]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/firewire/fw-sbp2.c
firewire: fw-sbp2: set dual-phase cycle_limit
[linux-2.6-omap-h63xx.git] / drivers / firewire / fw-sbp2.c
index d406c34fd378b37e01f4abbd56f85b769d310dfe..e99a33fcc923852d5653a2651938e3954828fdbf 100644 (file)
  * 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/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 <linux/workqueue.h>
+#include <asm/system.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.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
@@ -81,6 +83,9 @@ MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
  *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
  *   Don't use this with devices which don't have this bug.
  *
+ * - delay inquiry
+ *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
+ *
  * - override internal blacklist
  *   Instead of adding to the built-in blacklist, use only the workarounds
  *   specified in the module load parameter.
@@ -90,6 +95,8 @@ MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
 #define SBP2_WORKAROUND_INQUIRY_36     0x2
 #define SBP2_WORKAROUND_MODE_SENSE_8   0x4
 #define SBP2_WORKAROUND_FIX_CAPACITY   0x8
+#define SBP2_WORKAROUND_DELAY_INQUIRY  0x10
+#define SBP2_INQUIRY_DELAY             12
 #define SBP2_WORKAROUND_OVERRIDE       0x100
 
 static int sbp2_param_workarounds;
@@ -99,6 +106,7 @@ MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
        ", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
        ", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
        ", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
+       ", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
        ", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
        ", or a combination)");
 
@@ -114,7 +122,6 @@ static const char sbp2_driver_name[] = "sbp2";
 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;
 
@@ -131,6 +138,8 @@ struct sbp2_logical_unit {
        int generation;
        int retries;
        struct delayed_work work;
+       bool has_sdev;
+       bool blocked;
 };
 
 /*
@@ -140,24 +149,35 @@ struct sbp2_logical_unit {
 struct sbp2_target {
        struct kref kref;
        struct fw_unit *unit;
+       const char *bus_id;
+       struct list_head lu_list;
 
        u64 management_agent_address;
        int directory_id;
        int node_id;
        int address_high;
+       unsigned int workarounds;
+       unsigned int mgt_orb_timeout;
 
-       unsigned workarounds;
-       struct list_head lu_list;
+       int dont_block; /* counter for each logical unit */
+       int blocked;    /* ditto */
 };
 
-#define SBP2_MAX_SG_ELEMENT_LENGTH     0xf000
-#define SBP2_ORB_TIMEOUT               2000    /* Timeout in ms */
+/*
+ * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
+ * provided in the config rom. Most devices do provide a value, which
+ * we'll use for login management orbs, but with some sane limits.
+ */
+#define SBP2_MIN_LOGIN_ORB_TIMEOUT     5000U   /* Timeout in ms */
+#define SBP2_MAX_LOGIN_ORB_TIMEOUT     40000U  /* Timeout in ms */
+#define SBP2_ORB_TIMEOUT               2000U   /* Timeout in ms */
 #define SBP2_ORB_NULL                  0x80000000
-
-#define SBP2_DIRECTION_TO_MEDIA                0x0
-#define SBP2_DIRECTION_FROM_MEDIA      0x1
+#define SBP2_MAX_SG_ELEMENT_LENGTH     0xf000
+#define SBP2_RETRY_LIMIT               0xf             /* 15 retries */
+#define SBP2_CYCLE_LIMIT               (0xc8 << 12)    /* 200 125us cycles */
 
