linux/drivers/scsi/libsas/sas_discover.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Serial Attached SCSI (SAS) Discover process
   4 *
   5 * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
   6 * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
   7 */
   8
   9#include <linux/scatterlist.h>
  10#include <linux/slab.h>
  11#include <linux/async.h>
  12#include <scsi/scsi_host.h>
  13#include <scsi/scsi_eh.h>
  14#include "sas_internal.h"
  15
  16#include <scsi/scsi_transport.h>
  17#include <scsi/scsi_transport_sas.h>
  18#include <scsi/sas_ata.h>
  19#include "../scsi_sas_internal.h"
  20
  21/* ---------- Basic task processing for discovery purposes ---------- */
  22
  23void sas_init_dev(struct domain_device *dev)
  24{
  25        switch (dev->dev_type) {
  26        case SAS_END_DEVICE:
  27                INIT_LIST_HEAD(&dev->ssp_dev.eh_list_node);
  28                break;
  29        case SAS_EDGE_EXPANDER_DEVICE:
  30        case SAS_FANOUT_EXPANDER_DEVICE:
  31                INIT_LIST_HEAD(&dev->ex_dev.children);
  32                mutex_init(&dev->ex_dev.cmd_mutex);
  33                break;
  34        default:
  35                break;
  36        }
  37}
  38
  39/* ---------- Domain device discovery ---------- */
  40
  41/**
  42 * sas_get_port_device - Discover devices which caused port creation
  43 * @port: pointer to struct sas_port of interest
  44 *
  45 * Devices directly attached to a HA port, have no parent.  This is
  46 * how we know they are (domain) "root" devices.  All other devices
  47 * do, and should have their "parent" pointer set appropriately as
  48 * soon as a child device is discovered.
  49 */
  50static int sas_get_port_device(struct asd_sas_port *port)
  51{
  52        struct asd_sas_phy *phy;
  53        struct sas_rphy *rphy;
  54        struct domain_device *dev;
  55        int rc = -ENODEV;
  56
  57        dev = sas_alloc_device();
  58        if (!dev)
  59                return -ENOMEM;
  60
  61        spin_lock_irq(&port->phy_list_lock);
  62        if (list_empty(&port->phy_list)) {
  63                spin_unlock_irq(&port->phy_list_lock);
  64                sas_put_device(dev);
  65                return -ENODEV;
  66        }
  67        phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
  68        spin_lock(&phy->frame_rcvd_lock);
  69        memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
  70                                             (size_t)phy->frame_rcvd_size));
  71        spin_unlock(&phy->frame_rcvd_lock);
  72        spin_unlock_irq(&port->phy_list_lock);
  73
  74        if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
  75                struct dev_to_host_fis *fis =
  76                        (struct dev_to_host_fis *) dev->frame_rcvd;
  77                if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
  78                    fis->byte_count_low == 0x69 && fis->byte_count_high == 0x96
  79                    && (fis->device & ~0x10) == 0)
  80                        dev->dev_type = SAS_SATA_PM;
  81                else
  82                        dev->dev_type = SAS_SATA_DEV;
  83                dev->tproto = SAS_PROTOCOL_SATA;
  84        } else if (port->oob_mode == SAS_OOB_MODE) {
  85                struct sas_identify_frame *id =
  86                        (struct sas_identify_frame *) dev->frame_rcvd;
  87                dev->dev_type = id->dev_type;
  88                dev->iproto = id->initiator_bits;
  89                dev->tproto = id->target_bits;
  90        } else {
  91                /* If the oob mode is OOB_NOT_CONNECTED, the port is
  92                 * disconnected due to race with PHY down. We cannot
  93                 * continue to discover this port
  94                 */
  95                sas_put_device(dev);
  96                pr_warn("Port %016llx is disconnected when discovering\n",
