[PATCH v3 0/3] Changes for ufshcd.c

[PATCH v3 0/3] Changes for ufshcd.c

[Bean Huo]

From: Bean Huo <beanhuo@micron.com>

v2--v3:
    1. Add patch 3/3
    2. Add remove unused parameter param_offset in patch 1/3 based on Daejun's comment
    3. Further optimized patch 2/3 based on Bart's comment

v1--v2:
    1. change in ufshcd_lu_init() in  patch 2/2:
        1) Remove duplicate parameter initialization
        2) Move lun parameter initialization before kmalloc()

Bean Huo (3):
  scsi: ufs: core: Remove unnecessary if statement
  scsi: ufs: core: Cleanup ufshcd_slave_alloc()
  scsi: ufs: core: Use is_visible to control UFS unit descriptor sysfs
    nodes

 drivers/ufs/core/ufs-sysfs.c   |  21 ++++-
 drivers/ufs/core/ufshcd-priv.h |   6 +-
 drivers/ufs/core/ufshcd.c      | 155 ++++++++++++---------------------
 3 files changed, 77 insertions(+), 105 deletions(-)

-- 
2.34.1

[PATCH v3 1/3] scsi: ufs: core: Remove unnecessary if statement

[Bean Huo]

From: Bean Huo <beanhuo@micron.com>

LUs with WB potential support are properly checked in ufshcd_wb_probe()
before calling ufshcd_read_unit_desc_param(), so remove this unnecessary
if-checkup in ufs_is_valid_unit_desc_lun() to match its function definition.

Signed-off-by: Bean Huo <beanhuo@micron.com>
---
 drivers/ufs/core/ufs-sysfs.c   | 3 +--
 drivers/ufs/core/ufshcd-priv.h | 6 +-----
 drivers/ufs/core/ufshcd.c      | 2 +-
 3 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index 53aea56d1de1..eb6b278c4e79 100644
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -1234,8 +1234,7 @@ static ssize_t _pname##_show(struct device *dev,			\
 	struct scsi_device *sdev = to_scsi_device(dev);			\
 	struct ufs_hba *hba = shost_priv(sdev->host);			\
 	u8 lun = ufshcd_scsi_to_upiu_lun(sdev->lun);			\
-	if (!ufs_is_valid_unit_desc_lun(&hba->dev_info, lun,		\
-				_duname##_DESC_PARAM##_puname))		\
+	if (!ufs_is_valid_unit_desc_lun(&hba->dev_info, lun))		\
 		return -EINVAL;						\
 	return ufs_sysfs_read_desc_param(hba, QUERY_DESC_IDN_##_duname,	\
 		lun, _duname##_DESC_PARAM##_puname, buf, _size);	\
diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
index f68ca33f6ac7..a9e8e1f5afe7 100644
--- a/drivers/ufs/core/ufshcd-priv.h
+++ b/drivers/ufs/core/ufshcd-priv.h
@@ -293,16 +293,12 @@ static inline int ufshcd_rpm_put(struct ufs_hba *hba)
  * @lun: LU number to check
  * @return: true if the lun has a matching unit descriptor, false otherwise
  */
-static inline bool ufs_is_valid_unit_desc_lun(struct ufs_dev_info *dev_info,
-		u8 lun, u8 param_offset)
+static inline bool ufs_is_valid_unit_desc_lun(struct ufs_dev_info *dev_info, u8 lun)
 {
 	if (!dev_info || !dev_info->max_lu_supported) {
 		pr_err("Max General LU supported by UFS isn't initialized\n");
 		return false;
 	}
-	/* WB is available only for the logical unit from 0 to 7 */
-	if (param_offset == UNIT_DESC_PARAM_WB_BUF_ALLOC_UNITS)
-		return lun < UFS_UPIU_MAX_WB_LUN_ID;
 	return lun == UFS_UPIU_RPMB_WLUN || (lun < dev_info->max_lu_supported);
 }
 
