[PATCH v4 00/19] Add Command Duration Limits support

[PATCH v4 00/19] Add Command Duration Limits support

[Niklas Cassel]

Hello,

This series adds support for Command Duration Limits.
The series is based on linux tag: v6.3-rc1
The series can also be found in git:
https://github.com/floatious/linux/commits/cdl-v4


=================
CDL in ATA / SCSI
=================
Command Duration Limits is defined in:
T13 ATA Command Set - 5 (ACS-5) and
T10 SCSI Primary Commands - 6 (SPC-6) respectively
(a simpler version of CDL is defined in T10 SPC-5).

CDL defines Duration Limits Descriptors (DLD).
7 DLDs for read commands and 7 DLDs for write commands.
Simply put, a DLD contains a limit and a policy.

A command can specify that a certain limit should be applied by setting
the DLD index field (3 bits, so 0-7) in the command itself.

The DLD index points to one of the 7 DLDs.
DLD index 0 means no descriptor, so no limit.
DLD index 1-7 means DLD 1-7.

A DLD can have a few different policies, but the two major ones are:
-Policy 0xF (abort), command will be completed with command aborted error
(ATA) or status CHECK CONDITION (SCSI), with sense data indicating that
the command timed out.
-Policy 0xD (complete-unavailable), command will be completed without
error (ATA) or status GOOD (SCSI), with sense data indicating that the
command timed out. Note that the command will not have transferred any
data to/from the device when the command timed out, even though the
command returned success.

Regardless of the CDL policy, in case of a CDL timeout, the I/O will
result in a -ETIME error to user-space.

The DLDs are defined in the CDL log page(s) and are readable and writable.
Reading and writing the CDL DLDs are outside the scope of the kernel.
If a user wants to read or write the descriptors, they can do so using a
user-space application that sends passthrough commands, such as cdl-tools:
https://github.com/westerndigitalcorporation/cdl-tools/commits/cdl-v4


================================
The introduction of ioprio hints
================================
What the kernel does provide, is a method to let I/O use one of the CDL DLDs
defined in the device. Note that the kernel will simply forward the DLD index
to the device, so the kernel currently does not know, nor does it need to know,
how the DLDs are defined inside the device.

The way that the CDL DLD index is supplied to the kernel is by introducing a
new 10 bit "ioprio hint" field within the existing 16 bit ioprio definition.

Currently, only 6 out of the 16 ioprio bits are in use, the remaining 10 bits
are unused, and are currently explicitly disallowed to be set by the kernel.

For now, we only add ioprio hints representing CDL DLD index 1-7. Additional
ioprio hints for other QoS features could be defined in the future.

A theoretical future work could be to make an I/O scheduler aware of these
hints. E.g. for CDL, an I/O scheduler could make use of the duration limit
in each descriptor, and take that information into account while scheduling
commands. Right now, the ioprio hints will be ignored by the I/O schedulers.


==============================
How to use CDL from user-space
==============================
Since CDL is mutually exclusive with NCQ priority
(see ncq_prio_enable and sas_ncq_prio_enable in
Documentation/ABI/testing/sysfs-block-device),
CDL has to be explicitly enabled using:
echo 1 > /sys/block/$bdev/device/cdl_enable

Since the ioprio hints are supplied through the existing I/O priority API,
it should be simple for an application to make use of the ioprio hints.

It simply has to reuse one of the new macros defined in
include/uapi/linux/ioprio.h: IOPRIO_PRIO_HINT() or IOPRIO_PRIO_VALUE_HINT(),
and supply one of the new hints defined in include/uapi/linux/ioprio.h:
IOPRIO_HINT_DEV_DURATION_LIMIT_[1-7], which indicates that the I/O should
use the corresponding CDL DLD index 1-7.

By reusing the I/O priority API, the user can both define a DLD to use per
AIO (io_uring sqe->ioprio or libaio iocb->aio_reqprio) or per-thread
(ioprio_set()).


=======
Testing
=======
With the following fio patches (authored by Damien):
https://github.com/floatious/fio/commits/cdl-v4

fio adds support for ioprio hints, such that CDL can be tested using e.g.:
fio --ioengine=io_uring --cmdprio_percentage=10 --cmdprio_hint=DLD_index

A simple way to test is to use a DLD with a very short duration limit,
and send large reads. Regardless of the CDL policy, in case of a CDL
timeout, the I/O will result in a -ETIME error to user-space.

We also provide a CDL test suite located in the cdl-tools repo, see:
https://github.com/westerndigitalcorporation/cdl-tools/blob/cdl-v4/README.md#testing-a-system-command-duration-limits-support


We have tested this patch series using:
-real hardware
-the following QEMU implementation:
https://github.com/floatious/qemu/tree/cdl
(NOTE: the QEMU implementation requires you to define the CDL policy at compile
time, so you currently need to recompile QEMU when switching between policies.)


===================
Further information
===================
For further information about CDL, see Damien's slides:

Presented at SDC 2021:
https://www.snia.org/sites/default/files/SDC/2021/pdfs/SNIA-SDC21-LeMoal-Be-On-Time-command-duration-limits-Feature-Support-in%20Linux.pdf

Presented at Lund Linux Con 2022:
https://drive.google.com/file/d/1I6ChFc0h4JY9qZdO1bY5oCAdYCSZVqWw/view?usp=sharing


================
Changes since V3
================
-Changed user-facing API, instead of introducing a new ioprio class, introduce
 new ioprio hints.
-Dropped sysfs API for reading the DLDs. We can introduce a new block level
 (sysfs) API later on (instead of exposing an API that is tied to ATA/SCSI).
-Picked up Reviewed-by tags from Hannes and Bart.
-Improved commit message for patch "block: introduce BLK_STS_DURATION_LIMIT"
 (thanks Bart).
-Patch "scsi: sd: set read/write commands CDL index" is now split into two
 patches: "scsi: allow enabling and disabling command duration limits" and
 "scsi: sd: set read/write commands CDL index".
-The cdl_enable sysfs attribute is now defined in scsi_sysfs.c instead of sd.c.
 CDL is defined in SPC-6, so the feature is not really unique to disks.


For older change logs, see previous patch series versions:
https://lore.kernel.org/linux-scsi/20230124190308.127318-1-niklas.cassel@wdc.com/
https://lore.kernel.org/linux-scsi/20230112140412.667308-1-niklas.cassel@wdc.com/
https://lore.kernel.org/linux-scsi/20221208105947.2399894-1-niklas.cassel@wdc.com/


Kind regards,
Niklas & Damien

Damien Le Moal (13):
  ioprio: cleanup interface definition
  block: introduce ioprio hints
  block: introduce BLK_STS_DURATION_LIMIT
  scsi: support retrieving sub-pages of mode pages
  scsi: support service action in scsi_report_opcode()
  scsi: detect support for command duration limits
  scsi: allow enabling and disabling command duration limits
  scsi: sd: set read/write commands CDL index
  ata: libata: detect support for command duration limits
  ata: libata-scsi: handle CDL bits in ata_scsiop_maint_in()
  ata: libata-scsi: add support for CDL pages mode sense
  ata: libata: add ATA feature control sub-page translation
  ata: libata: set read/write commands CDL index

Niklas Cassel (6):
  scsi: core: allow libata to complete successful commands via EH
  scsi: rename and move get_scsi_ml_byte()
  scsi: sd: handle read/write CDL timeout failures
  ata: libata-scsi: remove unnecessary !cmd checks
  ata: libata: change ata_eh_request_sense() to not set CHECK_CONDITION
  ata: libata: handle completion of CDL commands using policy 0xD

 Documentation/ABI/testing/sysfs-block-device |  22 ++
 block/bfq-iosched.c                          |   8 +-
 block/blk-core.c                             |   3 +
 block/ioprio.c                               |   6 +-
 drivers/ata/libata-core.c                    | 214 ++++++++++-
 drivers/ata/libata-eh.c                      | 130 ++++++-
 drivers/ata/libata-sata.c                    | 103 ++++-
 drivers/ata/libata-scsi.c                    | 371 +++++++++++++++----
 drivers/ata/libata.h                         |   2 +-
 drivers/scsi/scsi.c                          | 171 ++++++++-
 drivers/scsi/scsi_error.c                    |  48 ++-
 drivers/scsi/scsi_lib.c                      |  15 +-
 drivers/scsi/scsi_priv.h                     |   6 +
 drivers/scsi/scsi_scan.c                     |   3 +
 drivers/scsi/scsi_sysfs.c                    |  33 ++
 drivers/scsi/scsi_transport_sas.c            |   2 +-
 drivers/scsi/sd.c                            |  59 ++-
 drivers/scsi/sr.c                            |   2 +-
 include/linux/ata.h                          |  11 +-
 include/linux/blk_types.h                    |   6 +
 include/linux/libata.h                       |  42 ++-
 include/scsi/scsi_cmnd.h                     |   5 +
 include/scsi/scsi_device.h                   |  18 +-
 include/uapi/linux/ioprio.h                  |  68 +++-
 24 files changed, 1195 insertions(+), 153 deletions(-)

-- 
2.39.2

[PATCH v4 01/19] ioprio: cleanup interface definition

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

The IO priority user interface defines the 16-bits ioprio values as
the combination of the upper 3-bits for an IO priority class and the
lower 13-bits as priority data. However, the kernel only uses the
lower 3-bits of the priority data to define priority levels for the RT
and BE priority classes. The data part of an ioprio value is completely
ignored for the IDLE and NONE classes. This is enforced by checks done
in ioprio_check_cap(), which is called for all paths that allow defining
an IO priority for IOs: the per-context ioprio_set() system call, aio
interface and io-uring interface.

Clarify this fact in the uapi ioprio.h header file and introduce the
IOPRIO_PRIO_LEVEL_MASK and IOPRIO_PRIO_LEVEL() macros for users to
define and get priority levels in an ioprio value. The coarser macro
IOPRIO_PRIO_DATA() is retained for backward compatibility with old
applications already using it. There is no functional change introduced
with this.

In-kernel users of the IOPRIO_PRIO_DATA() macro which are explicitly
handling IO priority data as a priority level are modified to use the
new IOPRIO_PRIO_LEVEL() macro without any functional change. Since f2fs
is the only user of this macro not explicitly using that value as a
priority level, it is left unchanged.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
---
 block/bfq-iosched.c         |  8 ++++----
 block/ioprio.c              |  6 +++---
 include/uapi/linux/ioprio.h | 19 ++++++++++++++-----
 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 8a8d4441519c..e4ca0a3483d3 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5523,16 +5523,16 @@ bfq_set_next_ioprio_data(struct bfq_queue *bfqq, struct bfq_io_cq *bic)
 		bfqq->new_ioprio_class = task_nice_ioclass(tsk);
 		break;
 	case IOPRIO_CLASS_RT:
-		bfqq->new_ioprio = IOPRIO_PRIO_DATA(bic->ioprio);
+		bfqq->new_ioprio = IOPRIO_PRIO_LEVEL(bic->ioprio);
 		bfqq->new_ioprio_class = IOPRIO_CLASS_RT;
 		break;
 	case IOPRIO_CLASS_BE:
-		bfqq->new_ioprio = IOPRIO_PRIO_DATA(bic->ioprio);
+		bfqq->new_ioprio = IOPRIO_PRIO_LEVEL(bic->ioprio);
 		bfqq->new_ioprio_class = IOPRIO_CLASS_BE;
 		break;
 	case IOPRIO_CLASS_IDLE:
 		bfqq->new_ioprio_class = IOPRIO_CLASS_IDLE;
-		bfqq->new_ioprio = 7;
+		bfqq->new_ioprio = IOPRIO_NR_LEVELS - 1;
 		break;
 	}
 
@@ -5829,7 +5829,7 @@ static struct bfq_queue *bfq_get_queue(struct bfq_data *bfqd,
 				       struct bfq_io_cq *bic,
 				       bool respawn)
 {
-	const int ioprio = IOPRIO_PRIO_DATA(bic->ioprio);
+	const int ioprio = IOPRIO_PRIO_LEVEL(bic->ioprio);
 	const int ioprio_class = IOPRIO_PRIO_CLASS(bic->ioprio);
 	struct bfq_queue **async_bfqq = NULL;
 	struct bfq_queue *bfqq;
diff --git a/block/ioprio.c b/block/ioprio.c
index 32a456b45804..f0d9e818abc5 100644
--- a/block/ioprio.c
+++ b/block/ioprio.c
@@ -33,7 +33,7 @@
 int ioprio_check_cap(int ioprio)
 {
 	int class = IOPRIO_PRIO_CLASS(ioprio);
-	int data = IOPRIO_PRIO_DATA(ioprio);
+	int level = IOPRIO_PRIO_LEVEL(ioprio);
 
 	switch (class) {
 		case IOPRIO_CLASS_RT:
@@ -49,13 +49,13 @@ int ioprio_check_cap(int ioprio)
 			fallthrough;
 			/* rt has prio field too */
 		case IOPRIO_CLASS_BE:
-			if (data >= IOPRIO_NR_LEVELS || data < 0)
+			if (level >= IOPRIO_NR_LEVELS)
 				return -EINVAL;
 			break;
 		case IOPRIO_CLASS_IDLE:
 			break;
 		case IOPRIO_CLASS_NONE:
-			if (data)
+			if (level)
 				return -EINVAL;
 			break;
 		default:
diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h
index f70f2596a6bf..4444b4e4fdad 100644
--- a/include/uapi/linux/ioprio.h
+++ b/include/uapi/linux/ioprio.h
@@ -17,7 +17,7 @@
 	 ((data) & IOPRIO_PRIO_MASK))
 
 /*
- * These are the io priority groups as implemented by the BFQ and mq-deadline
+ * These are the io priority classes as implemented by the BFQ and mq-deadline
  * schedulers. RT is the realtime class, it always gets premium service. For
  * ATA disks supporting NCQ IO priority, RT class IOs will be processed using
  * high priority NCQ commands. BE is the best-effort scheduling class, the
@@ -32,11 +32,20 @@ enum {
 };
 
 /*
- * The RT and BE priority classes both support up to 8 priority levels.
+ * The RT and BE priority classes both support up to 8 priority levels that
+ * can be specified using the lower 3-bits of the priority data.
  */
-#define IOPRIO_NR_LEVELS	8
-#define IOPRIO_BE_NR		IOPRIO_NR_LEVELS
+#define IOPRIO_LEVEL_NR_BITS		3
+#define IOPRIO_NR_LEVELS		(1 << IOPRIO_LEVEL_NR_BITS)
+#define IOPRIO_LEVEL_MASK		(IOPRIO_NR_LEVELS - 1)
+#define IOPRIO_PRIO_LEVEL(ioprio)	((ioprio) & IOPRIO_LEVEL_MASK)
 
+#define IOPRIO_BE_NR			IOPRIO_NR_LEVELS
+
+/*
+ * Possible values for the "which" argument of the ioprio_get() and
+ * ioprio_set() system calls (see "man ioprio_set").
+ */
 enum {
 	IOPRIO_WHO_PROCESS = 1,
 	IOPRIO_WHO_PGRP,
@@ -44,7 +53,7 @@ enum {
 };
 
 /*
- * Fallback BE priority level.
+ * Fallback BE class priority level.
  */
 #define IOPRIO_NORM	4
 #define IOPRIO_BE_NORM	IOPRIO_NORM
-- 
2.39.2

[PATCH v4 02/19] block: introduce ioprio hints

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

IO priorities currently only use 6-bits of the 16-bits ioprio value: the
3-upper bits are used to define up to 8 priority classes (4 of which are
valid) and the 3 lower bits of the value are used to define a priority
level for the real-time and best-effort class.

The remaining 10-bits between the IO priority class and level are
unused, and in fact, cannot be used by the user as doing so would
either result in the value being completely ignored, or in an error
returned by ioprio_check_cap().

Use these 10-bits of an ioprio value to allow a user to specify IO
hints. An IO hint is defined as a 10-bits value, allowing up to 1023
different hints to be specified, with the value 0 being reserved as the
"no hint" case. An IO hint can apply to any IO that specifies a valid
priority class other than NONE, regardless of the IO priority level
specified.

To do so, the macros IOPRIO_PRIO_HINT() and IOPRIO_PRIO_VALUE_HINT() are
introduced in include/uapi/linux/ioprio.h to respectively allow a user
to get and set a hint in an ioprio value.

To support the ATA and SCSI command duration limits feature, 7 hints
are defined: IOPRIO_HINT_DEV_DURATION_LIMIT_1 to
IOPRIO_HINT_DEV_DURATION_LIMIT_7, allowing a user to specify which
command duration limit descriptor should be applied to the commands
serving an IO. Specifying these hints has for now no effect whatsoever
if the target block devices do not support the command duration limits
feature. However, in the future, block IO schedulers can be modified to
optimize IO issuing order based on these hints, even for devices that
do not support the command duration limits feature.

