[PATCH v2 12/30] cxlflash: Refine host/device attributes

[PATCH v2 12/30] cxlflash: Refine host/device attributes

[Matthew R. Ochs]

Implement the following suggestions and add two new attributes
to allow for debugging the port LUN table.

 - use scnprintf() instead of snprintf()
 - use DEVICE_ATTR_RO and DEVICE_ATTR_RW

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Suggested-by: Shane Seymour <shane.seymour@hp.com>
---
 drivers/scsi/cxlflash/main.c | 180 +++++++++++++++++++++++++++++++++----------
 1 file changed, 138 insertions(+), 42 deletions(-)

diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index f2f41a7..919dfb1 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -2004,33 +2004,24 @@ static int cxlflash_change_queue_depth(struct scsi_device *sdev, int qdepth)
 
 /**
  * cxlflash_show_port_status() - queries and presents the current port status
- * @dev:	Generic device associated with the host owning the port.
- * @attr:	Device attribute representing the port.
+ * @port:	Desired port for status reporting.
+ * @afu:	AFU owning the specified port.
  * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
  *
  * Return: The size of the ASCII string returned in @buf.
  */
-static ssize_t cxlflash_show_port_status(struct device *dev,
-					 struct device_attribute *attr,
-					 char *buf)
+static ssize_t cxlflash_show_port_status(u32 port, struct afu *afu, char *buf)
 {
-	struct Scsi_Host *shost = class_to_shost(dev);
-	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
-	struct afu *afu = cfg->afu;
-
 	char *disp_status;
-	int rc;
-	u32 port;
 	u64 status;
-	u64 *fc_regs;
+	__be64 __iomem *fc_regs;
 
-	rc = kstrtouint((attr->attr.name + 4), 10, &port);
-	if (rc || (port >= NUM_FC_PORTS))
+	if (port >= NUM_FC_PORTS)
 		return 0;
 
 	fc_regs = &afu->afu_map->global.fc_regs[port][0];
-	status =
-	    (readq_be(&fc_regs[FC_MTIP_STATUS / 8]) & FC_MTIP_STATUS_MASK);
+	status = readq_be(&fc_regs[FC_MTIP_STATUS / 8]);
+	status &= FC_MTIP_STATUS_MASK;
 
 	if (status == FC_MTIP_STATUS_ONLINE)
 		disp_status = "online";
@@ -2039,31 +2030,69 @@ static ssize_t cxlflash_show_port_status(struct device *dev,
 	else
 		disp_status = "unknown";
 
-	return snprintf(buf, PAGE_SIZE, "%s\n", disp_status);
+	return scnprintf(buf, PAGE_SIZE, "%s\n", disp_status);
+}
+
+/**
+ * port0_show() - queries and presents the current status of port 0
+ * @dev:	Generic device associated with the host owning the port.
+ * @attr:	Device attribute representing the port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t port0_show(struct device *dev,
+			  struct device_attribute *attr,
+			  char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return cxlflash_show_port_status(0, afu, buf);
 }
 
 /**
- * cxlflash_show_lun_mode() - presents the current LUN mode of the host
+ * port1_show() - queries and presents the current status of port 1
+ * @dev:	Generic device associated with the host owning the port.
+ * @attr:	Device attribute representing the port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t port1_show(struct device *dev,
+			  struct device_attribute *attr,
+			  char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return cxlflash_show_port_status(1, afu, buf);
+}
+
+/**
+ * lun_mode_show() - presents the current LUN mode of the host
  * @dev:	Generic device associated with the host.
- * @attr:	Device attribute representing the lun mode.
+ * @attr:	Device attribute representing the LUN mode.
  * @buf:	Buffer of length PAGE_SIZE to report back the LUN mode in ASCII.
  *
  * Return: The size of the ASCII string returned in @buf.
  */
-static ssize_t cxlflash_show_lun_mode(struct device *dev,
-				      struct device_attribute *attr, char *buf)
+static ssize_t lun_mode_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
 {
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
 	struct afu *afu = cfg->afu;
 