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 7c15cbc737b4..85679e8a043b 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -3609,7 +3609,7 @@ static inline int ufshcd_read_unit_desc_param(struct ufs_hba *hba,
 	 * Unit descriptors are only available for general purpose LUs (LUN id
 	 * from 0 to 7) and RPMB Well known LU.
 	 */
-	if (!ufs_is_valid_unit_desc_lun(&hba->dev_info, lun, param_offset))
+	if (!ufs_is_valid_unit_desc_lun(&hba->dev_info, lun))
 		return -EOPNOTSUPP;
 
 	return ufshcd_read_desc_param(hba, QUERY_DESC_IDN_UNIT, lun,
-- 
2.34.1

Re: [PATCH v3 1/3] scsi: ufs: core: Remove unnecessary if statement

[Bart Van Assche]

On 10/18/22 11:16, Bean Huo wrote:
> From: Bean Huo <beanhuo@micron.com>
> 
> LUs with WB potential support are properly checked in ufshcd_wb_probe()
> before calling ufshcd_read_unit_desc_param(), so remove this unnecessary
> if-checkup in ufs_is_valid_unit_desc_lun() to match its function definition.

Hi Bean,

Does this patch differ from a revert of Jaegeuk's patch? If not, please 
change the patch title into "Revert scsi: ufs: WB is only available on 
LUN #0 to #7" and add "Cc: Jaegeuk Kim <jaegeuk@kernel.org>" just above 
the Signed-off-by line.

Thanks,

Bart.

Re: [PATCH v3 1/3] scsi: ufs: core: Remove unnecessary if statement

[Bean Huo]

On Tue, 2022-10-18 at 11:20 -0700, Bart Van Assche wrote:
> On 10/18/22 11:16, Bean Huo wrote:
> > From: Bean Huo <beanhuo@micron.com>
> > 
> > LUs with WB potential support are properly checked in
> > ufshcd_wb_probe()
> > before calling ufshcd_read_unit_desc_param(), so remove this
> > unnecessary
> > if-checkup in ufs_is_valid_unit_desc_lun() to match its function
> > definition.
> 
> Hi Bean,
> 
> Does this patch differ from a revert of Jaegeuk's patch? If not,
> please 
> change the patch title into "Revert scsi: ufs: WB is only available
> on 
> LUN #0 to #7" and add "Cc: Jaegeuk Kim <jaegeuk@kernel.org>" just
> above 
> the Signed-off-by line.
> 
> Thanks,
> 
> Bart.

Bart, 

no difference, I will change its title and CC Jaegeuk.

thanks,
Bean

[PATCH v3 2/3] scsi: ufs: core: Cleanup ufshcd_slave_alloc()

[Bean Huo]

From: Bean Huo <beanhuo@micron.com>

Combine ufshcd_get_lu_power_on_wp_status() and ufshcd_set_queue_depth()
into one single ufshcd_lu_init(), so that we only need to read the LUN
descriptor once.

Signed-off-by: Bean Huo <beanhuo@micron.com>
---
 drivers/ufs/core/ufshcd.c | 153 ++++++++++++++------------------------
 1 file changed, 56 insertions(+), 97 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 85679e8a043b..8bf64dea1130 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -4862,100 +4862,6 @@ static int ufshcd_verify_dev_init(struct ufs_hba *hba)
 	return err;
 }
 