Given that the 7 duration limits hints defined have no effect on any
block layer component, the actual definition of the duration limits
implied by these hints remains at the device level.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
---
 include/uapi/linux/ioprio.h | 49 +++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h
index 4444b4e4fdad..607c7617b9d2 100644
--- a/include/uapi/linux/ioprio.h
+++ b/include/uapi/linux/ioprio.h
@@ -58,4 +58,53 @@ enum {
 #define IOPRIO_NORM	4
 #define IOPRIO_BE_NORM	IOPRIO_NORM
 
+/*
+ * The 10-bits between the priority class and the priority level are used to
+ * optionally define IO hints for any combination of IO priority class and
+ * level. Depending on the kernel configuration, IO scheduler being used and
+ * the target IO device being used, hints can influence how IOs are processed
+ * without affecting the IO scheduling ordering defined by the IO priority
+ * class and level.
+ */
+#define IOPRIO_HINT_SHIFT		IOPRIO_LEVEL_NR_BITS
+#define IOPRIO_HINT_NR_BITS		10
+#define IOPRIO_NR_HINTS			(1 << IOPRIO_HINT_NR_BITS)
+#define IOPRIO_HINT_MASK		(IOPRIO_NR_HINTS - 1)
+#define IOPRIO_PRIO_HINT(ioprio)	\
+	(((ioprio) >> IOPRIO_HINT_SHIFT) & IOPRIO_HINT_MASK)
+
+/*
+ * Alternate macro for IOPRIO_PRIO_VALUE() to define an IO priority with
+ * a class, level and hint.
+ */
+#define IOPRIO_PRIO_VALUE_HINT(class, level, hint)		 \
+	((((class) & IOPRIO_CLASS_MASK) << IOPRIO_CLASS_SHIFT) | \
+	 (((hint) & IOPRIO_HINT_MASK) << IOPRIO_HINT_SHIFT) |	 \
+	 ((level) & IOPRIO_LEVEL_MASK))
+
+/*
+ * IO hints.
+ */
+enum {
+	/* No hint */
+	IOPRIO_HINT_NONE = 0,
+
+	/*
+	 * Device command duration limits: indicate to the device a desired
+	 * duration limit for the commands that will be used to process an IO.
+	 * These will currently only be effective for SCSI and ATA devices that
+	 * support the command duration limits feature. If this feature is
+	 * enabled, then the commands issued to the device to process an IO with
+	 * one of these hints set will have the duration limit index (dld field)
+	 * set to the value of the hint.
+	 */
+	IOPRIO_HINT_DEV_DURATION_LIMIT_1 = 1,
+	IOPRIO_HINT_DEV_DURATION_LIMIT_2 = 2,
+	IOPRIO_HINT_DEV_DURATION_LIMIT_3 = 3,
+	IOPRIO_HINT_DEV_DURATION_LIMIT_4 = 4,
+	IOPRIO_HINT_DEV_DURATION_LIMIT_5 = 5,
+	IOPRIO_HINT_DEV_DURATION_LIMIT_6 = 6,
+	IOPRIO_HINT_DEV_DURATION_LIMIT_7 = 7,
+};
+
 #endif /* _UAPI_LINUX_IOPRIO_H */
-- 
2.39.2

[PATCH v4 03/19] block: introduce BLK_STS_DURATION_LIMIT

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Introduce the new block IO status BLK_STS_DURATION_LIMIT for LLDDs to
report command that failed due to a command duration limit being
exceeded. This new status is mapped to the ETIME error code to allow
users to differentiate "soft" duration limit failures from other more
serious hardware related errors.

If we compare BLK_STS_DURATION_LIMIT with BLK_STS_TIMEOUT:
-BLK_STS_DURATION_LIMIT means that the drive gave a reply indicating that
the command duration limit was exceeded before the command could be
completed. This IO status is mapped to ETIME for user space.

-BLK_STS_TIMEOUT means that the drive never gave a reply at all.
This IO status is mapped to ETIMEDOUT for user space.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c          | 3 +++
 include/linux/blk_types.h | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/block/blk-core.c b/block/blk-core.c
index 9e5e0277a4d9..84b8b8b482b5 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -170,6 +170,9 @@ static const struct {
 	[BLK_STS_ZONE_OPEN_RESOURCE]	= { -ETOOMANYREFS, "open zones exceeded" },
 	[BLK_STS_ZONE_ACTIVE_RESOURCE]	= { -EOVERFLOW, "active zones exceeded" },
 
+	/* Command duration limit device-side timeout */
+	[BLK_STS_DURATION_LIMIT]	= { -ETIME, "duration limit exceeded" },
+
 	/* everything else not covered above: */
 	[BLK_STS_IOERR]		= { -EIO,	"I/O" },
 };
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 99be590f952f..cde997590765 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -166,6 +166,12 @@ typedef u16 blk_short_t;
  */
 #define BLK_STS_OFFLINE		((__force blk_status_t)17)
 
+/*
+ * BLK_STS_DURATION_LIMIT is returned from the driver when the target device
+ * aborted the command because it exceeded one of its Command Duration Limits.
+ */
+#define BLK_STS_DURATION_LIMIT	((__force blk_status_t)18)
+
 /**
  * blk_path_error - returns true if error may be path related
  * @error: status the request was completed with
-- 
2.39.2

[PATCH v4 04/19] scsi: core: allow libata to complete successful commands via EH

[Niklas Cassel]

In SCSI, we get the sense data as part of the completion, for ATA
however, we need to fetch the sense data as an extra step. For an
aborted ATA command the sense data is fetched via libata's
->eh_strategy_handler().

For Command Duration Limits policy 0xD:
The device shall complete the command without error with the additional
sense code set to DATA CURRENTLY UNAVAILABLE.

In order to handle this policy in libata, we intend to send a successful
command via SCSI EH, and let libata's ->eh_strategy_handler() fetch the
sense data for the good command. This is similar to how we handle an
aborted ATA command, just that we need to read the Successful NCQ
Commands log instead of the NCQ Command Error log.

When we get a SATA completion with successful commands, ATA_SENSE will
be set, indicating that some commands in the completion have sense data.

The sense_valid bitmask in the Sense Data for Successful NCQ Commands
log will inform exactly which commands that had sense data, which might
be a subset of all the commands that was completed in the same
completion. (Yet all will have ATA_SENSE set, since the status is per
completion.)

The successful commands that have e.g. a "DATA CURRENTLY UNAVAILABLE"
sense data will have a SCSI ML byte set, so scsi_eh_flush_done_q() will
not set the scmd->result to DID_TIME_OUT for these commands. However,
the successful commands that did not have sense data, must not get their
result marked as DID_TIME_OUT by SCSI EH.

Add a new flag SCMD_FORCE_EH_SUCCESS, which tells SCSI EH to not mark a
command as DID_TIME_OUT, even if it has scmd->result == SAM_STAT_GOOD.

This will be used by libata in a follow-up patch.

Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/scsi_error.c | 3 ++-
 include/scsi/scsi_cmnd.h  | 5 +++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 2aa2c2aee6e7..cf5ec5f5f4f6 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -2165,7 +2165,8 @@ void scsi_eh_flush_done_q(struct list_head *done_q)
 			 * scsi_eh_get_sense), scmd->result is already
 			 * set, do not set DID_TIME_OUT.
 			 */
-			if (!scmd->result)
+			if (!scmd->result &&
+			    !(scmd->flags & SCMD_FORCE_EH_SUCCESS))
 				scmd->result |= (DID_TIME_OUT << 16);
 			SCSI_LOG_ERROR_RECOVERY(3,
 				scmd_printk(KERN_INFO, scmd,
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index c2cb5f69635c..526def14e7fb 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -52,6 +52,11 @@ struct scsi_pointer {
 #define SCMD_TAGGED		(1 << 0)
 #define SCMD_INITIALIZED	(1 << 1)
 #define SCMD_LAST		(1 << 2)
+/*
+ * libata uses SCSI EH to fetch sense data for successful commands.
+ * SCSI EH should not overwrite scmd->result when SCMD_FORCE_EH_SUCCESS is set.
+ */
+#define SCMD_FORCE_EH_SUCCESS	(1 << 3)
 #define SCMD_FAIL_IF_RECOVERING	(1 << 4)
 /* flags preserved across unprep / reprep */
 #define SCMD_PRESERVED_FLAGS	(SCMD_INITIALIZED | SCMD_FAIL_IF_RECOVERING)
-- 
2.39.2

[PATCH v4 05/19] scsi: rename and move get_scsi_ml_byte()

[Niklas Cassel]

SCSI has two different getters:
- get_XXX_byte() (in scsi_cmnd.h) which takes a struct scsi_cmnd *, and
- XXX_byte() (in scsi.h) which takes a scmd->result.
The proper name for get_scsi_ml_byte() should thus be without the get_
prefix, as it takes a scmd->result. Rename the function to rectify this.
(This change was suggested by Mike Christie.)

Additionally, move get_scsi_ml_byte() to scsi_priv.h since both scsi_lib.c
and scsi_error.c will need to use this helper in a follow-up patch.

Cc: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_lib.c  | 7 +------
 drivers/scsi/scsi_priv.h | 5 +++++
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b7c569a42aa4..fac9c31161d2 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -578,11 +578,6 @@ static bool scsi_end_request(struct request *req, blk_status_t error,
 	return false;
 }
 
-static inline u8 get_scsi_ml_byte(int result)
-{
-	return (result >> 8) & 0xff;
-}
-
 /**
  * scsi_result_to_blk_status - translate a SCSI result code into blk_status_t
  * @result:	scsi error code
@@ -595,7 +590,7 @@ static blk_status_t scsi_result_to_blk_status(int result)
 	 * Check the scsi-ml byte first in case we converted a host or status
 	 * byte.
 	 */
-	switch (get_scsi_ml_byte(result)) {
+	switch (scsi_ml_byte(result)) {
 	case SCSIML_STAT_OK:
 		break;
 	case SCSIML_STAT_RESV_CONFLICT:
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index 96284a0e13fe..74324fba4281 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -29,6 +29,11 @@ enum scsi_ml_status {
 	SCSIML_STAT_TGT_FAILURE		= 0x04,	/* Permanent target failure */
 };
 
+static inline u8 scsi_ml_byte(int result)
+{
+	return (result >> 8) & 0xff;
+}
+
 /*
  * Scsi Error Handler Flags
  */
-- 
2.39.2

[PATCH v4 06/19] scsi: support retrieving sub-pages of mode pages

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Allow scsi_mode_sense() to retrieve sub-pages of mode pages by adding
the subpage argument. Change all the current caller sites to specify
the subpage 0.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_lib.c           | 4 +++-
 drivers/scsi/scsi_transport_sas.c | 2 +-
 drivers/scsi/sd.c                 | 9 ++++-----
 drivers/scsi/sr.c                 | 2 +-
 include/scsi/scsi_device.h        | 8 ++++----
 5 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index fac9c31161d2..633c4e8af830 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2144,6 +2144,7 @@ EXPORT_SYMBOL_GPL(scsi_mode_select);
  *	@sdev:	SCSI device to be queried
  *	@dbd:	set to prevent mode sense from returning block descriptors
  *	@modepage: mode page being requested
+ *	@subpage: sub-page of the mode page being requested
  *	@buffer: request buffer (may not be smaller than eight bytes)
  *	@len:	length of request buffer.
  *	@timeout: command timeout
@@ -2155,7 +2156,7 @@ EXPORT_SYMBOL_GPL(scsi_mode_select);
  *	Returns zero if successful, or a negative error number on failure
  */
 int
-scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
+scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, int subpage,
 		  unsigned char *buffer, int len, int timeout, int retries,
 		  struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
 {
@@ -2175,6 +2176,7 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
 	dbd = sdev->set_dbd_for_ms ? 8 : dbd;
 	cmd[1] = dbd & 0x18;	/* allows DBD and LLBA bits */
 	cmd[2] = modepage;
+	cmd[3] = subpage;
 
 	sshdr = exec_args.sshdr;
 
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index 74b99f2b0b74..d704c484a251 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -1245,7 +1245,7 @@ int sas_read_port_mode_page(struct scsi_device *sdev)
 	if (!buffer)
 		return -ENOMEM;
 
-	error = scsi_mode_sense(sdev, 1, 0x19, buffer, BUF_SIZE, 30*HZ, 3,
+	error = scsi_mode_sense(sdev, 1, 0x19, 0, buffer, BUF_SIZE, 30*HZ, 3,
 				&mode_data, NULL);
 
 	if (error)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 4f28dd617eca..8e856a7a6338 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -183,7 +183,7 @@ cache_type_store(struct device *dev, struct device_attribute *attr,
 		return count;
 	}
 
-	if (scsi_mode_sense(sdp, 0x08, 8, buffer, sizeof(buffer), SD_TIMEOUT,
+	if (scsi_mode_sense(sdp, 0x08, 8, 0, buffer, sizeof(buffer), SD_TIMEOUT,
 			    sdkp->max_retries, &data, NULL))
 		return -EINVAL;
 	len = min_t(size_t, sizeof(buffer), data.length - data.header_length -
@@ -2610,9 +2610,8 @@ sd_do_mode_sense(struct scsi_disk *sdkp, int dbd, int modepage,
 	if (sdkp->device->use_10_for_ms && len < 8)
 		len = 8;
 
-	return scsi_mode_sense(sdkp->device, dbd, modepage, buffer, len,
-			       SD_TIMEOUT, sdkp->max_retries, data,
-			       sshdr);
+	return scsi_mode_sense(sdkp->device, dbd, modepage, 0, buffer, len,
+			       SD_TIMEOUT, sdkp->max_retries, data, sshdr);
 }
 
 /*
@@ -2869,7 +2868,7 @@ static void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
 	if (sdkp->protection_type == 0)
 		return;
 
-	res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,
+	res = scsi_mode_sense(sdp, 1, 0x0a, 0, buffer, 36, SD_TIMEOUT,
 			      sdkp->max_retries, &data, &sshdr);
 
 	if (res < 0 || !data.header_length ||
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 9e51dcd30bfd..09fdb0e269d9 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -830,7 +830,7 @@ static int get_capabilities(struct scsi_cd *cd)
 	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 
 	/* ask for mode page 0x2a */
-	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, ms_len,
+	rc = scsi_mode_sense(cd->device, 0, 0x2a, 0, buffer, ms_len,
 			     SR_TIMEOUT, 3, &data, NULL);
 
 	if (rc < 0 || data.length > ms_len ||
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index de310f21406c..ff4ad3596fa7 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -419,10 +419,10 @@ extern int scsi_track_queue_full(struct scsi_device *, int);
 
 extern int scsi_set_medium_removal(struct scsi_device *, char);
 
-extern int scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
-			   unsigned char *buffer, int len, int timeout,
-			   int retries, struct scsi_mode_data *data,
-			   struct scsi_sense_hdr *);
+int scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
+		    int subpage, unsigned char *buffer, int len, int timeout,
+		    int retries, struct scsi_mode_data *data,
+		    struct scsi_sense_hdr *);
 extern int scsi_mode_select(struct scsi_device *sdev, int pf, int sp,
 			    unsigned char *buffer, int len, int timeout,
 			    int retries, struct scsi_mode_data *data,
-- 
2.39.2

[PATCH v4 07/19] scsi: support service action in scsi_report_opcode()

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

The REPORT_SUPPORTED_OPERATION_CODES command allows checking for support
of commands that have the same opcode but different service actions,
such as READ 32 and WRITE 32. However, the current implementation of
scsi_report_opcode() only allows checking an operation code without a
service action differentiation.

Add the "sa" argument to scsi_report_opcode() to allow passing a service
action. If a non-zero service action is specified, the reporting
options field value is set to 3 to have the service action field taken
into account by the device. If no service action field is specified
(zero), the reporting options field is set to 1 as before.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi.c        | 28 +++++++++++++++++++---------
 drivers/scsi/sd.c          | 10 +++++-----
 include/scsi/scsi_device.h |  5 +++--
 3 files changed, 27 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 7d2210a006f0..43ef70556027 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -494,18 +494,22 @@ void scsi_attach_vpd(struct scsi_device *sdev)
 }
 
 /**
- * scsi_report_opcode - Find out if a given command opcode is supported
+ * scsi_report_opcode - Find out if a given command is supported
  * @sdev:	scsi device to query
  * @buffer:	scratch buffer (must be at least 20 bytes long)
  * @len:	length of buffer
- * @opcode:	opcode for command to look up
- *
- * Uses the REPORT SUPPORTED OPERATION CODES to look up the given
- * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
- * unsupported and 1 if the device claims to support the command.
+ * @opcode:	opcode for the command to look up
+ * @sa:		service action for the command to look up
+ *
+ * Uses the REPORT SUPPORTED OPERATION CODES to check support for the
+ * command identified with @opcode and @sa. If the command does not
+ * have a service action, @sa must be 0. Returns -EINVAL if RSOC fails,
+ * 0 if the command is not supported and 1 if the device claims to
+ * support the command.
  */
 int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
-		       unsigned int len, unsigned char opcode)
+		       unsigned int len, unsigned char opcode,
+		       unsigned short sa)
 {
 	unsigned char cmd[16];
 	struct scsi_sense_hdr sshdr;
@@ -529,8 +533,14 @@ int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
 	memset(cmd, 0, 16);
 	cmd[0] = MAINTENANCE_IN;
 	cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
-	cmd[2] = 1;		/* One command format */
-	cmd[3] = opcode;
+	if (!sa) {
+		cmd[2] = 1;	/* One command format */
+		cmd[3] = opcode;
+	} else {
+		cmd[2] = 3;	/* One command format with service action */
+		cmd[3] = opcode;
+		put_unaligned_be16(sa, &cmd[4]);
+	}
 	put_unaligned_be32(request_len, &cmd[6]);
 	memset(buffer, 0, len);
 
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 8e856a7a6338..c4be44832b49 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3052,7 +3052,7 @@ static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer)
 		return;
 	}
 
-	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, INQUIRY) < 0) {
+	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, INQUIRY, 0) < 0) {
 		struct scsi_vpd *vpd;
 
 		sdev->no_report_opcodes = 1;
@@ -3068,10 +3068,10 @@ static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer)
 		rcu_read_unlock();
 	}
 
-	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME_16) == 1)
+	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME_16, 0) == 1)
 		sdkp->ws16 = 1;
 
-	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME) == 1)
+	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME, 0) == 1)
 		sdkp->ws10 = 1;
 }
 
@@ -3083,9 +3083,9 @@ static void sd_read_security(struct scsi_disk *sdkp, unsigned char *buffer)
 		return;
 
 	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE,
-			SECURITY_PROTOCOL_IN) == 1 &&
+			SECURITY_PROTOCOL_IN, 0) == 1 &&
 	    scsi_report_opcode(sdev, buffer, SD_BUF_SIZE,
-			SECURITY_PROTOCOL_OUT) == 1)
+			SECURITY_PROTOCOL_OUT, 0) == 1)
 		sdkp->security = 1;
 }
 
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index ff4ad3596fa7..9564b47cf2ab 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -431,8 +431,9 @@ extern int scsi_test_unit_ready(struct scsi_device *sdev, int timeout,
 				int retries, struct scsi_sense_hdr *sshdr);
 extern int scsi_get_vpd_page(struct scsi_device *, u8 page, unsigned char *buf,
 			     int buf_len);
-extern int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
-			      unsigned int len, unsigned char opcode);
+int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
+		       unsigned int len, unsigned char opcode,
+		       unsigned short sa);
 extern int scsi_device_set_state(struct scsi_device *sdev,
 				 enum scsi_device_state state);
 extern struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
-- 
2.39.2

[PATCH v4 08/19] scsi: detect support for command duration limits

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Introduce the function scsi_cdl_check() to detect if a device supports
command duration limits (CDL). Support for the READ 16, WRITE 16,
READ 32 and WRITE 32 commands are checked using the function
scsi_report_opcode() to probe the rwcdlp and cdlp bits as they indicate
the mode page defining the command duration limits descriptors that
apply to the command being tested.

