linux/drivers/scsi/libsas/sas_discover.c
Dan Williams b202445925 [SCSI] libsas, libata: fix start of life for a sas ata_port
This changes the ordering of initialization and probing events from:
  1/ allocate rphy in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
  2/ allocate ata_port and schedule port probe in DISCE_PROBE
...to:
  1/ allocate ata_port in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
  2/ allocate rphy in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
  3/ schedule port probe in DISCE_PROBE

This ordering prevents PHYE_SIGNAL_LOSS_EVENTS from sneaking in to
destrory ata devices before they have been fully initialized:

  BUG: unable to handle kernel paging request at 0000000000003b10
  IP: [<ffffffffa0053d7e>] sas_ata_end_eh+0x12/0x5e [libsas]
  ...
  [<ffffffffa004d1af>] sas_unregister_common_dev+0x78/0xc9 [libsas]
  [<ffffffffa004d4d4>] sas_unregister_dev+0x4f/0xad [libsas]
  [<ffffffffa004d5b1>] sas_unregister_domain_devices+0x7f/0xbf [libsas]
  [<ffffffffa004c487>] sas_deform_port+0x61/0x1b8 [libsas]
  [<ffffffffa004bed0>] sas_phye_loss_of_signal+0x29/0x2b [libsas]

...and kills the awkward "sata domain_device briefly existing in the
domain without an ata_port" state.

Reported-by: Michal Kosciowski <michal.kosciowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-04-23 12:11:47 +01:00

