path: root/drivers/scsi/libsas/sas_ata.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Support for SATA devices on Serial Attached SCSI (SAS) controllers
 *
 * Copyright (C) 2006 IBM Corporation
 *
 * Written by: Darrick J. Wong <djwong@us.ibm.com>, IBM Corporation
 */

#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/async.h>
#include <linux/export.h>

#include <scsi/sas_ata.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_transport.h>
#include <scsi/scsi_transport_sas.h>
#include "scsi_sas_internal.h"
#include "scsi_transport_api.h"
#include <scsi/scsi_eh.h>

static enum ata_completion_errors sas_to_ata_err(struct task_status_struct *ts)
{
	/* Cheesy attempt to translate SAS errors into ATA.  Hah! */

	/* transport error */
	if (ts->resp == SAS_TASK_UNDELIVERED)
		return AC_ERR_ATA_BUS;

	/* ts->resp == SAS_TASK_COMPLETE */
	/* task delivered, what happened afterwards? */
	switch (ts->stat) {
	case SAS_DEV_NO_RESPONSE:
		return AC_ERR_TIMEOUT;
	case SAS_INTERRUPTED:
	case SAS_PHY_DOWN:
	case SAS_NAK_R_ERR:
		return AC_ERR_ATA_BUS;
	case SAS_DATA_UNDERRUN:
		/*
		 * Some programs that use the taskfile interface
		 * (smartctl in particular) can cause underrun
		 * problems.  Ignore these errors, perhaps at our
		 * peril.
		 */
		return 0;
	case SAS_DATA_OVERRUN:
	case SAS_QUEUE_FULL:
	case SAS_DEVICE_UNKNOWN:
	case SAS_OPEN_TO:
	case SAS_OPEN_REJECT:
		pr_warn("%s: Saw error %d.  What to do?\n",
			__func__, ts->stat);
		return AC_ERR_OTHER;
	case SAM_STAT_CHECK_CONDITION:
	case SAS_ABORTED_TASK:
		return AC_ERR_DEV;
	case SAS_PROTO_RESPONSE:
		/* This means the ending_fis has the error
		 * value; return 0 here to collect it
		 */
		return 0;
	default:
		return 0;
	}
}

static void sas_ata_task_done(struct sas_task *task)
{
	struct ata_queued_cmd *qc = task->uldd_task;
	struct domain_device *dev = task->dev;
	struct task_status_struct *stat = &task->task_status;
	struct ata_task_resp *resp = (struct ata_task_resp *)stat->buf;
	struct sas_ha_struct *sas_ha = dev->port->ha;
	enum ata_completion_errors ac;
	unsigned long flags;
	struct ata_link *link;
	struct ata_port *ap;

	spin_lock_irqsave(&dev->done_lock, flags);
	if (test_bit(SAS_HA_FROZEN, &sas_ha->state))
		task = NULL;
	else if (qc && qc->scsicmd)
		ASSIGN_SAS_TASK(qc->scsicmd, NULL);
	spin_unlock_irqrestore(&dev->done_lock, flags);

	/* check if libsas-eh got to the task before us */
	if (unlikely(!task))
		return;

	if (!qc)
		goto qc_already_gone;

	ap = qc->ap;
	link = &ap->link;

	spin_lock_irqsave(ap->lock, flags);
	/* check if we lost the race with libata/sas_ata_post_internal() */
	if (unlikely(ata_port_is_frozen(ap))) {
		spin_unlock_irqrestore(ap->lock, flags);
		if (qc->scsicmd)
			goto qc_already_gone;
		else {
			/* if eh is not involved and the port is frozen then the
			 * ata internal abort process has taken responsibility
			 * for this sas_task
			 */
			return;
		}
	}

	if (stat->stat == SAS_PROTO_RESPONSE ||
	    stat->stat == SAS_SAM_STAT_GOOD ||
	    (stat->stat == SAS_SAM_STAT_CHECK_CONDITION &&
	      dev->sata_dev.class == ATA_DEV_ATAPI)) {
		memcpy(dev->sata_dev.fis, resp->ending_fis, ATA_RESP_FIS_SIZE);

		if (!link->sactive) {
			qc->err_mask |= ac_err_mask(dev->sata_dev.fis[2]);
		} else {
			link->eh_info.err_mask |= ac_err_mask(dev->sata_dev.fis[2]);
			if (unlikely(link->eh_info.err_mask))
				qc->flags |= ATA_QCFLAG_EH;
		}
	} else {
		ac = sas_to_ata_err(stat);
		if (ac) {
			pr_warn("%s: SAS error 0x%x\n", __func__, stat->stat);
			/* We saw a SAS error. Send a vague error. */
			if (!link->sactive) {
				qc->err_mask = ac;
			} else {
				link->eh_info.err_mask |= AC_ERR_DEV;
				qc->flags |= ATA_QCFLAG_EH;
			}

			dev->sata_dev.fis[2] = ATA_ERR | ATA_DRDY; /* tf status */
			dev->sata_dev.fis[3] = ATA_ABORTED; /* tf error */
		}
	}

	qc->lldd_task = NULL;
	ata_qc_complete(qc);
	spin_unlock_irqrestore(ap->lock, flags);

qc_already_gone:
	sas_free_task(task);
}

static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc)
	__must_hold(ap->lock)
{
	struct sas_task *task;
	struct scatterlist *sg;
	int ret = AC_ERR_SYSTEM;
	unsigned int si, xfer = 0;
	struct ata_port *ap = qc->ap;
	struct domain_device *dev = ap->private_data;
	struct sas_ha_struct *sas_ha = dev->port->ha;
	struct Scsi_Host *host = sas_ha->shost;
	struct sas_internal *i = to_sas_internal(host->transportt);

	/* TODO: we should try to remove that unlock */
	spin_unlock(ap->lock);

	/* If the device fell off, no sense in issuing commands */
	if