sas_scsi_host.c

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/*
 * Serial Attached SCSI (SAS) class SCSI Host glue.
 *
 * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
 * Copyright (C) 2005 Luben Tuikov <[e-mail]>
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 */

#include <linux/kthread.h>

#include "sas_internal.h"

#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_sas.h>
#include <scsi/sas_ata.h>
#include "../scsi_sas_internal.h"
#include "../scsi_transport_api.h"
#include "../scsi_priv.h"

#include <linux/err.h>
#include <linux/blkdev.h>
#include <linux/freezer.h>
#include <linux/scatterlist.h>
#include <linux/libata.h>

/* ---------- SCSI Host glue ---------- */

static void sas_scsi_task_done(struct sas_task *task)
{
	struct task_status_struct *ts = &task->task_status;
	struct scsi_cmnd *sc = task->uldd_task;
	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(sc->device->host);
	unsigned ts_flags = task->task_state_flags;
	int hs = 0, stat = 0;

	if (unlikely(!sc)) {
		SAS_DPRINTK("task_done called with non existing SCSI cmnd!\n");
		list_del_init(&task->list);
		sas_free_task(task);
		return;
	}

	if (ts->resp == SAS_TASK_UNDELIVERED) {
		/* transport error */
		hs = DID_NO_CONNECT;
	} else { /* ts->resp == SAS_TASK_COMPLETE */
		/* task delivered, what happened afterwards? */
		switch (ts->stat) {
		case SAS_DEV_NO_RESPONSE:
		case SAS_INTERRUPTED:
		case SAS_PHY_DOWN:
		case SAS_NAK_R_ERR:
		case SAS_OPEN_TO:
			hs = DID_NO_CONNECT;
			break;
		case SAS_DATA_UNDERRUN:
			scsi_set_resid(sc, ts->residual);
			if (scsi_bufflen(sc) - scsi_get_resid(sc) < sc->underflow)
				hs = DID_ERROR;
			break;
		case SAS_DATA_OVERRUN:
			hs = DID_ERROR;
			break;
		case SAS_QUEUE_FULL:
			hs = DID_SOFT_ERROR; /* retry */
			break;
		case SAS_DEVICE_UNKNOWN:
			hs = DID_BAD_TARGET;
			break;
		case SAS_SG_ERR:
			hs = DID_PARITY;
			break;
		case SAS_OPEN_REJECT:
			if (ts->open_rej_reason == SAS_OREJ_RSVD_RETRY)
				hs = DID_SOFT_ERROR; /* retry */
			else
				hs = DID_ERROR;
			break;
		case SAS_PROTO_RESPONSE:
			SAS_DPRINTK("LLDD:%s sent SAS_PROTO_RESP for an SSP "
				    "task; please report this\n",
				    task->dev->port->ha->sas_ha_name);
			break;
		case SAS_ABORTED_TASK:
			hs = DID_ABORT;
			break;
		case SAM_CHECK_COND:
			memcpy(sc->sense_buffer, ts->buf,
			       max(SCSI_SENSE_BUFFERSIZE, ts->buf_valid_size));
			stat = SAM_CHECK_COND;
			break;
		default:
			stat = ts->stat;
			break;
		}
	}
	ASSIGN_SAS_TASK(sc, NULL);
	sc->result = (hs << 16) | stat;
	list_del_init(&task->list);
	sas_free_task(task);
	/* This is very ugly but this is how SCSI Core works. */
	if (ts_flags & SAS_TASK_STATE_ABORTED)
		scsi_eh_finish_cmd(sc, &sas_ha->eh_done_q);
	else
		sc->scsi_done(sc);
}

static enum task_attribute sas_scsi_get_task_attr(struct scsi_cmnd *cmd)
{
	enum task_attribute ta = TASK_ATTR_SIMPLE;
	if (cmd->request && blk_rq_tagged(cmd->request)) {
		if (cmd->device->ordered_tags &&
		    (cmd->request->cmd_flags & REQ_HARDBARRIER))
			ta = TASK_ATTR_ORDERED;
	}
	return ta;
}

static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
					       struct domain_device *dev,
					       gfp_t gfp_flags)
{
	struct sas_task *task = sas_alloc_task(gfp_flags);
	struct scsi_lun lun;

	if (!task)
		return NULL;