If any of these commands support CDL, the field cdl_supported of
struct scsi_device is set to 1 to indicate that the device supports CDL.

Support for CDL for a device is advertizes through sysfs using the new
cdl_supported device attribute. This attribute value is 1 for a device
supporting CDL and 0 otherwise.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
---
 Documentation/ABI/testing/sysfs-block-device |  9 +++
 drivers/scsi/scsi.c                          | 81 ++++++++++++++++++++
 drivers/scsi/scsi_scan.c                     |  3 +
 drivers/scsi/scsi_sysfs.c                    |  2 +
 include/scsi/scsi_device.h                   |  3 +
 5 files changed, 98 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-block-device b/Documentation/ABI/testing/sysfs-block-device
index 7ac7b19b2f72..ee3610a25845 100644
--- a/Documentation/ABI/testing/sysfs-block-device
+++ b/Documentation/ABI/testing/sysfs-block-device
@@ -95,3 +95,12 @@ Description:
 		This file does not exist if the HBA driver does not implement
 		support for the SATA NCQ priority feature, regardless of the
 		device support for this feature.
+
+
+What:		/sys/block/*/device/cdl_supported
+Date:		Mar, 2023
+KernelVersion:	v6.4
+Contact:	linux-scsi@vger.kernel.org
+Description:
+		(RO) Indicates if the device supports the command duration
+		limits feature found in some ATA and SCSI devices.
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 43ef70556027..e233eb6cce11 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -560,6 +560,87 @@ int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
 }
 EXPORT_SYMBOL(scsi_report_opcode);
 
+#define SCSI_CDL_CHECK_BUF_LEN	64
+
+static bool scsi_cdl_check_cmd(struct scsi_device *sdev, u8 opcode, u16 sa,
+			       unsigned char *buf)
+{
+	int ret;
+	u8 cdlp;
+
+	/* Check operation code */
+	ret = scsi_report_opcode(sdev, buf, SCSI_CDL_CHECK_BUF_LEN, opcode, sa);
+	if (ret <= 0)
+		return false;
+
+	if ((buf[1] & 0x03) != 0x03)
+		return false;
+
+	/* See SPC-6, one command format of REPORT SUPPORTED OPERATION CODES */
+	cdlp = (buf[1] & 0x18) >> 3;
+	if (buf[0] & 0x01) {
+		/* rwcdlp == 1 */
+		switch (cdlp) {
+		case 0x01:
+			/* T2A page */
+			return true;
+		case 0x02:
+			/* T2B page */
+			return true;
+		}
+	} else {
+		/* rwcdlp == 0 */
+		switch (cdlp) {
+		case 0x01:
+			/* A page */
+			return true;
+		case 0x02:
+			/* B page */
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/**
+ * scsi_cdl_check - Check if a SCSI device supports Command Duration Limits
+ * @sdev: The device to check
+ */
+void scsi_cdl_check(struct scsi_device *sdev)
+{
+	bool cdl_supported;
+	unsigned char *buf;
+
+	buf = kmalloc(SCSI_CDL_CHECK_BUF_LEN, GFP_KERNEL);
+	if (!buf) {
+		sdev->cdl_supported = 0;
+		return;
+	}
+
+	/* Check support for READ_16, WRITE_16, READ_32 and WRITE_32 commands */
+	cdl_supported =
+		scsi_cdl_check_cmd(sdev, READ_16, 0, buf) ||
+		scsi_cdl_check_cmd(sdev, WRITE_16, 0, buf) ||
+		scsi_cdl_check_cmd(sdev, VARIABLE_LENGTH_CMD, READ_32, buf) ||
+		scsi_cdl_check_cmd(sdev, VARIABLE_LENGTH_CMD, WRITE_32, buf);
+	if (cdl_supported) {
+		/*
+		 * We have CDL support: force the use of READ16/WRITE16.
+		 * READ32 and WRITE32 will be used for devices that support
+		 * the T10_PI_TYPE2_PROTECTION protection type.
+		 */
+		sdev->use_16_for_rw = 1;
+		sdev->use_10_for_rw = 0;
+
+		sdev->cdl_supported = 1;
+	} else {
+		sdev->cdl_supported = 0;
+	}
+
+	kfree(buf);
+}
+
 /**
  * scsi_device_get  -  get an additional reference to a scsi_device
  * @sdev:	device to get a reference to
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 4e842d79de31..0b703c136266 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1084,6 +1084,8 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
 	if (sdev->scsi_level >= SCSI_3)
 		scsi_attach_vpd(sdev);
 
+	scsi_cdl_check(sdev);
+
 	sdev->max_queue_depth = sdev->queue_depth;
 	WARN_ON_ONCE(sdev->max_queue_depth > sdev->budget_map.depth);
 	sdev->sdev_bflags = *bflags;
@@ -1621,6 +1623,7 @@ void scsi_rescan_device(struct device *dev)
 	device_lock(dev);
 
 	scsi_attach_vpd(sdev);
+	scsi_cdl_check(sdev);
 
 	if (sdev->handler && sdev->handler->rescan)
 		sdev->handler->rescan(sdev);
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index ee28f73af4d4..4994148e685b 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -670,6 +670,7 @@ sdev_rd_attr (scsi_level, "%d\n");
 sdev_rd_attr (vendor, "%.8s\n");
 sdev_rd_attr (model, "%.16s\n");
 sdev_rd_attr (rev, "%.4s\n");
+sdev_rd_attr (cdl_supported, "%d\n");
 
 static ssize_t
 sdev_show_device_busy(struct device *dev, struct device_attribute *attr,
@@ -1300,6 +1301,7 @@ static struct attribute *scsi_sdev_attrs[] = {
 	&dev_attr_preferred_path.attr,
 #endif
 	&dev_attr_queue_ramp_up_period.attr,
+	&dev_attr_cdl_supported.attr,
 	REF_EVT(media_change),
 	REF_EVT(inquiry_change_reported),
 	REF_EVT(capacity_change_reported),
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 9564b47cf2ab..1cce42ad9f5c 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -216,6 +216,8 @@ struct scsi_device {
 	unsigned ignore_media_change:1; /* Ignore MEDIA CHANGE on resume */
 	unsigned silence_suspend:1;	/* Do not print runtime PM related messages */
 
+	unsigned cdl_supported:1;	/* Command duration limits supported */
+
 	unsigned int queue_stopped;	/* request queue is quiesced */
 	bool offline_already;		/* Device offline message logged */
 
@@ -362,6 +364,7 @@ extern int scsi_register_device_handler(struct scsi_device_handler *scsi_dh);
 extern void scsi_remove_device(struct scsi_device *);
 extern int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh);
 void scsi_attach_vpd(struct scsi_device *sdev);
+void scsi_cdl_check(struct scsi_device *sdev);
 
 extern struct scsi_device *scsi_device_from_queue(struct request_queue *q);
 extern int __must_check scsi_device_get(struct scsi_device *);
-- 
2.39.2

[PATCH v4 09/19] scsi: allow enabling and disabling command duration limits

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Add the sysfs scsi device attribute cdl_enable to allow a user to turn
enable or disable a device command duration limits feature. CDL is
disabled by default. This feature must be explicitly enabled by a user by
setting the cdl_enable attribute to 1.

The new function scsi_cdl_enable() does not do anything beside setting
the cdl_enable field of struct scsi_device in the case of a (real) scsi
device (e.g. a SAS HDD). For ATA devices, the command duration limits
feature needs to be enabled/disabled using the ATA feature sub-page of
the control mode page. To do so, the scsi_cdl_enable() function checks
if this mode page is supported using scsi_mode_sense(). If it is,
scsi_mode_select() is used to enable and disable CDL.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
---
 Documentation/ABI/testing/sysfs-block-device | 13 ++++
 drivers/scsi/scsi.c                          | 62 ++++++++++++++++++++
 drivers/scsi/scsi_sysfs.c                    | 31 ++++++++++
 include/scsi/scsi_device.h                   |  2 +
 4 files changed, 108 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-block-device b/Documentation/ABI/testing/sysfs-block-device
index ee3610a25845..626d48ac504b 100644
--- a/Documentation/ABI/testing/sysfs-block-device
+++ b/Documentation/ABI/testing/sysfs-block-device
@@ -104,3 +104,16 @@ Contact:	linux-scsi@vger.kernel.org
 Description:
 		(RO) Indicates if the device supports the command duration
 		limits feature found in some ATA and SCSI devices.
+
+
+What:		/sys/block/*/device/cdl_enable
+Date:		Mar, 2023
+KernelVersion:	v6.4
+Contact:	linux-scsi@vger.kernel.org
+Description:
+		(RW) For a device supporting the command duration limits
+		feature, write to the file to turn on or off the feature.
+		By default this feature is turned off.
+		Writing "1" to this file enables the use of command duration
+		limits for read and write commands in the kernel and turns on
+		the feature on the device. Writing "0" disables the feature.
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index e233eb6cce11..385a09a387b2 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -641,6 +641,68 @@ void scsi_cdl_check(struct scsi_device *sdev)
 	kfree(buf);
 }
 
+/**
+ * scsi_cdl_enable - Enable or disable a SCSI device supports for Command
+ *                   Duration Limits
+ * @sdev: The target device
+ * @enable: the target state
+ */
+int scsi_cdl_enable(struct scsi_device *sdev, bool enable)
+{
+	struct scsi_mode_data data;
+	struct scsi_sense_hdr sshdr;
+	struct scsi_vpd *vpd;
+	bool is_ata = false;
+	char buf[64];
+	int ret;
+
+	if (!sdev->cdl_supported)
+		return -EOPNOTSUPP;
+
+	rcu_read_lock();
+	vpd = rcu_dereference(sdev->vpd_pg89);
+	if (vpd)
+		is_ata = true;
+	rcu_read_unlock();
+
+	/*
+	 * For ATA devices, CDL needs to be enabled with a SET FEATURES command.
+	 */
+	if (is_ata) {
+		char *buf_data;
+		int len;
+
+		ret = scsi_mode_sense(sdev, 0x08, 0x0a, 0xf2, buf, sizeof(buf),
+				      5 * HZ, 3, &data, NULL);
+		if (ret)
+			return -EINVAL;
+
+		/* Enable CDL using the ATA feature page */
+		len = min_t(size_t, sizeof(buf),
+			    data.length - data.header_length -
+			    data.block_descriptor_length);
+		buf_data = buf + data.header_length +
+			data.block_descriptor_length;
+		if (enable)
+			buf_data[4] = 0x02;
+		else
+			buf_data[4] = 0;
+
+		ret = scsi_mode_select(sdev, 1, 0, buf_data, len, 5 * HZ, 3,
+				       &data, &sshdr);
+		if (ret) {
+			if (scsi_sense_valid(&sshdr))
+				scsi_print_sense_hdr(sdev,
+					dev_name(&sdev->sdev_gendev), &sshdr);
+			return ret;
+		}
+	}
+
+	sdev->cdl_enable = enable;
+
+	return 0;
+}
+
 /**
  * scsi_device_get  -  get an additional reference to a scsi_device
  * @sdev:	device to get a reference to
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 4994148e685b..9a54b2c0fee7 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1222,6 +1222,36 @@ static DEVICE_ATTR(queue_ramp_up_period, S_IRUGO | S_IWUSR,
 		   sdev_show_queue_ramp_up_period,
 		   sdev_store_queue_ramp_up_period);
 
+static ssize_t sdev_show_cdl_enable(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+
+	return sysfs_emit(buf, "%d\n", (int)sdev->cdl_enable);
+}
+
+static ssize_t sdev_store_cdl_enable(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	int ret;
+	bool v;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	if (kstrtobool(buf, &v))
+		return -EINVAL;
+
+	ret = scsi_cdl_enable(to_scsi_device(dev), v);
+	if (ret)
+		return ret;
+
+	return count;
+}
+static DEVICE_ATTR(cdl_enable, S_IRUGO | S_IWUSR,
+		   sdev_show_cdl_enable, sdev_store_cdl_enable);
+
 static umode_t scsi_sdev_attr_is_visible(struct kobject *kobj,
 					 struct attribute *attr, int i)
 {
@@ -1302,6 +1332,7 @@ static struct attribute *scsi_sdev_attrs[] = {
 #endif
 	&dev_attr_queue_ramp_up_period.attr,
 	&dev_attr_cdl_supported.attr,
+	&dev_attr_cdl_enable.attr,
 	REF_EVT(media_change),
 	REF_EVT(inquiry_change_reported),
 	REF_EVT(capacity_change_reported),
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 1cce42ad9f5c..970467d451bf 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -217,6 +217,7 @@ struct scsi_device {
 	unsigned silence_suspend:1;	/* Do not print runtime PM related messages */
 
 	unsigned cdl_supported:1;	/* Command duration limits supported */
+	unsigned cdl_enable:1;		/* Enable/disable Command duration limits */
 
 	unsigned int queue_stopped;	/* request queue is quiesced */
 	bool offline_already;		/* Device offline message logged */
@@ -365,6 +366,7 @@ extern void scsi_remove_device(struct scsi_device *);
 extern int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh);
 void scsi_attach_vpd(struct scsi_device *sdev);
 void scsi_cdl_check(struct scsi_device *sdev);
+int scsi_cdl_enable(struct scsi_device *sdev, bool enable);
 
 extern struct scsi_device *scsi_device_from_queue(struct request_queue *q);
 extern int __must_check scsi_device_get(struct scsi_device *);
-- 
2.39.2

[PATCH v4 10/19] scsi: sd: set read/write commands CDL index

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Introduce the command duration limits helper function sd_cdl_dld() to
set the DLD bits of READ/WRITE 16 and READ/WRITE 32 commands to
indicate to the device the command duration limit descriptor to apply
to the commands.

When command duration limits are enabled, sd_cdl_dld() obtains the
index of the descriptor to apply to the command using the hints field of
the request IO priority value (hints IOPRIO_HINT_DEV_DURATION_LIMIT_1 to
IOPRIO_HINT_DEV_DURATION_LIMIT_7).