-/**
- * ufshcd_set_queue_depth - set lun queue depth
- * @sdev: pointer to SCSI device
- *
- * Read bLUQueueDepth value and activate scsi tagged command
- * queueing. For WLUN, queue depth is set to 1. For best-effort
- * cases (bLUQueueDepth = 0) the queue depth is set to a maximum
- * value that host can queue.
- */
-static void ufshcd_set_queue_depth(struct scsi_device *sdev)
-{
-	int ret = 0;
-	u8 lun_qdepth;
-	struct ufs_hba *hba;
-
-	hba = shost_priv(sdev->host);
-
-	lun_qdepth = hba->nutrs;
-	ret = ufshcd_read_unit_desc_param(hba,
-					  ufshcd_scsi_to_upiu_lun(sdev->lun),
-					  UNIT_DESC_PARAM_LU_Q_DEPTH,
-					  &lun_qdepth,
-					  sizeof(lun_qdepth));
-
-	/* Some WLUN doesn't support unit descriptor */
-	if (ret == -EOPNOTSUPP)
-		lun_qdepth = 1;
-	else if (!lun_qdepth)
-		/* eventually, we can figure out the real queue depth */
-		lun_qdepth = hba->nutrs;
-	else
-		lun_qdepth = min_t(int, lun_qdepth, hba->nutrs);
-
-	dev_dbg(hba->dev, "%s: activate tcq with queue depth %d\n",
-			__func__, lun_qdepth);
-	scsi_change_queue_depth(sdev, lun_qdepth);
-}
-
-/*
- * ufshcd_get_lu_wp - returns the "b_lu_write_protect" from UNIT DESCRIPTOR
- * @hba: per-adapter instance
- * @lun: UFS device lun id
- * @b_lu_write_protect: pointer to buffer to hold the LU's write protect info
- *
- * Returns 0 in case of success and b_lu_write_protect status would be returned
- * @b_lu_write_protect parameter.
- * Returns -ENOTSUPP if reading b_lu_write_protect is not supported.
- * Returns -EINVAL in case of invalid parameters passed to this function.
- */
-static int ufshcd_get_lu_wp(struct ufs_hba *hba,
-			    u8 lun,
-			    u8 *b_lu_write_protect)
-{
-	int ret;
-
-	if (!b_lu_write_protect)
-		ret = -EINVAL;
-	/*
-	 * According to UFS device spec, RPMB LU can't be write
-	 * protected so skip reading bLUWriteProtect parameter for
-	 * it. For other W-LUs, UNIT DESCRIPTOR is not available.
-	 */
-	else if (lun >= hba->dev_info.max_lu_supported)
-		ret = -ENOTSUPP;
-	else
-		ret = ufshcd_read_unit_desc_param(hba,
-					  lun,
-					  UNIT_DESC_PARAM_LU_WR_PROTECT,
-					  b_lu_write_protect,
-					  sizeof(*b_lu_write_protect));
-	return ret;
-}
-
-/**
- * ufshcd_get_lu_power_on_wp_status - get LU's power on write protect
- * status
- * @hba: per-adapter instance
- * @sdev: pointer to SCSI device
- *
- */
-static inline void ufshcd_get_lu_power_on_wp_status(struct ufs_hba *hba,
-						    const struct scsi_device *sdev)
-{
-	if (hba->dev_info.f_power_on_wp_en &&
-	    !hba->dev_info.is_lu_power_on_wp) {
-		u8 b_lu_write_protect;
-
-		if (!ufshcd_get_lu_wp(hba, ufshcd_scsi_to_upiu_lun(sdev->lun),
-				      &b_lu_write_protect) &&
-		    (b_lu_write_protect == UFS_LU_POWER_ON_WP))
-			hba->dev_info.is_lu_power_on_wp = true;
-	}
-}
-
 /**
  * ufshcd_setup_links - associate link b/w device wlun and other luns
  * @sdev: pointer to SCSI device
@@ -4993,6 +4899,61 @@ static void ufshcd_setup_links(struct ufs_hba *hba, struct scsi_device *sdev)
 	}
 }
 
