* and many others.
*/
+#include <linux/blkdev.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
-#include <linux/mod_devicetable.h>
-#include <linux/delay.h>
-#include <linux/device.h>
#include <linux/scatterlist.h>
-#include <linux/dma-mapping.h>
-#include <linux/blkdev.h>
#include <linux/string.h>
#include <linux/stringify.h>
#include <linux/timer.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
-#include "fw-transaction.h"
-#include "fw-topology.h"
#include "fw-device.h"
+#include "fw-topology.h"
+#include "fw-transaction.h"
/*
* So far only bridges from Oxford Semiconductor are known to support
struct sbp2_logical_unit {
struct sbp2_target *tgt;
struct list_head link;
- struct scsi_device *sdev;
struct fw_address_handler address_handler;
struct list_head orb_list;
int generation;
int retries;
struct delayed_work work;
+ bool has_sdev;
+ bool blocked;
};
/*
int address_high;
unsigned int workarounds;
unsigned int mgt_orb_timeout;
+
+ int dont_block; /* counter for each logical unit */
+ int blocked; /* ditto */
};
/*
#define SBP2_ORB_TIMEOUT 2000U /* Timeout in ms */
#define SBP2_ORB_NULL 0x80000000
#define SBP2_MAX_SG_ELEMENT_LENGTH 0xf000
+#define SBP2_RETRY_LIMIT 0xf /* 15 retries */
#define SBP2_DIRECTION_TO_MEDIA 0x0
#define SBP2_DIRECTION_FROM_MEDIA 0x1
.model = ~0,
.workarounds = SBP2_WORKAROUND_128K_MAX_TRANS,
},
+ /* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
+ .firmware_revision = 0x002600,
+ .model = ~0,
+ .workarounds = SBP2_WORKAROUND_128K_MAX_TRANS,
+ },
/*
* There are iPods (2nd gen, 3rd gen) with model_id == 0, but
&z, sizeof(z), complete_agent_reset_write_no_wait, t);
}
+static void sbp2_set_generation(struct sbp2_logical_unit *lu, int generation)
+{
+ struct fw_card *card = fw_device(lu->tgt->unit->device.parent)->card;
+ unsigned long flags;
+
+ /* serialize with comparisons of lu->generation and card->generation */
+ spin_lock_irqsave(&card->lock, flags);
+ lu->generation = generation;
+ spin_unlock_irqrestore(&card->lock, flags);
+}
+
+static inline void sbp2_allow_block(struct sbp2_logical_unit *lu)
+{
+ /*
+ * We may access dont_block without taking card->lock here:
+ * All callers of sbp2_allow_block() and all callers of sbp2_unblock()
+ * are currently serialized against each other.
+ * And a wrong result in sbp2_conditionally_block()'s access of
+ * dont_block is rather harmless, it simply misses its first chance.
+ */
+ --lu->tgt->dont_block;
+}
+
+/*
+ * Blocks lu->tgt if all of the following conditions are met:
+ * - Login, INQUIRY, and high-level SCSI setup of all of the target's
+ * logical units have been finished (indicated by dont_block == 0).
+ * - lu->generation is stale.
+ *
+ * Note, scsi_block_requests() must be called while holding card->lock,
+ * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
+ * unblock the target.
+ */
+static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
+{
+ struct sbp2_target *tgt = lu->tgt;
+ struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
+ struct Scsi_Host *shost =
+ container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+ unsigned long flags;
+
+ spin_lock_irqsave(&card->lock, flags);
+ if (!tgt->dont_block && !lu->blocked &&
+ lu->generation != card->generation) {
+ lu->blocked = true;
+ if (++tgt->blocked == 1) {
+ scsi_block_requests(shost);
+ fw_notify("blocked %s\n", lu->tgt->bus_id);
+ }
+ }
+ spin_unlock_irqrestore(&card->lock, flags);
+}
+
+/*
+ * Unblocks lu->tgt as soon as all its logical units can be unblocked.
+ * Note, it is harmless to run scsi_unblock_requests() outside the
+ * card->lock protected section. On the other hand, running it inside
+ * the section might clash with shost->host_lock.
+ */
+static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
+{
+ struct sbp2_target *tgt = lu->tgt;
+ struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
+ struct Scsi_Host *shost =
+ container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+ unsigned long flags;
+ bool unblock = false;
+
+ spin_lock_irqsave(&card->lock, flags);
+ if (lu->blocked && lu->generation == card->generation) {
+ lu->blocked = false;
+ unblock = --tgt->blocked == 0;
+ }
+ spin_unlock_irqrestore(&card->lock, flags);
+
+ if (unblock) {
+ scsi_unblock_requests(shost);
+ fw_notify("unblocked %s\n", lu->tgt->bus_id);
+ }
+}
+
+/*
+ * Prevents future blocking of tgt and unblocks it.
+ * Note, it is harmless to run scsi_unblock_requests() outside the
+ * card->lock protected section. On the other hand, running it inside
+ * the section might clash with shost->host_lock.