 /* Unit directory keys */
+#define SBP2_CSR_UNIT_CHARACTERISTICS  0x3a
 #define SBP2_CSR_FIRMWARE_REVISION     0x3c
 #define SBP2_CSR_LOGICAL_UNIT_NUMBER   0x14
 #define SBP2_CSR_LOGICAL_UNIT_DIRECTORY        0xd4
@@ -202,8 +222,8 @@ struct sbp2_status {
 };
 
 struct sbp2_pointer {
-       u32 high;
-       u32 low;
+       __be32 high;
+       __be32 low;
 };
 
 struct sbp2_orb {
@@ -231,8 +251,8 @@ struct sbp2_management_orb {
        struct {
                struct sbp2_pointer password;
                struct sbp2_pointer response;
-               u32 misc;
-               u32 length;
+               __be32 misc;
+               __be32 length;
                struct sbp2_pointer status_fifo;
        } request;
        __be32 response[4];
@@ -241,20 +261,17 @@ struct sbp2_management_orb {
        struct sbp2_status status;
 };
 
-#define LOGIN_RESPONSE_GET_LOGIN_ID(v) ((v).misc & 0xffff)
-#define LOGIN_RESPONSE_GET_LENGTH(v)   (((v).misc >> 16) & 0xffff)
-
 struct sbp2_login_response {
-       u32 misc;
+       __be32 misc;
        struct sbp2_pointer command_block_agent;
-       u32 reconnect_hold;
+       __be32 reconnect_hold;
 };
 #define COMMAND_ORB_DATA_SIZE(v)       ((v))
 #define COMMAND_ORB_PAGE_SIZE(v)       ((v) << 16)
 #define COMMAND_ORB_PAGE_TABLE_PRESENT ((1) << 19)
 #define COMMAND_ORB_MAX_PAYLOAD(v)     ((v) << 20)
 #define COMMAND_ORB_SPEED(v)           ((v) << 24)
-#define COMMAND_ORB_DIRECTION(v)       ((v) << 27)
+#define COMMAND_ORB_DIRECTION          ((1) << 27)
 #define COMMAND_ORB_REQUEST_FORMAT(v)  ((v) << 29)
 #define COMMAND_ORB_NOTIFY             ((1) << 31)
 
@@ -263,7 +280,7 @@ struct sbp2_command_orb {
        struct {
                struct sbp2_pointer next;
                struct sbp2_pointer data_descriptor;
-               u32 misc;
+               __be32 misc;
                u8 command_block[12];
        } request;
        struct scsi_cmnd *cmd;
@@ -286,7 +303,7 @@ struct sbp2_command_orb {
 static const struct {
        u32 firmware_revision;
        u32 model;
-       unsigned workarounds;
+       unsigned int workarounds;
 } sbp2_workarounds_table[] = {
        /* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
                .firmware_revision      = 0x002800,
@@ -294,6 +311,11 @@ static const struct {
                .workarounds            = SBP2_WORKAROUND_INQUIRY_36 |
                                          SBP2_WORKAROUND_MODE_SENSE_8,
        },
+       /* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
+               .firmware_revision      = 0x002800,
+               .model                  = 0x000000,
+               .workarounds            = SBP2_WORKAROUND_DELAY_INQUIRY,
+       },
        /* Initio bridges, actually only needed for some older ones */ {
                .firmware_revision      = 0x000200,
                .model                  = ~0,
@@ -304,6 +326,11 @@ static const struct {
                .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
@@ -427,8 +454,7 @@ sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
        unsigned long flags;
 
        orb->pointer.high = 0;
-       orb->pointer.low = orb->request_bus;
-       fw_memcpy_to_be32(&orb->pointer, &orb->pointer, sizeof(orb->pointer));
+       orb->pointer.low = cpu_to_be32(orb->request_bus);
 
        spin_lock_irqsave(&device->card->lock, flags);
        list_add_tail(&orb->link, &lu->orb_list);
@@ -487,8 +513,12 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 {
        struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
        struct sbp2_management_orb *orb;
+       unsigned int timeout;
        int retval = -ENOMEM;
 
+       if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
+               return 0;
+
        orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
        if (orb == NULL)
                return -ENOMEM;
@@ -500,28 +530,31 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
        if (dma_mapping_error(orb->response_bus))
                goto fail_mapping_response;
 