  97                        SAS_ADDR(port->attached_sas_addr));
  98                return -ENODEV;
  99        }
 100
 101        sas_init_dev(dev);
 102
 103        dev->port = port;
 104        switch (dev->dev_type) {
 105        case SAS_SATA_DEV:
 106                rc = sas_ata_init(dev);
 107                if (rc) {
 108                        rphy = NULL;
 109                        break;
 110                }
 111                fallthrough;
 112        case SAS_END_DEVICE:
 113                rphy = sas_end_device_alloc(port->port);
 114                break;
 115        case SAS_EDGE_EXPANDER_DEVICE:
 116                rphy = sas_expander_alloc(port->port,
 117                                          SAS_EDGE_EXPANDER_DEVICE);
 118                break;
 119        case SAS_FANOUT_EXPANDER_DEVICE:
 120                rphy = sas_expander_alloc(port->port,
 121                                          SAS_FANOUT_EXPANDER_DEVICE);
 122                break;
 123        default:
 124                pr_warn("ERROR: Unidentified device type %d\n", dev->dev_type);
 125                rphy = NULL;
 126                break;
 127        }
 128
 129        if (!rphy) {
 130                sas_put_device(dev);
 131                return rc;
 132        }
 133
 134        rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
 135        memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
 136        sas_fill_in_rphy(dev, rphy);
 137        sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
 138        port->port_dev = dev;
 139        dev->linkrate = port->linkrate;
 140        dev->min_linkrate = port->linkrate;
 141        dev->max_linkrate = port->linkrate;
 142        dev->pathways = port->num_phys;
 143        memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
 144        memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
 145        memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
 146        port->disc.max_level = 0;
 147        sas_device_set_phy(dev, port->port);
 148
 149        dev->rphy = rphy;
 150        get_device(&dev->rphy->dev);
 151
 152        if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEVICE)
 153                list_add_tail(&dev->disco_list_node, &port->disco_list);
 154        else {
 155                spin_lock_irq(&port->dev_list_lock);
 156                list_add_tail(&dev->dev_list_node, &port->dev_list);
 157                spin_unlock_irq(&port->dev_list_lock);
 158        }
 159
 160        spin_lock_irq(&port->phy_list_lock);
 161        list_for_each_entry(phy, &port->phy_list, port_phy_el)
 162                sas_phy_set_target(phy, dev);
 163        spin_unlock_irq(&port->phy_list_lock);
 164
 165        return 0;
 166}
 167
 168/* ---------- Discover and Revalidate ---------- */
 169
 170int sas_notify_lldd_dev_found(struct domain_device *dev)
 171{
 172        int res = 0;
 173        struct sas_ha_struct *sas_ha = dev->port->ha;
 174        struct Scsi_Host *shost = sas_ha->core.shost;
 175        struct sas_internal *i = to_sas_internal(shost->transportt);
 176
 177        if (!i->dft->lldd_dev_found)
 178                return 0;
 179
 180        res = i->dft->lldd_dev_found(dev);
 181        if (res) {
 182                pr_warn("driver on host %s cannot handle device %016llx, error:%d\n",
 183                        dev_name(sas_ha->dev),
 184                        SAS_ADDR(dev->sas_addr), res);
 185                return res;
 186        }
 187        set_bit(SAS_DEV_FOUND, &dev->state);
 188        kref_get(&dev->kref);
 189        return 0;
 190}
 191
 192
 193void sas_notify_lldd_dev_gone(struct domain_device *dev)
 194{
 195        struct sas_ha_struct *sas_ha = dev->port->ha;
 196        struct Scsi_Host *shost = sas_ha->core.shost;
 197        struct sas_internal *i = to_sas_internal(shost->transportt);
 198
 199        if (!i->dft->lldd_dev_gone)