+ */
+static void sbp2_unblock(struct sbp2_target *tgt)
+{
+ struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
+ struct Scsi_Host *shost =
+ container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+ unsigned long flags;
+
+ spin_lock_irqsave(&card->lock, flags);
+ ++tgt->dont_block;
+ spin_unlock_irqrestore(&card->lock, flags);
+
+ scsi_unblock_requests(shost);
+}
+
+static int sbp2_lun2int(u16 lun)
+{
+ struct scsi_lun eight_bytes_lun;
+
+ memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
+ eight_bytes_lun.scsi_lun[0] = (lun >> 8) & 0xff;
+ eight_bytes_lun.scsi_lun[1] = lun & 0xff;
+
+ return scsilun_to_int(&eight_bytes_lun);
+}
+
static void sbp2_release_target(struct kref *kref)
{
struct sbp2_target *tgt = container_of(kref, struct sbp2_target, kref);
struct sbp2_logical_unit *lu, *next;
struct Scsi_Host *shost =
container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+ struct scsi_device *sdev;
+ struct fw_device *device = fw_device(tgt->unit->device.parent);
- list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
- if (lu->sdev)
- scsi_remove_device(lu->sdev);
+ /* prevent deadlocks */
+ sbp2_unblock(tgt);
+ list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
+ sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
+ if (sdev) {
+ scsi_remove_device(sdev);
+ scsi_device_put(sdev);
+ }
sbp2_send_management_orb(lu, tgt->node_id, lu->generation,
SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
scsi_remove_host(shost);
fw_notify("released %s\n", tgt->bus_id);
- put_device(&tgt->unit->device);
+ fw_unit_put(tgt->unit);
scsi_host_put(shost);
+ fw_device_put(device);
}
static struct workqueue_struct *sbp2_wq;
kref_put(&tgt->kref, sbp2_release_target);
}
+static void
+complete_set_busy_timeout(struct fw_card *card, int rcode,
+ void *payload, size_t length, void *done)
+{
+ complete(done);
+}
+
+static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
+{
+ struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
+ DECLARE_COMPLETION_ONSTACK(done);
+ struct fw_transaction t;
+ static __be32 busy_timeout;
+
+ /* FIXME: we should try to set dual-phase cycle_limit too */
+ busy_timeout = cpu_to_be32(SBP2_RETRY_LIMIT);
+
+ fw_send_request(device->card, &t, TCODE_WRITE_QUADLET_REQUEST,
+ lu->tgt->node_id, lu->generation, device->max_speed,
+ CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT, &busy_timeout,
+ sizeof(busy_timeout), complete_set_busy_timeout, &done);
+ wait_for_completion(&done);
+}
+
static void sbp2_reconnect(struct work_struct *work);
static void sbp2_login(struct work_struct *work)
struct fw_device *device = fw_device(tgt->unit->device.parent);
struct Scsi_Host *shost;
struct scsi_device *sdev;
- struct scsi_lun eight_bytes_lun;
struct sbp2_login_response response;
int generation, node_id, local_node_id;
node_id = device->node_id;
local_node_id = device->card->node_id;
+ /* If this is a re-login attempt, log out, or we might be rejected. */
+ if (lu->has_sdev)
+ sbp2_send_management_orb(lu, device->node_id, generation,
+ SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
+
if (sbp2_send_management_orb(lu, node_id, generation,
SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
- if (lu->retries++ < 5)
+ if (lu->retries++ < 5) {
sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
- else
+ } else {
fw_error("%s: failed to login to LUN %04x\n",
tgt->bus_id, lu->lun);
+ /* Let any waiting I/O fail from now on. */
+ sbp2_unblock(lu->tgt);
+ }
goto out;
}
- lu->generation = generation;
tgt->node_id = node_id;
tgt->address_high = local_node_id << 16;
+ sbp2_set_generation(lu, generation);
/* Get command block agent offset and login id. */
lu->command_block_agent_address =
fw_notify("%s: logged in to LUN %04x (%d retries)\n",
tgt->bus_id, lu->lun, lu->retries);
-#if 0
- /* FIXME: The linux1394 sbp2 does this last step. */
- sbp2_set_busy_timeout(scsi_id);
-#endif
+ /* set appropriate retry limit(s) in BUSY_TIMEOUT register */
+ sbp2_set_busy_timeout(lu);
PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);
sbp2_agent_reset(lu);
/* This was a re-login. */
- if (lu->sdev) {
+ if (lu->has_sdev) {
sbp2_cancel_orbs(lu);
+ sbp2_conditionally_unblock(lu);
goto out;
}
if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
ssleep(SBP2_INQUIRY_DELAY);
- memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
- eight_bytes_lun.scsi_lun[0] = (lu->lun >> 8) & 0xff;
- eight_bytes_lun.scsi_lun[1] = lu->lun & 0xff;
shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+ sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
+ /*
+ * FIXME: We are unable to perform reconnects while in sbp2_login().
