FAILED: patch "[PATCH] ata: libata: disallow dev-initiated LPM transitions to" failed to apply to 4.14-stable tree

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.14.y
git checkout FETCH_HEAD
git cherry-pick -x 24e0e61db3cb86a66824531989f1df80e0939f26
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023092002-mobster-onset-2af9@gregkh' --subject-prefix 'PATCH 4.14.y' HEAD^..

Possible dependencies:

24e0e61db3cb ("ata: libata: disallow dev-initiated LPM transitions to unsupported states") 7fe183c773c4 ("ata: start separating SATA specific code from libata-core.c") a52fbcfc7b38 ("ata: move EXPORT_SYMBOL_GPL()s close to exported code")
10a663a1b151 ("ata: ahci: Add shutdown to freeze hardware resources of ahci") 95364f36701e ("ata: make qc_prep return ata_completion_errors")
c82ee6d3beaa ("treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 18") 4e8065aa6c6f ("scsi: libata: Add missing newline at end of file")
051935978432 ("Merge branch 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 24e0e61db3cb86a66824531989f1df80e0939f26 Mon Sep 17 00:00:00 2001
From: Niklas Cassel <[email protected]>
Date: Mon, 4 Sep 2023 22:42:56 +0200
Subject: [PATCH] ata: libata: disallow dev-initiated LPM transitions to
unsupported states
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

In AHCI 1.3.1, the register description for CAP.SSC:
"When cleared to ‘0’, software must not allow the HBA to initiate transitions to the Slumber state via agressive link power management nor the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port must be programmed to disallow device initiated Slumber requests."

In AHCI 1.3.1, the register description for CAP.PSC:
"When cleared to ‘0’, software must not allow the HBA to initiate transitions to the Partial state via agressive link power management nor the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port must be programmed to disallow device initiated Partial requests."

Ensure that we always set the corresponding bits in PxSCTL.IPM, such that a device is not allowed to initiate transitions to power states which are unsupported by the HBA.

DevSleep is always initiated by the HBA, however, for completeness, set the corresponding bit in PxSCTL.IPM such that agressive link power management cannot transition to DevSleep if DevSleep is not supported.

sata_link_scr_lpm() is used by libahci, ata_piix and libata-pmp. However, only libahci has the ability to read the CAP/CAP2 register to see if these features are supported. Therefore, in order to not introduce any regressions on ata_piix or libata-pmp, create flags that indicate that the respective feature is NOT supported. This way, the behavior for ata_piix and libata-pmp should remain unchanged.

This change is based on a patch originally submitted by Runa Guo-oc.

index abb5911c9d09..08745e7db820 100644
@@ -1883,6 +1883,15 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	else
 		dev_info(&pdev->dev, "SSS flag set, parallel bus scan disabled\n");
 
+	if (!(hpriv->cap & HOST_CAP_PART))
+		host->flags |= ATA_HOST_NO_PART;
+
+	if (!(hpriv->cap & HOST_CAP_SSC))
+		host->flags |= ATA_HOST_NO_SSC;
+
+	if (!(hpriv->cap2 & HOST_CAP2_SDS))
+		host->flags |= ATA_HOST_NO_DEVSLP;
+
 	if (pi.flags & ATA_FLAG_EM)
 		ahci_reset_em(host);
 

index 5d31c08be013..a701e1538482 100644
@@ -396,10 +396,23 @@ int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
 	case ATA_LPM_MED_POWER_WITH_DIPM:
 	case ATA_LPM_MIN_POWER_WITH_PARTIAL:
 	case ATA_LPM_MIN_POWER:
-		if (ata_link_nr_enabled(link) > 0)
-			/* no restrictions on LPM transitions */
+		if (ata_link_nr_enabled(link) > 0) {
+			/* assume no restrictions on LPM transitions */
 			scontrol &= ~(0x7 << 8);
-		else {
+
+			/*
+			 * If the controller does not support partial, slumber,
+			 * or devsleep, then disallow these transitions.
+			 */
+			if (link->ap->host->flags & ATA_HOST_NO_PART)
+				scontrol |= (0x1 << 8);
+
+			if (link->ap->host->flags & ATA_HOST_NO_SSC)
+				scontrol |= (0x2 << 8);
+
+			if (link->ap->host->flags & ATA_HOST_NO_DEVSLP)
+				scontrol |= (0x4 << 8);
+		} else {
 			/* empty port, power off */
 			scontrol &= ~0xf;
 			scontrol |= (0x1 << 2);

index 52d58b13e5ee..bf4913f4d7ac 100644
@@ -222,6 +222,10 @@ enum {
 	ATA_HOST_PARALLEL_SCAN	= (1 << 2),	/* Ports on this host can be scanned in parallel */
 	ATA_HOST_IGNORE_ATA	= (1 << 3),	/* Ignore ATA devices on this host. */
 
+	ATA_HOST_NO_PART	= (1 << 4), /* Host does not support partial */
+	ATA_HOST_NO_SSC		= (1 << 5), /* Host does not support slumber */
+	ATA_HOST_NO_DEVSLP	= (1 << 6), /* Host does not support devslp */
+
 	/* bits 24:31 of host->flags are reserved for LLD specific flags */
 
 	/* various lengths of time */

In AHCI 1.3.1, the register description for CAP.SSC:
"When cleared to ‘0’, software must not allow the HBA to initiate transitions to the Slumber state via agressive link power management nor the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port must be programmed to disallow device initiated Slumber requests."

