scsi: ufs: Add support for Auto-Hibernate Idle Timer

PATCH Superseded Adrian Hunter 2 participants 4 messages Mar 19, 2018 – Mar 20, 2018 SCSI

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Adrian Hunter

author

2018-03-19 08:01 UTC #0 lore raw

v2 cover scsi: ufs: Add support for Auto-Hibernate Idle Timer

Here is V2, now re-based on top of patch "scsi: ufs: sysfs:reworking of the rpm_lvl and spm_lvl entries".

Michał Potomski has previously sent a patch for Auto-Hibernate, but this patch is slightly different, based on the latest ufs-sysfs changes, it also takes care to restore auto-hibernate during resume, and otherwise avoids updating the register if the device is runtime suspended. Also a default value of 150ms is set.

Changes in V2:

Re-based on top of (yet to be applied) patch "scsi: ufs: sysfs:
reworking of the rpm_lvl and spm_lvl entries"

Adrian Hunter (1):
scsi: ufs: Add support for Auto-Hibernate Idle Timer

 Documentation/ABI/testing/sysfs-driver-ufs | 15 ++++++
 drivers/scsi/ufs/ufs-sysfs.c               | 77 ++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshcd.c                  | 26 ++++++++++
 drivers/scsi/ufs/ufshcd.h                  |  3 ++
 drivers/scsi/ufs/ufshci.h                  |  7 +++
 5 files changed, 128 insertions(+)

Regards
Adrian

Adrian Hunter

author

2018-03-19 08:01 UTC #1 lore raw

PATCH v2 1/1 scsi: ufs: Add support for Auto-Hibernate Idle Timer

UFS host controllers may support an autonomous power management feature called the Auto-Hibernate Idle Timer. The timer is set to the number of microseconds of idle time before the UFS host controller will autonomously put the link into Hibernate state. That will save power at the expense of increased latency. Any access to the host controller interface registers will automatically put the link out of Hibernate state. So once configured, the feature is transparent to the driver.

Expose the Auto-Hibernate Idle Timer value via SysFS to allow users to choose between power efficiency or lower latency. Set a default value of 150 ms.

Signed-off-by Adrian Hunter <[email protected]>

---
 Documentation/ABI/testing/sysfs-driver-ufs | 15 ++++++
 drivers/scsi/ufs/ufs-sysfs.c               | 77 ++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshcd.c                  | 26 ++++++++++
 drivers/scsi/ufs/ufshcd.h                  |  3 ++
 drivers/scsi/ufs/ufshci.h                  |  7 +++
 5 files changed, 128 insertions(+)

Documentation/ABI/testing/sysfs-driver-ufs +15 -0

index 83735f79e572..a4142329cc34 100644
@@ -1,3 +1,18 @@
+What:		/sys/bus/*/drivers/ufshcd/*/auto_hibern8
+Date:		February 2018
+Contact:	[email protected]
+Description:
+		This file contains the auto-hibernate idle timer setting of a
+		UFS host controller. A value of '-1' means auto-hibernate is not
+		supported. A value of '0' means auto-hibernate is not enabled.
+		Otherwise the value is the number of microseconds of idle time
+		before the UFS host controller will autonomously put the link
+		into hibernate state. That will save power at the expense of
+		increased latency. Note that the hardware supports 10-bit values
+		with a power-of-ten multiplier which allows a maximum value of
+		102300000. Refer to the UFS Host Controller Interface
+		specification for more details.
+
 What:		/sys/bus/platform/drivers/ufshcd/*/device_descriptor/device_type
 Date:		February 2018
 Contact:	Stanislav Nijnikov <[email protected]>

drivers/scsi/ufs/ufs-sysfs.c +77 -0

101 lines not on this page · raw message

drivers/scsi/ufs/ufshcd.c +26 -0

index 3abcd31646eb..facee2b97926 100644
@@ -41,6 +41,7 @@
 #include <linux/devfreq.h>
 #include <linux/nls.h>
 #include <linux/of.h>
+#include <linux/bitfield.h>
 #include "ufshcd.h"
 #include "ufs_quirks.h"
 #include "unipro.h"