+/**
+ * ufshcd_lu_init - Initialize the relevant parameters of the LU
+ * @hba: per-adapter instance
+ * @sdev: pointer to SCSI device
+ */
+static void ufshcd_lu_init(struct ufs_hba *hba, struct scsi_device *sdev)
+{
+	u8 lun_qdepth;
+	u8 *desc_buf;
+	int ret;
+	int len;
+	u8 lun;
+
+	lun_qdepth = hba->nutrs;
+	lun = ufshcd_scsi_to_upiu_lun(sdev->lun);
+	len = hba->desc_size[QUERY_DESC_IDN_UNIT];
+
+	desc_buf = kzalloc(len, GFP_KERNEL);
+	if (!desc_buf)
+		goto set_qdepth;
+
+	ret = ufshcd_read_unit_desc_param(hba, lun, 0, desc_buf, len);
+	if (ret < 0) {
+		if (ret == -EOPNOTSUPP)
+			/* If LU doesn't support unit descriptor, its queue depth is set to 1 */
+			lun_qdepth = 1;
+		kfree(desc_buf);
+		goto set_qdepth;
+	}
+
+	if (desc_buf[UNIT_DESC_PARAM_LU_Q_DEPTH])
+		/*
+		 * In per-LU queueing architecture, bLUQueueDepth will not be 0, then we will
+		 * use the smaller between UFSHCI CAP.NUTRS and UFS LU bLUQueueDepth
+		 */
+		lun_qdepth = min_t(int, desc_buf[UNIT_DESC_PARAM_LU_Q_DEPTH], hba->nutrs);
+	/*
+	 * According to UFS device specification, the write protection mode is only supported by
+	 * normal LU, not supported by WLUN.
+	 */
+	if (hba->dev_info.f_power_on_wp_en && lun < hba->dev_info.max_lu_supported &&
+	    !hba->dev_info.is_lu_power_on_wp &&
+	    desc_buf[UNIT_DESC_PARAM_LU_WR_PROTECT] == UFS_LU_POWER_ON_WP)
+		hba->dev_info.is_lu_power_on_wp = true;
+
+	kfree(desc_buf);
+set_qdepth:
+	/*
+	 * For WLUNs that don't support unit descriptor, queue depth is set to 1. For LUs whose
+	 * bLUQueueDepth == 0, the queue depth is set to a maximum value that host can queue.
+	 */
+	dev_dbg(hba->dev, "Set LU %x queue depth %d\n", lun, lun_qdepth);
+	scsi_change_queue_depth(sdev, lun_qdepth);
+}
+
 /**
  * ufshcd_slave_alloc - handle initial SCSI device configurations
  * @sdev: pointer to SCSI device
@@ -5020,9 +4981,7 @@ static int ufshcd_slave_alloc(struct scsi_device *sdev)
 	/* WRITE_SAME command is not supported */
 	sdev->no_write_same = 1;
 
-	ufshcd_set_queue_depth(sdev);
-
-	ufshcd_get_lu_power_on_wp_status(hba, sdev);
+	ufshcd_lu_init(hba, sdev);
 
 	ufshcd_setup_links(hba, sdev);
 
-- 
2.34.1

Re: [PATCH v3 2/3] scsi: ufs: core: Cleanup ufshcd_slave_alloc()

[Bart Van Assche]

On 10/18/22 11:16, Bean Huo wrote:
> +static void ufshcd_lu_init(struct ufs_hba *hba, struct scsi_device *sdev)
> +{
> +	u8 lun_qdepth;
> +	u8 *desc_buf;
> +	int ret;
> +	int len;
> +	u8 lun;
> +
> +	lun_qdepth = hba->nutrs;
> +	lun = ufshcd_scsi_to_upiu_lun(sdev->lun);
> +	len = hba->desc_size[QUERY_DESC_IDN_UNIT];

Isn't the preferred style for kernel code to combine the above 
declarations and assignments (but not memory allocation calls)?

> +	desc_buf = kzalloc(len, GFP_KERNEL);
> +	if (!desc_buf)
> +		goto set_qdepth;
> +
> +	ret = ufshcd_read_unit_desc_param(hba, lun, 0, desc_buf, len);
> +	if (ret < 0) {
> +		if (ret == -EOPNOTSUPP)
> +			/* If LU doesn't support unit descriptor, its queue depth is set to 1 */
> +			lun_qdepth = 1;
> +		kfree(desc_buf);
> +		goto set_qdepth;
> +	}
> +
> +	if (desc_buf[UNIT_DESC_PARAM_LU_Q_DEPTH])
> +		/*
> +		 * In per-LU queueing architecture, bLUQueueDepth will not be 0, then we will
> +		 * use the smaller between UFSHCI CAP.NUTRS and UFS LU bLUQueueDepth
> +		 */
> +		lun_qdepth = min_t(int, desc_buf[UNIT_DESC_PARAM_LU_Q_DEPTH], hba->nutrs);

Should a test be added that verifies that UNIT_DESC_PARAM_LU_Q_DEPTH < len?

Additionally, please use braces ({}) around multi-line if-statement bodies.

> +	/*
> +	 * According to UFS device specification, the write protection mode is only supported by
> +	 * normal LU, not supported by WLUN.
> +	 */
> +	if (hba->dev_info.f_power_on_wp_en && lun < hba->dev_info.max_lu_supported &&
> +	    !hba->dev_info.is_lu_power_on_wp &&
> +	    desc_buf[UNIT_DESC_PARAM_LU_WR_PROTECT] == UFS_LU_POWER_ON_WP)
> +		hba->dev_info.is_lu_power_on_wp = true;

Also here, should the following test be added: 
UNIT_DESC_PARAM_LU_WR_PROTECT < len?