-	return snprintf(buf, PAGE_SIZE, "%u\n", afu->internal_lun);
+	return scnprintf(buf, PAGE_SIZE, "%u\n", afu->internal_lun);
 }
 
 /**
- * cxlflash_store_lun_mode() - sets the LUN mode of the host
+ * lun_mode_store() - sets the LUN mode of the host
  * @dev:	Generic device associated with the host.
- * @attr:	Device attribute representing the lun mode.
+ * @attr:	Device attribute representing the LUN mode.
  * @buf:	Buffer of length PAGE_SIZE containing the LUN mode in ASCII.
  * @count:	Length of data resizing in @buf.
  *
@@ -2082,9 +2111,9 @@ static ssize_t cxlflash_show_lun_mode(struct device *dev,
  *
  * Return: The size of the ASCII string returned in @buf.
  */
-static ssize_t cxlflash_store_lun_mode(struct device *dev,
-				       struct device_attribute *attr,
-				       const char *buf, size_t count)
+static ssize_t lun_mode_store(struct device *dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t count)
 {
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
@@ -2103,58 +2132,125 @@ static ssize_t cxlflash_store_lun_mode(struct device *dev,
 }
 
 /**
- * cxlflash_show_ioctl_version() - presents the hosts current ioctl version
+ * ioctl_version_show() - presents the current ioctl version of the host
  * @dev:	Generic device associated with the host.
  * @attr:	Device attribute representing the ioctl version.
  * @buf:	Buffer of length PAGE_SIZE to report back the ioctl version.
  *
  * Return: The size of the ASCII string returned in @buf.
  */
-static ssize_t cxlflash_show_ioctl_version(struct device *dev,
-					   struct device_attribute *attr,
-					   char *buf)
+static ssize_t ioctl_version_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
 {
 	return scnprintf(buf, PAGE_SIZE, "%u\n", DK_CXLFLASH_VERSION_0);
 }
 
 /**
- * cxlflash_show_dev_mode() - presents the current mode of the device
+ * cxlflash_show_port_lun_table() - queries and presents the port LUN table
+ * @port:	Desired port for status reporting.
+ * @afu:	AFU owning the specified port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t cxlflash_show_port_lun_table(u32 port,
+					    struct afu *afu,
+					    char *buf)
+{
+	int i;
+	ssize_t bytes = 0;
+	__be64 __iomem *fc_port;
+
+	if (port >= NUM_FC_PORTS)
+		return 0;
+
+	fc_port = &afu->afu_map->global.fc_port[port][0];
+
+	for (i = 0; i < CXLFLASH_NUM_VLUNS; i++, buf += 22)
+		bytes += scnprintf(buf, PAGE_SIZE, "%03d: %016llX\n",
+				   i, readq_be(&fc_port[i]));
+	return bytes;
+}
+
+/**
+ * port0_lun_table_show() - presents the current LUN table of port 0
+ * @dev:	Generic device associated with the host owning the port.
+ * @attr:	Device attribute representing the port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t port0_lun_table_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return cxlflash_show_port_lun_table(0, afu, buf);
+}
+
+/**
+ * port1_lun_table_show() - presents the current LUN table of port 1
+ * @dev:	Generic device associated with the host owning the port.
+ * @attr:	Device attribute representing the port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t port1_lun_table_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return cxlflash_show_port_lun_table(1, afu, buf);
+}
+
+/**
+ * mode_show() - presents the current mode of the device
  * @dev:	Generic device associated with the device.
  * @attr:	Device attribute representing the device mode.
  * @buf:	Buffer of length PAGE_SIZE to report back the dev mode in ASCII.
  *
  * Return: The size of the ASCII string returned in @buf.
  */
-static ssize_t cxlflash_show_dev_mode(struct device *dev,
-				      struct device_attribute *attr, char *buf)
+static ssize_t mode_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
 {
 	struct scsi_device *sdev = to_scsi_device(dev);
 