535 lines
14 KiB
C

/*
* Serial Attached SCSI (SAS) Discover process
*
* Copyright (C) 2005 Adaptec, Inc. All rights reserved.
* Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
*
* This file is licensed under GPLv2.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_eh.h>
#include "sas_internal.h"
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_sas.h>
#include <scsi/sas_ata.h>
#include "../scsi_sas_internal.h"
/* ---------- Basic task processing for discovery purposes ---------- */
void sas_init_dev(struct domain_device *dev)
{
switch (dev->dev_type) {
case SAS_END_DEV:
break;
case EDGE_DEV:
case FANOUT_DEV:
INIT_LIST_HEAD(&dev->ex_dev.children);
mutex_init(&dev->ex_dev.cmd_mutex);
break;
case SATA_DEV:
case SATA_PM:
case SATA_PM_PORT:
case SATA_PENDING:
INIT_LIST_HEAD(&dev->sata_dev.children);
break;
default:
break;
}
}
/* ---------- Domain device discovery ---------- */
/**
* sas_get_port_device -- Discover devices which caused port creation
* @port: pointer to struct sas_port of interest
*
* Devices directly attached to a HA port, have no parent. This is
* how we know they are (domain) "root" devices. All other devices
* do, and should have their "parent" pointer set appropriately as
* soon as a child device is discovered.
*/
static int sas_get_port_device(struct asd_sas_port *port)
{
struct asd_sas_phy *phy;
struct sas_rphy *rphy;
struct domain_device *dev;
int rc = -ENODEV;
dev = sas_alloc_device();
if (!dev)
return -ENOMEM;
spin_lock_irq(&port->phy_list_lock);
if (list_empty(&port->phy_list)) {
spin_unlock_irq(&port->phy_list_lock);
sas_put_device(dev);
return -ENODEV;
}
phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
spin_lock(&phy->frame_rcvd_lock);
memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
(size_t)phy->frame_rcvd_size));
spin_unlock(&phy->frame_rcvd_lock);
spin_unlock_irq(&port->phy_list_lock);
if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
struct dev_to_host_fis *fis =
(struct dev_to_host_fis *) dev->frame_rcvd;
if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
fis->byte_count_low==0x69 && fis->byte_count_high == 0x96
&& (fis->device & ~0x10) == 0)
dev->dev_type = SATA_PM;
else
dev->dev_type = SATA_DEV;
dev->tproto = SAS_PROTOCOL_SATA;
} else {
struct sas_identify_frame *id =
(struct sas_identify_frame *) dev->frame_rcvd;
dev->dev_type = id->dev_type;
dev->iproto = id->initiator_bits;
dev->tproto = id->target_bits;
}
sas_init_dev(dev);
dev->port = port;
switch (dev->dev_type) {
case SATA_DEV:
rc = sas_ata_init(dev);
if (rc) {
rphy = NULL;
break;
}
/* fall through */
case SAS_END_DEV:
rphy = sas_end_device_alloc(port->port);
break;
case EDGE_DEV:
rphy = sas_expander_alloc(port->port,
SAS_EDGE_EXPANDER_DEVICE);
break;
case FANOUT_DEV:
rphy = sas_expander_alloc(port->port,
SAS_FANOUT_EXPANDER_DEVICE);
break;
default:
printk("ERROR: Unidentified device type %d\n", dev->dev_type);
rphy = NULL;
break;
}
if (!rphy) {
sas_put_device(dev);
return rc;
}
rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
sas_fill_in_rphy(dev, rphy);
sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
port->port_dev = dev;
dev->linkrate = port->linkrate;
dev->min_linkrate = port->linkrate;
dev->max_linkrate = port->linkrate;
dev->pathways = port->num_phys;
memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
port->disc.max_level = 0;
sas_device_set_phy(dev, port->port);
dev->rphy = rphy;
get_device(&dev->rphy->dev);
if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEV)
list_add_tail(&dev->disco_list_node, &port->disco_list);
else {
spin_lock_irq(&port->dev_list_lock);
list_add_tail(&dev->dev_list_node, &port->dev_list);
spin_unlock_irq(&port->dev_list_lock);
}
spin_lock_irq(&port->phy_list_lock);
list_for_each_entry(phy, &port->phy_list, port_phy_el)
sas_phy_set_target(phy, dev);
spin_unlock_irq(&port->phy_list_lock);
return 0;
}
/* ---------- Discover and Revalidate ---------- */
int sas_notify_lldd_dev_found(struct domain_device *dev)
{
int res = 0;
struct sas_ha_struct *sas_ha = dev->port->ha;
struct Scsi_Host *shost = sas_ha->core.shost;
struct sas_internal *i = to_sas_internal(shost->transportt);
if (i->dft->lldd_dev_found) {
res = i->dft->lldd_dev_found(dev);
if (res) {
printk("sas: driver on pcidev %s cannot handle "
"device %llx, error:%d\n",
dev_name(sas_ha->dev),
SAS_ADDR(dev->sas_addr), res);
}
kref_get(&dev->kref);
}
return res;
}
void sas_notify_lldd_dev_gone(struct domain_device *dev)
{
struct sas_ha_struct *sas_ha = dev->port->ha;
struct Scsi_Host *shost = sas_ha->core.shost;
struct sas_internal *i = to_sas_internal(shost->transportt);
if (i->dft->lldd_dev_gone) {
i->dft->lldd_dev_gone(dev);
sas_put_device(dev);
}
}
static void sas_probe_devices(struct work_struct *work)
{
struct domain_device *dev, *n;
struct sas_discovery_event *ev = to_sas_discovery_event(work);
struct asd_sas_port *port = ev->port;
clear_bit(DISCE_PROBE, &port->disc.pending);
/* devices must be domain members before link recovery and probe */
list_for_each_entry(dev, &port->disco_list, disco_list_node) {
spin_lock_irq(&port->dev_list_lock);
list_add_tail(&dev->dev_list_node, &port->dev_list);
spin_unlock_irq(&port->dev_list_lock);
}
sas_probe_sata(port);
list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
int err;
err = sas_rphy_add(dev->rphy);
if (err)
sas_fail_probe(dev, __func__, err);
else
list_del_init(&dev->disco_list_node);
}
}
/**
* sas_discover_end_dev -- discover an end device (SSP, etc)
* @end: pointer to domain device of interest
*
* See comment in sas_discover_sata().
*/
int sas_discover_end_dev(struct domain_device *dev)
{
int res;
res = sas_notify_lldd_dev_found(dev);
if (res)
return res;
sas_discover_event(dev->port, DISCE_PROBE);
return 0;
}
/* ---------- Device registration and unregistration ---------- */
void sas_free_device(struct kref *kref)
{
struct domain_device *dev = container_of(kref, typeof(*dev), kref);
put_device(&dev->rphy->dev);
dev->rphy = NULL;
if (dev->parent)
sas_put_device(dev->parent);
sas_port_put_phy(dev->phy);
dev->phy = NULL;
/* remove the phys and ports, everything else should be gone */