Otherwise this patch looks good to me.

Thanks,

Bart.

Re: [PATCH v3 2/3] scsi: ufs: core: Cleanup ufshcd_slave_alloc()

[Bean Huo]

On Tue, 2022-10-18 at 11:27 -0700, Bart Van Assche wrote:
> Should a test be added that verifies that UNIT_DESC_PARAM_LU_Q_DEPTH
> < len?
> 
> Additionally, please use braces ({}) around multi-line if-statement
> bodies.
> 
> > +       /*
> > +        * According to UFS device specification, the write
> > protection mode is only supported by
> > +        * normal LU, not supported by WLUN.
> > +        */
> > +       if (hba->dev_info.f_power_on_wp_en && lun < hba-
> > >dev_info.max_lu_supported &&
> > +           !hba->dev_info.is_lu_power_on_wp &&
> > +           desc_buf[UNIT_DESC_PARAM_LU_WR_PROTECT] ==
> > UFS_LU_POWER_ON_WP)
> > +               hba->dev_info.is_lu_power_on_wp = true;
> 
> Also here, should the following test be added: 
> UNIT_DESC_PARAM_LU_WR_PROTECT < len?
> 
> Otherwise this patch looks good to me.

Bart, 

len is already the LU descriptor size. UNIT_DESC_PARAM_LU_Q_DEPTH (0x6)
and UNIT_DESC_PARAM_LU_WR_PROTECT(0x5) are very basic parameters in the
LU descriptor, no matter what version of UFS is, there are these two
parameters in the descriptor. So the return value of
ufshcd_read_unit_desc_param() will be -EOPNOTSUPP, -EINVAL, -ENOMEM or
0 (successful read of LU descriptor). the checkup of "< len" is not
neccessary.

Kind regards,
Bean

[PATCH v3 3/3] scsi: ufs: core: Use is_visible to control UFS unit descriptor sysfs nodes

[Bean Huo]

From: Bean Huo <beanhuo@micron.com>

UFS Boot and Device W-LUs do not have unit descriptors, and PRMB does not
support WB, we can use is_visible() to control which nodes are visible
and which are not.

Signed-off-by: Bean Huo <beanhuo@micron.com>
---
 drivers/ufs/core/ufs-sysfs.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index eb6b278c4e79..883f0e44b54e 100644
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -1285,9 +1285,27 @@ static struct attribute *ufs_sysfs_unit_descriptor[] = {
 	NULL,
 };
 
+static umode_t ufs_unit_descriptor_is_visible(struct kobject *kobj, struct attribute *attr, int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct scsi_device *sdev = to_scsi_device(dev);
+	u8 lun = ufshcd_scsi_to_upiu_lun(sdev->lun);
+	umode_t mode = attr->mode;
+
+	if (lun == UFS_UPIU_BOOT_WLUN || lun == UFS_UPIU_UFS_DEVICE_WLUN)
+		/* Boot and device WLUN have no unit descriptors */
+		mode = 0;
+	if (lun == UFS_UPIU_RPMB_WLUN && attr == &dev_attr_wb_buf_alloc_units.attr)
+		mode = 0;
+
+	return mode;
+}
+
+
 const struct attribute_group ufs_sysfs_unit_descriptor_group = {
 	.name = "unit_descriptor",
 	.attrs = ufs_sysfs_unit_descriptor,
+	.is_visible = ufs_unit_descriptor_is_visible,
 };
 
 static ssize_t dyn_cap_needed_attribute_show(struct device *dev,
-- 
2.34.1

Re: [PATCH v3 3/3] scsi: ufs: core: Use is_visible to control UFS unit descriptor sysfs nodes

[Bart Van Assche]

On 10/18/22 11:16, Bean Huo wrote:
> From: Bean Huo <beanhuo@micron.com>
> 
> UFS Boot and Device W-LUs do not have unit descriptors, and PRMB does not
                                                               ^^^^
                                                               RPMB?
> support WB, we can use is_visible() to control which nodes are visible
> and which are not.

Otherwise this patch looks good to me. Hence:

Reviewed-by: Bart Van Assche <bvanassche@acm.org>