If command duration limits is disabled (which is the default), the limit
index "0" is always used to indicate "no limit" for a command.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
---
 drivers/scsi/sd.c | 40 ++++++++++++++++++++++++++++++++++------
 1 file changed, 34 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index c4be44832b49..791c160e6eca 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1042,13 +1042,14 @@ static blk_status_t sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
 
 static blk_status_t sd_setup_rw32_cmnd(struct scsi_cmnd *cmd, bool write,
 				       sector_t lba, unsigned int nr_blocks,
-				       unsigned char flags)
+				       unsigned char flags, unsigned int dld)
 {
 	cmd->cmd_len = SD_EXT_CDB_SIZE;
 	cmd->cmnd[0]  = VARIABLE_LENGTH_CMD;
 	cmd->cmnd[7]  = 0x18; /* Additional CDB len */
 	cmd->cmnd[9]  = write ? WRITE_32 : READ_32;
 	cmd->cmnd[10] = flags;
+	cmd->cmnd[11] = dld & 0x07;
 	put_unaligned_be64(lba, &cmd->cmnd[12]);
 	put_unaligned_be32(lba, &cmd->cmnd[20]); /* Expected Indirect LBA */
 	put_unaligned_be32(nr_blocks, &cmd->cmnd[28]);
@@ -1058,12 +1059,12 @@ static blk_status_t sd_setup_rw32_cmnd(struct scsi_cmnd *cmd, bool write,
 
 static blk_status_t sd_setup_rw16_cmnd(struct scsi_cmnd *cmd, bool write,
 				       sector_t lba, unsigned int nr_blocks,
-				       unsigned char flags)
+				       unsigned char flags, unsigned int dld)
 {
 	cmd->cmd_len  = 16;
 	cmd->cmnd[0]  = write ? WRITE_16 : READ_16;
-	cmd->cmnd[1]  = flags;
-	cmd->cmnd[14] = 0;
+	cmd->cmnd[1]  = flags | ((dld >> 2) & 0x01);
+	cmd->cmnd[14] = (dld & 0x03) << 6;
 	cmd->cmnd[15] = 0;
 	put_unaligned_be64(lba, &cmd->cmnd[2]);
 	put_unaligned_be32(nr_blocks, &cmd->cmnd[10]);
@@ -1115,6 +1116,31 @@ static blk_status_t sd_setup_rw6_cmnd(struct scsi_cmnd *cmd, bool write,
 	return BLK_STS_OK;
 }
 
+/*
+ * Check if a command has a duration limit set. If it does, and the target
+ * device supports CDL and the feature is enabled, return the limit
+ * descriptor index to use. Return 0 (no limit) otherwise.
+ */
+static int sd_cdl_dld(struct scsi_disk *sdkp, struct scsi_cmnd *scmd)
+{
+	struct scsi_device *sdp = sdkp->device;
+	int hint;
+
+	if (!sdp->cdl_supported || !sdp->cdl_enable)
+		return 0;
+
+	/*
+	 * Use "no limit" if the request ioprio does not specify a duration
+	 * limit hint.
+	 */
+	hint = IOPRIO_PRIO_HINT(req_get_ioprio(scsi_cmd_to_rq(scmd)));
+	if (hint < IOPRIO_HINT_DEV_DURATION_LIMIT_1 ||
+	    hint > IOPRIO_HINT_DEV_DURATION_LIMIT_7)
+		return 0;
+
+	return (hint - IOPRIO_HINT_DEV_DURATION_LIMIT_1) + 1;
+}
+
 static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *cmd)
 {
 	struct request *rq = scsi_cmd_to_rq(cmd);
@@ -1126,6 +1152,7 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *cmd)
 	unsigned int mask = logical_to_sectors(sdp, 1) - 1;
 	bool write = rq_data_dir(rq) == WRITE;
 	unsigned char protect, fua;
+	unsigned int dld;
 	blk_status_t ret;
 	unsigned int dif;
 	bool dix;
@@ -1175,6 +1202,7 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *cmd)
 	fua = rq->cmd_flags & REQ_FUA ? 0x8 : 0;
 	dix = scsi_prot_sg_count(cmd);
 	dif = scsi_host_dif_capable(cmd->device->host, sdkp->protection_type);
+	dld = sd_cdl_dld(sdkp, cmd);
 
 	if (dif || dix)
 		protect = sd_setup_protect_cmnd(cmd, dix, dif);
@@ -1183,10 +1211,10 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *cmd)
 
 	if (protect && sdkp->protection_type == T10_PI_TYPE2_PROTECTION) {
 		ret = sd_setup_rw32_cmnd(cmd, write, lba, nr_blocks,
-					 protect | fua);
+					 protect | fua, dld);
 	} else if (sdp->use_16_for_rw || (nr_blocks > 0xffff)) {
 		ret = sd_setup_rw16_cmnd(cmd, write, lba, nr_blocks,
-					 protect | fua);
+					 protect | fua, dld);
 	} else if ((nr_blocks > 0xff) || (lba > 0x1fffff) ||
 		   sdp->use_10_for_rw || protect) {
 		ret = sd_setup_rw10_cmnd(cmd, write, lba, nr_blocks,
-- 
2.39.2

[PATCH v4 11/19] scsi: sd: handle read/write CDL timeout failures

[Niklas Cassel]

Commands using a duration limit descriptor that has limit policies set
to a value other than 0x0 may be failed by the device if one of the
limits are exceeded. For such commands, since the failure is the result
of the user duration limit configuration and workload, the commands
should not be retried and terminated immediately. Furthermore, to allow
the user to differentiate these "soft" failures from hard errors due to
hardware problem, a different error code than EIO should be returned.

There are 2 cases to consider:
(1) The failure is due to a limit policy failing the command with a
check condition sense key, that is, any limit policy other than 0xD.
For this case, scsi_check_sense() is modified to detect failures with
the ABORTED COMMAND sense key and the COMMAND TIMEOUT BEFORE PROCESSING
or COMMAND TIMEOUT DURING PROCESSING or COMMAND TIMEOUT DURING
PROCESSING DUE TO ERROR RECOVERY additional sense code. For these
failures, a SUCCESS disposition is returned so that
scsi_finish_command() is called to terminate the command.

(2) The failure is due to a limit policy set to 0xD, which result in the
command being terminated with a GOOD status, COMPLETED sense key, and
DATA CURRENTLY UNAVAILABLE additional sense code. To handle this case,
the scsi_check_sense() is modified to return a SUCCESS disposition so
that scsi_finish_command() is called to terminate the command.
In addition, scsi_decide_disposition() has to be modified to see if a
command being terminated with GOOD status has sense data.
This is as defined in SCSI Primary Commands - 6 (SPC-6), so all
according to spec, even if GOOD status commands were not checked before.

If scsi_check_sense() detects sense data representing a duration limit,
scsi_check_sense() will set the newly introduced SCSI ML byte
SCSIML_STAT_DL_TIMEOUT. This SCSI ML byte is checked in
scsi_noretry_cmd(), so that a command that failed because of a CDL
timeout cannot be retried. The SCSI ML byte is also checked in
scsi_result_to_blk_status() to complete the command request with the
BLK_STS_DURATION_LIMIT status, which result in the user seeing ETIME
errors for the failed commands.

Co-developed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
---
 drivers/scsi/scsi_error.c | 45 +++++++++++++++++++++++++++++++++++++++
 drivers/scsi/scsi_lib.c   |  4 ++++
 drivers/scsi/scsi_priv.h  |  1 +
 3 files changed, 50 insertions(+)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index cf5ec5f5f4f6..dc85a75b33d9 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -536,6 +536,7 @@ static inline void set_scsi_ml_byte(struct scsi_cmnd *cmd, u8 status)
  */
 enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd)
 {
+	struct request *req = scsi_cmd_to_rq(scmd);
 	struct scsi_device *sdev = scmd->device;
 	struct scsi_sense_hdr sshdr;
 
@@ -595,6 +596,22 @@ enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd)
 		if (sshdr.asc == 0x10) /* DIF */
 			return SUCCESS;
 
+		/*
+		 * Check aborts due to command duration limit policy:
+		 * ABORTED COMMAND additional sense code with the
+		 * COMMAND TIMEOUT BEFORE PROCESSING or
+		 * COMMAND TIMEOUT DURING PROCESSING or
+		 * COMMAND TIMEOUT DURING PROCESSING DUE TO ERROR RECOVERY
+		 * additional sense code qualifiers.
+		 */
+		if (sshdr.asc == 0x2e &&
+		    sshdr.ascq >= 0x01 && sshdr.ascq <= 0x03) {
+			set_scsi_ml_byte(scmd, SCSIML_STAT_DL_TIMEOUT);
+			req->cmd_flags |= REQ_FAILFAST_DEV;
+			req->rq_flags |= RQF_QUIET;
+			return SUCCESS;
+		}
+
 		if (sshdr.asc == 0x44 && sdev->sdev_bflags & BLIST_RETRY_ITF)
 			return ADD_TO_MLQUEUE;
 		if (sshdr.asc == 0xc1 && sshdr.ascq == 0x01 &&
@@ -691,6 +708,14 @@ enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd)
 		}
 		return SUCCESS;
 
+	case COMPLETED:
+		if (sshdr.asc == 0x55 && sshdr.ascq == 0x0a) {
+			set_scsi_ml_byte(scmd, SCSIML_STAT_DL_TIMEOUT);
+			req->cmd_flags |= REQ_FAILFAST_DEV;
+			req->rq_flags |= RQF_QUIET;
+		}
+		return SUCCESS;
+
 	default:
 		return SUCCESS;
 	}
@@ -785,6 +810,14 @@ static enum scsi_disposition scsi_eh_completed_normally(struct scsi_cmnd *scmd)
 	switch (get_status_byte(scmd)) {
 	case SAM_STAT_GOOD:
 		scsi_handle_queue_ramp_up(scmd->device);
+		if (scmd->sense_buffer && SCSI_SENSE_VALID(scmd))
+			/*
+			 * If we have sense data, call scsi_check_sense() in
+			 * order to set the correct SCSI ML byte (if any).
+			 * No point in checking the return value, since the
+			 * command has already completed successfully.
+			 */
+			scsi_check_sense(scmd);
 		fallthrough;
 	case SAM_STAT_COMMAND_TERMINATED:
 		return SUCCESS;
@@ -1807,6 +1840,10 @@ bool scsi_noretry_cmd(struct scsi_cmnd *scmd)
 		return !!(req->cmd_flags & REQ_FAILFAST_DRIVER);
 	}
 
+	/* Never retry commands aborted due to a duration limit timeout */
+	if (scsi_ml_byte(scmd->result) == SCSIML_STAT_DL_TIMEOUT)
+		return true;
+
 	if (!scsi_status_is_check_condition(scmd->result))
 		return false;
 
@@ -1966,6 +2003,14 @@ enum scsi_disposition scsi_decide_disposition(struct scsi_cmnd *scmd)
 		if (scmd->cmnd[0] == REPORT_LUNS)
 			scmd->device->sdev_target->expecting_lun_change = 0;
 		scsi_handle_queue_ramp_up(scmd->device);
+		if (scmd->sense_buffer && SCSI_SENSE_VALID(scmd))
+			/*
+			 * If we have sense data, call scsi_check_sense() in
+			 * order to set the correct SCSI ML byte (if any).
+			 * No point in checking the return value, since the
+			 * command has already completed successfully.
+			 */
+			scsi_check_sense(scmd);
 		fallthrough;
 	case SAM_STAT_COMMAND_TERMINATED:
 		return SUCCESS;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 633c4e8af830..b894432ca0b9 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -601,6 +601,8 @@ static blk_status_t scsi_result_to_blk_status(int result)
 		return BLK_STS_MEDIUM;
 	case SCSIML_STAT_TGT_FAILURE:
 		return BLK_STS_TARGET;
+	case SCSIML_STAT_DL_TIMEOUT:
+		return BLK_STS_DURATION_LIMIT;
 	}
 
 	switch (host_byte(result)) {
@@ -798,6 +800,8 @@ static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result)
 				blk_stat = BLK_STS_ZONE_OPEN_RESOURCE;
 			}
 			break;
+		case COMPLETED:
+			fallthrough;
 		default:
 			action = ACTION_FAIL;
 			break;
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index 74324fba4281..f42388ecb024 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -27,6 +27,7 @@ enum scsi_ml_status {
 	SCSIML_STAT_NOSPC		= 0x02,	/* Space allocation on the dev failed */
 	SCSIML_STAT_MED_ERROR		= 0x03,	/* Medium error */
 	SCSIML_STAT_TGT_FAILURE		= 0x04,	/* Permanent target failure */
+	SCSIML_STAT_DL_TIMEOUT		= 0x05, /* Command Duration Limit timeout */
 };
 
 static inline u8 scsi_ml_byte(int result)
-- 
2.39.2

[PATCH v4 12/19] ata: libata-scsi: remove unnecessary !cmd checks

[Niklas Cassel]

There is no need to check if !cmd as this can only happen for
ATA internal commands which uses the ATA internal tag (32).

Most users of ata_scsi_set_sense() are from _xlat functions that
translate a scsicmd to an ATA command. These obviously have a qc->scsicmd.

ata_scsi_qc_complete() can also call ata_scsi_set_sense() via
ata_gen_passthru_sense() / ata_gen_ata_sense(), called via
ata_scsi_qc_complete(). This callback is only called for translated
commands, so it also has a qc->scsicmd.

ata_eh_analyze_ncq_error(): the NCQ error log can only contain a 0-31
value, so it will never be able to get the ATA internal tag (32).

ata_eh_request_sense(): only called by ata_eh_analyze_tf(), which
is only called when iteratating the QCs using ata_qc_for_each_raw(),
which does not include the internal tag.

Since there is no existing call site where cmd can be NULL, remove the
!cmd check from ata_scsi_set_sense() and ata_scsi_set_sense_information().

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/ata/libata-scsi.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index e093c7a7deeb..26746609bf76 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -209,9 +209,6 @@ void ata_scsi_set_sense(struct ata_device *dev, struct scsi_cmnd *cmd,
 {
 	bool d_sense = (dev->flags & ATA_DFLAG_D_SENSE);
 
-	if (!cmd)
-		return;
-
 	scsi_build_sense(cmd, d_sense, sk, asc, ascq);
 }
 
@@ -221,9 +218,6 @@ void ata_scsi_set_sense_information(struct ata_device *dev,
 {
 	u64 information;
 
-	if (!cmd)
-		return;
-
 	information = ata_tf_read_block(tf, dev);
 	if (information == U64_MAX)
 		return;
-- 
2.39.2

[PATCH v4 13/19] ata: libata: change ata_eh_request_sense() to not set CHECK_CONDITION

[Niklas Cassel]

Currently, ata_eh_request_sense() unconditionally sets the scsicmd->result
to SAM_STAT_CHECK_CONDITION.

For Command Duration Limits policy 0xD:
The device shall complete the command without error (SAM_STAT_GOOD)
with the additional sense code set to DATA CURRENTLY UNAVAILABLE.

It is perfectly fine to have sense data for a command that returned
completion without error.

In order to support for CDL policy 0xD, we have to remove this
assumption that having sense data means that the command failed
(SAM_STAT_CHECK_CONDITION).

Change ata_eh_request_sense() to not set SAM_STAT_CHECK_CONDITION,
and instead move the setting of SAM_STAT_CHECK_CONDITION to the single
caller that wants SAM_STAT_CHECK_CONDITION set, that way
ata_eh_request_sense() can be reused in a follow-up patch that adds
support for CDL policy 0xD.

The only caller of ata_eh_request_sense() is protected by:
if (!(qc->flags & ATA_QCFLAG_SENSE_VALID)), so we can remove this
duplicated check from ata_eh_request_sense() itself.

Additionally, ata_eh_request_sense() is only called from
ata_eh_analyze_tf(), which is only called when iteratating the QCs using
ata_qc_for_each_raw(), which does not include the internal tag,
so cmd can never be NULL (all non-internal commands have qc->scsicmd set),
so remove the !cmd check as well.

Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/ata/libata-eh.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index a6c901811802..598ae07195b6 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1401,8 +1401,11 @@ unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key)
  *
  *	LOCKING:
  *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	true if sense data could be fetched, false otherwise.
  */
-static void ata_eh_request_sense(struct ata_queued_cmd *qc)
+static bool ata_eh_request_sense(struct ata_queued_cmd *qc)
 {
 	struct scsi_cmnd *cmd = qc->scsicmd;
 	struct ata_device *dev = qc->dev;
@@ -1411,15 +1414,12 @@ static void ata_eh_request_sense(struct ata_queued_cmd *qc)
 
 	if (ata_port_is_frozen(qc->ap)) {
 		ata_dev_warn(dev, "sense data available but port frozen\n");
-		return;
+		return false;
 	}
 
-	if (!cmd || qc->flags & ATA_QCFLAG_SENSE_VALID)
-		return;
-
 	if (!ata_id_sense_reporting_enabled(dev->id)) {
 		ata_dev_warn(qc->dev, "sense data reporting disabled\n");
-		return;
+		return false;
 	}
 
 	ata_tf_init(dev, &tf);
@@ -1432,13 +1432,19 @@ static void ata_eh_request_sense(struct ata_queued_cmd *qc)
 	/* Ignore err_mask; ATA_ERR might be set */
 	if (tf.status & ATA_SENSE) {
 		if (ata_scsi_sense_is_valid(tf.lbah, tf.lbam, tf.lbal)) {
-			ata_scsi_set_sense(dev, cmd, tf.lbah, tf.lbam, tf.lbal);
+			/* Set sense without also setting scsicmd->result */
+			scsi_build_sense_buffer(dev->flags & ATA_DFLAG_D_SENSE,
+						cmd->sense_buffer, tf.lbah,
+						tf.lbam, tf.lbal);
 			qc->flags |= ATA_QCFLAG_SENSE_VALID;
+			return true;
 		}
 	} else {
 		ata_dev_warn(dev, "request sense failed stat %02x emask %x\n",
 			     tf.status, err_mask);
 	}
+
+	return false;
 }
 
 /**
@@ -1588,8 +1594,9 @@ static unsigned int ata_eh_analyze_tf(struct ata_queued_cmd *qc)
 		 *  was not included in the NCQ command error log
 		 *  (i.e. NCQ autosense is not supported by the device).
 		 */
-		if (!(qc->flags & ATA_QCFLAG_SENSE_VALID) && (stat & ATA_SENSE))
-			ata_eh_request_sense(qc);
+		if (!(qc->flags & ATA_QCFLAG_SENSE_VALID) &&
+		    (stat & ATA_SENSE) && ata_eh_request_sense(qc))
+			set_status_byte(qc->scsicmd, SAM_STAT_CHECK_CONDITION);
 		if (err & ATA_ICRC)
 			qc->err_mask |= AC_ERR_ATA_BUS;
 		if (err & (ATA_UNC | ATA_AMNF))
-- 
2.39.2

[PATCH v4 14/19] ata: libata: detect support for command duration limits

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Use the supported capabilities identify device data log page to detect
if a device supports the command duration limits feature. For devices
supporting this feature, set the device flag ATA_DFLAG_CDL. To support
scsi-ata translation, retrieve the command duration limits log page 18h
and cache this page content using the cdl array added to the ata_device
data structure.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/ata/libata-core.c | 52 ++++++++++++++++++++++++++++++++++++++-
 drivers/ata/libata-scsi.c | 17 ++++++-------
 include/linux/ata.h       |  5 +++-
 include/linux/libata.h    | 29 +++++++++++++---------
 4 files changed, 80 insertions(+), 23 deletions(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 14c17c3bda4e..78e53f4fa741 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2367,6 +2367,54 @@ static void ata_dev_config_trusted(struct ata_device *dev)
 		dev->flags |= ATA_DFLAG_TRUSTED;
 }
 
