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                /* fall through */
 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        }
 186        set_bit(SAS_DEV_FOUND, &dev->state);
 187        kref_get(&dev->kref);
 188        return res;
 189}
 190
 191
 192void sas_notify_lldd_dev_gone(struct domain_device *dev)
 193{
 194        struct sas_ha_struct *sas_ha = dev->port->ha;
 195        struct Scsi_Host *shost = sas_ha->core.shost;
 196        struct sas_internal *i = to_sas_internal(shost->transportt);
 197
 198        if (!i->dft->lldd_dev_gone)
 199                return;
 200
 201        if (test_and_clear_bit(SAS_DEV_FOUND, &dev->state)) {
 202                i->dft->lldd_dev_gone(dev);
 203                sas_put_device(dev);
 204        }
 205}
 206
 207static void sas_probe_devices(struct asd_sas_port *port)
 208{
 209        struct domain_device *dev, *n;
 210
 211        /* devices must be domain members before link recovery and probe */
 212        list_for_each_entry(dev, &port->disco_list, disco_list_node) {
 213                spin_lock_irq(&port->dev_list_lock);
 214                list_add_tail(&dev->dev_list_node, &port->dev_list);
 215                spin_unlock_irq(&port->dev_list_lock);
 216        }
 217
 218        sas_probe_sata(port);
 219
 220        list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
 221                int err;
 222
 223                err = sas_rphy_add(dev->rphy);
 224                if (err)
 225                        sas_fail_probe(dev, __func__, err);
 226                else
 227                        list_del_init(&dev->disco_list_node);
 228        }
 229}
 230
 231static void sas_suspend_devices(struct work_struct *work)
 232{
 233        struct asd_sas_phy *phy;
 234        struct domain_device *dev;
 235        struct sas_discovery_event *ev = to_sas_discovery_event(work);
 236        struct asd_sas_port *port = ev->port;
 237        struct Scsi_Host *shost = port->ha->core.shost;
 238        struct sas_internal *si = to_sas_internal(shost->transportt);
 239
 240        clear_bit(DISCE_SUSPEND, &port->disc.pending);
 241
 242        sas_suspend_sata(port);
 243
 244        /* lldd is free to forget the domain_device across the
 245         * suspension, we force the issue here to keep the reference
 246         * counts aligned
 247         */
 248        list_for_each_entry(dev, &port->dev_list, dev_list_node)
 249                sas_notify_lldd_dev_gone(dev);
 250
 251        /* we are suspending, so we know events are disabled and
 252         * phy_list is not being mutated
 253         */
 254        list_for_each_entry(phy, &port->phy_list, port_phy_el) {
 255                if (si->dft->lldd_port_deformed)
 256                        si->dft->lldd_port_deformed(phy);
 257                phy->suspended = 1;
 258                port->suspended = 1;
 259        }
 260}
 261
 262static void sas_resume_devices(struct work_struct *work)
 263{
 264        struct sas_discovery_event *ev = to_sas_discovery_event(work);
 265        struct asd_sas_port *port = ev->port;
 266
 267        clear_bit(DISCE_RESUME, &port->disc.pending);
 268
 269        sas_resume_sata(port);
 270}
 271
 272/**
 273 * sas_discover_end_dev - discover an end device (SSP, etc)
 274 * @dev: pointer to domain device of interest
 275 *
 276 * See comment in sas_discover_sata().