-	return snprintf(buf, PAGE_SIZE, "%s\n",
-			sdev->hostdata ? "superpipe" : "legacy");
+	return scnprintf(buf, PAGE_SIZE, "%s\n",
+			 sdev->hostdata ? "superpipe" : "legacy");
 }
 
 /*
  * Host attributes
  */
-static DEVICE_ATTR(port0, S_IRUGO, cxlflash_show_port_status, NULL);
-static DEVICE_ATTR(port1, S_IRUGO, cxlflash_show_port_status, NULL);
-static DEVICE_ATTR(lun_mode, S_IRUGO | S_IWUSR, cxlflash_show_lun_mode,
-		   cxlflash_store_lun_mode);
-static DEVICE_ATTR(ioctl_version, S_IRUGO, cxlflash_show_ioctl_version, NULL);
+static DEVICE_ATTR_RO(port0);
+static DEVICE_ATTR_RO(port1);
+static DEVICE_ATTR_RW(lun_mode);
+static DEVICE_ATTR_RO(ioctl_version);
+static DEVICE_ATTR_RO(port0_lun_table);
+static DEVICE_ATTR_RO(port1_lun_table);
 
 static struct device_attribute *cxlflash_host_attrs[] = {
 	&dev_attr_port0,
 	&dev_attr_port1,
 	&dev_attr_lun_mode,
 	&dev_attr_ioctl_version,
+	&dev_attr_port0_lun_table,
+	&dev_attr_port1_lun_table,
 	NULL
 };
 
 /*
  * Device attributes
  */
-static DEVICE_ATTR(mode, S_IRUGO, cxlflash_show_dev_mode, NULL);
+static DEVICE_ATTR_RO(mode);
 
 static struct device_attribute *cxlflash_dev_attrs[] = {
 	&dev_attr_mode,
-- 
2.1.0

[PATCH v2 12/30] cxlflash: Refine host/device attributes

[Matthew R. Ochs]

Implement the following suggestions and add two new attributes
to allow for debugging the port LUN table.

 - use scnprintf() instead of snprintf()
 - use DEVICE_ATTR_RO and DEVICE_ATTR_RW

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Suggested-by: Shane Seymour <shane.seymour@hp.com>
---
 drivers/scsi/cxlflash/main.c | 180 +++++++++++++++++++++++++++++++++----------
 1 file changed, 138 insertions(+), 42 deletions(-)

diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index f2f41a7..919dfb1 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -2004,33 +2004,24 @@ static int cxlflash_change_queue_depth(struct scsi_device *sdev, int qdepth)
 
 /**
  * cxlflash_show_port_status() - queries and presents the current port status
- * @dev:	Generic device associated with the host owning the port.
- * @attr:	Device attribute representing the port.
+ * @port:	Desired port for status reporting.
+ * @afu:	AFU owning the specified port.
  * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
  *
  * Return: The size of the ASCII string returned in @buf.
  */
-static ssize_t cxlflash_show_port_status(struct device *dev,
-					 struct device_attribute *attr,
-					 char *buf)
+static ssize_t cxlflash_show_port_status(u32 port, struct afu *afu, char *buf)
 {
-	struct Scsi_Host *shost = class_to_shost(dev);
-	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
-	struct afu *afu = cfg->afu;
-
 	char *disp_status;
-	int rc;
-	u32 port;
 	u64 status;
-	u64 *fc_regs;
+	__be64 __iomem *fc_regs;
 