@@ -3708,6 +3709,18 @@ static int ufshcd_uic_hibern8_exit(struct ufs_hba *hba)
 	return ret;
 }
 
+static void ufshcd_auto_hibern8_enable(struct ufs_hba *hba)
+{
+	unsigned long flags;
+
+	if (!(hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT) || !hba->ahit)
+		return;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_writel(hba, hba->ahit, REG_AUTO_HIBERNATE_IDLE_TIMER);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+}
+
  /**
  * ufshcd_init_pwr_info - setting the POR (power on reset)
  * values in hba power info

@@ -6307,6 +6320,9 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 	/* UniPro link is active now */
 	ufshcd_set_link_active(hba);
 
+	/* Enable Auto-Hibernate if configured */
+	ufshcd_auto_hibern8_enable(hba);
+
 	ret = ufshcd_verify_dev_init(hba);
 	if (ret)
 		goto out;

@@ -7391,6 +7407,10 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 
 	/* Schedule clock gating in case of no access to UFS device yet */
 	ufshcd_release(hba);
+
+	/* Enable Auto-Hibernate if configured */
+	ufshcd_auto_hibern8_enable(hba);
+
 	goto out;
 
 set_old_link_state:

@@ -7834,6 +7854,12 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 						UFS_SLEEP_PWR_MODE,
 						UIC_LINK_HIBERN8_STATE);
 
+	/* Set the default auto-hiberate idle timer value to 150 ms */
+	if (hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT) {
+		hba->ahit = FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 150) |
+			    FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3);
+	}
+
 	/* Hold auto suspend until async scan completes */
 	pm_runtime_get_sync(dev);

drivers/scsi/ufs/ufshcd.h +3 -0

index deb3c5d382e9..8110dcd04d22 100644
@@ -531,6 +531,9 @@ struct ufs_hba {
 	struct device_attribute spm_lvl_attr;
 	int pm_op_in_progress;
 
+	/* Auto-Hibernate Idle Timer register value */
+	u32 ahit;
+
 	struct ufshcd_lrb *lrb;
 	unsigned long lrb_in_use;

drivers/scsi/ufs/ufshci.h +7 -0

index 1a1b5d9fe514..bb5d9c7f3353 100644
@@ -86,6 +86,7 @@ enum {
 enum {
 	MASK_TRANSFER_REQUESTS_SLOTS		= 0x0000001F,
 	MASK_TASK_MANAGEMENT_REQUEST_SLOTS	= 0x00070000,
+	MASK_AUTO_HIBERN8_SUPPORT		= 0x00800000,
 	MASK_64_ADDRESSING_SUPPORT		= 0x01000000,
 	MASK_OUT_OF_ORDER_DATA_DELIVERY_SUPPORT	= 0x02000000,
 	MASK_UIC_DME_TEST_MODE_SUPPORT		= 0x04000000,

@@ -119,6 +120,12 @@ enum {
 #define MANUFACTURE_ID_MASK	UFS_MASK(0xFFFF, 0)
 #define PRODUCT_ID_MASK		UFS_MASK(0xFFFF, 16)
 
+/* AHIT - Auto-Hibernate Idle Timer */
+#define UFSHCI_AHIBERN8_TIMER_MASK		GENMASK(9, 0)
+#define UFSHCI_AHIBERN8_SCALE_MASK		GENMASK(12, 10)
+#define UFSHCI_AHIBERN8_SCALE_FACTOR		10
+#define UFSHCI_AHIBERN8_MAX			(1023 * 100000)
+
 /*
  * IS - Interrupt Status - 20h
  */

