scsi: ata: libata: Handle completion of CDL commands using policy 0xD

A CDL timeout for policy 0xF is defined as a NCQ error, just with a CDL
specific sk/asc/ascq in the sense data. Therefore, the existing code in
libata does not need to be modified to handle a policy 0xF CDL timeout.

For Command Duration Limits policy 0xD:

  The device shall complete the command without error with the additional
  sense code set to DATA CURRENTLY UNAVAILABLE.

Since a CDL timeout for policy 0xD is not an error, we cannot use the NCQ
Command Error log (10h).

Instead, we need to read the Sense Data for Successful NCQ Commands log
(0Fh).

In the success case, just like in the error case, we cannot simply read a
log page from the interrupt handler itself, since reading a log page
involves sending a READ LOG DMA EXT or READ LOG EXT command.

Therefore, we add a new EH action ATA_EH_GET_SUCCESS_SENSE.  When a command
completes without error, and when the ATA_SENSE bit is set, this new action
is set as pending, and EH is scheduled.

This way, similar to the NCQ error case, the log page will be read from EH
context.

An alternative would have been to add a new kthread or workqueue to handle
this. However, extending EH can be done with minimal changes and avoids the
need to synchronize a new kthread/workqueue with EH.

Co-developed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-20-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 13 insertions, 1 deletions

diff --git a/include/linux/ata.h b/include/linux/ata.h
index 21108471c6af..792e10a09787 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -325,6 +325,8 @@ enum {
 	ATA_LOG_CDL		= 0x18,
 	ATA_LOG_CDL_SIZE	= ATA_SECT_SIZE,
 	ATA_LOG_IDENTIFY_DEVICE	= 0x30,
+	ATA_LOG_SENSE_NCQ	= 0x0F,
+	ATA_LOG_SENSE_NCQ_SIZE	= ATA_SECT_SIZE * 2,
 	ATA_LOG_CONCURRENT_POSITIONING_RANGES = 0x47,
 
 	/* Identify device log pages: */
@@ -431,6 +433,7 @@ enum {
 	SATA_DEVSLP		= 0x09,	/* Device Sleep */
 
 	SETFEATURE_SENSE_DATA	= 0xC3, /* Sense Data Reporting feature */
+	SETFEATURE_SENSE_DATA_SUCC_NCQ = 0xC4, /* Sense Data for successful NCQ commands */
 
 	/* feature values for SET_MAX */
 	ATA_SET_MAX_ADDR	= 0x00,
diff --git a/include/linux/libata.h b/include/linux/libata.h
index f679abd2e61f..5c8ef33b0af2 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -214,6 +214,7 @@ enum {
 	ATA_QCFLAG_EH		= (1 << 16), /* cmd aborted and owned by EH */
 	ATA_QCFLAG_SENSE_VALID	= (1 << 17), /* sense data valid */
 	ATA_QCFLAG_EH_SCHEDULED = (1 << 18), /* EH scheduled (obsolete) */
+	ATA_QCFLAG_EH_SUCCESS_CMD = (1 << 19), /* EH should fetch sense for this successful cmd */
 
 	/* host set flags */
 	ATA_HOST_SIMPLEX	= (1 << 0),	/* Host is simplex, one DMA channel per host only */
@@ -312,8 +313,10 @@ enum {
 	ATA_EH_RESET		= ATA_EH_SOFTRESET | ATA_EH_HARDRESET,
 	ATA_EH_ENABLE_LINK	= (1 << 3),
 	ATA_EH_PARK		= (1 << 5), /* unload heads and stop I/O */
+	ATA_EH_GET_SUCCESS_SENSE = (1 << 6), /* Get sense data for successful cmd */
 
-	ATA_EH_PERDEV_MASK	= ATA_EH_REVALIDATE | ATA_EH_PARK,
+	ATA_EH_PERDEV_MASK	= ATA_EH_REVALIDATE | ATA_EH_PARK |
+				  ATA_EH_GET_SUCCESS_SENSE,
 	ATA_EH_ALL_ACTIONS	= ATA_EH_REVALIDATE | ATA_EH_RESET |
 				  ATA_EH_ENABLE_LINK,
 
@@ -867,6 +870,7 @@ struct ata_port {
 	struct ata_acpi_gtm	__acpi_init_gtm; /* use ata_acpi_init_gtm() */
 #endif
 	/* owned by EH */
+	u8			*ncq_sense_buf;
 	u8			sector_buf[ATA_SECT_SIZE] ____cacheline_aligned;
 };
 
@@ -1185,6 +1189,7 @@ extern int sata_link_hardreset(struct ata_link *link,
 			bool *online, int (*check_ready)(struct ata_link *));
 extern int sata_link_resume(struct ata_link *link, const unsigned long *params,
 			    unsigned long deadline);
+extern int ata_eh_read_sense_success_ncq_log(struct ata_link *link);
 extern void ata_eh_analyze_ncq_error(struct ata_link *link);
 #else
 static inline const unsigned long *
@@ -1222,6 +1227,10 @@ static inline int sata_link_resume(struct ata_link *link,
 {
 	return -EOPNOTSUPP;
 }
+static inline int ata_eh_read_sense_success_ncq_log(struct ata_link *link)
+{
+	return -EOPNOTSUPP;
+}
 static inline void ata_eh_analyze_ncq_error(struct ata_link *link) { }
 #endif
 extern int sata_link_debounce(struct ata_link *link,