-	rc = kstrtouint((attr->attr.name + 4), 10, &port);
-	if (rc || (port >= NUM_FC_PORTS))
+	if (port >= NUM_FC_PORTS)
 		return 0;
 
 	fc_regs = &afu->afu_map->global.fc_regs[port][0];
-	status =
-	    (readq_be(&fc_regs[FC_MTIP_STATUS / 8]) & FC_MTIP_STATUS_MASK);
+	status = readq_be(&fc_regs[FC_MTIP_STATUS / 8]);
+	status &= FC_MTIP_STATUS_MASK;
 
 	if (status == FC_MTIP_STATUS_ONLINE)
 		disp_status = "online";
@@ -2039,31 +2030,69 @@ static ssize_t cxlflash_show_port_status(struct device *dev,
 	else
 		disp_status = "unknown";
 
-	return snprintf(buf, PAGE_SIZE, "%s\n", disp_status);
+	return scnprintf(buf, PAGE_SIZE, "%s\n", disp_status);
+}
+
+/**
+ * port0_show() - queries and presents the current status of port 0
+ * @dev:	Generic device associated with the host owning the port.
+ * @attr:	Device attribute representing the port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t port0_show(struct device *dev,
+			  struct device_attribute *attr,
+			  char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return cxlflash_show_port_status(0, afu, buf);
 }
 
 /**
- * cxlflash_show_lun_mode() - presents the current LUN mode of the host
+ * port1_show() - queries and presents the current status of port 1
+ * @dev:	Generic device associated with the host owning the port.
+ * @attr:	Device attribute representing the port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t port1_show(struct device *dev,
+			  struct device_attribute *attr,
+			  char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return cxlflash_show_port_status(1, afu, buf);
+}
+
+/**
+ * lun_mode_show() - presents the current LUN mode of the host
  * @dev:	Generic device associated with the host.
- * @attr:	Device attribute representing the lun mode.
+ * @attr:	Device attribute representing the LUN mode.
  * @buf:	Buffer of length PAGE_SIZE to report back the LUN mode in ASCII.
  *
  * Return: The size of the ASCII string returned in @buf.
  */
-static ssize_t cxlflash_show_lun_mode(struct device *dev,
-				      struct device_attribute *attr, char *buf)
+static ssize_t lun_mode_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
 {
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
 	struct afu *afu = cfg->afu;
 
-	return snprintf(buf, PAGE_SIZE, "%u\n", afu->internal_lun);
+	return scnprintf(buf, PAGE_SIZE, "%u\n", afu->internal_lun);
 }
 
 /**
- * cxlflash_store_lun_mode() - sets the LUN mode of the host
+ * lun_mode_store() - sets the LUN mode of the host
  * @dev:	Generic device associated with the host.
- * @attr:	Device attribute representing the lun mode.
+ * @attr:	Device attribute representing the LUN mode.
  * @buf:	Buffer of length PAGE_SIZE containing the LUN mode in ASCII.
  * @count:	Length of data resizing in @buf.
  *
@@ -2082,9 +2111,9 @@ static ssize_t cxlflash_show_lun_mode(struct device *dev,
  *
  * Return: The size of the ASCII string returned in @buf.
  */
-static ssize_t cxlflash_store_lun_mode(struct device *dev,
-				       struct device_attribute *attr,
-				       const char *buf, size_t count)
+static ssize_t lun_mode_store(struct device *dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t count)
 {
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
@@ -2103,58 +2132,125 @@ static ssize_t cxlflash_store_lun_mode(struct device *dev,
 }
 
 /**
- * cxlflash_show_ioctl_version() - presents the hosts current ioctl version
+ * ioctl_version_show() - presents the current ioctl version of the host
  * @dev:	Generic device associated with the host.
  * @attr:	Device attribute representing the ioctl version.
  * @buf:	Buffer of length PAGE_SIZE to report back the ioctl version.
  *
  * Return: The size of the ASCII string returned in @buf.
  */
-static ssize_t cxlflash_show_ioctl_version(struct device *dev,
-					   struct device_attribute *attr,
-					   char *buf)
+static ssize_t ioctl_version_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
 {
 	return scnprintf(buf, PAGE_SIZE, "%u\n", DK_CXLFLASH_VERSION_0);
 }
 
