
  69                 return;
  70         }
  71
  72         for (i = 0; i < num_irqs; i++) {
  73                 nm->isr_ctx[i].irq_idx = i;
  74                 nm->isr_ctx[i].nm = nm;
  75
  76                 if (!nm->isr_ctx[i].irq_num) {
  77                         irq = ntbm_msi_request_irq(nm->ntb, ntb_msit_isr,
  78                                                    KBUILD_MODNAME,
  79                                                    &nm->isr_ctx[i],
  80                                                    &nm->isr_ctx[i].desc);
  81                         if (irq < 0)
  82                                 break;
  83
  84                         nm->isr_ctx[i].irq_num = irq;
  85                 }
  86
  87                 ret = ntb_spad_write(nm->ntb, 2 * i + 1,
  88                                      nm->isr_ctx[i].desc.addr_offset);
  89                 if (ret)
  90                         break;
  91
  92                 ret = ntb_spad_write(nm->ntb, 2 * i + 2,
  93                                      nm->isr_ctx[i].desc.data);
  94                 if (ret)
  95                         break;
  96
  97                 irq_count++;
  98         }
  99
 100         ntb_spad_write(nm->ntb, 0, irq_count);
 101         ntb_peer_db_set(nm->ntb, BIT(ntb_port_number(nm->ntb)));
 102 }
 103
 104 static void ntb_msit_desc_changed(void *ctx)
 105 {
 106         struct ntb_msit_ctx *nm = ctx;
 107         int i;
 108
 109         dev_dbg(&nm->ntb->dev, "MSI Descriptors Changed\n");
 110
 111         for (i = 0; i < num_irqs; i++) {
 112                 ntb_spad_write(nm->ntb, 2 * i + 1,
 113                                nm->isr_ctx[i].desc.addr_offset);
 114                 ntb_spad_write(nm->ntb, 2 * i + 2,
 115                                nm->isr_ctx[i].desc.data);
 116         }
 117
 118         ntb_peer_db_set(nm->ntb, BIT(ntb_port_number(nm->ntb)));
 119 }
 120
 121 static void ntb_msit_link_event(void *ctx)
 122 {
 123         struct ntb_msit_ctx *nm = ctx;
 124
 125         if (!ntb_link_is_up(nm->ntb, NULL, NULL))
 126                 return;
 127
 128         schedule_work(&nm->setup_work);
 129 }
 130
 131 static void ntb_msit_copy_peer_desc(struct ntb_msit_ctx *nm, int peer)
 132 {
 133         int i;
 134         struct ntb_msi_desc *desc = nm->peers[peer].msi_desc;
 135         int irq_count = nm->peers[peer].num_irqs;
 136
 137         for (i = 0; i < irq_count; i++) {
 138                 desc[i].addr_offset = ntb_peer_spad_read(nm->ntb, peer,
 139                                                          2 * i + 1);
 140                 desc[i].data = ntb_peer_spad_read(nm->ntb, peer, 2 * i + 2);
 141         }
 142
 143         dev_info(&nm->ntb->dev, "Found %d interrupts on peer %d\n",
 144                  irq_count, peer);
 145
 146         complete_all(&nm->peers[peer].init_comp);
 147 }
 148
 149 static void ntb_msit_db_event(void *ctx, int vec)
 150 {
 151         struct ntb_msit_ctx *nm = ctx;
 152         struct ntb_msi_desc *desc;
 153         u64 peer_mask = ntb_db_read(nm->ntb);
 154         u32 irq_count;
 155         int peer;
 156
 157         ntb_db_clear(nm->ntb, peer_mask);
 158
 159         for (peer = 0; peer < sizeof(peer_mask) * 8; peer++) {
 160                 if (!(peer_mask & BIT(peer)))
 161                         continue;
 162
 163                 irq_count = ntb_peer_spad_read(nm->ntb, peer, 0);
 164                 if (irq_count == -1)
 165                         continue;
 166
 167                 desc = kcalloc(irq_count, sizeof(*desc), GFP_ATOMIC);
 168                 if (!desc)
 169                         continue;
 170
 171                 kfree(nm->peers[peer].msi_desc);
 172                 nm->peers[peer].msi_desc = desc;
 173                 nm->peers[peer].num_irqs = irq_count;
 174
 175                 ntb_msit_copy_peer_desc(nm, peer);
 176         }
 177 }
 178
 179 static const struct ntb_ctx_ops ntb_msit_ops = {
 180         .link_event = ntb_msit_link_event,
 181         .db_event = ntb_msit_db_event,
 182 };
 183
 184 static int ntb_msit_dbgfs_trigger(void *data, u64 idx)
 185 {
 186         struct ntb_msit_peer *peer = data;
 187
 188         if (idx >= peer->num_irqs)