 200                return;
 201
 202        if (test_and_clear_bit(SAS_DEV_FOUND, &dev->state)) {
 203                i->dft->lldd_dev_gone(dev);
 204                sas_put_device(dev);
 205        }
 206}
 207
 208static void sas_probe_devices(struct asd_sas_port *port)
 209{
 210        struct domain_device *dev, *n;
 211
 212        /* devices must be domain members before link recovery and probe */
 213        list_for_each_entry(dev, &port->disco_list, disco_list_node) {
 214                spin_lock_irq(&port->dev_list_lock);
 215                list_add_tail(&dev->dev_list_node, &port->dev_list);
 216                spin_unlock_irq(&port->dev_list_lock);
 217        }
 218
 219        sas_probe_sata(port);
 220
 221        list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
 222                int err;
 223
 224                err = sas_rphy_add(dev->rphy);
 225                if (err)
 226                        sas_fail_probe(dev, __func__, err);
 227                else
 228                        list_del_init(&dev->disco_list_node);
 229        }
 230}
 231
 232static void sas_suspend_devices(struct work_struct *work)
 233{
 234        struct asd_sas_phy *phy;
 235        struct domain_device *dev;
 236        struct sas_discovery_event *ev = to_sas_discovery_event(work);
 237        struct asd_sas_port *port = ev->port;
 238        struct Scsi_Host *shost = port->ha->core.shost;
 239        struct sas_internal *si = to_sas_internal(shost->transportt);
 240
 241        clear_bit(DISCE_SUSPEND, &port->disc.pending);
 242
 243        sas_suspend_sata(port);
 244
 245        /* lldd is free to forget the domain_device across the
 246         * suspension, we force the issue here to keep the reference
 247         * counts aligned
 248         */
 249        list_for_each_entry(dev, &port->dev_list, dev_list_node)
 250                sas_notify_lldd_dev_gone(dev);
 251
 252        /* we are suspending, so we know events are disabled and
 253         * phy_list is not being mutated
 254         */
 255        list_for_each_entry(phy, &port->phy_list, port_phy_el) {
 256                if (si->dft->lldd_port_deformed)
 257                        si->dft->lldd_port_deformed(phy);
 258                phy->suspended = 1;
 259                port->suspended = 1;
 260        }
 261}
 262
 263static void sas_resume_devices(struct work_struct *work)
 264{
 265        struct sas_discovery_event *ev = to_sas_discovery_event(work);
 266        struct asd_sas_port *port = ev->port;
 267
 268        clear_bit(DISCE_RESUME, &port->disc.pending);
 269
 270        sas_resume_sata(port);
 271}
 272
 273/**
 274 * sas_discover_end_dev - discover an end device (SSP, etc)
 275 * @dev: pointer to domain device of interest
 276 *
 277 * See comment in sas_discover_sata().
 278 */
 279int sas_discover_end_dev(struct domain_device *dev)
 280{
 281        return sas_notify_lldd_dev_found(dev);
 282}
 283
 284/* ---------- Device registration and unregistration ---------- */
 285
 286void sas_free_device(struct kref *kref)
 287{
 288        struct domain_device *dev = container_of(kref, typeof(*dev), kref);
 289
 290        put_device(&dev->rphy->dev);
 291        dev->rphy = NULL;
 292
 293        if (dev->parent)
 294                sas_put_device(dev->parent);
 295
 296        sas_port_put_phy(dev->phy);
 297        dev->phy = NULL;
 298
 299        /* remove the phys and ports, everything else should be gone */
 300        if (dev_is_expander(dev->dev_type))
 301                kfree(dev->ex_dev.ex_phy);
 302
 303        if (dev_is_sata(dev) && dev->sata_dev.ap) {
 304                ata_sas_tport_delete(dev->sata_dev.ap);
 305                ata_sas_port_destroy(dev->sata_dev.ap);
 306                ata_host_put(dev->sata_dev.ata_host);
 307                dev->sata_dev.ata_host = NULL;
 308                dev->sata_dev.ap = NULL;
 309        }