 /**
- * cxlflash_show_dev_mode() - presents the current mode of the device
+ * cxlflash_show_port_lun_table() - queries and presents the port LUN table
+ * @port:	Desired port for status reporting.
+ * @afu:	AFU owning the specified port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t cxlflash_show_port_lun_table(u32 port,
+					    struct afu *afu,
+					    char *buf)
+{
+	int i;
+	ssize_t bytes = 0;
+	__be64 __iomem *fc_port;
+
+	if (port >= NUM_FC_PORTS)
+		return 0;
+
+	fc_port = &afu->afu_map->global.fc_port[port][0];
+
+	for (i = 0; i < CXLFLASH_NUM_VLUNS; i++, buf += 22)
+		bytes += scnprintf(buf, PAGE_SIZE, "%03d: %016llX\n",
+				   i, readq_be(&fc_port[i]));
+	return bytes;
+}
+
+/**
+ * port0_lun_table_show() - presents the current LUN table of port 0
+ * @dev:	Generic device associated with the host owning the port.
+ * @attr:	Device attribute representing the port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t port0_lun_table_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return cxlflash_show_port_lun_table(0, afu, buf);
+}
+
+/**
+ * port1_lun_table_show() - presents the current LUN table of port 1
+ * @dev:	Generic device associated with the host owning the port.
+ * @attr:	Device attribute representing the port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t port1_lun_table_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return cxlflash_show_port_lun_table(1, afu, buf);
+}
+
+/**
+ * mode_show() - presents the current mode of the device
  * @dev:	Generic device associated with the device.
  * @attr:	Device attribute representing the device mode.
  * @buf:	Buffer of length PAGE_SIZE to report back the dev mode in ASCII.
  *
  * Return: The size of the ASCII string returned in @buf.
  */
-static ssize_t cxlflash_show_dev_mode(struct device *dev,
-				      struct device_attribute *attr, char *buf)
+static ssize_t mode_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
 {
 	struct scsi_device *sdev = to_scsi_device(dev);
 
-	return snprintf(buf, PAGE_SIZE, "%s\n",
-			sdev->hostdata ? "superpipe" : "legacy");
+	return scnprintf(buf, PAGE_SIZE, "%s\n",
+			 sdev->hostdata ? "superpipe" : "legacy");
 }
 
 /*
  * Host attributes
  */
-static DEVICE_ATTR(port0, S_IRUGO, cxlflash_show_port_status, NULL);
-static DEVICE_ATTR(port1, S_IRUGO, cxlflash_show_port_status, NULL);
-static DEVICE_ATTR(lun_mode, S_IRUGO | S_IWUSR, cxlflash_show_lun_mode,
-		   cxlflash_store_lun_mode);
-static DEVICE_ATTR(ioctl_version, S_IRUGO, cxlflash_show_ioctl_version, NULL);
+static DEVICE_ATTR_RO(port0);
+static DEVICE_ATTR_RO(port1);
+static DEVICE_ATTR_RW(lun_mode);
+static DEVICE_ATTR_RO(ioctl_version);
+static DEVICE_ATTR_RO(port0_lun_table);
+static DEVICE_ATTR_RO(port1_lun_table);
 
 static struct device_attribute *cxlflash_host_attrs[] = {
 	&dev_attr_port0,
 	&dev_attr_port1,
 	&dev_attr_lun_mode,
 	&dev_attr_ioctl_version,
+	&dev_attr_port0_lun_table,
+	&dev_attr_port1_lun_table,
 	NULL
 };
 
 /*
  * Device attributes
  */
-static DEVICE_ATTR(mode, S_IRUGO, cxlflash_show_dev_mode, NULL);
+static DEVICE_ATTR_RO(mode);
 
 static struct device_attribute *cxlflash_dev_attrs[] = {
 	&dev_attr_mode,
-- 
2.1.0

Re: [PATCH v2 12/30] cxlflash: Refine host/device attributes

[Brian King]