+static void ata_dev_config_cdl(struct ata_device *dev)
+{
+	struct ata_port *ap = dev->link->ap;
+	unsigned int err_mask;
+	u64 val;
+
+	if (ata_id_major_version(dev->id) < 12)
+		goto not_supported;
+
+	if (!ata_log_supported(dev, ATA_LOG_IDENTIFY_DEVICE) ||
+	    !ata_identify_page_supported(dev, ATA_LOG_SUPPORTED_CAPABILITIES))
+		goto not_supported;
+
+	err_mask = ata_read_log_page(dev, ATA_LOG_IDENTIFY_DEVICE,
+				     ATA_LOG_SUPPORTED_CAPABILITIES,
+				     ap->sector_buf, 1);
+	if (err_mask)
+		goto not_supported;
+
+	/* Check Command Duration Limit Supported bits */
+	val = get_unaligned_le64(&ap->sector_buf[168]);
+	if (!(val & BIT_ULL(63)) || !(val & BIT_ULL(0)))
+		goto not_supported;
+
+	/* Warn the user if command duration guideline is not supported */
+	if (!(val & BIT_ULL(1)))
+		ata_dev_warn(dev,
+			"Command duration guideline is not supported\n");
+
+	/*
+	 * Command duration limits is supported: cache the CDL log page 18h
+	 * (command duration descriptors).
+	 */
+	err_mask = ata_read_log_page(dev, ATA_LOG_CDL, 0, ap->sector_buf, 1);
+	if (err_mask) {
+		ata_dev_warn(dev, "Read Command Duration Limits log failed\n");
+		goto not_supported;
+	}
+
+	memcpy(dev->cdl, ap->sector_buf, ATA_LOG_CDL_SIZE);
+	dev->flags |= ATA_DFLAG_CDL;
+
+	return;
+
+not_supported:
+	dev->flags &= ~ATA_DFLAG_CDL;
+}
+
 static int ata_dev_config_lba(struct ata_device *dev)
 {
 	const u16 *id = dev->id;
@@ -2534,13 +2582,14 @@ static void ata_dev_print_features(struct ata_device *dev)
 		return;
 
 	ata_dev_info(dev,
-		     "Features:%s%s%s%s%s%s%s\n",
+		     "Features:%s%s%s%s%s%s%s%s\n",
 		     dev->flags & ATA_DFLAG_FUA ? " FUA" : "",
 		     dev->flags & ATA_DFLAG_TRUSTED ? " Trust" : "",
 		     dev->flags & ATA_DFLAG_DA ? " Dev-Attention" : "",
 		     dev->flags & ATA_DFLAG_DEVSLP ? " Dev-Sleep" : "",
 		     dev->flags & ATA_DFLAG_NCQ_SEND_RECV ? " NCQ-sndrcv" : "",
 		     dev->flags & ATA_DFLAG_NCQ_PRIO ? " NCQ-prio" : "",
+		     dev->flags & ATA_DFLAG_CDL ? " CDL" : "",
 		     dev->cpr_log ? " CPR" : "");
 }
 
@@ -2702,6 +2751,7 @@ int ata_dev_configure(struct ata_device *dev)
 		ata_dev_config_zac(dev);
 		ata_dev_config_trusted(dev);
 		ata_dev_config_cpr(dev);
+		ata_dev_config_cdl(dev);
 		dev->cdb_len = 32;
 
 		if (print_info)
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 26746609bf76..716c33af999c 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -47,15 +47,14 @@ typedef unsigned int (*ata_xlat_func_t)(struct ata_queued_cmd *qc);
 static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
 					const struct scsi_device *scsidev);
 
-#define RW_RECOVERY_MPAGE 0x1
-#define RW_RECOVERY_MPAGE_LEN 12
-#define CACHE_MPAGE 0x8
-#define CACHE_MPAGE_LEN 20
-#define CONTROL_MPAGE 0xa
-#define CONTROL_MPAGE_LEN 12
-#define ALL_MPAGES 0x3f
-#define ALL_SUB_MPAGES 0xff
-
+#define RW_RECOVERY_MPAGE		0x1
+#define RW_RECOVERY_MPAGE_LEN		12
+#define CACHE_MPAGE			0x8
+#define CACHE_MPAGE_LEN			20
+#define CONTROL_MPAGE			0xa
+#define CONTROL_MPAGE_LEN		12
+#define ALL_MPAGES			0x3f
+#define ALL_SUB_MPAGES			0xff
 
 static const u8 def_rw_recovery_mpage[RW_RECOVERY_MPAGE_LEN] = {
 	RW_RECOVERY_MPAGE,
diff --git a/include/linux/ata.h b/include/linux/ata.h
index 0c18499f60b6..b01e2cebe1fe 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -323,15 +323,18 @@ enum {
 	ATA_LOG_SATA_NCQ	= 0x10,
 	ATA_LOG_NCQ_NON_DATA	= 0x12,
 	ATA_LOG_NCQ_SEND_RECV	= 0x13,
+	ATA_LOG_CDL		= 0x18,
+	ATA_LOG_CDL_SIZE	= ATA_SECT_SIZE,
 	ATA_LOG_IDENTIFY_DEVICE	= 0x30,
 	ATA_LOG_CONCURRENT_POSITIONING_RANGES = 0x47,
 
 	/* Identify device log pages: */
+	ATA_LOG_SUPPORTED_CAPABILITIES	= 0x03,
 	ATA_LOG_SECURITY	  = 0x06,
 	ATA_LOG_SATA_SETTINGS	  = 0x08,
 	ATA_LOG_ZONED_INFORMATION = 0x09,
 
-	/* Identify device SATA settings log:*/
+	/* Identify device SATA settings log: */
 	ATA_LOG_DEVSLP_OFFSET	  = 0x30,
 	ATA_LOG_DEVSLP_SIZE	  = 0x08,
 	ATA_LOG_DEVSLP_MDAT	  = 0x00,
diff --git a/include/linux/libata.h b/include/linux/libata.h
index a759dfbdcc91..2b17d6c99a37 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -94,17 +94,18 @@ enum {
 	ATA_DFLAG_DMADIR	= (1 << 10), /* device requires DMADIR */
 	ATA_DFLAG_NCQ_SEND_RECV = (1 << 11), /* device supports NCQ SEND and RECV */
 	ATA_DFLAG_NCQ_PRIO	= (1 << 12), /* device supports NCQ priority */
-	ATA_DFLAG_CFG_MASK	= (1 << 13) - 1,
-
-	ATA_DFLAG_PIO		= (1 << 13), /* device limited to PIO mode */
-	ATA_DFLAG_NCQ_OFF	= (1 << 14), /* device limited to non-NCQ mode */
-	ATA_DFLAG_SLEEPING	= (1 << 15), /* device is sleeping */
-	ATA_DFLAG_DUBIOUS_XFER	= (1 << 16), /* data transfer not verified */
-	ATA_DFLAG_NO_UNLOAD	= (1 << 17), /* device doesn't support unload */
-	ATA_DFLAG_UNLOCK_HPA	= (1 << 18), /* unlock HPA */
-	ATA_DFLAG_INIT_MASK	= (1 << 19) - 1,
-
-	ATA_DFLAG_NCQ_PRIO_ENABLED = (1 << 19), /* Priority cmds sent to dev */
+	ATA_DFLAG_CDL		= (1 << 13), /* supports cmd duration limits */
+	ATA_DFLAG_CFG_MASK	= (1 << 14) - 1,
+
+	ATA_DFLAG_PIO		= (1 << 14), /* device limited to PIO mode */
+	ATA_DFLAG_NCQ_OFF	= (1 << 15), /* device limited to non-NCQ mode */
+	ATA_DFLAG_SLEEPING	= (1 << 16), /* device is sleeping */
+	ATA_DFLAG_DUBIOUS_XFER	= (1 << 17), /* data transfer not verified */
+	ATA_DFLAG_NO_UNLOAD	= (1 << 18), /* device doesn't support unload */
+	ATA_DFLAG_UNLOCK_HPA	= (1 << 19), /* unlock HPA */
+	ATA_DFLAG_INIT_MASK	= (1 << 20) - 1,
+
+	ATA_DFLAG_NCQ_PRIO_ENABLED = (1 << 20), /* Priority cmds sent to dev */
 	ATA_DFLAG_DETACH	= (1 << 24),
 	ATA_DFLAG_DETACHED	= (1 << 25),
 	ATA_DFLAG_DA		= (1 << 26), /* device supports Device Attention */
@@ -115,7 +116,8 @@ enum {
 
 	ATA_DFLAG_FEATURES_MASK	= (ATA_DFLAG_TRUSTED | ATA_DFLAG_DA |	\
 				   ATA_DFLAG_DEVSLP | ATA_DFLAG_NCQ_SEND_RECV | \
-				   ATA_DFLAG_NCQ_PRIO | ATA_DFLAG_FUA),
+				   ATA_DFLAG_NCQ_PRIO | ATA_DFLAG_FUA | \
+				   ATA_DFLAG_CDL),
 
 	ATA_DEV_UNKNOWN		= 0,	/* unknown device */
 	ATA_DEV_ATA		= 1,	/* ATA device */
@@ -709,6 +711,9 @@ struct ata_device {
 	/* Concurrent positioning ranges */
 	struct ata_cpr_log	*cpr_log;
 
+	/* Command Duration Limits log support */
+	u8			cdl[ATA_LOG_CDL_SIZE];
+
 	/* error history */
 	int			spdn_cnt;
 	/* ering is CLEAR_END, read comment above CLEAR_END */
-- 
2.39.2

[PATCH v4 15/19] ata: libata-scsi: handle CDL bits in ata_scsiop_maint_in()

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

For a scsi MAINTENANCE_IN/MI_REPORT_SUPPORTED_OPERATION_CODES operation,
add the translation of the rwcdlp and cdlp bits for the READ16 and
WRITE16 commands. If the ATA device does not support command duration
limits, these bits are always 0. If the ATA device supports command
duration limits, the rwcdlp bit is set to 1 for READ16 and WRITE16 and
the cdlp bits are set to 0x1 for READ16 and 0x2 for WRITE16. These
correspond to the T2A mode page containing the read descriptors and
to the T2B mode page containing the write descriptors, as defined in
SAT-5.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/ata/libata-scsi.c | 30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 716c33af999c..2a0a04c9e658 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3235,7 +3235,7 @@ static unsigned int ata_scsiop_maint_in(struct ata_scsi_args *args, u8 *rbuf)
 {
 	struct ata_device *dev = args->dev;
 	u8 *cdb = args->cmd->cmnd;
-	u8 supported = 0;
+	u8 supported = 0, cdlp = 0, rwcdlp = 0;
 	unsigned int err = 0;
 
 	if (cdb[2] != 1 && cdb[2] != 3) {
@@ -3262,10 +3262,8 @@ static unsigned int ata_scsiop_maint_in(struct ata_scsi_args *args, u8 *rbuf)
 	case MAINTENANCE_IN:
 	case READ_6:
 	case READ_10:
-	case READ_16:
 	case WRITE_6:
 	case WRITE_10:
-	case WRITE_16:
 	case ATA_12:
 	case ATA_16:
 	case VERIFY:
@@ -3275,6 +3273,28 @@ static unsigned int ata_scsiop_maint_in(struct ata_scsi_args *args, u8 *rbuf)
 	case START_STOP:
 		supported = 3;
 		break;
+	case READ_16:
+		supported = 3;
+		if (dev->flags & ATA_DFLAG_CDL) {
+			/*
+			 * CDL read descriptors map to the T2A page, that is,
+			 * rwcdlp = 0x01 and cdlp = 0x01
+			 */
+			rwcdlp = 0x01;
+			cdlp = 0x01 << 3;
+		}
+		break;
+	case WRITE_16:
+		supported = 3;
+		if (dev->flags & ATA_DFLAG_CDL) {
+			/*
+			 * CDL write descriptors map to the T2B page, that is,
+			 * rwcdlp = 0x01 and cdlp = 0x02
+			 */
+			rwcdlp = 0x01;
+			cdlp = 0x02 << 3;
+		}
+		break;
 	case ZBC_IN:
 	case ZBC_OUT:
 		if (ata_id_zoned_cap(dev->id) ||
@@ -3290,7 +3310,9 @@ static unsigned int ata_scsiop_maint_in(struct ata_scsi_args *args, u8 *rbuf)
 		break;
 	}
 out:
-	rbuf[1] = supported; /* supported */
+	/* One command format */
+	rbuf[0] = rwcdlp;
+	rbuf[1] = cdlp | supported;
 	return err;
 }
 
-- 
2.39.2

[PATCH v4 16/19] ata: libata-scsi: add support for CDL pages mode sense

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Modify ata_scsiop_mode_sense() and ata_msense_control() to support mode
sense access to the T2A and T2B sub-pages of the control mode page.
ata_msense_control() is modified to support sub-pages. The T2A sub-page
is generated using the read descriptors of the command duration limits
log page 18h. The T2B sub-page is generated using the write descriptors
of the same log page. With the addition of these sub-pages, getting all
sub-pages of the control mode page is also supported by increasing the
value of ATA_SCSI_RBUF_SIZE from 576B up to 2048B to ensure that all
sub-pages fit in the fill buffer.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/ata/libata-scsi.c | 150 ++++++++++++++++++++++++++++++++------
 1 file changed, 128 insertions(+), 22 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 2a0a04c9e658..9315a4c01276 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -37,7 +37,7 @@
 #include "libata.h"
 #include "libata-transport.h"
 
-#define ATA_SCSI_RBUF_SIZE	576
+#define ATA_SCSI_RBUF_SIZE	2048
 
 static DEFINE_SPINLOCK(ata_scsi_rbuf_lock);
 static u8 ata_scsi_rbuf[ATA_SCSI_RBUF_SIZE];
@@ -55,6 +55,9 @@ static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
 #define CONTROL_MPAGE_LEN		12
 #define ALL_MPAGES			0x3f
 #define ALL_SUB_MPAGES			0xff
+#define CDL_T2A_SUB_MPAGE		0x07
+#define CDL_T2B_SUB_MPAGE		0x08
+#define CDL_T2_SUB_MPAGE_LEN		232
 
 static const u8 def_rw_recovery_mpage[RW_RECOVERY_MPAGE_LEN] = {
 	RW_RECOVERY_MPAGE,
@@ -2196,10 +2199,98 @@ static unsigned int ata_msense_caching(u16 *id, u8 *buf, bool changeable)
 	return sizeof(def_cache_mpage);
 }
 
+/*
+ * Simulate MODE SENSE control mode page, sub-page 0.
+ */
+static unsigned int ata_msense_control_spg0(struct ata_device *dev, u8 *buf,
+					    bool changeable)
+{
+	modecpy(buf, def_control_mpage,
+		sizeof(def_control_mpage), changeable);
+	if (changeable) {
+		/* ata_mselect_control() */
+		buf[2] |= (1 << 2);
+	} else {
+		bool d_sense = (dev->flags & ATA_DFLAG_D_SENSE);
+
+		/* descriptor format sense data */
+		buf[2] |= (d_sense << 2);
+	}
+
+	return sizeof(def_control_mpage);
+}
+
+/*
+ * Translate an ATA duration limit in microseconds to a SCSI duration limit
+ * using the t2cdlunits 0xa (10ms). Since the SCSI duration limits are 2-bytes
+ * only, take care of overflows.
+ */
+static inline u16 ata_xlat_cdl_limit(u8 *buf)
+{
+	u32 limit = get_unaligned_le32(buf);
+
+	return min_t(u32, limit / 10000, 65535);
+}
+
+/*
+ * Simulate MODE SENSE control mode page, sub-pages 07h and 08h
+ * (command duration limits T2A and T2B mode pages).
+ */
+static unsigned int ata_msense_control_spgt2(struct ata_device *dev, u8 *buf,
+					     u8 spg)
+{
+	u8 *b, *cdl = dev->cdl, *desc;
+	u32 policy;
+	int i;
+
+	/*
+	 * Fill the subpage. The first four bytes of the T2A/T2B mode pages
+	 * are a header. The PAGE LENGTH field is the size of the page
+	 * excluding the header.
+	 */
+	buf[0] = CONTROL_MPAGE;
+	buf[1] = spg;
+	put_unaligned_be16(CDL_T2_SUB_MPAGE_LEN - 4, &buf[2]);
+	if (spg == CDL_T2A_SUB_MPAGE) {
+		/*
+		 * Read descriptors map to the T2A page:
+		 * set perf_vs_duration_guidleine.
+		 */
+		buf[7] = (cdl[0] & 0x03) << 4;
+		desc = cdl + 64;
+	} else {
+		/* Write descriptors map to the T2B page */
+		desc = cdl + 288;
+	}
+
+	/* Fill the T2 page descriptors */
+	b = &buf[8];
+	policy = get_unaligned_le32(&cdl[0]);
+	for (i = 0; i < 7; i++, b += 32, desc += 32) {
+		/* t2cdlunits: fixed to 10ms */
+		b[0] = 0x0a;
+
+		/* Max inactive time and its policy */
+		put_unaligned_be16(ata_xlat_cdl_limit(&desc[8]), &b[2]);
+		b[6] = ((policy >> 8) & 0x0f) << 4;
+
+		/* Max active time and its policy */
+		put_unaligned_be16(ata_xlat_cdl_limit(&desc[4]), &b[4]);
+		b[6] |= (policy >> 4) & 0x0f;
+
+		/* Command duration guideline and its policy */
+		put_unaligned_be16(ata_xlat_cdl_limit(&desc[16]), &b[10]);
+		b[14] = policy & 0x0f;
+	}
+
+	return CDL_T2_SUB_MPAGE_LEN;
+}
+
 /**
  *	ata_msense_control - Simulate MODE SENSE control mode page
  *	@dev: ATA device of interest
  *	@buf: output buffer
+ *	@spg: sub-page code
  *	@changeable: whether changeable parameters are requested
  *
  *	Generate a generic MODE SENSE control mode page.
@@ -2208,17 +2299,24 @@ static unsigned int ata_msense_caching(u16 *id, u8 *buf, bool changeable)
  *	None.
  */
 static unsigned int ata_msense_control(struct ata_device *dev, u8 *buf,
-					bool changeable)
+				       u8 spg, bool changeable)
 {
-	modecpy(buf, def_control_mpage, sizeof(def_control_mpage), changeable);
-	if (changeable) {
-		buf[2] |= (1 << 2);	/* ata_mselect_control() */
-	} else {
-		bool d_sense = (dev->flags & ATA_DFLAG_D_SENSE);
-
-		buf[2] |= (d_sense << 2);	/* descriptor format sense data */
+	unsigned int n;
+
+	switch (spg) {
+	case 0:
+		return ata_msense_control_spg0(dev, buf, changeable);
+	case CDL_T2A_SUB_MPAGE:
+	case CDL_T2B_SUB_MPAGE:
+		return ata_msense_control_spgt2(dev, buf, spg);
+	case ALL_SUB_MPAGES:
+		n = ata_msense_control_spg0(dev, buf, changeable);
+		n += ata_msense_control_spgt2(dev, buf + n, CDL_T2A_SUB_MPAGE);
+		n += ata_msense_control_spgt2(dev, buf + n, CDL_T2A_SUB_MPAGE);
+		return n;
+	default:
+		return 0;
 	}
-	return sizeof(def_control_mpage);
 }
 