Signature · 1 line

1.9.1

Stanislav Nijnikov

2018-03-20 11:56 UTC #2 lore raw

Quoted 120 lines

-----Original Message-----
From: Adrian Hunter [mailto:[email protected]]
Sent: Monday, March 19, 2018 10:01 AM
To: Vinayak Holikatti <[email protected]>; Martin K. Petersen <[email protected]>; James E.J. Bottomley <[email protected]>
Cc: Stanislav Nijnikov <[email protected]>; Jaegeuk Kim <[email protected]>; Bart Van Assche <[email protected]>; linux- [email protected]; [email protected]; Szymon Mielczarek <[email protected]>; Alim Akhtar <[email protected]>; Alex Lemberg <[email protected]>; Vivek Gautam <[email protected]>
Subject: [PATCH V2 1/1] scsi: ufs: Add support for Auto-Hibernate Idle Timer
UFS host controllers may support an autonomous power management feature called the Auto-Hibernate Idle Timer. The timer is set to the number of microseconds of idle time before the UFS host controller will autonomously put the link into Hibernate state. That will save power at the expense of increased latency. Any access to the host controller interface registers will automatically put the link out of Hibernate state. So once configured, the feature is transparent to the driver.
Expose the Auto-Hibernate Idle Timer value via SysFS to allow users to choose between power efficiency or lower latency. Set a default value of 150 ms.
Signed-off-by Adrian Hunter <[email protected]>
---
 Documentation/ABI/testing/sysfs-driver-ufs | 15 ++++++
 drivers/scsi/ufs/ufs-sysfs.c               | 77
++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshcd.c                  | 26 ++++++++++
 drivers/scsi/ufs/ufshcd.h                  |  3 ++
 drivers/scsi/ufs/ufshci.h                  |  7 +++
 5 files changed, 128 insertions(+)
Documentation/ABI/testing/sysfs-driver-ufs +6 -0
index 83735f79e572..a4142329cc34 100644
@@ -1,3 +1,18 @@
+What:		/sys/bus/*/drivers/ufshcd/*/auto_hibern8
+Date:		February 2018
+Contact:	[email protected]
+Description:
+		This file contains the auto-hibernate idle timer setting of a
+		UFS host controller. A value of '-1' means auto-hibernate is
not
Documentation/ABI/testing/sysfs-driver-ufs +1 -0
+		supported. A value of '0' means auto-hibernate is not
enabled.
Documentation/ABI/testing/sysfs-driver-ufs +1 -0
+		Otherwise the value is the number of microseconds of idle
time
Documentation/ABI/testing/sysfs-driver-ufs +3 -0
+		before the UFS host controller will autonomously put the link
+		into hibernate state. That will save power at the expense of
+		increased latency. Note that the hardware supports 10-bit
values
Documentation/ABI/testing/sysfs-driver-ufs +1 -0
+		with a power-of-ten multiplier which allows a maximum
value of
Documentation/ABI/testing/sysfs-driver-ufs +3 -0
+		102300000. Refer to the UFS Host Controller Interface
+		specification for more details.
+
 What:
/sys/bus/platform/drivers/ufshcd/*/device_descriptor/device_type
Date: February 2018
Contact: Stanislav Nijnikov <[email protected]>
drivers/scsi/ufs/ufs-sysfs.c index renamed from drivers/scsi/ufs/ufs-sysfs.c +0 -0
4ff9e0b7eba1..17ad661b1cb5 100644
drivers/scsi/ufs/ufs-sysfs.c +34 -0
@@ -3,6 +3,7 @@
 
 #include <linux/err.h>
 #include <linux/string.h>
+#include <linux/bitfield.h>
 #include <asm/unaligned.h>
 
 #include "ufs.h"
@@ -117,12 +118,87 @@ static ssize_t spm_target_link_state_show(struct
 device *dev,
 				ufs_pm_lvl_states[hba-
 >spm_lvl].link_state));
 }
 