On 09/16/2015 04:29 PM, Matthew R. Ochs wrote:
> Implement the following suggestions and add two new attributes
> to allow for debugging the port LUN table.
> 
>  - use scnprintf() instead of snprintf()
>  - use DEVICE_ATTR_RO and DEVICE_ATTR_RW
> 
> Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
> Suggested-by: Shane Seymour <shane.seymour@hp.com>
> ---
>  drivers/scsi/cxlflash/main.c | 180 +++++++++++++++++++++++++++++++++----------
>  1 file changed, 138 insertions(+), 42 deletions(-)
> 

>  /**
> - * cxlflash_show_dev_mode() - presents the current mode of the device
> + * cxlflash_show_port_lun_table() - queries and presents the port LUN table
> + * @port:	Desired port for status reporting.
> + * @afu:	AFU owning the specified port.
> + * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
> + *
> + * Return: The size of the ASCII string returned in @buf.
> + */
> +static ssize_t cxlflash_show_port_lun_table(u32 port,
> +					    struct afu *afu,
> +					    char *buf)
> +{
> +	int i;
> +	ssize_t bytes = 0;
> +	__be64 __iomem *fc_port;
> +
> +	if (port >= NUM_FC_PORTS)
> +		return 0;
> +
> +	fc_port = &afu->afu_map->global.fc_port[port][0];
> +
> +	for (i = 0; i < CXLFLASH_NUM_VLUNS; i++, buf += 22)

Rather than this bug prone hard coded 22, how about never incrementing buf and do something
similar to this:

> +		bytes += scnprintf(buf, PAGE_SIZE, "%03d: %016llX\n",
> +				   i, readq_be(&fc_port[i]));

		bytes += scnprintf(&buf[bytes], PAGE_SIZE, "%03d: %016llX\n",
				   i, readq_be(&fc_port[i]));

> +	return bytes;
> +}
> +



-- 
Brian King
Power Linux I/O
IBM Linux Technology Center

Re: [PATCH v2 12/30] cxlflash: Refine host/device attributes

[Matthew R. Ochs]

> On Sep 18, 2015, at 4:34 PM, Brian King <brking@linux.vnet.ibm.com> wrote:
> On 09/16/2015 04:29 PM, Matthew R. Ochs wrote:
>> 
>> +	ssize_t bytes = 0;
>> +	__be64 __iomem *fc_port;
>> +
>> +	if (port >= NUM_FC_PORTS)
>> +		return 0;
>> +
>> +	fc_port = &afu->afu_map->global.fc_port[port][0];
>> +
>> +	for (i = 0; i < CXLFLASH_NUM_VLUNS; i++, buf += 22)
> 
> Rather than this bug prone hard coded 22, how about never incrementing buf and do something
> similar to this:
> 
>> +		bytes += scnprintf(buf, PAGE_SIZE, "%03d: %016llX\n",
>> +				   i, readq_be(&fc_port[i]));
> 
> 		bytes += scnprintf(&buf[bytes], PAGE_SIZE, "%03d: %016llX\n",
> 				   i, readq_be(&fc_port[i]));
> 
>> +	return bytes;
>> +}
>> +

Great suggestion! Will fix in v3.


-matt

RE: [PATCH v2 12/30] cxlflash: Refine host/device attributes

[David Laight]

From: Brian King
> Sent: 18 September 2015 22:35
...
> > +	for (i = 0; i < CXLFLASH_NUM_VLUNS; i++, buf += 22)
> 
> Rather than this bug prone hard coded 22, how about never incrementing buf and do something
> similar to this:
> 
> > +		bytes += scnprintf(buf, PAGE_SIZE, "%03d: %016llX\n",
> > +				   i, readq_be(&fc_port[i]));
> 
> 		bytes += scnprintf(&buf[bytes], PAGE_SIZE, "%03d: %016llX\n",
> 				   i, readq_be(&fc_port[i]));
...

	bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes, ....

You need to check scnprintf()'s return value though.
The above is wrong for libc's snprintf().

	David

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