 /**
@@ -2291,13 +2389,24 @@ static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
 
 	pg = scsicmd[2] & 0x3f;
 	spg = scsicmd[3];
+
 	/*
-	 * No mode subpages supported (yet) but asking for _all_
-	 * subpages may be valid
+	 * Supported subpages: all subpages and sub-pages 07h and 08h of
+	 * the control page.
 	 */
-	if (spg && (spg != ALL_SUB_MPAGES)) {
-		fp = 3;
-		goto invalid_fld;
+	if (spg) {
+		switch (spg) {
+		case ALL_SUB_MPAGES:
+			break;
+		case CDL_T2A_SUB_MPAGE:
+		case CDL_T2B_SUB_MPAGE:
+			if (dev->flags & ATA_DFLAG_CDL && pg == CONTROL_MPAGE)
+				break;
+			fallthrough;
+		default:
+			fp = 3;
+			goto invalid_fld;
+		}
 	}
 
 	switch(pg) {
@@ -2310,13 +2419,13 @@ static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
 		break;
 
 	case CONTROL_MPAGE:
-		p += ata_msense_control(args->dev, p, page_control == 1);
+		p += ata_msense_control(args->dev, p, spg, page_control == 1);
 		break;
 
 	case ALL_MPAGES:
 		p += ata_msense_rw_recovery(p, page_control == 1);
 		p += ata_msense_caching(args->id, p, page_control == 1);
-		p += ata_msense_control(args->dev, p, page_control == 1);
+		p += ata_msense_control(args->dev, p, spg, page_control == 1);
 		break;
 
 	default:		/* invalid page code */
@@ -2335,10 +2444,7 @@ static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
 			memcpy(rbuf + 4, sat_blk_desc, sizeof(sat_blk_desc));
 		}
 	} else {
-		unsigned int output_len = p - rbuf - 2;
-
-		rbuf[0] = output_len >> 8;
-		rbuf[1] = output_len;
+		put_unaligned_be16(p - rbuf - 2, &rbuf[0]);
 		rbuf[3] |= dpofua;
 		if (ebd) {
 			rbuf[7] = sizeof(sat_blk_desc);
@@ -3637,7 +3743,7 @@ static int ata_mselect_control(struct ata_queued_cmd *qc,
 	/*
 	 * Check that read-only bits are not modified.
 	 */
-	ata_msense_control(dev, mpage, false);
+	ata_msense_control_spg0(dev, mpage, false);
 	for (i = 0; i < CONTROL_MPAGE_LEN - 2; i++) {
 		if (i == 0)
 			continue;
-- 
2.39.2

[PATCH v4 17/19] ata: libata: add ATA feature control sub-page translation

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Add support for the ATA feature control sub-page of the control mode
page to enable/disable the command duration limits feature using the
cdl_ctrl field of the ATA feature control sub-page.

Both mode sense and mode select translation are supported. For mode
sense, the ata device flag ATA_DFLAG_CDL_ENABLED is used to cache the
status of the command duration limits feature. Enabling this feature is
done using a SET FEATURES command with a cdl action set to 1 when the
page cdl_ctrl field value is 0x2 (T2A and T2B pages supported). If this
field is 0, CDL is disabled using the SET FEATURES command with a cdl
action set to 0.

Since a device CDL and NCQ priority features should not be used
simultaneously, ata_mselect_control_ata_feature() returns an error when
attempting to enable CDL with the device priority feature enabled.
Conversely, the function ata_ncq_prio_enable_store() used to enable the
use of the device NCQ priority feature through sysfs is modified to
return an error if the device CDL feature is enabled.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/ata/libata-core.c |  40 ++++++++-
 drivers/ata/libata-sata.c |  11 ++-
 drivers/ata/libata-scsi.c | 167 ++++++++++++++++++++++++++++++++------
 include/linux/ata.h       |   3 +
 include/linux/libata.h    |   1 +
 5 files changed, 193 insertions(+), 29 deletions(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 78e53f4fa741..62e100fa90e2 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2371,13 +2371,15 @@ static void ata_dev_config_cdl(struct ata_device *dev)
 {
 	struct ata_port *ap = dev->link->ap;
 	unsigned int err_mask;
+	bool cdl_enabled;
 	u64 val;
 
 	if (ata_id_major_version(dev->id) < 12)
 		goto not_supported;
 
 	if (!ata_log_supported(dev, ATA_LOG_IDENTIFY_DEVICE) ||
-	    !ata_identify_page_supported(dev, ATA_LOG_SUPPORTED_CAPABILITIES))
+	    !ata_identify_page_supported(dev, ATA_LOG_SUPPORTED_CAPABILITIES) ||
+	    !ata_identify_page_supported(dev, ATA_LOG_CURRENT_SETTINGS))
 		goto not_supported;
 
 	err_mask = ata_read_log_page(dev, ATA_LOG_IDENTIFY_DEVICE,
@@ -2396,6 +2398,40 @@ static void ata_dev_config_cdl(struct ata_device *dev)
 		ata_dev_warn(dev,
 			"Command duration guideline is not supported\n");
 
+	/*
+	 * If CDL is marked as enabled, make sure the feature is enabled too.
+	 * Conversely, if CDL is disabled, make sure the feature is turned off.
+	 */
+	err_mask = ata_read_log_page(dev, ATA_LOG_IDENTIFY_DEVICE,
+				     ATA_LOG_CURRENT_SETTINGS,
+				     ap->sector_buf, 1);
+	if (err_mask)
+		goto not_supported;
+
+	val = get_unaligned_le64(&ap->sector_buf[8]);
+	cdl_enabled = val & BIT_ULL(63) && val & BIT_ULL(21);
+	if (dev->flags & ATA_DFLAG_CDL_ENABLED) {
+		if (!cdl_enabled) {
+			/* Enable CDL on the device */
+			err_mask = ata_dev_set_feature(dev, SETFEATURES_CDL, 1);
+			if (err_mask) {
+				ata_dev_err(dev,
+					    "Enable CDL feature failed\n");
+				goto not_supported;
+			}
+		}
+	} else {
+		if (cdl_enabled) {
+			/* Disable CDL on the device */
+			err_mask = ata_dev_set_feature(dev, SETFEATURES_CDL, 0);
+			if (err_mask) {
+				ata_dev_err(dev,
+					    "Disable CDL feature failed\n");
+				goto not_supported;
+			}
+		}
+	}
+
 	/*
 	 * Command duration limits is supported: cache the CDL log page 18h
 	 * (command duration descriptors).
@@ -2412,7 +2448,7 @@ static void ata_dev_config_cdl(struct ata_device *dev)
 	return;
 
 not_supported:
-	dev->flags &= ~ATA_DFLAG_CDL;
+	dev->flags &= ~(ATA_DFLAG_CDL | ATA_DFLAG_CDL_ENABLED);
 }
 
 static int ata_dev_config_lba(struct ata_device *dev)
diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
index f3e7396e3191..57cb33060c9d 100644
--- a/drivers/ata/libata-sata.c
+++ b/drivers/ata/libata-sata.c
@@ -907,10 +907,17 @@ static ssize_t ata_ncq_prio_enable_store(struct device *device,
 		goto unlock;
 	}
 
-	if (input)
+	if (input) {
+		if (dev->flags & ATA_DFLAG_CDL_ENABLED) {
+			ata_dev_err(dev,
+				"CDL must be disabled to enable NCQ priority\n");
+			rc = -EINVAL;
+			goto unlock;
+		}
 		dev->flags |= ATA_DFLAG_NCQ_PRIO_ENABLED;
-	else
+	} else {
 		dev->flags &= ~ATA_DFLAG_NCQ_PRIO_ENABLED;
+	}
 
 unlock:
 	spin_unlock_irq(ap->lock);
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 9315a4c01276..8dde1cede5ca 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -58,6 +58,8 @@ static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
 #define CDL_T2A_SUB_MPAGE		0x07
 #define CDL_T2B_SUB_MPAGE		0x08
 #define CDL_T2_SUB_MPAGE_LEN		232
+#define ATA_FEATURE_SUB_MPAGE		0xf2
+#define ATA_FEATURE_SUB_MPAGE_LEN	16
 
 static const u8 def_rw_recovery_mpage[RW_RECOVERY_MPAGE_LEN] = {
 	RW_RECOVERY_MPAGE,
@@ -2286,6 +2288,31 @@ static unsigned int ata_msense_control_spgt2(struct ata_device *dev, u8 *buf,
 	return CDL_T2_SUB_MPAGE_LEN;
 }
 
+/*
+ * Simulate MODE SENSE control mode page, sub-page f2h
+ * (ATA feature control mode page).
+ */
+static unsigned int ata_msense_control_ata_feature(struct ata_device *dev,
+						   u8 *buf)
+{
+	/* PS=0, SPF=1 */
+	buf[0] = CONTROL_MPAGE | (1 << 6);
+	buf[1] = ATA_FEATURE_SUB_MPAGE;
+
+	/*
+	 * The first four bytes of ATA Feature Control mode page are a header.
+	 * The PAGE LENGTH field is the size of the page excluding the header.
+	 */
+	put_unaligned_be16(ATA_FEATURE_SUB_MPAGE_LEN - 4, &buf[2]);
+
+	if (dev->flags & ATA_DFLAG_CDL)
+		buf[4] = 0x02; /* Support T2A and T2B pages */
+	else
+		buf[4] = 0;
+
+	return ATA_FEATURE_SUB_MPAGE_LEN;
+}
+
 /**
  *	ata_msense_control - Simulate MODE SENSE control mode page
  *	@dev: ATA device of interest
@@ -2309,10 +2336,13 @@ static unsigned int ata_msense_control(struct ata_device *dev, u8 *buf,
 	case CDL_T2A_SUB_MPAGE:
 	case CDL_T2B_SUB_MPAGE:
 		return ata_msense_control_spgt2(dev, buf, spg);
+	case ATA_FEATURE_SUB_MPAGE:
+		return ata_msense_control_ata_feature(dev, buf);
 	case ALL_SUB_MPAGES:
 		n = ata_msense_control_spg0(dev, buf, changeable);
 		n += ata_msense_control_spgt2(dev, buf + n, CDL_T2A_SUB_MPAGE);
 		n += ata_msense_control_spgt2(dev, buf + n, CDL_T2A_SUB_MPAGE);
+		n += ata_msense_control_ata_feature(dev, buf + n);
 		return n;
 	default:
 		return 0;
@@ -2391,7 +2421,7 @@ static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
 	spg = scsicmd[3];
 
 	/*
-	 * Supported subpages: all subpages and sub-pages 07h and 08h of
+	 * Supported subpages: all subpages and sub-pages 07h, 08h and f2h of
 	 * the control page.
 	 */
 	if (spg) {
@@ -2400,6 +2430,7 @@ static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
 			break;
 		case CDL_T2A_SUB_MPAGE:
 		case CDL_T2B_SUB_MPAGE:
+		case ATA_FEATURE_SUB_MPAGE:
 			if (dev->flags & ATA_DFLAG_CDL && pg == CONTROL_MPAGE)
 				break;
 			fallthrough;
@@ -3708,20 +3739,11 @@ static int ata_mselect_caching(struct ata_queued_cmd *qc,
 	return 0;
 }
 
-/**
- *	ata_mselect_control - Simulate MODE SELECT for control page
- *	@qc: Storage for translated ATA taskfile
- *	@buf: input buffer
- *	@len: number of valid bytes in the input buffer
- *	@fp: out parameter for the failed field on error
- *
- *	Prepare a taskfile to modify caching information for the device.
- *
- *	LOCKING:
- *	None.
+/*
+ * Simulate MODE SELECT control mode page, sub-page 0.
  */
-static int ata_mselect_control(struct ata_queued_cmd *qc,
-			       const u8 *buf, int len, u16 *fp)
+static int ata_mselect_control_spg0(struct ata_queued_cmd *qc,
+				    const u8 *buf, int len, u16 *fp)
 {
 	struct ata_device *dev = qc->dev;
 	u8 mpage[CONTROL_MPAGE_LEN];
@@ -3759,6 +3781,83 @@ static int ata_mselect_control(struct ata_queued_cmd *qc,
 	return 0;
 }
 
+/*
+ * Translate MODE SELECT control mode page, sub-pages f2h (ATA feature mode
+ * page) into a SET FEATURES command.
+ */
+static unsigned int ata_mselect_control_ata_feature(struct ata_queued_cmd *qc,
+						    const u8 *buf, int len,
+						    u16 *fp)
+{
+	struct ata_device *dev = qc->dev;
+	struct ata_taskfile *tf = &qc->tf;
+	u8 cdl_action;
+
+	/*
+	 * The first four bytes of ATA Feature Control mode page are a header,
+	 * so offsets in mpage are off by 4 compared to buf.  Same for len.
+	 */
+	if (len != ATA_FEATURE_SUB_MPAGE_LEN - 4) {
+		*fp = min(len, ATA_FEATURE_SUB_MPAGE_LEN - 4);
+		return -EINVAL;
+	}
+
+	/* Check cdl_ctrl */
+	switch (buf[0] & 0x03) {
+	case 0:
+		/* Disable CDL */
+		cdl_action = 0;
+		dev->flags &= ~ATA_DFLAG_CDL_ENABLED;
+		break;
+	case 0x02:
+		/* Enable CDL T2A/T2B: NCQ priority must be disabled */
+		if (dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED) {
+			ata_dev_err(dev,
+				"NCQ priority must be disabled to enable CDL\n");
+			return -EINVAL;
+		}
+		cdl_action = 1;
+		dev->flags |= ATA_DFLAG_CDL_ENABLED;
+		break;
+	default:
+		*fp = 0;
+		return -EINVAL;
+	}
+
+	tf->flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
+	tf->protocol = ATA_PROT_NODATA;
+	tf->command = ATA_CMD_SET_FEATURES;
+	tf->feature = SETFEATURES_CDL;
+	tf->nsect = cdl_action;
+
+	return 1;
+}
+
+/**
+ *	ata_mselect_control - Simulate MODE SELECT for control page
+ *	@qc: Storage for translated ATA taskfile
+ *	@buf: input buffer
+ *	@len: number of valid bytes in the input buffer
+ *	@fp: out parameter for the failed field on error
+ *
+ *	Prepare a taskfile to modify caching information for the device.
+ *
+ *	LOCKING:
+ *	None.
+ */
+static int ata_mselect_control(struct ata_queued_cmd *qc, u8 spg,
+			       const u8 *buf, int len, u16 *fp)
+{
+	switch (spg) {
+	case 0:
+		return ata_mselect_control_spg0(qc, buf, len, fp);
+	case ATA_FEATURE_SUB_MPAGE:
+		return ata_mselect_control_ata_feature(qc, buf, len, fp);
+	default:
+		return -EINVAL;
+	}
+}
+
 /**
  *	ata_scsi_mode_select_xlat - Simulate MODE SELECT 6, 10 commands
  *	@qc: Storage for translated ATA taskfile
@@ -3776,7 +3875,7 @@ static unsigned int ata_scsi_mode_select_xlat(struct ata_queued_cmd *qc)
 	const u8 *cdb = scmd->cmnd;
 	u8 pg, spg;
 	unsigned six_byte, pg_len, hdr_len, bd_len;
-	int len;
+	int len, ret;
 	u16 fp = (u16)-1;
 	u8 bp = 0xff;
 	u8 buffer[64];
@@ -3861,13 +3960,29 @@ static unsigned int ata_scsi_mode_select_xlat(struct ata_queued_cmd *qc)
 	}
 