 277 */
 278int sas_discover_end_dev(struct domain_device *dev)
 279{
 280        int res;
 281
 282        res = sas_notify_lldd_dev_found(dev);
 283        if (res)
 284                return res;
 285
 286        return 0;
 287}
 288
 289/* ---------- Device registration and unregistration ---------- */
 290
 291void sas_free_device(struct kref *kref)
 292{
 293        struct domain_device *dev = container_of(kref, typeof(*dev), kref);
 294
 295        put_device(&dev->rphy->dev);
 296        dev->rphy = NULL;
 297
 298        if (dev->parent)
 299                sas_put_device(dev->parent);
 300
 301        sas_port_put_phy(dev->phy);
 302        dev->phy = NULL;
 303
 304        /* remove the phys and ports, everything else should be gone */
 305        if (dev_is_expander(dev->dev_type))
 306                kfree(dev->ex_dev.ex_phy);
 307
 308        if (dev_is_sata(dev) && dev->sata_dev.ap) {
 309                ata_sas_tport_delete(dev->sata_dev.ap);
 310                ata_sas_port_destroy(dev->sata_dev.ap);
 311                ata_host_put(dev->sata_dev.ata_host);
 312                dev->sata_dev.ata_host = NULL;
 313                dev->sata_dev.ap = NULL;
 314        }
 315
 316        kfree(dev);
 317}
 318
 319static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
 320{
 321        struct sas_ha_struct *ha = port->ha;
 322
 323        sas_notify_lldd_dev_gone(dev);
 324        if (!dev->parent)
 325                dev->port->port_dev = NULL;
 326        else
 327                list_del_init(&dev->siblings);
 328
 329        spin_lock_irq(&port->dev_list_lock);
 330        list_del_init(&dev->dev_list_node);
 331        if (dev_is_sata(dev))
 332                sas_ata_end_eh(dev->sata_dev.ap);
 333        spin_unlock_irq(&port->dev_list_lock);
 334
 335        spin_lock_irq(&ha->lock);
 336        if (dev->dev_type == SAS_END_DEVICE &&
 337            !list_empty(&dev->ssp_dev.eh_list_node)) {
 338                list_del_init(&dev->ssp_dev.eh_list_node);
 339                ha->eh_active--;
 340        }
 341        spin_unlock_irq(&ha->lock);
 342
 343        sas_put_device(dev);
 344}
 345
 346void sas_destruct_devices(struct asd_sas_port *port)
 347{
 348        struct domain_device *dev, *n;
 349
 350        list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
 351                list_del_init(&dev->disco_list_node);
 352
 353                sas_remove_children(&dev->rphy->dev);
 354                sas_rphy_delete(dev->rphy);
 355                sas_unregister_common_dev(port, dev);
 356        }
 357}
 358
 359static void sas_destruct_ports(struct asd_sas_port *port)
 360{
 361        struct sas_port *sas_port, *p;
 362
 363        list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, del_list) {
 364                list_del_init(&sas_port->del_list);
 365                sas_port_delete(sas_port);
 366        }
 367}
 368
 369void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
 370{
 371        if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
 372            !list_empty(&dev->disco_list_node)) {
 373                /* this rphy never saw sas_rphy_add */
 374                list_del_init(&dev->disco_list_node);
 375                sas_rphy_free(dev->rphy);
 376                sas_unregister_common_dev(port, dev);
 377                return;
 378        }
 379
 380        if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
 381                sas_rphy_unlink(dev->rphy);
 382                list_move_tail(&dev->disco_list_node, &port->destroy_list);
 383        }
 384}
 385
 386void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
 387{
 388        struct domain_device *dev, *n;
 389
 390        list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
 391                if (gone)
 392                        set_bit(SAS_DEV_GONE, &dev->state);
 393                sas_unregister_dev(port, dev);
 394        }
 395
 396        list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
 397                sas_unregister_dev(port, dev);
 398
 399        port->port->rphy = NULL;
 400
 401}
 402
 403void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
 404{
 405        struct sas_ha_struct *ha;
 406        struct sas_phy *new_phy;
 407
 408        if (!dev)
 409                return;
 410
 411        ha = dev->port->ha;
 412        new_phy = sas_port_get_phy(port);
 413
 414        /* pin and record last seen phy */
 415        spin_lock_irq(&ha->phy_port_lock);
 416        if (new_phy) {
 417                sas_port_put_phy(dev->phy);
 418                dev->phy = new_phy;
 419        }
 420        spin_unlock_irq(&ha->phy_port_lock);
 421}
 422
 423/* ---------- Discovery and Revalidation ---------- */
 424
 425/**
 426 * sas_discover_domain - discover the domain
 427 * @work: work structure embedded in port domain device.
 428 *
 429 * NOTE: this process _must_ quit (return) as soon as any connection
 430 * errors are encountered.  Connection recovery is done elsewhere.
 431 * Discover process only interrogates devices in order to discover the
 432 * domain.