 189                 return -EINVAL;
 190
 191         dev_dbg(&peer->nm->ntb->dev, "trigger irq %llu on peer %u\n",
 192                 idx, peer->pidx);
 193
 194         return ntb_msi_peer_trigger(peer->nm->ntb, peer->pidx,
 195                                     &peer->msi_desc[idx]);
 196 }
 197
 198 DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_trigger_fops, NULL,
 199                          ntb_msit_dbgfs_trigger, "%llu\n");
 200
 201 static int ntb_msit_dbgfs_port_get(void *data, u64 *port)
 202 {
 203         struct ntb_msit_peer *peer = data;
 204
 205         *port = ntb_peer_port_number(peer->nm->ntb, peer->pidx);
 206
 207         return 0;
 208 }
 209
 210 DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_port_fops, ntb_msit_dbgfs_port_get,
 211                          NULL, "%llu\n");
 212
 213 static int ntb_msit_dbgfs_count_get(void *data, u64 *count)
 214 {
 215         struct ntb_msit_peer *peer = data;
 216
 217         *count = peer->num_irqs;
 218
 219         return 0;
 220 }
 221
 222 DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_count_fops, ntb_msit_dbgfs_count_get,
 223                          NULL, "%llu\n");
 224
 225 static int ntb_msit_dbgfs_ready_get(void *data, u64 *ready)
 226 {
 227         struct ntb_msit_peer *peer = data;
 228
 229         *ready = try_wait_for_completion(&peer->init_comp);
 230
 231         return 0;
 232 }
 233
 234 static int ntb_msit_dbgfs_ready_set(void *data, u64 ready)
 235 {
 236         struct ntb_msit_peer *peer = data;
 237
 238         return wait_for_completion_interruptible(&peer->init_comp);
 239 }
 240
 241 DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_ready_fops, ntb_msit_dbgfs_ready_get,
 242                          ntb_msit_dbgfs_ready_set, "%llu\n");
 243
 244 static int ntb_msit_dbgfs_occurrences_get(void *data, u64 *occurrences)
 245 {
 246         struct ntb_msit_isr_ctx *isr_ctx = data;
 247
 248         *occurrences = isr_ctx->occurrences;
 249
 250         return 0;
 251 }
 252
 253 DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_occurrences_fops,
 254                          ntb_msit_dbgfs_occurrences_get,
 255                          NULL, "%llu\n");
 256
 257 static int ntb_msit_dbgfs_local_port_get(void *data, u64 *port)
 258 {
 259         struct ntb_msit_ctx *nm = data;
 260
 261         *port = ntb_port_number(nm->ntb);
 262
 263         return 0;
 264 }
 265
 266 DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_local_port_fops,
 267                          ntb_msit_dbgfs_local_port_get,
 268                          NULL, "%llu\n");
 269
 270 static void ntb_msit_create_dbgfs(struct ntb_msit_ctx *nm)
 271 {
 272         struct pci_dev *pdev = nm->ntb->pdev;
 273         char buf[32];
 274         int i;
 275         struct dentry *peer_dir;
 276
 277         nm->dbgfs_dir = debugfs_create_dir(pci_name(pdev),
 278                                            ntb_msit_dbgfs_topdir);
 279         debugfs_create_file("port", 0400, nm->dbgfs_dir, nm,
 280                             &ntb_msit_local_port_fops);
 281
 282         for (i = 0; i < ntb_peer_port_count(nm->ntb); i++) {
 283                 nm->peers[i].pidx = i;
 284                 nm->peers[i].nm = nm;
 285                 init_completion(&nm->peers[i].init_comp);
 286
 287                 snprintf(buf, sizeof(buf), "peer%d", i);
 288                 peer_dir = debugfs_create_dir(buf, nm->dbgfs_dir);
 289
 290                 debugfs_create_file_unsafe("trigger", 0200, peer_dir,
 291                                            &nm->peers[i],
 292                                            &ntb_msit_trigger_fops);
 293
 294                 debugfs_create_file_unsafe("port", 0400, peer_dir,
 295                                            &nm->peers[i], &ntb_msit_port_fops);
 296
 297                 debugfs_create_file_unsafe("count", 0400, peer_dir,
 298                                            &nm->peers[i],
 299                                            &ntb_msit_count_fops);
 300
 301                 debugfs_create_file_unsafe("ready", 0600, peer_dir,
 302                                            &nm->peers[i],