 	/*
-	 * No mode subpages supported (yet) but asking for _all_
-	 * subpages may be valid
+	 * Supported subpages: all subpages and ATA feature sub-page f2h of
+	 * the control page.
 	 */
-	if (spg && (spg != ALL_SUB_MPAGES)) {
-		fp = (p[0] & 0x40) ? 1 : 0;
-		fp += hdr_len + bd_len;
-		goto invalid_param;
+	if (spg) {
+		switch (spg) {
+		case ALL_SUB_MPAGES:
+			/* All subpages is not supported for the control page */
+			if (pg == CONTROL_MPAGE) {
+				fp = (p[0] & 0x40) ? 1 : 0;
+				fp += hdr_len + bd_len;
+				goto invalid_param;
+			}
+			break;
+		case ATA_FEATURE_SUB_MPAGE:
+			if (qc->dev->flags & ATA_DFLAG_CDL &&
+			    pg == CONTROL_MPAGE)
+				break;
+			fallthrough;
+		default:
+			fp = (p[0] & 0x40) ? 1 : 0;
+			fp += hdr_len + bd_len;
+			goto invalid_param;
+		}
 	}
 	if (pg_len > len)
 		goto invalid_param_len;
@@ -3880,14 +3995,16 @@ static unsigned int ata_scsi_mode_select_xlat(struct ata_queued_cmd *qc)
 		}
 		break;
 	case CONTROL_MPAGE:
-		if (ata_mselect_control(qc, p, pg_len, &fp) < 0) {
+		ret = ata_mselect_control(qc, spg, p, pg_len, &fp);
+		if (ret < 0) {
 			fp += hdr_len + bd_len;
 			goto invalid_param;
-		} else {
-			goto skip; /* No ATA command to send */
 		}
+		if (!ret)
+			goto skip; /* No ATA command to send */
 		break;
-	default:		/* invalid page code */
+	default:
+		/* Invalid page code */
 		fp = bd_len + hdr_len;
 		goto invalid_param;
 	}
diff --git a/include/linux/ata.h b/include/linux/ata.h
index b01e2cebe1fe..a59b17d6ad11 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -330,6 +330,7 @@ enum {
 
 	/* Identify device log pages: */
 	ATA_LOG_SUPPORTED_CAPABILITIES	= 0x03,
+	ATA_LOG_CURRENT_SETTINGS  = 0x04,
 	ATA_LOG_SECURITY	  = 0x06,
 	ATA_LOG_SATA_SETTINGS	  = 0x08,
 	ATA_LOG_ZONED_INFORMATION = 0x09,
@@ -419,6 +420,8 @@ enum {
 	SETFEATURES_SATA_ENABLE = 0x10, /* Enable use of SATA feature */
 	SETFEATURES_SATA_DISABLE = 0x90, /* Disable use of SATA feature */
 
+	SETFEATURES_CDL		= 0x0d, /* Enable/disable cmd duration limits */
+
 	/* SETFEATURE Sector counts for SATA features */
 	SATA_FPDMA_OFFSET	= 0x01,	/* FPDMA non-zero buffer offsets */
 	SATA_FPDMA_AA		= 0x02, /* FPDMA Setup FIS Auto-Activate */
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 2b17d6c99a37..d7fe735e6322 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -106,6 +106,7 @@ enum {
 	ATA_DFLAG_INIT_MASK	= (1 << 20) - 1,
 
 	ATA_DFLAG_NCQ_PRIO_ENABLED = (1 << 20), /* Priority cmds sent to dev */
+	ATA_DFLAG_CDL_ENABLED	= (1 << 21), /* cmd duration limits is enabled */
 	ATA_DFLAG_DETACH	= (1 << 24),
 	ATA_DFLAG_DETACHED	= (1 << 25),
 	ATA_DFLAG_DA		= (1 << 26), /* device supports Device Attention */
-- 
2.39.2

[PATCH v4 18/19] ata: libata: set read/write commands CDL index

[Niklas Cassel]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

For devices supporting the command duration limits feature, when a read
or write operation has an IO priority specifying one of the
IOPRIO_HINT_DEV_DURATION_LIMIT_X hint and the command duration limits
feature is enabled, set the command duration limit index field of the
command using the hint value.

The function ata_set_tf_cdl() is introduced to do this. For unqueued
(non NCQ) read and write operations, this function sets the command
duration limit index set as the lower 2 bits of the feature field.
For queued NCQ read/write commands, the index is set as the lower
2 bits of the auxiliary field.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
---
 drivers/ata/libata-core.c | 42 ++++++++++++++++++++++++++++++++++-----
 drivers/ata/libata-scsi.c |  3 +--
 drivers/ata/libata.h      |  2 +-
 include/linux/libata.h    |  1 +
 4 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 62e100fa90e2..90764aeb5446 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -665,13 +665,36 @@ u64 ata_tf_read_block(const struct ata_taskfile *tf, struct ata_device *dev)
 	return block;
 }
 
+/*
+ * Set a taskfile CDL index.
+ */
+static inline void ata_set_tf_cdl(struct ata_queued_cmd *qc, int ioprio)
+{
+	struct ata_taskfile *tf = &qc->tf;
+	unsigned int hint = IOPRIO_PRIO_HINT(ioprio);
+	int cdl;
+
+	if (hint < IOPRIO_HINT_DEV_DURATION_LIMIT_1 ||
+	    hint > IOPRIO_HINT_DEV_DURATION_LIMIT_7)
+		return;
+
+	cdl = (hint - IOPRIO_HINT_DEV_DURATION_LIMIT_1) + 1;
+	if (tf->protocol == ATA_PROT_NCQ)
+		tf->auxiliary |= cdl;
+	else
+		tf->feature |= cdl;
+
+	/* Mark this command as having a CDL */
+	qc->flags |= ATA_QCFLAG_HAS_CDL;
+}
+
 /**
  *	ata_build_rw_tf - Build ATA taskfile for given read/write request
  *	@qc: Metadata associated with the taskfile to build
  *	@block: Block address
  *	@n_block: Number of blocks
  *	@tf_flags: RW/FUA etc...
- *	@class: IO priority class
+ *	@ioprio: IO priority class and level
  *
  *	LOCKING:
  *	None.
@@ -685,7 +708,7 @@ u64 ata_tf_read_block(const struct ata_taskfile *tf, struct ata_device *dev)
  *	-EINVAL if the request is invalid.
  */
 int ata_build_rw_tf(struct ata_queued_cmd *qc, u64 block, u32 n_block,
-		    unsigned int tf_flags, int class)
+		    unsigned int tf_flags, int ioprio)
 {
 	struct ata_taskfile *tf = &qc->tf;
 	struct ata_device *dev = qc->dev;
@@ -722,13 +745,22 @@ int ata_build_rw_tf(struct ata_queued_cmd *qc, u64 block, u32 n_block,
 			tf->device |= 1 << 7;
 
 		if (dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED &&
-		    class == IOPRIO_CLASS_RT)
+		    IOPRIO_PRIO_CLASS(ioprio) == IOPRIO_CLASS_RT)
 			tf->hob_nsect |= ATA_PRIO_HIGH << ATA_SHIFT_PRIO;
+
+		if (dev->flags & ATA_DFLAG_CDL_ENABLED)
+			ata_set_tf_cdl(qc, ioprio);
+
 	} else if (dev->flags & ATA_DFLAG_LBA) {
 		tf->flags |= ATA_TFLAG_LBA;
 
-		/* We need LBA48 for FUA writes */
-		if (!(tf->flags & ATA_TFLAG_FUA) && lba_28_ok(block, n_block)) {
+		if (dev->flags & ATA_DFLAG_CDL_ENABLED)
+			ata_set_tf_cdl(qc, ioprio);
+
+		/* Both FUA writes and a CDL index require 48-bit commands */
+		if (!(tf->flags & ATA_TFLAG_FUA) &&
+		    !(qc->flags & ATA_QCFLAG_HAS_CDL) &&
+		    lba_28_ok(block, n_block)) {
 			/* use LBA28 */
 			tf->device |= (block >> 24) & 0xf;
 		} else if (lba_48_ok(block, n_block)) {
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 8dde1cede5ca..ce5c6a49a098 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1546,7 +1546,6 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc)
 	struct scsi_cmnd *scmd = qc->scsicmd;
 	const u8 *cdb = scmd->cmnd;
 	struct request *rq = scsi_cmd_to_rq(scmd);
-	int class = IOPRIO_PRIO_CLASS(req_get_ioprio(rq));
 	unsigned int tf_flags = 0;
 	u64 block;
 	u32 n_block;
@@ -1622,7 +1621,7 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc)
 	qc->flags |= ATA_QCFLAG_IO;
 	qc->nbytes = n_block * scmd->device->sector_size;
 
-	rc = ata_build_rw_tf(qc, block, n_block, tf_flags, class);
+	rc = ata_build_rw_tf(qc, block, n_block, tf_flags, req_get_ioprio(rq));
 	if (likely(rc == 0))
 		return 0;
 
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 2cd6124a01e8..26aa777a2ad0 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -45,7 +45,7 @@ static inline void ata_force_cbl(struct ata_port *ap) { }
 extern u64 ata_tf_to_lba(const struct ata_taskfile *tf);
 extern u64 ata_tf_to_lba48(const struct ata_taskfile *tf);
 extern int ata_build_rw_tf(struct ata_queued_cmd *qc, u64 block, u32 n_block,
-			   unsigned int tf_flags, int class);
+			   unsigned int tf_flags, int ioprio);
 extern u64 ata_tf_read_block(const struct ata_taskfile *tf,
 			     struct ata_device *dev);
 extern unsigned ata_exec_internal(struct ata_device *dev,
diff --git a/include/linux/libata.h b/include/linux/libata.h
index d7fe735e6322..ab8b62036c12 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -209,6 +209,7 @@ enum {
 	ATA_QCFLAG_CLEAR_EXCL	= (1 << 5), /* clear excl_link on completion */
 	ATA_QCFLAG_QUIET	= (1 << 6), /* don't report device error */
 	ATA_QCFLAG_RETRY	= (1 << 7), /* retry after failure */
+	ATA_QCFLAG_HAS_CDL	= (1 << 8), /* qc has CDL a descriptor set */
 
 	ATA_QCFLAG_EH		= (1 << 16), /* cmd aborted and owned by EH */
 	ATA_QCFLAG_SENSE_VALID	= (1 << 17), /* sense data valid */
-- 
2.39.2

[PATCH v4 19/19] ata: libata: handle completion of CDL commands using policy 0xD

[Niklas Cassel]

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 <damien.lemoal@opensource.wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/ata/libata-core.c |  88 +++++++++++++++++++++++++++++++-
 drivers/ata/libata-eh.c   | 105 +++++++++++++++++++++++++++++++++++++-
 drivers/ata/libata-sata.c |  92 +++++++++++++++++++++++++++++++++
 include/linux/ata.h       |   3 ++
 include/linux/libata.h    |  11 +++-
 5 files changed, 295 insertions(+), 4 deletions(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 90764aeb5446..44ac541c4472 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -684,8 +684,12 @@ static inline void ata_set_tf_cdl(struct ata_queued_cmd *qc, int ioprio)
 	else
 		tf->feature |= cdl;
 
-	/* Mark this command as having a CDL */
-	qc->flags |= ATA_QCFLAG_HAS_CDL;
+	/*
+	 * Mark this command as having a CDL and request the result
+	 * task file so that we can inspect the sense data available
+	 * bit on completion.
+	 */
+	qc->flags |= ATA_QCFLAG_HAS_CDL | ATA_QCFLAG_RESULT_TF;
 }
 
 /**
@@ -2430,6 +2434,24 @@ static void ata_dev_config_cdl(struct ata_device *dev)
 		ata_dev_warn(dev,
 			"Command duration guideline is not supported\n");
 
+	/*
+	 * We must have support for the sense data for successful NCQ commands
+	 * log indicated by the successful NCQ command sense data supported bit.
+	 */
+	val = get_unaligned_le64(&ap->sector_buf[8]);
+	if (!(val & BIT_ULL(63)) || !(val & BIT_ULL(47))) {
+		ata_dev_warn(dev,
+			"CDL supported but Successful NCQ Command Sense Data is not supported\n");
+		goto not_supported;
+	}
+
+	/* Without NCQ autosense, the successful NCQ commands log is useless. */
+	if (!ata_id_has_ncq_autosense(dev->id)) {
+		ata_dev_warn(dev,
+			"CDL supported but NCQ autosense is not supported\n");
+		goto not_supported;
+	}
+
 	/*
 	 * If CDL is marked as enabled, make sure the feature is enabled too.
 	 * Conversely, if CDL is disabled, make sure the feature is turned off.
@@ -2464,6 +2486,35 @@ static void ata_dev_config_cdl(struct ata_device *dev)
 		}
 	}
 
+	/*
+	 * While CDL itself has to be enabled using sysfs, CDL requires that
+	 * sense data for successful NCQ commands is enabled to work properly.
+	 * Just like ata_dev_config_sense_reporting(), enable it unconditionally
+	 * if supported.
+	 */
+	if (!(val & BIT_ULL(63)) || !(val & BIT_ULL(18))) {
+		err_mask = ata_dev_set_feature(dev,
+					SETFEATURE_SENSE_DATA_SUCC_NCQ, 0x1);
+		if (err_mask) {
+			ata_dev_warn(dev,
+				     "failed to enable Sense Data for successful NCQ commands, Emask 0x%x\n",
+				     err_mask);
+			goto not_supported;
+		}
+	}
+
+	/*
+	 * Allocate a buffer to handle reading the sense data for successful
+	 * NCQ Commands log page for commands using a CDL with one of the limit
+	 * policy set to 0xD (successful completion with sense data available
+	 * bit set).
+	 */
+	if (!ap->ncq_sense_buf) {
+		ap->ncq_sense_buf = kmalloc(ATA_LOG_SENSE_NCQ_SIZE, GFP_KERNEL);
+		if (!ap->ncq_sense_buf)
+			goto not_supported;
+	}
+
 	/*
 	 * Command duration limits is supported: cache the CDL log page 18h
 	 * (command duration descriptors).
@@ -2481,6 +2532,8 @@ static void ata_dev_config_cdl(struct ata_device *dev)
 
 not_supported:
 	dev->flags &= ~(ATA_DFLAG_CDL | ATA_DFLAG_CDL_ENABLED);
+	kfree(ap->ncq_sense_buf);
+	ap->ncq_sense_buf = NULL;
 }
 
 static int ata_dev_config_lba(struct ata_device *dev)
@@ -4884,6 +4937,36 @@ void ata_qc_complete(struct ata_queued_cmd *qc)
 			fill_result_tf(qc);
 
 		trace_ata_qc_complete_done(qc);
+
+		/*
+		 * For CDL commands that completed without an error, check if
+		 * we have sense data (ATA_SENSE is set). If we do, then the
+		 * command may have been aborted by the device due to a limit
+		 * timeout using the policy 0xD. For these commands, invoke EH
+		 * to get the command sense data.
+		 */
+		if (qc->result_tf.status & ATA_SENSE &&
+		    ((ata_is_ncq(qc->tf.protocol) &&
+		      dev->flags & ATA_DFLAG_CDL_ENABLED) ||
+		     (!(ata_is_ncq(qc->tf.protocol) &&
+			ata_id_sense_reporting_enabled(dev->id))))) {
+			/*
+			 * Tell SCSI EH to not overwrite scmd->result even if
+			 * this command is finished with result SAM_STAT_GOOD.
+			 */
+			qc->scsicmd->flags |= SCMD_FORCE_EH_SUCCESS;
+			qc->flags |= ATA_QCFLAG_EH_SUCCESS_CMD;
+			ehi->dev_action[dev->devno] |= ATA_EH_GET_SUCCESS_SENSE;
+
+			/*
+			 * set pending so that ata_qc_schedule_eh() does not
+			 * trigger fast drain, and freeze the port.
+			 */
+			ap->pflags |= ATA_PFLAG_EH_PENDING;
+			ata_qc_schedule_eh(qc);
+			return;
+		}
+
 		/* Some commands need post-processing after successful
 		 * completion.
 		 */
@@ -5516,6 +5599,7 @@ static void ata_host_release(struct kref *kref)
 
 		kfree(ap->pmp_link);
 		kfree(ap->slave_link);
+		kfree(ap->ncq_sense_buf);
 		kfree(ap);
 		host->ports[i] = NULL;
 	}
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 598ae07195b6..05af292eb8ce 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1917,6 +1917,99 @@ static inline bool ata_eh_quiet(struct ata_queued_cmd *qc)
 	return qc->flags & ATA_QCFLAG_QUIET;
 }
 