 433 */
 434static void sas_discover_domain(struct work_struct *work)
 435{
 436        struct domain_device *dev;
 437        int error = 0;
 438        struct sas_discovery_event *ev = to_sas_discovery_event(work);
 439        struct asd_sas_port *port = ev->port;
 440
 441        clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
 442
 443        if (port->port_dev)
 444                return;
 445
 446        error = sas_get_port_device(port);
 447        if (error)
 448                return;
 449        dev = port->port_dev;
 450
 451        pr_debug("DOING DISCOVERY on port %d, pid:%d\n", port->id,
 452                 task_pid_nr(current));
 453
 454        switch (dev->dev_type) {
 455        case SAS_END_DEVICE:
 456                error = sas_discover_end_dev(dev);
 457                break;
 458        case SAS_EDGE_EXPANDER_DEVICE:
 459        case SAS_FANOUT_EXPANDER_DEVICE:
 460                error = sas_discover_root_expander(dev);
 461                break;
 462        case SAS_SATA_DEV:
 463        case SAS_SATA_PM:
 464#ifdef CONFIG_SCSI_SAS_ATA
 465                error = sas_discover_sata(dev);
 466                break;
 467#else
 468                pr_notice("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
 469                /* Fall through */
 470#endif
 471                /* Fall through - only for the #else condition above. */
 472        default:
 473                error = -ENXIO;
 474                pr_err("unhandled device %d\n", dev->dev_type);
 475                break;
 476        }
 477
 478        if (error) {
 479                sas_rphy_free(dev->rphy);
 480                list_del_init(&dev->disco_list_node);
 481                spin_lock_irq(&port->dev_list_lock);
 482                list_del_init(&dev->dev_list_node);
 483                spin_unlock_irq(&port->dev_list_lock);
 484
 485                sas_put_device(dev);
 486                port->port_dev = NULL;
 487        }
 488
 489        sas_probe_devices(port);
 490
 491        pr_debug("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
 492                 task_pid_nr(current), error);
 493}
 494
 495static void sas_revalidate_domain(struct work_struct *work)
 496{
 497        int res = 0;
 498        struct sas_discovery_event *ev = to_sas_discovery_event(work);
 499        struct asd_sas_port *port = ev->port;
 500        struct sas_ha_struct *ha = port->ha;
 501        struct domain_device *ddev = port->port_dev;
 502
 503        /* prevent revalidation from finding sata links in recovery */
 504        mutex_lock(&ha->disco_mutex);
 505        if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
 506                pr_debug("REVALIDATION DEFERRED on port %d, pid:%d\n",
 507                         port->id, task_pid_nr(current));
 508                goto out;
 509        }
 510
 511        clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
 512
 513        pr_debug("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
 514                 task_pid_nr(current));
 515
 516        if (ddev && dev_is_expander(ddev->dev_type))
 517                res = sas_ex_revalidate_domain(ddev);
 518
 519        pr_debug("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
 520                 port->id, task_pid_nr(current), res);
 521 out:
 522        mutex_unlock(&ha->disco_mutex);
 523
 524        sas_destruct_devices(port);
 525        sas_destruct_ports(port);
 526        sas_probe_devices(port);
 527}
 528
 529/* ---------- Events ---------- */
 530
 531static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
 532{
 533        /* chained work is not subject to SA_HA_DRAINING or
 534         * SAS_HA_REGISTERED, because it is either submitted in the
 535         * workqueue, or known to be submitted from a context that is
 536         * not racing against draining
 537         */
 538        queue_work(ha->disco_q, &sw->work);
 539}
 540
 541static void sas_chain_event(int event, unsigned long *pending,
 542                            struct sas_work *sw,
 543                            struct sas_ha_struct *ha)
 544{
 545        if (!test_and_set_bit(event, pending)) {
 546                unsigned long flags;
 547
 548                spin_lock_irqsave(&ha->lock, flags);
 549                sas_chain_work(ha, sw);
 550                spin_unlock_irqrestore(&ha->lock, flags);
 551        }
 552}
 553
 554int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
 555{
 556        struct sas_discovery *disc;
 557
 558        if (!port)
 559                return 0;
 560        disc = &port->disc;
 561
 562        BUG_ON(ev >= DISC_NUM_EVENTS);
 563
 564        sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
 565
 566        return 0;
 567}
 568
 569/**
 570 * sas_init_disc - initialize the discovery struct in the port
 571 * @disc: port discovery structure
 572 * @port: pointer to struct port
 573 *
 574 * Called when the ports are being initialized.
 575 */
 576void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
 577{
 578        int i;
 579
 580        static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
 581                [DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
 582                [DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
 583                [DISCE_SUSPEND] = sas_suspend_devices,
 584                [DISCE_RESUME] = sas_resume_devices,
 585        };
 586
 587        disc->pending = 0;
 588        for (i = 0; i < DISC_NUM_EVENTS; i++) {
 589                INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
 590                disc->disc_work[i].port = port;
 591        }
 592}
 593