+static void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit) {
+	unsigned long flags;
+
+	if (!(hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT))
+		return;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	if (hba->ahit == ahit)
+		goto out_unlock;
+	hba->ahit = ahit;
+	if (!pm_runtime_suspended(hba->dev))
+		ufshcd_writel(hba, hba->ahit,
 REG_AUTO_HIBERNATE_IDLE_TIMER);
+out_unlock:
+	spin_unlock_irqrestore(hba->host->host_lock, flags); }
+
+/* Convert Auto-Hibernate Idle Timer register value to microseconds */
+static int ufshcd_ahit_to_us(u32 ahit) {
+	int timer = FIELD_GET(UFSHCI_AHIBERN8_TIMER_MASK, ahit);
+	int scale = FIELD_GET(UFSHCI_AHIBERN8_SCALE_MASK, ahit);
+
+	for (; scale > 0; --scale)
+		timer *= UFSHCI_AHIBERN8_SCALE_FACTOR;
+
+	return timer;
+}
+
+/* Convert microseconds to Auto-Hibernate Idle Timer register value */
+static u32 ufshcd_us_to_ahit(unsigned int timer) {
+	unsigned int scale;
+
+	for (scale = 0; timer > UFSHCI_AHIBERN8_TIMER_MASK; ++scale)
+		timer /= UFSHCI_AHIBERN8_SCALE_FACTOR;
+

drivers/scsi/ufs/ufs-sysfs.c static ssize_t spm_target_link_state_show(struct · line 166

Quoted 10 lines

drivers/scsi/ufs/ufs-sysfs.c +10 -0

+	return FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, timer) |
+	       FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, scale); }
+
+static ssize_t auto_hibern8_show(struct device *dev,
+				 struct device_attribute *attr, char *buf) {
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	int timer = -1;
+
+	if (hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT)
+		timer = ufshcd_ahit_to_us(hba->ahit);

I think it's better to return EOPNOTSUPP when the feature is not supported than to show "-1".

Quoted 151 lines

drivers/scsi/ufs/ufs-sysfs.c +26 -0

+
+	return snprintf(buf, PAGE_SIZE, "%d\n", timer); }
+
+static ssize_t auto_hibern8_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	unsigned int timer;
+
+	if (!(hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT))
+		return -EOPNOTSUPP;
+
+	if (kstrtouint(buf, 0, &timer))
+		return -EINVAL;
+
+	if (timer > UFSHCI_AHIBERN8_MAX)
+		return -EINVAL;
+
+	ufshcd_auto_hibern8_update(hba, ufshcd_us_to_ahit(timer));
+
+	return count;
+}
+
 static DEVICE_ATTR_RW(rpm_lvl);
 static DEVICE_ATTR_RO(rpm_target_dev_state);
 static DEVICE_ATTR_RO(rpm_target_link_state);
 static DEVICE_ATTR_RW(spm_lvl);
 static DEVICE_ATTR_RO(spm_target_dev_state);
 static DEVICE_ATTR_RO(spm_target_link_state);
+static DEVICE_ATTR_RW(auto_hibern8);
 
 static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
 	&dev_attr_rpm_lvl.attr,

@@ -131,6 +207,7 @@ static ssize_t spm_target_link_state_show(struct
 device *dev,
 	&dev_attr_spm_lvl.attr,
 	&dev_attr_spm_target_dev_state.attr,
 	&dev_attr_spm_target_link_state.attr,
+	&dev_attr_auto_hibern8.attr,
 	NULL
 };

drivers/scsi/ufs/ufshcd.c index renamed from drivers/scsi/ufs/ufshcd.c +0 -0

3abcd31646eb..facee2b97926 100644

drivers/scsi/ufs/ufshcd.c +18 -0

@@ -41,6 +41,7 @@
 #include <linux/devfreq.h>
 #include <linux/nls.h>
 #include <linux/of.h>
+#include <linux/bitfield.h>
 #include "ufshcd.h"
 #include "ufs_quirks.h"
 #include "unipro.h"

@@ -3708,6 +3709,18 @@ static int ufshcd_uic_hibern8_exit(struct ufs_hba
 *hba)
 	return ret;
 }
 
+static void ufshcd_auto_hibern8_enable(struct ufs_hba *hba) {
+	unsigned long flags;
+
+	if (!(hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT) || !hba-
 >ahit)
+		return;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_writel(hba, hba->ahit, REG_AUTO_HIBERNATE_IDLE_TIMER);
+	spin_unlock_irqrestore(hba->host->host_lock, flags); }
+
  /**
  * ufshcd_init_pwr_info - setting the POR (power on reset)
  * values in hba power info