-       orb->request.response.high    = 0;
-       orb->request.response.low     = orb->response_bus;
+       orb->request.response.high = 0;
+       orb->request.response.low  = cpu_to_be32(orb->response_bus);
 
-       orb->request.misc =
+       orb->request.misc = cpu_to_be32(
                MANAGEMENT_ORB_NOTIFY |
                MANAGEMENT_ORB_FUNCTION(function) |
-               MANAGEMENT_ORB_LUN(lun_or_login_id);
-       orb->request.length =
-               MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response));
+               MANAGEMENT_ORB_LUN(lun_or_login_id));
+       orb->request.length = cpu_to_be32(
+               MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
 
-       orb->request.status_fifo.high = lu->address_handler.offset >> 32;
-       orb->request.status_fifo.low  = lu->address_handler.offset;
+       orb->request.status_fifo.high =
+               cpu_to_be32(lu->address_handler.offset >> 32);
+       orb->request.status_fifo.low  =
+               cpu_to_be32(lu->address_handler.offset);
 
        if (function == SBP2_LOGIN_REQUEST) {
                /* Ask for 2^2 == 4 seconds reconnect grace period */
-               orb->request.misc |=
+               orb->request.misc |= cpu_to_be32(
                        MANAGEMENT_ORB_RECONNECT(2) |
-                       MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login);
+                       MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
+               timeout = lu->tgt->mgt_orb_timeout;
+       } else {
+               timeout = SBP2_ORB_TIMEOUT;
        }
 
-       fw_memcpy_to_be32(&orb->request, &orb->request, sizeof(orb->request));
-
        init_completion(&orb->done);
        orb->base.callback = complete_management_orb;
 
@@ -534,25 +567,24 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
        sbp2_send_orb(&orb->base, lu, node_id, generation,
                      lu->tgt->management_agent_address);
 
-       wait_for_completion_timeout(&orb->done,
-                                   msecs_to_jiffies(SBP2_ORB_TIMEOUT));
+       wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
 
        retval = -EIO;
        if (sbp2_cancel_orbs(lu) == 0) {
-               fw_error("orb reply timed out, rcode=0x%02x\n",
-                        orb->base.rcode);
+               fw_error("%s: orb reply timed out, rcode=0x%02x\n",
+                        lu->tgt->bus_id, orb->base.rcode);
                goto out;
        }
 
        if (orb->base.rcode != RCODE_COMPLETE) {
-               fw_error("management write failed, rcode 0x%02x\n",
-                        orb->base.rcode);
+               fw_error("%s: management write failed, rcode 0x%02x\n",
+                        lu->tgt->bus_id, orb->base.rcode);
                goto out;
        }
 
        if (STATUS_GET_RESPONSE(orb->status) != 0 ||
            STATUS_GET_SBP_STATUS(orb->status) != 0) {
-               fw_error("error status: %d:%d\n",
+               fw_error("%s: error status: %d:%d\n", lu->tgt->bus_id,
                         STATUS_GET_RESPONSE(orb->status),
                         STATUS_GET_SBP_STATUS(orb->status));
                goto out;
@@ -567,8 +599,7 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
                         sizeof(orb->response), DMA_FROM_DEVICE);
  fail_mapping_response:
        if (response)
-               fw_memcpy_from_be32(response,
-                                   orb->response, sizeof(orb->response));
+               memcpy(response, orb->response, sizeof(orb->response));
        kref_put(&orb->base.kref, free_orb);
 
        return retval;
@@ -576,29 +607,154 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 
 static void
 complete_agent_reset_write(struct fw_card *card, int rcode,
-                          void *payload, size_t length, void *data)
+                          void *payload, size_t length, void *done)
 {
-       struct fw_transaction *t = data;
+       complete(done);
+}
 