	*(u32 *)cmd->sense_buffer = 0;
	task->uldd_task = cmd;
	ASSIGN_SAS_TASK(cmd, task);

	task->dev = dev;
	task->task_proto = task->dev->tproto; /* BUG_ON(!SSP) */

	task->ssp_task.retry_count = 1;
	int_to_scsilun(cmd->device->lun, &lun);
	memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
	task->ssp_task.task_attr = sas_scsi_get_task_attr(cmd);
	memcpy(task->ssp_task.cdb, cmd->cmnd, 16);

	task->scatter = scsi_sglist(cmd);
	task->num_scatter = scsi_sg_count(cmd);
	task->total_xfer_len = scsi_bufflen(cmd);
	task->data_dir = cmd->sc_data_direction;

	task->task_done = sas_scsi_task_done;

	return task;
}

int sas_queue_up(struct sas_task *task)
{
	struct sas_ha_struct *sas_ha = task->dev->port->ha;
	struct scsi_core *core = &sas_ha->core;
	unsigned long flags;
	LIST_HEAD(list);

	spin_lock_irqsave(&core->task_queue_lock, flags);
	if (sas_ha->lldd_queue_size < core->task_queue_size + 1) {
		spin_unlock_irqrestore(&core->task_queue_lock, flags);
		return -SAS_QUEUE_FULL;
	}
	list_add_tail(&task->list, &core->task_queue);
	core->task_queue_size += 1;
	spin_unlock_irqrestore(&core->task_queue_lock, flags);
	wake_up_process(core->queue_thread);

	return 0;
}

/**
 * sas_queuecommand -- Enqueue a command for processing
 * @parameters: See SCSI Core documentation
 *
 * Note: XXX: Remove the host unlock/lock pair when SCSI Core can
 * call us without holding an IRQ spinlock...
 */
int sas_queuecommand(struct scsi_cmnd *cmd,
		     void (*scsi_done)(struct scsi_cmnd *))
{
	int res = 0;
	struct domain_device *dev = cmd_to_domain_dev(cmd);
	struct Scsi_Host *host = cmd->device->host;
	struct sas_internal *i = to_sas_internal(host->transportt);

	spin_unlock_irq(host->host_lock);

	{
		struct sas_ha_struct *sas_ha = dev->port->ha;
		struct sas_task *task;

		if (dev_is_sata(dev)) {
			unsigned long flags;

			spin_lock_irqsave(dev->sata_dev.ap->lock, flags);
			res = ata_sas_queuecmd(cmd, scsi_done,
					       dev->sata_dev.ap);
			spin_unlock_irqrestore(dev->sata_dev.ap->lock, flags);
			goto out;
		}

		res = -ENOMEM;
		task = sas_create_task(cmd, dev, GFP_ATOMIC);
		if (!task)
			goto out;

		cmd->scsi_done = scsi_done;
		/* Queue up, Direct Mode or Task Collector Mode. */
		if (sas_ha->lldd_max_execute_num < 2)
			res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
		else
			res = sas_queue_up(task);

		/* Examine */
		if (res) {
			SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
			ASSIGN_SAS_TASK(cmd, NULL);
			sas_free_task(task);
			if (res == -SAS_QUEUE_FULL) {
				cmd->result = DID_SOFT_ERROR << 16; /* retry */
				res = 0;
				scsi_done(cmd);
			}
			goto out;
		}
	}
out:
	spin_lock_irq(host->host_lock);
	return res;
}

static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
{
	struct scsi_cmnd *cmd, *n;

	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
		if (cmd == my_cmd)
			list_del_init(&cmd->eh_entry);
	}
}

static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
				     struct domain_device *dev)
{
	struct scsi_cmnd *cmd, *n;