@@ -6307,6 +6320,9 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 	/* UniPro link is active now */
 	ufshcd_set_link_active(hba);
 
+	/* Enable Auto-Hibernate if configured */
+	ufshcd_auto_hibern8_enable(hba);
+
 	ret = ufshcd_verify_dev_init(hba);
 	if (ret)
 		goto out;

@@ -7391,6 +7407,10 @@ static int ufshcd_resume(struct ufs_hba *hba,
 enum ufs_pm_op pm_op)
 
 	/* Schedule clock gating in case of no access to UFS device yet */
 	ufshcd_release(hba);
+
+	/* Enable Auto-Hibernate if configured */
+	ufshcd_auto_hibern8_enable(hba);
+
 	goto out;

set_old_link_state:

drivers/scsi/ufs/ufshcd.c +3 -0

@@ -7834,6 +7854,12 @@ int ufshcd_init(struct ufs_hba *hba, void
 __iomem *mmio_base, unsigned int irq)
 						UFS_SLEEP_PWR_MODE,
 						UIC_LINK_HIBERN8_STATE);
 
+	/* Set the default auto-hiberate idle timer value to 150 ms */
+	if (hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT) {
+		hba->ahit = FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK,

150) |

drivers/scsi/ufs/ufshcd.c +3 -0

+			    FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3);
+	}
+
 	/* Hold auto suspend until async scan completes */
 	pm_runtime_get_sync(dev);

drivers/scsi/ufs/ufshcd.h index renamed from drivers/scsi/ufs/ufshcd.h +0 -0

deb3c5d382e9..8110dcd04d22 100644

drivers/scsi/ufs/ufshcd.h +3 -0

@@ -531,6 +531,9 @@ struct ufs_hba {
 	struct device_attribute spm_lvl_attr;
 	int pm_op_in_progress;
 
+	/* Auto-Hibernate Idle Timer register value */
+	u32 ahit;
+
 	struct ufshcd_lrb *lrb;
 	unsigned long lrb_in_use;

drivers/scsi/ufs/ufshci.h index renamed from drivers/scsi/ufs/ufshci.h +0 -0

1a1b5d9fe514..bb5d9c7f3353 100644

drivers/scsi/ufs/ufshci.h +7 -1

@@ -86,6 +86,7 @@ enum {
 enum {
 	MASK_TRANSFER_REQUESTS_SLOTS		= 0x0000001F,
 	MASK_TASK_MANAGEMENT_REQUEST_SLOTS	= 0x00070000,
+	MASK_AUTO_HIBERN8_SUPPORT		= 0x00800000,
 	MASK_64_ADDRESSING_SUPPORT		= 0x01000000,
 	MASK_OUT_OF_ORDER_DATA_DELIVERY_SUPPORT	= 0x02000000,
 	MASK_UIC_DME_TEST_MODE_SUPPORT		= 0x04000000,

@@ -119,6 +120,12 @@ enum {
 #define MANUFACTURE_ID_MASK	UFS_MASK(0xFFFF, 0)
 #define PRODUCT_ID_MASK		UFS_MASK(0xFFFF, 16)
 
+/* AHIT - Auto-Hibernate Idle Timer */
+#define UFSHCI_AHIBERN8_TIMER_MASK		GENMASK(9, 0)
+#define UFSHCI_AHIBERN8_SCALE_MASK		GENMASK(12, 10)
+#define UFSHCI_AHIBERN8_SCALE_FACTOR		10
+#define UFSHCI_AHIBERN8_MAX			(1023 * 100000)
+
 /*
  * IS - Interrupt Status - 20h
  */
--