-       kfree(t);
+static void sbp2_agent_reset(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 u32 z;
+
+       fw_send_request(device->card, &t, TCODE_WRITE_QUADLET_REQUEST,
+                       lu->tgt->node_id, lu->generation, device->max_speed,
+                       lu->command_block_agent_address + SBP2_AGENT_RESET,
+                       &z, sizeof(z), complete_agent_reset_write, &done);
+       wait_for_completion(&done);
+}
+
+static void
+complete_agent_reset_write_no_wait(struct fw_card *card, int rcode,
+                                  void *payload, size_t length, void *data)
+{
+       kfree(data);
 }
 
-static int sbp2_agent_reset(struct sbp2_logical_unit *lu)
+static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
 {
        struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
        struct fw_transaction *t;
-       static u32 zero;
+       static u32 z;
 
-       t = kzalloc(sizeof(*t), GFP_ATOMIC);
+       t = kmalloc(sizeof(*t), GFP_ATOMIC);
        if (t == NULL)
-               return -ENOMEM;
+               return;
 
        fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
                        lu->tgt->node_id, lu->generation, device->max_speed,
                        lu->command_block_agent_address + SBP2_AGENT_RESET,
-                       &zero, sizeof(zero), complete_agent_reset_write, t);
+                       &z, sizeof(z), complete_agent_reset_write_no_wait, t);
+}
 
-       return 0;
+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);
+       }
+       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);
+}
+
+/*
+ * 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)
@@ -607,26 +763,31 @@ static void sbp2_release_target(struct kref *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);
 
-               if (!fw_device_is_shutdown(device))
-                       sbp2_send_management_orb(lu, tgt->node_id,
-                                       lu->generation, SBP2_LOGOUT_REQUEST,
-                                       lu->login_id, NULL);
+       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);
 
                fw_core_remove_address_handler(&lu->address_handler);
                list_del(&lu->link);
                kfree(lu);
        }
        scsi_remove_host(shost);
-       fw_notify("released %s\n", tgt->unit->device.bus_id);
+       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;
@@ -646,76 +807,154 @@ static void sbp2_target_put(struct sbp2_target *tgt)
        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);
+}
+
+/*
+ * Write retransmit retry values into the BUSY_TIMEOUT register.
+ * - The single-phase retry protocol is supported by all SBP-2 devices, but the
+ *   default retry_limit value is 0 (i.e. never retry transmission). We write a
+ *   saner value after logging into the device.
+ * - The dual-phase retry protocol is optional to implement, and if not
+ *   supported, writes to the dual-phase portion of the register will be
+ *   ignored. We try to write the original 1394-1995 default here.
+ * - In the case of devices that are also SBP-3-compliant, all writes are
+ *   ignored, as the register is read-only, but contains single-phase retry of
+ *   15, which is what we're trying to set for all SBP-2 device anyway, so this
+ *   write attempt is safe and yields more consistent behavior for all devices.
+ *
+ * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
+ * and section 6.4 of the SBP-3 spec for further details.
+ */
+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;
+
+       busy_timeout = cpu_to_be32(SBP2_CYCLE_LIMIT | 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 sbp2_logical_unit *lu =
                container_of(work, struct sbp2_logical_unit, work.work);
-       struct Scsi_Host *shost =
-               container_of((void *)lu->tgt, struct Scsi_Host, hostdata[0]);
+       struct sbp2_target *tgt = lu->tgt;
+       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 fw_unit *unit = lu->tgt->unit;
-       struct fw_device *device = fw_device(unit->device.parent);
        struct sbp2_login_response response;
        int generation, node_id, local_node_id;
 
+       if (fw_device_is_shutdown(device))
+               goto out;
+
        generation    = device->generation;
+       smp_rmb();    /* node_id must not be older than generation */
        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
-                       fw_error("failed to login to %s LUN %04x\n",
-                                unit->device.bus_id, lu->lun);
+               } 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;
-       lu->tgt->node_id      = node_id;
-       lu->tgt->address_high = local_node_id << 16;
+       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 =
-               ((u64) (response.command_block_agent.high & 0xffff) << 32) |
-               response.command_block_agent.low;
-       lu->login_id = LOGIN_RESPONSE_GET_LOGIN_ID(response);
+               ((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
+                     << 32) | be32_to_cpu(response.command_block_agent.low);
+       lu->login_id = be32_to_cpu(response.misc) & 0xffff;
 