 310
 311        kfree(dev);
 312}
 313
 314static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
 315{
 316        struct sas_ha_struct *ha = port->ha;
 317
 318        sas_notify_lldd_dev_gone(dev);
 319        if (!dev->parent)
 320                dev->port->port_dev = NULL;
 321        else
 322                list_del_init(&dev->siblings);
 323
 324        spin_lock_irq(&port->dev_list_lock);
 325        list_del_init(&dev->dev_list_node);
 326        if (dev_is_sata(dev))
 327                sas_ata_end_eh(dev->sata_dev.ap);
 328        spin_unlock_irq(&port->dev_list_lock);
 329
 330        spin_lock_irq(&ha->lock);
 331        if (dev->dev_type == SAS_END_DEVICE &&
 332            !list_empty(&dev->ssp_dev.eh_list_node)) {
 333                list_del_init(&dev->ssp_dev.eh_list_node);
 334                ha->eh_active--;
 335        }
 336        spin_unlock_irq(&ha->lock);
 337
 338        sas_put_device(dev);
 339}
 340
 341void sas_destruct_devices(struct asd_sas_port *port)
 342{
 343        struct domain_device *dev, *n;
 344
 345        list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
 346                list_del_init(&dev->disco_list_node);
 347
 348                sas_remove_children(&dev->rphy->dev);
 349                sas_rphy_delete(dev->rphy);
 350                sas_unregister_common_dev(port, dev);
 351        }
 352}
 353
 354static void sas_destruct_ports(struct asd_sas_port *port)
 355{
 356        struct sas_port *sas_port, *p;
 357
 358        list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, del_list) {
 359                list_del_init(&sas_port->del_list);
 360                sas_port_delete(sas_port);
 361        }
 362}
 363
 364void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
 365{
 366        if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
 367            !list_empty(&dev->disco_list_node)) {
 368                /* this rphy never saw sas_rphy_add */
 369                list_del_init(&dev->disco_list_node);
 370                sas_rphy_free(dev->rphy);
 371                sas_unregister_common_dev(port, dev);
 372                return;
 373        }
 374
 375        if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
 376                sas_rphy_unlink(dev->rphy);
 377                list_move_tail(&dev->disco_list_node, &port->destroy_list);
 378        }
 379}
 380
 381void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
 382{
 383        struct domain_device *dev, *n;
 384
 385        list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
 386                if (gone)
 387                        set_bit(SAS_DEV_GONE, &dev->state);
 388                sas_unregister_dev(port, dev);
 389        }
 390
 391        list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
 392                sas_unregister_dev(port, dev);
 393
 394        port->port->rphy = NULL;
 395
 396}
 397
 398void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
 399{
 400        struct sas_ha_struct *ha;
 401        struct sas_phy *new_phy;
 402
 403        if (!dev)
 404                return;
 405
 406        ha = dev->port->ha;
 407        new_phy = sas_port_get_phy(port);
 408
 409        /* pin and record last seen phy */
 410        spin_lock_irq(&ha->phy_port_lock);
 411        if (new_phy) {
 412                sas_port_put_phy(dev->phy);
 413                dev->phy = new_phy;
 414        }
 415        spin_unlock_irq(&ha->phy_port_lock);
 416}
 417
 418/* ---------- Discovery and Revalidation ---------- */
 419
 420/**
 421 * sas_discover_domain - discover the domain
 422 * @work: work structure embedded in port domain device.
 423 *
 424 * NOTE: this process _must_ quit (return) as soon as any connection
 425 * errors are encountered.  Connection recovery is done elsewhere.
 426 * Discover process only interrogates devices in order to discover the
 427 * domain.