Quoted 1 line

1.9.1

Please fix all checkpatch errors.
Regards
Stas

Adrian Hunter

author

2018-03-20 12:09 UTC #3 lore raw

Quoted 123 lines · Stanislav Nijnikov

Quoted 123 lines
-----Original Message-----
From: Adrian Hunter [mailto:[email protected]]
Sent: Monday, March 19, 2018 10:01 AM
To: Vinayak Holikatti <[email protected]>; Martin K. Petersen <[email protected]>; James E.J. Bottomley <[email protected]>
Cc: Stanislav Nijnikov <[email protected]>; Jaegeuk Kim <[email protected]>; Bart Van Assche <[email protected]>; linux- [email protected]; [email protected]; Szymon Mielczarek <[email protected]>; Alim Akhtar <[email protected]>; Alex Lemberg <[email protected]>; Vivek Gautam <[email protected]>
Subject: [PATCH V2 1/1] scsi: ufs: Add support for Auto-Hibernate Idle Timer
UFS host controllers may support an autonomous power management feature called the Auto-Hibernate Idle Timer. The timer is set to the number of microseconds of idle time before the UFS host controller will autonomously put the link into Hibernate state. That will save power at the expense of increased latency. Any access to the host controller interface registers will automatically put the link out of Hibernate state. So once configured, the feature is transparent to the driver.
Expose the Auto-Hibernate Idle Timer value via SysFS to allow users to choose between power efficiency or lower latency. Set a default value of 150 ms.
Signed-off-by Adrian Hunter <[email protected]>
---
 Documentation/ABI/testing/sysfs-driver-ufs | 15 ++++++
 drivers/scsi/ufs/ufs-sysfs.c               | 77
++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshcd.c                  | 26 ++++++++++
 drivers/scsi/ufs/ufshcd.h                  |  3 ++
 drivers/scsi/ufs/ufshci.h                  |  7 +++
 5 files changed, 128 insertions(+)
Documentation/ABI/testing/sysfs-driver-ufs +6 -0
index 83735f79e572..a4142329cc34 100644
@@ -1,3 +1,18 @@
+What:		/sys/bus/*/drivers/ufshcd/*/auto_hibern8
+Date:		February 2018
+Contact:	[email protected]
+Description:
+		This file contains the auto-hibernate idle timer setting of a
+		UFS host controller. A value of '-1' means auto-hibernate is
not
Documentation/ABI/testing/sysfs-driver-ufs +1 -0
+		supported. A value of '0' means auto-hibernate is not
enabled.
Documentation/ABI/testing/sysfs-driver-ufs +1 -0
+		Otherwise the value is the number of microseconds of idle
time
Documentation/ABI/testing/sysfs-driver-ufs +3 -0
+		before the UFS host controller will autonomously put the link
+		into hibernate state. That will save power at the expense of
+		increased latency. Note that the hardware supports 10-bit
values
Documentation/ABI/testing/sysfs-driver-ufs +1 -0
+		with a power-of-ten multiplier which allows a maximum
value of
Documentation/ABI/testing/sysfs-driver-ufs +3 -0
+		102300000. Refer to the UFS Host Controller Interface
+		specification for more details.
+
 What:
/sys/bus/platform/drivers/ufshcd/*/device_descriptor/device_type
Date: February 2018
Contact: Stanislav Nijnikov <[email protected]>
drivers/scsi/ufs/ufs-sysfs.c index renamed from drivers/scsi/ufs/ufs-sysfs.c +0 -0
4ff9e0b7eba1..17ad661b1cb5 100644
drivers/scsi/ufs/ufs-sysfs.c +37 -0
@@ -3,6 +3,7 @@
 
 #include <linux/err.h>
 #include <linux/string.h>
+#include <linux/bitfield.h>
 #include <asm/unaligned.h>
 
 #include "ufs.h"
@@ -117,12 +118,87 @@ static ssize_t spm_target_link_state_show(struct
 device *dev,
 				ufs_pm_lvl_states[hba-
 > spm_lvl].link_state));
 }
 