In AHCI 1.3.1, the register description for CAP.PSC:
"When cleared to ‘0’, software must not allow the HBA to initiate transitions to the Partial state via agressive link power management nor the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port must be programmed to disallow device initiated Partial requests."

Ensure that we always set the corresponding bits in PxSCTL.IPM, such that a device is not allowed to initiate transitions to power states which are unsupported by the HBA.

DevSleep is always initiated by the HBA, however, for completeness, set the corresponding bit in PxSCTL.IPM such that agressive link power management cannot transition to DevSleep if DevSleep is not supported.

sata_link_scr_lpm() is used by libahci, ata_piix and libata-pmp. However, only libahci has the ability to read the CAP/CAP2 register to see if these features are supported. Therefore, in order to not introduce any regressions on ata_piix or libata-pmp, create flags that indicate that the respective feature is NOT supported. This way, the behavior for ata_piix and libata-pmp should remain unchanged.

This change is based on a patch originally submitted by Runa Guo-oc.

---
 drivers/ata/ahci.c        |  9 +++++++++
 drivers/ata/libata-core.c | 19 ++++++++++++++++---
 include/linux/libata.h    |  4 ++++
 3 files changed, 29 insertions(+), 3 deletions(-)

index 0905c07b8c7e..abb3dd048556 100644
@@ -1777,6 +1777,15 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	else
 		dev_info(&pdev->dev, "SSS flag set, parallel bus scan disabled\n");
 
+	if (!(hpriv->cap & HOST_CAP_PART))
+		host->flags |= ATA_HOST_NO_PART;
+
+	if (!(hpriv->cap & HOST_CAP_SSC))
+		host->flags |= ATA_HOST_NO_SSC;
+
+	if (!(hpriv->cap2 & HOST_CAP2_SDS))
+		host->flags |= ATA_HOST_NO_DEVSLP;
+
 	if (pi.flags & ATA_FLAG_EM)
 		ahci_reset_em(host);
 

index 08dc37a62f5a..69002ad15500 100644
@@ -3993,10 +3993,23 @@ int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
 		scontrol |= (0x6 << 8);
 		break;
 	case ATA_LPM_MIN_POWER:
-		if (ata_link_nr_enabled(link) > 0)
-			/* no restrictions on LPM transitions */
+		if (ata_link_nr_enabled(link) > 0) {
+			/* assume no restrictions on LPM transitions */
 			scontrol &= ~(0x7 << 8);
-		else {
+
+			/*
+			 * If the controller does not support partial, slumber,
+			 * or devsleep, then disallow these transitions.
+			 */
+			if (link->ap->host->flags & ATA_HOST_NO_PART)
+				scontrol |= (0x1 << 8);
+
+			if (link->ap->host->flags & ATA_HOST_NO_SSC)
+				scontrol |= (0x2 << 8);
+
+			if (link->ap->host->flags & ATA_HOST_NO_DEVSLP)
+				scontrol |= (0x4 << 8);
+		} else {
 			/* empty port, power off */
 			scontrol &= ~0xf;
 			scontrol |= (0x1 << 2);

index 0e9f8fd37eb9..ab2c5d6cabed 100644
@@ -279,6 +279,10 @@ enum {
 	ATA_HOST_PARALLEL_SCAN	= (1 << 2),	/* Ports on this host can be scanned in parallel */
 	ATA_HOST_IGNORE_ATA	= (1 << 3),	/* Ignore ATA devices on this host. */
 
+	ATA_HOST_NO_PART	= (1 << 4), /* Host does not support partial */
+	ATA_HOST_NO_SSC		= (1 << 5), /* Host does not support slumber */
+	ATA_HOST_NO_DEVSLP	= (1 << 6), /* Host does not support devslp */
+
 	/* bits 24:31 of host->flags are reserved for LLD specific flags */
 
 	/* various lengths of time */

2.41.0

In AHCI 1.3.1, the register description for CAP.SSC:
"When cleared to ‘0’, software must not allow the HBA to initiate transitions to the Slumber state via agressive link power management nor the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port must be programmed to disallow device initiated Slumber requests."

In AHCI 1.3.1, the register description for CAP.PSC:
"When cleared to ‘0’, software must not allow the HBA to initiate transitions to the Partial state via agressive link power management nor the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port must be programmed to disallow device initiated Partial requests."

Ensure that we always set the corresponding bits in PxSCTL.IPM, such that a device is not allowed to initiate transitions to power states which are unsupported by the HBA.