	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
		struct domain_device *x = cmd_to_domain_dev(cmd);

		if (x == dev)
			list_del_init(&cmd->eh_entry);
	}
}

static void sas_scsi_clear_queue_port(struct list_head *error_q,
				      struct asd_sas_port *port)
{
	struct scsi_cmnd *cmd, *n;

	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
		struct domain_device *dev = cmd_to_domain_dev(cmd);
		struct asd_sas_port *x = dev->port;

		if (x == port)
			list_del_init(&cmd->eh_entry);
	}
}

enum task_disposition {
	TASK_IS_DONE,
	TASK_IS_ABORTED,
	TASK_IS_AT_LU,
	TASK_IS_NOT_AT_LU,
	TASK_ABORT_FAILED,
};

static enum task_disposition sas_scsi_find_task(struct sas_task *task)
{
	struct sas_ha_struct *ha = task->dev->port->ha;
	unsigned long flags;
	int i, res;
	struct sas_internal *si =
		to_sas_internal(task->dev->port->ha->core.shost->transportt);

	if (ha->lldd_max_execute_num > 1) {
		struct scsi_core *core = &ha->core;
		struct sas_task *t, *n;

		spin_lock_irqsave(&core->task_queue_lock, flags);
		list_for_each_entry_safe(t, n, &core->task_queue, list) {
			if (task == t) {
				list_del_init(&t->list);
				spin_unlock_irqrestore(&core->task_queue_lock,
						       flags);
				SAS_DPRINTK("%s: task 0x%p aborted from "
					    "task_queue\n",
					    __FUNCTION__, task);
				return TASK_IS_ABORTED;
			}
		}
		spin_unlock_irqrestore(&core->task_queue_lock, flags);
	}

	for (i = 0; i < 5; i++) {
		SAS_DPRINTK("%s: aborting task 0x%p\n", __FUNCTION__, task);
		res = si->dft->lldd_abort_task(task);

		spin_lock_irqsave(&task->task_state_lock, flags);
		if (task->task_state_flags & SAS_TASK_STATE_DONE) {
			spin_unlock_irqrestore(&task->task_state_lock, flags);
			SAS_DPRINTK("%s: task 0x%p is done\n", __FUNCTION__,
				    task);
			return TASK_IS_DONE;
		}
		spin_unlock_irqrestore(&task->task_state_lock, flags);

		if (res == TMF_RESP_FUNC_COMPLETE) {
			SAS_DPRINTK("%s: task 0x%p is aborted\n",
				    __FUNCTION__, task);
			return TASK_IS_ABORTED;
		} else if (si->dft->lldd_query_task) {
			SAS_DPRINTK("%s: querying task 0x%p\n",
				    __FUNCTION__, task);
			res = si->dft->lldd_query_task(task);
			switch (res) {
			case TMF_RESP_FUNC_SUCC:
				SAS_DPRINTK("%s: task 0x%p at LU\n",
					    __FUNCTION__, task);
				return TASK_IS_AT_LU;
			case TMF_RESP_FUNC_COMPLETE:
				SAS_DPRINTK("%s: task 0x%p not at LU\n",
					    __FUNCTION__, task);
				return TASK_IS_NOT_AT_LU;
			case TMF_RESP_FUNC_FAILED:
                                SAS_DPRINTK("%s: task 0x%p failed to abort\n",
                                                __FUNCTION__, task);
                                return TASK_ABORT_FAILED;
                        }

		}
	}
	return res;
}

static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
{
	int res = TMF_RESP_FUNC_FAILED;
	struct scsi_lun lun;
	struct sas_internal *i =
		to_sas_internal(dev->port->ha->core.shost->transportt);

	int_to_scsilun(cmd->device->lun, &lun);

	SAS_DPRINTK("eh: device %llx LUN %x has the task\n",
		    SAS_ADDR(dev->sas_addr),
		    cmd->device->lun);

	if (i->dft->lldd_abort_task_set)
		res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);

	if (res == TMF_RESP_FUNC_FAILED) {
		if (i->dft->lldd_clear_task_set)
			res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
	}

	if (res == TMF_RESP_FUNC_FAILED) {
		if (i->dft->lldd_lu_reset)
			res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
	}

	return res;
}

static int sas_recover_I_T(struct domain_device *dev)
{
	int res = TMF_RESP_FUNC_FAILED;
	struct sas_internal *i =
		to_sas_internal(dev->port->ha->core.shost->transportt);