 303                                            &ntb_msit_ready_fops);
 304         }
 305
 306         for (i = 0; i < num_irqs; i++) {
 307                 snprintf(buf, sizeof(buf), "irq%d_occurrences", i);
 308                 debugfs_create_file_unsafe(buf, 0400, nm->dbgfs_dir,
 309                                            &nm->isr_ctx[i],
 310                                            &ntb_msit_occurrences_fops);
 311         }
 312 }
 313
 314 static void ntb_msit_remove_dbgfs(struct ntb_msit_ctx *nm)
 315 {
 316         debugfs_remove_recursive(nm->dbgfs_dir);
 317 }
 318
 319 static int ntb_msit_probe(struct ntb_client *client, struct ntb_dev *ntb)
 320 {
 321         struct ntb_msit_ctx *nm;
 322         int peers;
 323         int ret;
 324
 325         peers = ntb_peer_port_count(ntb);
 326         if (peers <= 0)
 327                 return -EINVAL;
 328
 329         if (ntb_spad_is_unsafe(ntb) || ntb_spad_count(ntb) < 2 * num_irqs + 1) {
 330                 dev_err(&ntb->dev, "NTB MSI test requires at least %d spads for %d irqs\n",
 331                         2 * num_irqs + 1, num_irqs);
 332                 return -EFAULT;
 333         }
 334
 335         ret = ntb_spad_write(ntb, 0, -1);
 336         if (ret) {
 337                 dev_err(&ntb->dev, "Unable to write spads: %d\n", ret);
 338                 return ret;
 339         }
 340
 341         ret = ntb_db_clear_mask(ntb, GENMASK(peers - 1, 0));
 342         if (ret) {
 343                 dev_err(&ntb->dev, "Unable to clear doorbell mask: %d\n", ret);
 344                 return ret;
 345         }
 346
 347         ret = ntb_msi_init(ntb, ntb_msit_desc_changed);
 348         if (ret) {
 349                 dev_err(&ntb->dev, "Unable to initialize MSI library: %d\n",
 350                         ret);
 351                 return ret;
 352         }
 353
 354         nm = devm_kzalloc(&ntb->dev, struct_size(nm, peers, peers), GFP_KERNEL);
 355         if (!nm)
 356                 return -ENOMEM;
 357
 358         nm->isr_ctx = devm_kcalloc(&ntb->dev, num_irqs, sizeof(*nm->isr_ctx),
 359                                    GFP_KERNEL);
 360         if (!nm->isr_ctx)
 361                 return -ENOMEM;
 362
 363         INIT_WORK(&nm->setup_work, ntb_msit_setup_work);
 364         nm->ntb = ntb;
 365
 366         ntb_msit_create_dbgfs(nm);
 367
 368         ret = ntb_set_ctx(ntb, nm, &ntb_msit_ops);
 369         if (ret)
 370                 goto remove_dbgfs;
 371
 372         if (!nm->isr_ctx)
 373                 goto remove_dbgfs;
 374
 375         ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
 376
 377         return 0;
 378
 379 remove_dbgfs:
 380         ntb_msit_remove_dbgfs(nm);
 381         devm_kfree(&ntb->dev, nm->isr_ctx);
 382         devm_kfree(&ntb->dev, nm);
 383         return ret;
 384 }
 385
 386 static void ntb_msit_remove(struct ntb_client *client, struct ntb_dev *ntb)
 387 {
 388         struct ntb_msit_ctx *nm = ntb->ctx;
 389         int i;
 390
 391         ntb_link_disable(ntb);
 392         ntb_db_set_mask(ntb, ntb_db_valid_mask(ntb));
 393         ntb_msi_clear_mws(ntb);
 394
 395         for (i = 0; i < ntb_peer_port_count(ntb); i++)
 396                 kfree(nm->peers[i].msi_desc);
 397
 398         ntb_clear_ctx(ntb);
 399         ntb_msit_remove_dbgfs(nm);
 400 }
 401
 402 static struct ntb_client ntb_msit_client = {
 403         .ops = {
 404                 .probe = ntb_msit_probe,
 405                 .remove = ntb_msit_remove
 406         }
 407 };
 408
 409 static int __init ntb_msit_init(void)
 410 {
 411         int ret;
 412
 413         if (debugfs_initialized())
 414                 ntb_msit_dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME,
 415                                                            NULL);
 416
 417         ret = ntb_register_client(&ntb_msit_client);
 418         if (ret)
 419                 debugfs_remove_recursive(ntb_msit_dbgfs_topdir);
 420
 421         return ret;
 422 }
 423 module_init(ntb_msit_init);
 424
 425 static void __exit ntb_msit_exit(void)
 426 {
 427         ntb_unregister_client(&ntb_msit_client);
 428         debugfs_remove_recursive(ntb_msit_dbgfs_topdir);
 429 }
 430 module_exit(ntb_msit_exit);