-       fw_notify("logged in to %s LUN %04x (%d retries)\n",
-                 unit->device.bus_id, lu->lun, lu->retries);
+       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);
 
-       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;
+       /* This was a re-login. */
+       if (lu->has_sdev) {
+               sbp2_cancel_orbs(lu);
+               sbp2_conditionally_unblock(lu);
+               goto out;
+       }
 
-       sdev = __scsi_add_device(shost, 0, 0,
-                                scsilun_to_int(&eight_bytes_lun), lu);
-       if (IS_ERR(sdev)) {
-               sbp2_send_management_orb(lu, 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;
+       if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
+               ssleep(SBP2_INQUIRY_DELAY);
+
+       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.
+        */
+
+       /* Reported error during __scsi_add_device() */
+       if (IS_ERR(sdev))
+               goto out_logout_login;
+
+       /* 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(lu->tgt);
+       sbp2_target_put(tgt);
 }
 
 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
@@ -736,10 +975,12 @@ static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
                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);
 
@@ -765,6 +1006,7 @@ static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
 {
        struct fw_csr_iterator ci;
        int key, value;
+       unsigned int timeout;
 
        fw_csr_iterator_init(&ci, directory);
        while (fw_csr_iterator_next(&ci, &key, &value)) {
@@ -787,6 +1029,21 @@ static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
                        *firmware_revision = value;
                        break;
 
+               case SBP2_CSR_UNIT_CHARACTERISTICS:
+                       /* the timeout value is stored in 500ms units */
+                       timeout = ((unsigned int) value >> 8 & 0xff) * 500;
+                       timeout = max(timeout, SBP2_MIN_LOGIN_ORB_TIMEOUT);
+                       tgt->mgt_orb_timeout =
+                                 min(timeout, SBP2_MAX_LOGIN_ORB_TIMEOUT);
+
+                       if (timeout > tgt->mgt_orb_timeout)
+                               fw_notify("%s: config rom contains %ds "
+                                         "management ORB timeout, limiting "
+                                         "to %ds\n", tgt->bus_id,
+                                         timeout / 1000,
+                                         tgt->mgt_orb_timeout / 1000);
+                       break;
+
                case SBP2_CSR_LOGICAL_UNIT_NUMBER:
                        if (sbp2_add_logical_unit(tgt, value) < 0)
                                return -ENOMEM;
@@ -805,12 +1062,12 @@ static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
                                  u32 firmware_revision)
 {
        int i;
-       unsigned w = sbp2_param_workarounds;
+       unsigned int w = sbp2_param_workarounds;
 
        if (w)
                fw_notify("Please notify linux1394-devel@lists.sourceforge.net "
                          "if you need the workarounds parameter for %s\n",
-                         tgt->unit->device.bus_id);
+                         tgt->bus_id);
 
        if (w & SBP2_WORKAROUND_OVERRIDE)
                goto out;
@@ -832,8 +1089,7 @@ static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
        if (w)
                fw_notify("Workarounds for %s: 0x%x "
                          "(firmware_revision 0x%06x, model_id 0x%06x)\n",
-                         tgt->unit->device.bus_id,
-                         w, firmware_revision, model);
+                         tgt->bus_id, w, firmware_revision, model);
        tgt->workarounds = w;
 }
 
@@ -857,6 +1113,7 @@ static int sbp2_probe(struct device *dev)
        tgt->unit = unit;
        kref_init(&tgt->kref);
        INIT_LIST_HEAD(&tgt->lu_list);
+       tgt->bus_id = unit->device.bus_id;
 
        if (fw_device_enable_phys_dma(device) < 0)
                goto fail_shost_put;
@@ -864,6 +1121,9 @@ static int sbp2_probe(struct device *dev)
        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;
@@ -878,8 +1138,6 @@ static int sbp2_probe(struct device *dev)
 