+ * Therefore __scsi_add_device() will get into trouble if a bus reset
+ * happens in parallel. It will either fail or leave us with an
+ * unusable sdev. As a workaround we check for this and retry the
+ * whole login and SCSI probing.
+ */
- sdev = __scsi_add_device(shost, 0, 0,
- scsilun_to_int(&eight_bytes_lun), lu);
- if (IS_ERR(sdev)) {
- smp_rmb(); /* generation may have changed */
- generation = device->generation;
- smp_rmb(); /* node_id must not be older than generation */
+ /* Reported error during __scsi_add_device() */
+ if (IS_ERR(sdev))
+ goto out_logout_login;
- sbp2_send_management_orb(lu, device->node_id, generation,
- SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
- /*
- * Set this back to sbp2_login so we fall back and
- * retry login on bus reset.
- */
- PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
- } else {
- lu->sdev = sdev;
+ /* Unreported error during __scsi_add_device() */
+ smp_rmb(); /* get current card generation */
+ if (generation != device->card->generation) {
+ scsi_remove_device(sdev);
scsi_device_put(sdev);
+ goto out_logout_login;
}
+
+ /* No error during __scsi_add_device() */
+ lu->has_sdev = true;
+ scsi_device_put(sdev);
+ sbp2_allow_block(lu);
+ goto out;
+
+ out_logout_login:
+ smp_rmb(); /* generation may have changed */
+ generation = device->generation;
+ smp_rmb(); /* node_id must not be older than generation */
+
+ sbp2_send_management_orb(lu, device->node_id, generation,
+ SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
+ /*
+ * If a bus reset happened, sbp2_update will have requeued
+ * lu->work already. Reset the work from reconnect to login.
+ */
+ PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
out:
sbp2_target_put(tgt);
}
return -ENOMEM;
}
- lu->tgt = tgt;
- lu->sdev = NULL;
- lu->lun = lun_entry & 0xffff;
- lu->retries = 0;
+ lu->tgt = tgt;
+ lu->lun = lun_entry & 0xffff;
+ lu->retries = 0;
+ lu->has_sdev = false;
+ lu->blocked = false;
+ ++tgt->dont_block;
INIT_LIST_HEAD(&lu->orb_list);
INIT_DELAYED_WORK(&lu->work, sbp2_login);
if (scsi_add_host(shost, &unit->device) < 0)
goto fail_shost_put;
+ fw_device_get(device);
+ fw_unit_get(unit);
+
/* Initialize to values that won't match anything in our table. */
firmware_revision = 0xff000000;
model = 0xff000000;
sbp2_init_workarounds(tgt, model, firmware_revision);
- get_device(&unit->device);
-
/* Do the login in a workqueue so we can easily reschedule retries. */
list_for_each_entry(lu, &tgt->lu_list, link)
sbp2_queue_work(lu, 0);
if (sbp2_send_management_orb(lu, node_id, generation,
SBP2_RECONNECT_REQUEST,
lu->login_id, NULL) < 0) {
- if (lu->retries++ >= 5) {
+ /*
+ * If reconnect was impossible even though we are in the
+ * current generation, fall back and try to log in again.
+ *
+ * We could check for "Function rejected" status, but
+ * looking at the bus generation as simpler and more general.
+ */
+ smp_rmb(); /* get current card generation */
+ if (generation == device->card->generation ||
+ lu->retries++ >= 5) {
fw_error("%s: failed to reconnect\n", tgt->bus_id);
- /* Fall back and try to log in again. */
lu->retries = 0;
PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
}
goto out;
}
- lu->generation = generation;
tgt->node_id = node_id;
tgt->address_high = local_node_id << 16;
+ sbp2_set_generation(lu, generation);
fw_notify("%s: reconnected to LUN %04x (%d retries)\n",
tgt->bus_id, lu->lun, lu->retries);
sbp2_agent_reset(lu);
sbp2_cancel_orbs(lu);
+ sbp2_conditionally_unblock(lu);
out:
sbp2_target_put(tgt);
}
* Iteration over tgt->lu_list is therefore safe here.
*/
list_for_each_entry(lu, &tgt->lu_list, link) {
+ sbp2_conditionally_block(lu);
lu->retries = 0;
sbp2_queue_work(lu, 0);
}
* or when sending the write (less likely).
*/
result = DID_BUS_BUSY << 16;
+ sbp2_conditionally_block(orb->lu);
}
dma_unmap_single(device->card->device, orb->base.request_bus,
{
struct sbp2_logical_unit *lu = sdev->hostdata;
+ /* (Re-)Adding logical units via the SCSI stack is not supported. */
+ if (!lu)
+ return -ENOSYS;
+
sdev->allow_restart = 1;
- /*
- * Update the dma alignment (minimum alignment requirements for
- * start and end of DMA transfers) to be a sector
- */
- blk_queue_update_dma_alignment(sdev->request_queue, 511);
+ /* SBP-2 requires quadlet alignment of the data buffers. */
+ blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
sdev->inquiry_len = 36;
projects / cascardo / linux.git / blobdiff