if (dev->dev_type == EDGE_DEV || dev->dev_type == FANOUT_DEV)
kfree(dev->ex_dev.ex_phy);
if (dev_is_sata(dev) && dev->sata_dev.ap) {
ata_sas_port_destroy(dev->sata_dev.ap);
dev->sata_dev.ap = NULL;
}
kfree(dev);
}
static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
{
sas_notify_lldd_dev_gone(dev);
if (!dev->parent)
dev->port->port_dev = NULL;
else
list_del_init(&dev->siblings);
spin_lock_irq(&port->dev_list_lock);
list_del_init(&dev->dev_list_node);
spin_unlock_irq(&port->dev_list_lock);
sas_put_device(dev);
}
static void sas_destruct_devices(struct work_struct *work)
{
struct domain_device *dev, *n;
struct sas_discovery_event *ev = to_sas_discovery_event(work);
struct asd_sas_port *port = ev->port;
clear_bit(DISCE_DESTRUCT, &port->disc.pending);
list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
list_del_init(&dev->disco_list_node);
sas_remove_children(&dev->rphy->dev);
sas_rphy_delete(dev->rphy);
sas_unregister_common_dev(port, dev);
}
}
void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
{
if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
!list_empty(&dev->disco_list_node)) {
/* this rphy never saw sas_rphy_add */
list_del_init(&dev->disco_list_node);
sas_rphy_free(dev->rphy);
sas_unregister_common_dev(port, dev);
return;
}
if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
sas_rphy_unlink(dev->rphy);
list_move_tail(&dev->disco_list_node, &port->destroy_list);
sas_discover_event(dev->port, DISCE_DESTRUCT);
}
}
void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
{
struct domain_device *dev, *n;
list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
if (gone)
set_bit(SAS_DEV_GONE, &dev->state);
sas_unregister_dev(port, dev);
}
list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
sas_unregister_dev(port, dev);
port->port->rphy = NULL;
}
void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
{
struct sas_ha_struct *ha;
struct sas_phy *new_phy;
if (!dev)
return;
ha = dev->port->ha;
new_phy = sas_port_get_phy(port);
/* pin and record last seen phy */
spin_lock_irq(&ha->phy_port_lock);
if (new_phy) {
sas_port_put_phy(dev->phy);
dev->phy = new_phy;
}
spin_unlock_irq(&ha->phy_port_lock);
}
/* ---------- Discovery and Revalidation ---------- */
/**
* sas_discover_domain -- discover the domain
* @port: port to the domain of interest
*
* NOTE: this process _must_ quit (return) as soon as any connection
* errors are encountered. Connection recovery is done elsewhere.
* Discover process only interrogates devices in order to discover the
* domain.
*/
static void sas_discover_domain(struct work_struct *work)
{
struct domain_device *dev;
int error = 0;
struct sas_discovery_event *ev = to_sas_discovery_event(work);
struct asd_sas_port *port = ev->port;
clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
if (port->port_dev)
return;
error = sas_get_port_device(port);
if (error)
return;
dev = port->port_dev;
SAS_DPRINTK("DOING DISCOVERY on port %d, pid:%d\n", port->id,
task_pid_nr(current));
switch (dev->dev_type) {
case SAS_END_DEV:
error = sas_discover_end_dev(dev);
break;
case EDGE_DEV:
case FANOUT_DEV:
error = sas_discover_root_expander(dev);
break;
case SATA_DEV:
case SATA_PM:
#ifdef CONFIG_SCSI_SAS_ATA
error = sas_discover_sata(dev);
break;
#else
SAS_DPRINTK("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
/* Fall through */
#endif
default:
error = -ENXIO;
SAS_DPRINTK("unhandled device %d\n", dev->dev_type);
break;
}
if (error) {
sas_rphy_free(dev->rphy);
list_del_init(&dev->disco_list_node);
spin_lock_irq(&port->dev_list_lock);
list_del_init(&dev->dev_list_node);
spin_unlock_irq(&port->dev_list_lock);
sas_put_device(dev);
port->port_dev = NULL;
}
SAS_DPRINTK("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
task_pid_nr(current), error);
}
static void sas_revalidate_domain(struct work_struct *work)
{
int res = 0;
struct sas_discovery_event *ev = to_sas_discovery_event(work);
struct asd_sas_port *port = ev->port;
struct sas_ha_struct *ha = port->ha;
/* prevent revalidation from finding sata links in recovery */
mutex_lock(&ha->disco_mutex);
if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
SAS_DPRINTK("REVALIDATION DEFERRED on port %d, pid:%d\n",
port->id, task_pid_nr(current));
goto out;
}
clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
SAS_DPRINTK("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
task_pid_nr(current));
if (port->port_dev)
res = sas_ex_revalidate_domain(port->port_dev);
SAS_DPRINTK("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
port->id, task_pid_nr(current), res);
out:
mutex_unlock(&ha->disco_mutex);
}
/* ---------- Events ---------- */
static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
{
/* chained work is not subject to SA_HA_DRAINING or
* SAS_HA_REGISTERED, because it is either submitted in the
* workqueue, or known to be submitted from a context that is
* not racing against draining
*/
scsi_queue_work(ha->core.shost, &sw->work);
}
static void sas_chain_event(int event, unsigned long *pending,
struct sas_work *sw,
struct sas_ha_struct *ha)
{
if (!test_and_set_bit(event, pending)) {
unsigned long flags;
spin_lock_irqsave(&ha->state_lock, flags);
sas_chain_work(ha, sw);
spin_unlock_irqrestore(&ha->state_lock, flags);
}
}
int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
{
struct sas_discovery *disc;
if (!port)
return 0;
disc = &port->disc;
BUG_ON(ev >= DISC_NUM_EVENTS);
sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
return 0;
}
/**
* sas_init_disc -- initialize the discovery struct in the port
* @port: pointer to struct port
*
* Called when the ports are being initialized.
*/
void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
{
int i;
static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
[DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
[DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
[DISCE_PROBE] = sas_probe_devices,
[DISCE_DESTRUCT] = sas_destruct_devices,
};
disc->pending = 0;
for (i = 0; i < DISC_NUM_EVENTS; i++) {
INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
disc->disc_work[i].port = port;
}
}