DevSleep is always initiated by the HBA, however, for completeness, set the corresponding bit in PxSCTL.IPM such that agressive link power management cannot transition to DevSleep if DevSleep is not supported.

sata_link_scr_lpm() is used by libahci, ata_piix and libata-pmp. However, only libahci has the ability to read the CAP/CAP2 register to see if these features are supported. Therefore, in order to not introduce any regressions on ata_piix or libata-pmp, create flags that indicate that the respective feature is NOT supported. This way, the behavior for ata_piix and libata-pmp should remain unchanged.

This change is based on a patch originally submitted by Runa Guo-oc.

---
 drivers/ata/ahci.c        |  9 +++++++++
 drivers/ata/libata-core.c | 19 ++++++++++++++++---
 include/linux/libata.h    |  4 ++++
 3 files changed, 29 insertions(+), 3 deletions(-)

index 0905c07b8c7e..abb3dd048556 100644
@@ -1777,6 +1777,15 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	else
 		dev_info(&pdev->dev, "SSS flag set, parallel bus scan disabled\n");
 
+	if (!(hpriv->cap & HOST_CAP_PART))
+		host->flags |= ATA_HOST_NO_PART;
+
+	if (!(hpriv->cap & HOST_CAP_SSC))
+		host->flags |= ATA_HOST_NO_SSC;
+
+	if (!(hpriv->cap2 & HOST_CAP2_SDS))
+		host->flags |= ATA_HOST_NO_DEVSLP;
+
 	if (pi.flags & ATA_FLAG_EM)
 		ahci_reset_em(host);
 

index 08dc37a62f5a..69002ad15500 100644
@@ -3993,10 +3993,23 @@ int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
 		scontrol |= (0x6 << 8);
 		break;
 	case ATA_LPM_MIN_POWER:
-		if (ata_link_nr_enabled(link) > 0)
-			/* no restrictions on LPM transitions */
+		if (ata_link_nr_enabled(link) > 0) {
+			/* assume no restrictions on LPM transitions */
 			scontrol &= ~(0x7 << 8);
-		else {
+
+			/*
+			 * If the controller does not support partial, slumber,
+			 * or devsleep, then disallow these transitions.
+			 */
+			if (link->ap->host->flags & ATA_HOST_NO_PART)
+				scontrol |= (0x1 << 8);
+
+			if (link->ap->host->flags & ATA_HOST_NO_SSC)
+				scontrol |= (0x2 << 8);
+
+			if (link->ap->host->flags & ATA_HOST_NO_DEVSLP)
+				scontrol |= (0x4 << 8);
+		} else {
 			/* empty port, power off */
 			scontrol &= ~0xf;
 			scontrol |= (0x1 << 2);

index 0e9f8fd37eb9..ab2c5d6cabed 100644
@@ -279,6 +279,10 @@ enum {
 	ATA_HOST_PARALLEL_SCAN	= (1 << 2),	/* Ports on this host can be scanned in parallel */
 	ATA_HOST_IGNORE_ATA	= (1 << 3),	/* Ignore ATA devices on this host. */
 
+	ATA_HOST_NO_PART	= (1 << 4), /* Host does not support partial */
+	ATA_HOST_NO_SSC		= (1 << 5), /* Host does not support slumber */
+	ATA_HOST_NO_DEVSLP	= (1 << 6), /* Host does not support devslp */
+
 	/* bits 24:31 of host->flags are reserved for LLD specific flags */
 
 	/* various lengths of time */

2.41.0

Hi!

You have forgotten the upstream commit ID.
And there is a message of cherry-pick -x. This is not necessary. Could you please add commit ID and remove cherry-pick message?

commit 24e0e61db3cb86a66824531989f1df80e0939f26 upstream.

Best regards,
Nobuhiro

Hello Nobuhiro,

The Linux 4.14 stable kernel maintainers are:
Greg Kroah-Hartman & Sasha Levin

See:
https://www.kernel.org/category/releases.html

I followed the instructions provided by Greg Kroah-Hartman in email:
https://lore.kernel.org/stable/2023092002-mobster-onset-2af9@gregkh/

"""
To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.14.y
git checkout FETCH_HEAD
git cherry-pick -x 24e0e61db3cb86a66824531989f1df80e0939f26
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023092002-mobster-onset-2af9@gregkh' --subject-prefix 'PATCH 4.14.y' HEAD^.. """

I do find it slightly amusing that the instructions, provided by none other than the stable maintainer himself, which mentions linux-4.14.y, should not be good enough :)

I think you should bring up your concerns with the stable maintainers. If this is really an issue, perhaps you can convince them to update their instructions.

Until then, I will assume that the provided instructions are satisfactory.

Kind regards,
Niklas

They are, thank you for following them, I'll go queue these up now.

greg k-h

Hi Niklas Cassel,

Thank you for your point. My understanding was not sufficient. Sorry, that I have made noise.

Best regards,
Nobuhiro

As pointed out, the cherry-pick message is just fine, the documentation was being followed properly, so all is good.

thanks,

greg k-h