        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);
@@ -907,21 +1165,32 @@ static void sbp2_reconnect(struct work_struct *work)
 {
        struct sbp2_logical_unit *lu =
                container_of(work, struct sbp2_logical_unit, work.work);
-       struct fw_unit *unit = lu->tgt->unit;
-       struct fw_device *device = fw_device(unit->device.parent);
+       struct sbp2_target *tgt = lu->tgt;
+       struct fw_device *device = fw_device(tgt->unit->device.parent);
        int generation, node_id, local_node_id;
 
+       if (fw_device_is_shutdown(device))
+               goto out;
+
        generation    = device->generation;
+       smp_rmb();    /* node_id must not be older than generation */
        node_id       = device->node_id;
        local_node_id = device->card->node_id;
 
        if (sbp2_send_management_orb(lu, node_id, generation,
                                     SBP2_RECONNECT_REQUEST,
                                     lu->login_id, NULL) < 0) {
-               if (lu->retries++ >= 5) {
-                       fw_error("failed to reconnect to %s\n",
-                                unit->device.bus_id);
-                       /* Fall back and try to log in again. */
+               /*
+                * 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);
                        lu->retries = 0;
                        PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
                }
@@ -929,17 +1198,18 @@ static void sbp2_reconnect(struct work_struct *work)
                goto out;
        }
 
-       lu->generation        = generation;
-       lu->tgt->node_id      = node_id;
-       lu->tgt->address_high = local_node_id << 16;
+       tgt->node_id      = node_id;
+       tgt->address_high = local_node_id << 16;
+       sbp2_set_generation(lu, generation);
 
-       fw_notify("reconnected to %s LUN %04x (%d retries)\n",
-                 unit->device.bus_id, lu->lun, lu->retries);
+       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(lu->tgt);
+       sbp2_target_put(tgt);
 }
 
 static void sbp2_update(struct fw_unit *unit)
@@ -954,6 +1224,7 @@ static void sbp2_update(struct fw_unit *unit)
         * 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);
        }
@@ -1031,7 +1302,7 @@ complete_command_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
 
        if (status != NULL) {
                if (STATUS_GET_DEAD(*status))
-                       sbp2_agent_reset(orb->lu);
+                       sbp2_agent_reset_no_wait(orb->lu);
 
                switch (STATUS_GET_RESPONSE(*status)) {
                case SBP2_STATUS_REQUEST_COMPLETE:
@@ -1057,6 +1328,7 @@ complete_command_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
                 * 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,
@@ -1097,9 +1369,12 @@ sbp2_map_scatterlist(struct sbp2_command_orb *orb, struct fw_device *device,
         * tables.
         */
        if (count == 1 && sg_dma_len(sg) < SBP2_MAX_SG_ELEMENT_LENGTH) {
-               orb->request.data_descriptor.high = lu->tgt->address_high;
-               orb->request.data_descriptor.low  = sg_dma_address(sg);
-               orb->request.misc |= COMMAND_ORB_DATA_SIZE(sg_dma_len(sg));
+               orb->request.data_descriptor.high =
+                       cpu_to_be32(lu->tgt->address_high);
+               orb->request.data_descriptor.low  =
+                       cpu_to_be32(sg_dma_address(sg));
+               orb->request.misc |=
+                       cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
                return 0;
        }
 
@@ -1120,16 +1395,14 @@ sbp2_map_scatterlist(struct sbp2_command_orb *orb, struct fw_device *device,
                                goto fail_page_table;
                        }
                        l = min(sg_len, SBP2_MAX_SG_ELEMENT_LENGTH);
-                       orb->page_table[j].low = sg_addr;
-                       orb->page_table[j].high = (l << 16);
+                       orb->page_table[j].low = cpu_to_be32(sg_addr);
+                       orb->page_table[j].high = cpu_to_be32(l << 16);
                        sg_addr += l;
                        sg_len -= l;
                        j++;
                }
        }
 