	SAS_DPRINTK("I_T nexus reset for dev %016llx\n",
		    SAS_ADDR(dev->sas_addr));

	if (i->dft->lldd_I_T_nexus_reset)
		res = i->dft->lldd_I_T_nexus_reset(dev);

	return res;
}

/* Find the sas_phy that's attached to this device */
struct sas_phy *find_local_sas_phy(struct domain_device *dev)
{
	struct domain_device *pdev = dev->parent;
	struct ex_phy *exphy = NULL;
	int i;

	/* Directly attached device */
	if (!pdev)
		return dev->port->phy;

	/* Otherwise look in the expander */
	for (i = 0; i < pdev->ex_dev.num_phys; i++)
		if (!memcmp(dev->sas_addr,
			    pdev->ex_dev.ex_phy[i].attached_sas_addr,
			    SAS_ADDR_SIZE)) {
			exphy = &pdev->ex_dev.ex_phy[i];
			break;
		}

	BUG_ON(!exphy);
	return exphy->phy;
}

/* Attempt to send a LUN reset message to a device */
int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
{
	struct domain_device *dev = cmd_to_domain_dev(cmd);
	struct sas_internal *i =
		to_sas_internal(dev->port->ha->core.shost->transportt);
	struct scsi_lun lun;
	int res;

	int_to_scsilun(cmd->device->lun, &lun);

	if (!i->dft->lldd_lu_reset)
		return FAILED;

	res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
		return SUCCESS;

	return FAILED;
}

/* Attempt to send a phy (bus) reset */
int sas_eh_bus_reset_handler(struct scsi_cmnd *cmd)
{
	struct domain_device *dev = cmd_to_domain_dev(cmd);
	struct sas_phy *phy = find_local_sas_phy(dev);
	int res;

	res = sas_phy_reset(phy, 1);
	if (res)
		SAS_DPRINTK("Bus reset of %s failed 0x%x\n",
			    phy->dev.kobj.k_name,
			    res);
	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
		return SUCCESS;

	return FAILED;
}

/* Try to reset a device */
static int try_to_reset_cmd_device(struct Scsi_Host *shost,
				   struct scsi_cmnd *cmd)
{
	int res;

	if (!shost->hostt->eh_device_reset_handler)
		goto try_bus_reset;

	res = shost->hostt->eh_device_reset_handler(cmd);
	if (res == SUCCESS)
		return res;

try_bus_reset:
	if (shost->hostt->eh_bus_reset_handler)
		return shost->hostt->eh_bus_reset_handler(cmd);

	return FAILED;
}

static int sas_eh_handle_sas_errors(struct Scsi_Host *shost,
				    struct list_head *work_q,
				    struct list_head *done_q)
{
	struct scsi_cmnd *cmd, *n;
	enum task_disposition res = TASK_IS_DONE;
	int tmf_resp, need_reset;
	struct sas_internal *i = to_sas_internal(shost->transportt);
	unsigned long flags;
	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);

Again:
	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
		struct sas_task *task = TO_SAS_TASK(cmd);

		if (!task)
			continue;

		list_del_init(&cmd->eh_entry);

		spin_lock_irqsave(&task->task_state_lock, flags);
		need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
		spin_unlock_irqrestore(&task->task_state_lock, flags);

		SAS_DPRINTK("trying to find task 0x%p\n", task);
		res = sas_scsi_find_task(task);

		cmd->eh_eflags = 0;

		switch (res) {
		case TASK_IS_DONE:
			SAS_DPRINTK("%s: task 0x%p is done\n", __FUNCTION__,
				    task);
			task->task_done(task);
			if (need_reset)
				try_to_reset_cmd_device(shost, cmd);
			continue;
		case TASK_IS_ABORTED:
			SAS_DPRINTK("%s: task 0x%p is aborted\n",