+static int ata_eh_read_sense_success_non_ncq(struct ata_link *link)
+{
+	struct ata_port *ap = link->ap;
+	struct ata_queued_cmd *qc;
+
+	qc = __ata_qc_from_tag(ap, link->active_tag);
+	if (!qc)
+		return -EIO;
+
+	if (!(qc->flags & ATA_QCFLAG_EH) ||
+	    !(qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD) ||
+	    qc->err_mask)
+		return -EIO;
+
+	if (!ata_eh_request_sense(qc))
+		return -EIO;
+
+	/*
+	 * If we have sense data, call scsi_check_sense() in order to set the
+	 * correct SCSI ML byte (if any). No point in checking the return value,
+	 * since the command has already completed successfully.
+	 */
+	scsi_check_sense(qc->scsicmd);
+
+	return 0;
+}
+
+static void ata_eh_get_success_sense(struct ata_link *link)
+{
+	struct ata_eh_context *ehc = &link->eh_context;
+	struct ata_device *dev = link->device;
+	struct ata_port *ap = link->ap;
+	struct ata_queued_cmd *qc;
+	int tag, ret = 0;
+
+	if (!(ehc->i.dev_action[dev->devno] & ATA_EH_GET_SUCCESS_SENSE))
+		return;
+
+	/* if frozen, we can't do much */
+	if (ata_port_is_frozen(ap)) {
+		ata_dev_warn(dev,
+			"successful sense data available but port frozen\n");
+		goto out;
+	}
+
+	/*
+	 * If the link has sactive set, then we have outstanding NCQ commands
+	 * and have to read the Successful NCQ Commands log to get the sense
+	 * data. Otherwise, we are dealing with a non-NCQ command and use
+	 * request sense ext command to retrieve the sense data.
+	 */
+	if (link->sactive)
+		ret = ata_eh_read_sense_success_ncq_log(link);
+	else
+		ret = ata_eh_read_sense_success_non_ncq(link);
+	if (ret)
+		goto out;
+
+	ata_eh_done(link, dev, ATA_EH_GET_SUCCESS_SENSE);
+	return;
+
+out:
+	/*
+	 * If we failed to get sense data for a successful command that ought to
+	 * have sense data, we cannot simply return BLK_STS_OK to user space.
+	 * This is because we can't know if the sense data that we couldn't get
+	 * was actually "DATA CURRENTLY UNAVAILABLE". Reporting such a command
+	 * as success to user space would result in a silent data corruption.
+	 * Thus, add a bogus ABORTED_COMMAND sense data to such commands, such
+	 * that SCSI will report these commands as BLK_STS_IOERR to user space.
+	 */
+	ata_qc_for_each_raw(ap, qc, tag) {
+		if (!(qc->flags & ATA_QCFLAG_EH) ||
+		    !(qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD) ||
+		    qc->err_mask ||
+		    ata_dev_phys_link(qc->dev) != link)
+			continue;
+
+		/* We managed to get sense for this success command, skip. */
+		if (qc->flags & ATA_QCFLAG_SENSE_VALID)
+			continue;
+
+		/* This success command did not have any sense data, skip. */
+		if (!(qc->result_tf.status & ATA_SENSE))
+			continue;
+
+		/* This success command had sense data, but we failed to get. */
+		ata_scsi_set_sense(dev, qc->scsicmd, ABORTED_COMMAND, 0, 0);
+		qc->flags |= ATA_QCFLAG_SENSE_VALID;
+	}
+	ata_eh_done(link, dev, ATA_EH_GET_SUCCESS_SENSE);
+}
+
 /**
  *	ata_eh_link_autopsy - analyze error and determine recovery action
  *	@link: host link to perform autopsy on
@@ -1957,6 +2050,14 @@ static void ata_eh_link_autopsy(struct ata_link *link)
 	/* analyze NCQ failure */
 	ata_eh_analyze_ncq_error(link);
 
+	/*
+	 * Check if this was a successful command that simply needs sense data.
+	 * Since the sense data is not part of the completion, we need to fetch
+	 * it using an additional command. Since this can't be done from irq
+	 * context, the sense data for successful commands are fetched by EH.
+	 */
+	ata_eh_get_success_sense(link);
+
 	/* any real error trumps AC_ERR_OTHER */
 	if (ehc->i.err_mask & ~AC_ERR_OTHER)
 		ehc->i.err_mask &= ~AC_ERR_OTHER;
@@ -1966,6 +2067,7 @@ static void ata_eh_link_autopsy(struct ata_link *link)
 	ata_qc_for_each_raw(ap, qc, tag) {
 		if (!(qc->flags & ATA_QCFLAG_EH) ||
 		    qc->flags & ATA_QCFLAG_RETRY ||
+		    qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD ||
 		    ata_dev_phys_link(qc->dev) != link)
 			continue;
 
@@ -3825,7 +3927,8 @@ void ata_eh_finish(struct ata_port *ap)
 			else
 				ata_eh_qc_complete(qc);
 		} else {
-			if (qc->flags & ATA_QCFLAG_SENSE_VALID) {
+			if (qc->flags & ATA_QCFLAG_SENSE_VALID ||
+			    qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD) {
 				ata_eh_qc_complete(qc);
 			} else {
 				/* feed zero TF to sense generation */
diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
index 57cb33060c9d..7de4d8901fac 100644
--- a/drivers/ata/libata-sata.c
+++ b/drivers/ata/libata-sata.c
@@ -11,7 +11,9 @@
 #include <linux/module.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_device.h>
+#include <scsi/scsi_eh.h>
 #include <linux/libata.h>
+#include <asm/unaligned.h>
 
 #include "libata.h"
 #include "libata-transport.h"
@@ -1408,6 +1410,95 @@ static int ata_eh_read_log_10h(struct ata_device *dev,
 	return 0;
 }
 
+/**
+ *	ata_eh_read_sense_success_ncq_log - Read the sense data for successful
+ *					    NCQ commands log
+ *	@link: ATA link to get sense data for
+ *
+ *	Read the sense data for successful NCQ commands log page to obtain
+ *	sense data for all NCQ commands that completed successfully with
+ *	the sense data available bit set.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno otherwise.
+ */
+int ata_eh_read_sense_success_ncq_log(struct ata_link *link)
+{
+	struct ata_device *dev = link->device;
+	struct ata_port *ap = dev->link->ap;
+	u8 *buf = ap->ncq_sense_buf;
+	struct ata_queued_cmd *qc;
+	unsigned int err_mask, tag;
+	u8 *sense, sk = 0, asc = 0, ascq = 0;
+	u64 sense_valid, val;
+	int ret = 0;
+
+	err_mask = ata_read_log_page(dev, ATA_LOG_SENSE_NCQ, 0, buf, 2);
+	if (err_mask) {
+		ata_dev_err(dev,
+			"Failed to read Sense Data for Successful NCQ Commands log\n");
+		return -EIO;
+	}
+
+	/* Check the log header */
+	val = get_unaligned_le64(&buf[0]);
+	if ((val & 0xffff) != 1 || ((val >> 16) & 0xff) != 0x0f) {
+		ata_dev_err(dev,
+			"Invalid Sense Data for Successful NCQ Commands log\n");
+		return -EIO;
+	}
+
+	sense_valid = (u64)buf[8] | ((u64)buf[9] << 8) |
+		((u64)buf[10] << 16) | ((u64)buf[11] << 24);
+
+	ata_qc_for_each_raw(ap, qc, tag) {
+		if (!(qc->flags & ATA_QCFLAG_EH) ||
+		    !(qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD) ||
+		    qc->err_mask ||
+		    ata_dev_phys_link(qc->dev) != link)
+			continue;
+
+		/*
+		 * If the command does not have any sense data, clear ATA_SENSE.
+		 * Keep ATA_QCFLAG_EH_SUCCESS_CMD so that command is finished.
+		 */
+		if (!(sense_valid & (1ULL << tag))) {
+			qc->result_tf.status &= ~ATA_SENSE;
+			continue;
+		}
+
+		sense = &buf[32 + 24 * tag];
+		sk = sense[0];
+		asc = sense[1];
+		ascq = sense[2];
+
+		if (!ata_scsi_sense_is_valid(sk, asc, ascq)) {
+			ret = -EIO;
+			continue;
+		}
+
+		/* Set sense without also setting scsicmd->result */
+		scsi_build_sense_buffer(dev->flags & ATA_DFLAG_D_SENSE,
+					qc->scsicmd->sense_buffer, sk,
+					asc, ascq);
+		qc->flags |= ATA_QCFLAG_SENSE_VALID;
+
+		/*
+		 * If we have sense data, call scsi_check_sense() in order to
+		 * set the correct SCSI ML byte (if any). No point in checking
+		 * the return value, since the command has already completed
+		 * successfully.
+		 */
+		scsi_check_sense(qc->scsicmd);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ata_eh_read_sense_success_ncq_log);
+
 /**
  *	ata_eh_analyze_ncq_error - analyze NCQ error
  *	@link: ATA link to analyze NCQ error for
@@ -1488,6 +1579,7 @@ void ata_eh_analyze_ncq_error(struct ata_link *link)
 
 	ata_qc_for_each_raw(ap, qc, tag) {
 		if (!(qc->flags & ATA_QCFLAG_EH) ||
+		    qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD ||
 		    ata_dev_phys_link(qc->dev) != link)
 			continue;
 
diff --git a/include/linux/ata.h b/include/linux/ata.h
index a59b17d6ad11..2e2e22362096 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -326,6 +326,8 @@ 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: */
@@ -432,6 +434,7 @@ 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 ab8b62036c12..70ac635fe5d7 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,
-- 
2.39.2

Re: [PATCH v4 02/19] block: introduce ioprio hints

[Damien Le Moal]

On 2023/03/10 6:54, Niklas Cassel wrote:
> From: Damien Le Moal <damien.lemoal@opensource.wdc.com>
> 
> IO priorities currently only use 6-bits of the 16-bits ioprio value: the
> 3-upper bits are used to define up to 8 priority classes (4 of which are
> valid) and the 3 lower bits of the value are used to define a priority
> level for the real-time and best-effort class.
> 
> The remaining 10-bits between the IO priority class and level are
> unused, and in fact, cannot be used by the user as doing so would
> either result in the value being completely ignored, or in an error
> returned by ioprio_check_cap().
> 
> Use these 10-bits of an ioprio value to allow a user to specify IO
> hints. An IO hint is defined as a 10-bits value, allowing up to 1023
> different hints to be specified, with the value 0 being reserved as the
> "no hint" case. An IO hint can apply to any IO that specifies a valid
> priority class other than NONE, regardless of the IO priority level
> specified.
> 
> To do so, the macros IOPRIO_PRIO_HINT() and IOPRIO_PRIO_VALUE_HINT() are
> introduced in include/uapi/linux/ioprio.h to respectively allow a user
> to get and set a hint in an ioprio value.
> 
> To support the ATA and SCSI command duration limits feature, 7 hints
> are defined: IOPRIO_HINT_DEV_DURATION_LIMIT_1 to
> IOPRIO_HINT_DEV_DURATION_LIMIT_7, allowing a user to specify which
> command duration limit descriptor should be applied to the commands
> serving an IO. Specifying these hints has for now no effect whatsoever
> if the target block devices do not support the command duration limits
> feature. However, in the future, block IO schedulers can be modified to
> optimize IO issuing order based on these hints, even for devices that
> do not support the command duration limits feature.
> 
> Given that the 7 duration limits hints defined have no effect on any
> block layer component, the actual definition of the duration limits
> implied by these hints remains at the device level.
> 
> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
> Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>

Jens, Martin,

Any thoughts on this new interface ?

Bart,

I would like to hear your opinion as well.


> ---
>  include/uapi/linux/ioprio.h | 49 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 49 insertions(+)
> 
> diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h
> index 4444b4e4fdad..607c7617b9d2 100644
> --- a/include/uapi/linux/ioprio.h
> +++ b/include/uapi/linux/ioprio.h
> @@ -58,4 +58,53 @@ enum {
>  #define IOPRIO_NORM	4
>  #define IOPRIO_BE_NORM	IOPRIO_NORM
>  
> +/*
> + * The 10-bits between the priority class and the priority level are used to
> + * optionally define IO hints for any combination of IO priority class and
> + * level. Depending on the kernel configuration, IO scheduler being used and
> + * the target IO device being used, hints can influence how IOs are processed
> + * without affecting the IO scheduling ordering defined by the IO priority
> + * class and level.
> + */
> +#define IOPRIO_HINT_SHIFT		IOPRIO_LEVEL_NR_BITS
> +#define IOPRIO_HINT_NR_BITS		10
> +#define IOPRIO_NR_HINTS			(1 << IOPRIO_HINT_NR_BITS)
> +#define IOPRIO_HINT_MASK		(IOPRIO_NR_HINTS - 1)
> +#define IOPRIO_PRIO_HINT(ioprio)	\
> +	(((ioprio) >> IOPRIO_HINT_SHIFT) & IOPRIO_HINT_MASK)
> +
> +/*
> + * Alternate macro for IOPRIO_PRIO_VALUE() to define an IO priority with
> + * a class, level and hint.
> + */
> +#define IOPRIO_PRIO_VALUE_HINT(class, level, hint)		 \
> +	((((class) & IOPRIO_CLASS_MASK) << IOPRIO_CLASS_SHIFT) | \
> +	 (((hint) & IOPRIO_HINT_MASK) << IOPRIO_HINT_SHIFT) |	 \
> +	 ((level) & IOPRIO_LEVEL_MASK))
> +
> +/*
> + * IO hints.
> + */
> +enum {
> +	/* No hint */
> +	IOPRIO_HINT_NONE = 0,
> +
> +	/*
> +	 * Device command duration limits: indicate to the device a desired
> +	 * duration limit for the commands that will be used to process an IO.
> +	 * These will currently only be effective for SCSI and ATA devices that
> +	 * support the command duration limits feature. If this feature is
> +	 * enabled, then the commands issued to the device to process an IO with
> +	 * one of these hints set will have the duration limit index (dld field)
> +	 * set to the value of the hint.
> +	 */
> +	IOPRIO_HINT_DEV_DURATION_LIMIT_1 = 1,
> +	IOPRIO_HINT_DEV_DURATION_LIMIT_2 = 2,
> +	IOPRIO_HINT_DEV_DURATION_LIMIT_3 = 3,
> +	IOPRIO_HINT_DEV_DURATION_LIMIT_4 = 4,
> +	IOPRIO_HINT_DEV_DURATION_LIMIT_5 = 5,
> +	IOPRIO_HINT_DEV_DURATION_LIMIT_6 = 6,
> +	IOPRIO_HINT_DEV_DURATION_LIMIT_7 = 7,
> +};
> +
>  #endif /* _UAPI_LINUX_IOPRIO_H */

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH v4 01/19] ioprio: cleanup interface definition

[Bart Van Assche]

On 3/9/23 13:54, Niklas Cassel wrote:
>   /*
> - * The RT and BE priority classes both support up to 8 priority levels.
> + * The RT and BE priority classes both support up to 8 priority levels that
> + * can be specified using the lower 3-bits of the priority data.
>    */
> -#define IOPRIO_NR_LEVELS	8
> -#define IOPRIO_BE_NR		IOPRIO_NR_LEVELS
> +#define IOPRIO_LEVEL_NR_BITS		3
> +#define IOPRIO_NR_LEVELS		(1 << IOPRIO_LEVEL_NR_BITS)
> +#define IOPRIO_LEVEL_MASK		(IOPRIO_NR_LEVELS - 1)
> +#define IOPRIO_PRIO_LEVEL(ioprio)	((ioprio) & IOPRIO_LEVEL_MASK)
>   
> +#define IOPRIO_BE_NR			IOPRIO_NR_LEVELS

Is my understanding correct that today four I/O priority levels are 
supported and that these occupy two bits?

Thanks,

Bart.

Re: [PATCH v4 01/19] ioprio: cleanup interface definition

[Bart Van Assche]

On 3/16/23 10:58, Bart Van Assche wrote:
> On 3/9/23 13:54, Niklas Cassel wrote:
>>   /*
>> - * The RT and BE priority classes both support up to 8 priority levels.
>> + * The RT and BE priority classes both support up to 8 priority 
>> levels that
>> + * can be specified using the lower 3-bits of the priority data.
>>    */
>> -#define IOPRIO_NR_LEVELS    8
>> -#define IOPRIO_BE_NR        IOPRIO_NR_LEVELS
>> +#define IOPRIO_LEVEL_NR_BITS        3
>> +#define IOPRIO_NR_LEVELS        (1 << IOPRIO_LEVEL_NR_BITS)
>> +#define IOPRIO_LEVEL_MASK        (IOPRIO_NR_LEVELS - 1)
>> +#define IOPRIO_PRIO_LEVEL(ioprio)    ((ioprio) & IOPRIO_LEVEL_MASK)
>> +#define IOPRIO_BE_NR            IOPRIO_NR_LEVELS
> 
> Is my understanding correct that today four I/O priority levels are 
> supported and that these occupy two bits?

Please ignore the above question - according to the ioprio_get() man 
page there are eight levels.

Bart.

Re: [PATCH v4 02/19] block: introduce ioprio hints

[Bart Van Assche]

On 3/15/23 19:00, Damien Le Moal wrote:
> Bart,
> 
> I would like to hear your opinion as well.

Isn't sending a ping after only three days a bit soon for such a large 
patch?

Regarding your question: I like the block/ioprio.c changes in this 
version of this patch series much better than the changes in the 
previous version of this patch series.

No objections from my side about the changes in this patch (02/19).

Thanks,

Bart.

Re: [PATCH v4 02/19] block: introduce ioprio hints

[Niklas Cassel]

Hello Bart,

On Thu, Mar 16, 2023 at 11:41:21AM -0700, Bart Van Assche wrote:
> On 3/15/23 19:00, Damien Le Moal wrote:
> > Bart,
> > 
> > I would like to hear your opinion as well.
> 
> Isn't sending a ping after only three days a bit soon for such a large
> patch?

While I was never really any good at math, I'm quite sure that 16-9=7 :)

Which is the recommended (minimum) time to wait before you ping someone:
https://www.kernel.org/doc/html/latest/process/submitting-patches.html#don-t-get-discouraged-or-impatient


> 
> Regarding your question: I like the block/ioprio.c changes in this version
> of this patch series much better than the changes in the previous version of
> this patch series.
> 
> No objections from my side about the changes in this patch (02/19).

You are one of the main people who didn't fancy the old user facing API.
I think that you (and Martin) gave some really good points, we listened
and came up with a new user facing API.

When you have the time, we would be very grateful if you could provide
a more thorough review, i.e. provide a R-b tag or give some feedback.

Your help is appreciated!


Kind regards,
Niklas

Re: [PATCH v4 02/19] block: introduce ioprio hints

[Bart Van Assche]

On 3/17/23 02:23, Niklas Cassel wrote:
> When you have the time, we would be very grateful if you could provide
> a more thorough review, i.e. provide a R-b tag or give some feedback.
> 
> Your help is appreciated!

Although I'm overloaded, I will try to find some time to review this 
patch series.

Thanks,

Bart.