+static void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit) {
+	unsigned long flags;
+
+	if (!(hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT))
+		return;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	if (hba->ahit == ahit)
+		goto out_unlock;
+	hba->ahit = ahit;
+	if (!pm_runtime_suspended(hba->dev))
+		ufshcd_writel(hba, hba->ahit,
 REG_AUTO_HIBERNATE_IDLE_TIMER);
+out_unlock:
+	spin_unlock_irqrestore(hba->host->host_lock, flags); }
+
+/* Convert Auto-Hibernate Idle Timer register value to microseconds */
+static int ufshcd_ahit_to_us(u32 ahit) {
+	int timer = FIELD_GET(UFSHCI_AHIBERN8_TIMER_MASK, ahit);
+	int scale = FIELD_GET(UFSHCI_AHIBERN8_SCALE_MASK, ahit);
+
+	for (; scale > 0; --scale)
+		timer *= UFSHCI_AHIBERN8_SCALE_FACTOR;
+
+	return timer;
+}
+
+/* Convert microseconds to Auto-Hibernate Idle Timer register value */
+static u32 ufshcd_us_to_ahit(unsigned int timer) {
+	unsigned int scale;
+
+	for (scale = 0; timer > UFSHCI_AHIBERN8_TIMER_MASK; ++scale)
+		timer /= UFSHCI_AHIBERN8_SCALE_FACTOR;
+
+	return FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, timer) |
+	       FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, scale); }
+

Quoted 8 lines

drivers/scsi/ufs/ufs-sysfs.c static ssize_t spm_target_link_state_show(struct device *dev, · line 169
Quoted 7 lines
drivers/scsi/ufs/ufs-sysfs.c +7 -0
+static ssize_t auto_hibern8_show(struct device *dev,
+				 struct device_attribute *attr, char *buf) {
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	int timer = -1;
+
+	if (hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT)
+		timer = ufshcd_ahit_to_us(hba->ahit);
I think it's better to return EOPNOTSUPP when the feature is not supported than to show "-1".

Quoted 141 lines

drivers/scsi/ufs/ufs-sysfs.c +26 -0

+
+	return snprintf(buf, PAGE_SIZE, "%d\n", timer); }
+
+static ssize_t auto_hibern8_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	unsigned int timer;
+
+	if (!(hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT))
+		return -EOPNOTSUPP;
+
+	if (kstrtouint(buf, 0, &timer))
+		return -EINVAL;
+
+	if (timer > UFSHCI_AHIBERN8_MAX)
+		return -EINVAL;
+
+	ufshcd_auto_hibern8_update(hba, ufshcd_us_to_ahit(timer));
+
+	return count;
+}
+
 static DEVICE_ATTR_RW(rpm_lvl);
 static DEVICE_ATTR_RO(rpm_target_dev_state);
 static DEVICE_ATTR_RO(rpm_target_link_state);
 static DEVICE_ATTR_RW(spm_lvl);
 static DEVICE_ATTR_RO(spm_target_dev_state);
 static DEVICE_ATTR_RO(spm_target_link_state);
+static DEVICE_ATTR_RW(auto_hibern8);
 
 static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
 	&dev_attr_rpm_lvl.attr,

@@ -131,6 +207,7 @@ static ssize_t spm_target_link_state_show(struct
 device *dev,
 	&dev_attr_spm_lvl.attr,
 	&dev_attr_spm_target_dev_state.attr,
 	&dev_attr_spm_target_link_state.attr,
+	&dev_attr_auto_hibern8.attr,
 	NULL
 };

drivers/scsi/ufs/ufshcd.c index renamed from drivers/scsi/ufs/ufshcd.c +0 -0

3abcd31646eb..facee2b97926 100644

drivers/scsi/ufs/ufshcd.c +18 -0

@@ -41,6 +41,7 @@
 #include <linux/devfreq.h>
 #include <linux/nls.h>
 #include <linux/of.h>
+#include <linux/bitfield.h>
 #include "ufshcd.h"
 #include "ufs_quirks.h"
 #include "unipro.h"

@@ -3708,6 +3709,18 @@ static int ufshcd_uic_hibern8_exit(struct ufs_hba
 *hba)
 	return ret;
 }
 