 428 */
 429static void sas_discover_domain(struct work_struct *work)
 430{
 431        struct domain_device *dev;
 432        int error = 0;
 433        struct sas_discovery_event *ev = to_sas_discovery_event(work);
 434        struct asd_sas_port *port = ev->port;
 435
 436        clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
 437
 438        if (port->port_dev)
 439                return;
 440
 441        error = sas_get_port_device(port);
 442        if (error)
 443                return;
 444        dev = port->port_dev;
 445
 446        pr_debug("DOING DISCOVERY on port %d, pid:%d\n", port->id,
 447                 task_pid_nr(current));
 448
 449        switch (dev->dev_type) {
 450        case SAS_END_DEVICE:
 451                error = sas_discover_end_dev(dev);
 452                break;
 453        case SAS_EDGE_EXPANDER_DEVICE:
 454        case SAS_FANOUT_EXPANDER_DEVICE:
 455                error = sas_discover_root_expander(dev);
 456                break;
 457        case SAS_SATA_DEV:
 458        case SAS_SATA_PM:
 459#ifdef CONFIG_SCSI_SAS_ATA
 460                error = sas_discover_sata(dev);
 461                break;
 462#else
 463                pr_notice("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
 464                fallthrough;
 465#endif
 466                /* Fall through - only for the #else condition above. */
 467        default:
 468                error = -ENXIO;
 469                pr_err("unhandled device %d\n", dev->dev_type);
 470                break;
 471        }
 472
 473        if (error) {
 474                sas_rphy_free(dev->rphy);
 475                list_del_init(&dev->disco_list_node);
 476                spin_lock_irq(&port->dev_list_lock);
 477                list_del_init(&dev->dev_list_node);
 478                spin_unlock_irq(&port->dev_list_lock);
 479
 480                sas_put_device(dev);
 481                port->port_dev = NULL;
 482        }
 483
 484        sas_probe_devices(port);
 485
 486        pr_debug("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
 487                 task_pid_nr(current), error);
 488}
 489
 490static void sas_revalidate_domain(struct work_struct *work)
 491{
 492        int res = 0;
 493        struct sas_discovery_event *ev = to_sas_discovery_event(work);
 494        struct asd_sas_port *port = ev->port;
 495        struct sas_ha_struct *ha = port->ha;
 496        struct domain_device *ddev = port->port_dev;
 497
 498        /* prevent revalidation from finding sata links in recovery */
 499        mutex_lock(&ha->disco_mutex);
 500        if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
 501                pr_debug("REVALIDATION DEFERRED on port %d, pid:%d\n",
 502                         port->id, task_pid_nr(current));
 503                goto out;
 504        }
 505
 506        clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
 507
 508        pr_debug("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
 509                 task_pid_nr(current));
 510
 511        if (ddev && dev_is_expander(ddev->dev_type))
 512                res = sas_ex_revalidate_domain(ddev);
 513
 514        pr_debug("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
 515                 port->id, task_pid_nr(current), res);
 516 out:
 517        mutex_unlock(&ha->disco_mutex);
 518
 519        sas_destruct_devices(port);
 520        sas_destruct_ports(port);
 521        sas_probe_devices(port);
 522}
 523
 524/* ---------- Events ---------- */
 525
 526static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
 527{
 528        /* chained work is not subject to SA_HA_DRAINING or
 529         * SAS_HA_REGISTERED, because it is either submitted in the
 530         * workqueue, or known to be submitted from a context that is
 531         * not racing against draining
 532         */
 533        queue_work(ha->disco_q, &sw->work);
 534}
 535
 536static void sas_chain_event(int event, unsigned long *pending,
 537                            struct sas_work *sw,
 538                            struct sas_ha_struct *ha)
 539{
 540        if (!test_and_set_bit(event, pending)) {
 541                unsigned long flags;
 542
 543                spin_lock_irqsave(&ha->lock, flags);
 544                sas_chain_work(ha, sw);
 545                spin_unlock_irqrestore(&ha->lock, flags);
 546        }
 547}
 548
 549int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
 550{
 551        struct sas_discovery *disc;
 552
 553        if (!port)
 554                return 0;
 555        disc = &port->disc;
 556
 557        BUG_ON(ev >= DISC_NUM_EVENTS);
 558
 559        sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
 560
 561        return 0;
 562}
 563
 564/**
 565 * sas_init_disc - initialize the discovery struct in the port
 566 * @disc: port discovery structure
 567 * @port: pointer to struct port
 568 *
 569 * Called when the ports are being initialized.
 570 */
 571void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
 572{
 573        int i;
 574
 575        static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
 576                [DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
 577                [DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
 578                [DISCE_SUSPEND] = sas_suspend_devices,
 579                [DISCE_RESUME] = sas_resume_devices,
 580        };
 581
 582        disc->pending = 0;
 583        for (i = 0; i < DISC_NUM_EVENTS; i++) {
 584                INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
 585                disc->disc_work[i].port = port;
 586        }
 587}
 588