-       fw_memcpy_to_be32(orb->page_table, orb->page_table,
-                         sizeof(orb->page_table[0]) * j);
        orb->page_table_bus =
                dma_map_single(device->card->device, orb->page_table,
                               sizeof(orb->page_table), DMA_TO_DEVICE);
@@ -1143,11 +1416,10 @@ sbp2_map_scatterlist(struct sbp2_command_orb *orb, struct fw_device *device,
         * initiator (i.e. us), but data_descriptor can refer to data
         * on other nodes so we need to put our ID in descriptor.high.
         */
-       orb->request.data_descriptor.high = lu->tgt->address_high;
-       orb->request.data_descriptor.low  = orb->page_table_bus;
-       orb->request.misc |=
-               COMMAND_ORB_PAGE_TABLE_PRESENT |
-               COMMAND_ORB_DATA_SIZE(j);
+       orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
+       orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
+       orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
+                                        COMMAND_ORB_DATA_SIZE(j));
 
        return 0;
 
@@ -1165,7 +1437,7 @@ static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
        struct sbp2_logical_unit *lu = cmd->device->hostdata;
        struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
        struct sbp2_command_orb *orb;
-       unsigned max_payload;
+       unsigned int max_payload;
        int retval = SCSI_MLQUEUE_HOST_BUSY;
 
        /*
@@ -1193,8 +1465,7 @@ static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
        orb->done = done;
        orb->cmd  = cmd;
 
-       orb->request.next.high   = SBP2_ORB_NULL;
-       orb->request.next.low    = 0x0;
+       orb->request.next.high   = cpu_to_be32(SBP2_ORB_NULL);
        /*
         * At speed 100 we can do 512 bytes per packet, at speed 200,
         * 1024 bytes per packet etc.  The SBP-2 max_payload field
@@ -1203,25 +1474,17 @@ static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
         */
        max_payload = min(device->max_speed + 7,
                          device->card->max_receive - 1);
-       orb->request.misc =
+       orb->request.misc = cpu_to_be32(
                COMMAND_ORB_MAX_PAYLOAD(max_payload) |
                COMMAND_ORB_SPEED(device->max_speed) |
-               COMMAND_ORB_NOTIFY;
+               COMMAND_ORB_NOTIFY);
 
        if (cmd->sc_data_direction == DMA_FROM_DEVICE)
-               orb->request.misc |=
-                       COMMAND_ORB_DIRECTION(SBP2_DIRECTION_FROM_MEDIA);
-       else if (cmd->sc_data_direction == DMA_TO_DEVICE)
-               orb->request.misc |=
-                       COMMAND_ORB_DIRECTION(SBP2_DIRECTION_TO_MEDIA);
+               orb->request.misc |= cpu_to_be32(COMMAND_ORB_DIRECTION);
 
        if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
                goto out;
 
-       fw_memcpy_to_be32(&orb->request, &orb->request, sizeof(orb->request));
-
-       memset(orb->request.command_block,
-              0, sizeof(orb->request.command_block));
        memcpy(orb->request.command_block, cmd->cmnd, COMMAND_SIZE(*cmd->cmnd));
 
        orb->base.callback = complete_command_orb;
@@ -1243,13 +1506,14 @@ static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
 {
        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;
@@ -1287,7 +1551,7 @@ static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
 {
        struct sbp2_logical_unit *lu = cmd->device->hostdata;
 
-       fw_notify("sbp2_scsi_abort\n");
+       fw_notify("%s: sbp2_scsi_abort\n", lu->tgt->bus_id);
        sbp2_agent_reset(lu);
        sbp2_cancel_orbs(lu);