+static void ufshcd_auto_hibern8_enable(struct ufs_hba *hba) {
+	unsigned long flags;
+
+	if (!(hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT) || !hba-
 > ahit)
+		return;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_writel(hba, hba->ahit, REG_AUTO_HIBERNATE_IDLE_TIMER);
+	spin_unlock_irqrestore(hba->host->host_lock, flags); }
+
  /**
  * ufshcd_init_pwr_info - setting the POR (power on reset)
  * values in hba power info

@@ -6307,6 +6320,9 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 	/* UniPro link is active now */
 	ufshcd_set_link_active(hba);
 
+	/* Enable Auto-Hibernate if configured */
+	ufshcd_auto_hibern8_enable(hba);
+
 	ret = ufshcd_verify_dev_init(hba);
 	if (ret)
 		goto out;

@@ -7391,6 +7407,10 @@ static int ufshcd_resume(struct ufs_hba *hba,
 enum ufs_pm_op pm_op)
 
 	/* Schedule clock gating in case of no access to UFS device yet */
 	ufshcd_release(hba);
+
+	/* Enable Auto-Hibernate if configured */
+	ufshcd_auto_hibern8_enable(hba);
+
 	goto out;

set_old_link_state:

drivers/scsi/ufs/ufshcd.c +3 -0

@@ -7834,6 +7854,12 @@ int ufshcd_init(struct ufs_hba *hba, void
 __iomem *mmio_base, unsigned int irq)
 						UFS_SLEEP_PWR_MODE,
 						UIC_LINK_HIBERN8_STATE);
 
+	/* Set the default auto-hiberate idle timer value to 150 ms */
+	if (hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT) {
+		hba->ahit = FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK,

150) |

drivers/scsi/ufs/ufshcd.c +3 -0

+			    FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3);
+	}
+
 	/* Hold auto suspend until async scan completes */
 	pm_runtime_get_sync(dev);

drivers/scsi/ufs/ufshcd.h index renamed from drivers/scsi/ufs/ufshcd.h +0 -0

deb3c5d382e9..8110dcd04d22 100644

drivers/scsi/ufs/ufshcd.h +3 -0

@@ -531,6 +531,9 @@ struct ufs_hba {
 	struct device_attribute spm_lvl_attr;
 	int pm_op_in_progress;
 
+	/* Auto-Hibernate Idle Timer register value */
+	u32 ahit;
+
 	struct ufshcd_lrb *lrb;
 	unsigned long lrb_in_use;

drivers/scsi/ufs/ufshci.h index renamed from drivers/scsi/ufs/ufshci.h +0 -0

1a1b5d9fe514..bb5d9c7f3353 100644

drivers/scsi/ufs/ufshci.h +1 -0

@@ -86,6 +86,7 @@ enum {
 enum {
 	MASK_TRANSFER_REQUESTS_SLOTS		= 0x0000001F,
 	MASK_TASK_MANAGEMENT_REQUEST_SLOTS	= 0x00070000,
+	MASK_AUTO_HIBERN8_SUPPORT		= 0x00800000,
 	MASK_64_ADDRESSING_SUPPORT		= 0x01000000,
 	MASK_OUT_OF_ORDER_DATA_DELIVERY_SUPPORT	= 0x02000000,
 	MASK_UIC_DME_TEST_MODE_SUPPORT		= 0x04000000,

@@ -119,6 +120,12 @@ enum {
 #define MANUFACTURE_ID_MASK	UFS_MASK(0xFFFF, 0)
 #define PRODUCT_ID_MASK		UFS_MASK(0xFFFF, 16)

Quoted 12 lines

Quoted 11 lines

drivers/scsi/ufs/ufshci.h +6 -1

+/* AHIT - Auto-Hibernate Idle Timer */
+#define UFSHCI_AHIBERN8_TIMER_MASK		GENMASK(9, 0)
+#define UFSHCI_AHIBERN8_SCALE_MASK		GENMASK(12, 10)
+#define UFSHCI_AHIBERN8_SCALE_FACTOR		10
+#define UFSHCI_AHIBERN8_MAX			(1023 * 100000)
+
 /*
  * IS - Interrupt Status - 20h
  */
--

1.9.1

Please fix all checkpatch errors.

I don't get any checkpatch errors. Can you list them?