[PATCH v4 1/7] scsi: libsas: Add sas_ata_device_link_abort()

[John Garry]

Similar to how AHCI handles NCQ errors in ahci_error_intr() ->
ata_port_abort() -> ata_do_link_abort(), add an NCQ error handler for LLDDs
to call to initiate a link abort.

This will mark all outstanding QCs as failed and kick-off EH.

Note:
A "force reset" argument is added for drivers which require the ATA error
handling to always reset the device.

A driver may require this feature for when SATA device per-SCSI cmnd
resources are only released during reset for ATA EH. As such, we need an
option to force reset to be done, regardless of what any EH autopsy
decides.

Suggested-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
Tested-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
---
 drivers/scsi/libsas/sas_ata.c | 12 ++++++++++++
 include/scsi/sas_ata.h        |  6 ++++++
 2 files changed, 18 insertions(+)

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index d35c9296f738..bdffb6852dcf 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -861,6 +861,18 @@ void sas_ata_wait_eh(struct domain_device *dev)
 	ata_port_wait_eh(ap);
 }
 
+void sas_ata_device_link_abort(struct domain_device *device, bool force_reset)
+{
+	struct ata_port *ap = device->sata_dev.ap;
+	struct ata_link *link = &ap->link;
+
+	link->eh_info.err_mask |= AC_ERR_DEV;
+	if (force_reset)
+		link->eh_info.action |= ATA_EH_RESET;
+	ata_link_abort(link);
+}
+EXPORT_SYMBOL_GPL(sas_ata_device_link_abort);
+
 int sas_execute_ata_cmd(struct domain_device *device, u8 *fis, int force_phy_id)
 {
 	struct sas_tmf_task tmf_task = {};
diff --git a/include/scsi/sas_ata.h b/include/scsi/sas_ata.h
index a1df4f9d57a3..e47f0aec0722 100644
--- a/include/scsi/sas_ata.h
+++ b/include/scsi/sas_ata.h
@@ -32,6 +32,7 @@ void sas_probe_sata(struct asd_sas_port *port);
 void sas_suspend_sata(struct asd_sas_port *port);
 void sas_resume_sata(struct asd_sas_port *port);
 void sas_ata_end_eh(struct ata_port *ap);
+void sas_ata_device_link_abort(struct domain_device *dev, bool force_reset);
 int sas_execute_ata_cmd(struct domain_device *device, u8 *fis,
 			int force_phy_id);
 int sas_ata_wait_after_reset(struct domain_device *dev, unsigned long deadline);
@@ -87,6 +88,11 @@ static inline void sas_ata_end_eh(struct ata_port *ap)
 {
 }
 
+static inline void sas_ata_device_link_abort(struct domain_device *dev,
+					     bool force_reset)
+{
+}
+
 static inline int sas_execute_ata_cmd(struct domain_device *device, u8 *fis,
 				      int force_phy_id)
 {
-- 
2.35.3