3 files changed, 127 insertions, 254 deletions

diff --git a/drivers/staging/unisys/include/visorbus.h b/drivers/staging/unisys/include/visorbus.h
index 677627c..03d56f8 100644
--- a/drivers/staging/unisys/include/visorbus.h
+++ b/drivers/staging/unisys/include/visorbus.h
@@ -166,6 +166,8 @@ struct visor_device {
 	struct controlvm_message_header *pending_msg_hdr;
 	void *vbus_hdr_info;
 	uuid_le partition_uuid;
+	struct dentry *debugfs_dir;
+	struct dentry *debugfs_client_bus_info;
 };
 
 #define to_visor_device(x) container_of(x, struct visor_device, device)
diff --git a/drivers/staging/unisys/visorbus/vbuschannel.h b/drivers/staging/unisys/visorbus/vbuschannel.h
index e979175..2409b15 100644
--- a/drivers/staging/unisys/visorbus/vbuschannel.h
+++ b/drivers/staging/unisys/visorbus/vbuschannel.h
@@ -23,6 +23,7 @@
  *  the client devices and client drivers for the server end to see.
  */
 #include <linux/uuid.h>
+#include <linux/ctype.h>
 #include "channel.h"
 
 /* {193b331b-c58f-11da-95a9-00e08161165f} */
@@ -72,199 +73,38 @@ struct ultra_vbus_deviceinfo {
 };
 
 /**
- * vbuschannel_sanitize_buffer() - remove non-printable chars from buffer
- * @p: destination buffer where chars are written to
- * @remain: number of bytes that can be written starting at #p
- * @src: pointer to source buffer
- * @srcmax: number of valid characters at #src
- *
- * Reads chars from the buffer at @src for @srcmax bytes, and writes to
- * the buffer at @p, which is @remain bytes long, ensuring never to
- * overflow the buffer at @p, using the following rules:
- * - printable characters are simply copied from the buffer at @src to the
- *   buffer at @p
- * - intervening streaks of non-printable characters in the buffer at @src
- *   are replaced with a single space in the buffer at @p
- * Note that we pay no attention to '\0'-termination.
- *
- * Pass @p == NULL and @remain == 0 for this special behavior -- In this
- * case, we simply return the number of bytes that WOULD HAVE been written
- * to a buffer at @p, had it been infinitely big.
- *
- * Return: the number of bytes written to @p (or WOULD HAVE been written to
- *         @p, as described in the previous paragraph)
- */
-static inline int
-vbuschannel_sanitize_buffer(char *p, int remain, char *src, int srcmax)
-{
-	int chars = 0;
-	int nonprintable_streak = 0;
-
-	while (srcmax > 0) {
-		if ((*src >= ' ') && (*src < 0x7f)) {
-			if (nonprintable_streak) {
-				if (remain > 0) {
-					*p = ' ';
-					p++;
-					remain--;
-					chars++;
-				} else if (!p) {
-					chars++;
-				}
-				nonprintable_streak = 0;
-			}
-			if (remain > 0) {
-				*p = *src;
-				p++;
-				remain--;
-				chars++;
-			} else if (!p) {
-				chars++;
-			}
-		} else {
-			nonprintable_streak = 1;
-		}
-		src++;
-		srcmax--;
-	}
-	return chars;
-}
-
-#define VBUSCHANNEL_ADDACHAR(ch, p, remain, chars) \
-	do {					   \
-		if (remain <= 0)		   \
-			break;			   \
-		*p = ch;			   \
-		p++;  chars++;  remain--;	   \
-	} while (0)
-
-/**
- * vbuschannel_itoa() - convert non-negative int to string
- * @p: destination string
- * @remain: max number of bytes that can be written to @p
- * @num: input int to convert
- *
- * Converts the non-negative value at @num to an ascii decimal string
- * at @p, writing at most @remain bytes.  Note there is NO '\0' termination
- * written to @p.
- *
- * Return: number of bytes written to @p
- *
- */
-static inline int
-vbuschannel_itoa(char *p, int remain, int num)
-{
-	int digits = 0;
-	char s[32];
-	int i;
-
-	if (num == 0) {
-		/* '0' is a special case */
-		if (remain <= 0)
-			return 0;
-		*p = '0';
-		return 1;
-	}
-	/* form a backwards decimal ascii string in <s> */
-	while (num > 0) {
-		if (digits >= (int)sizeof(s))
-			return 0;
-		s[digits++] = (num % 10) + '0';
-		num = num / 10;
-	}
-	if (remain < digits) {
-		/* not enough room left at <p> to hold number, so fill with
-		 * '?'
-		 */
-		for (i = 0; i < remain; i++, p++)
-			*p = '?';
-		return remain;
-	}
-	/* plug in the decimal ascii string representing the number, by */
-	/* reversing the string we just built in <s> */
-	i = digits;
-	while (i > 0) {
-		i--;
-		*p = s[i];
-		p++;
-	}
-	return digits;
-}
-
-/**
- * vbuschannel_devinfo_to_string() - format a struct ultra_vbus_deviceinfo
- *                                   to a printable string
+ * vbuschannel_print_devinfo() - format a struct ultra_vbus_deviceinfo
+ *                               and write it to a seq_file
  * @devinfo: the struct ultra_vbus_deviceinfo to format
- * @p: destination string area
- * @remain: size of destination string area in bytes
+ * @seq: seq_file to write to
  * @devix: the device index to be included in the output data, or -1 if no
  *         device index is to be included
  *
- * Reads @devInfo, and converts its contents to a printable string at @p,
- * writing at most @remain bytes. Note there is NO '\0' termination
- * written to @p.
- *
- * Return: number of bytes written to @p
+ * Reads @devInfo, and writes it in human-readable notation to @seq.
  */
-static inline int
-vbuschannel_devinfo_to_string(struct ultra_vbus_deviceinfo *devinfo,
-			      char *p, int remain, int devix)
+static inline void
+vbuschannel_print_devinfo(struct ultra_vbus_deviceinfo *devinfo,
+			  struct seq_file *seq, int devix)
 {
-	char *psrc;
-	int nsrc, x, i, pad;
-	int chars = 0;
-
-	psrc = &devinfo->devtype[0];
-	nsrc = sizeof(devinfo->devtype);
-	if (vbuschannel_sanitize_buffer(NULL, 0, psrc, nsrc) <= 0)
-		return 0;
-
-	/* emit device index */
-	if (devix >= 0) {
-		VBUSCHANNEL_ADDACHAR('[', p, remain, chars);
-		x = vbuschannel_itoa(p, remain, devix);
-		p += x;
-		remain -= x;
-		chars += x;
-		VBUSCHANNEL_ADDACHAR(']', p, remain, chars);
-	} else {
-		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
-		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
-		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
-	}
-
-	/* emit device type */
-	x = vbuschannel_sanitize_buffer(p, remain, psrc, nsrc);
-	p += x;
-	remain -= x;
-	chars += x;
-	pad = 15 - x;		/* pad device type to be exactly 15 chars */
-	for (i = 0; i < pad; i++)
-		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
-	VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
-
-	/* emit driver name */
-	psrc = &devinfo->drvname[0];
-	nsrc = sizeof(devinfo->drvname);
-	x = vbuschannel_sanitize_buffer(p, remain, psrc, nsrc);
-	p += x;
-	remain -= x;
-	chars += x;
-	pad = 15 - x;		/* pad driver name to be exactly 15 chars */
-	for (i = 0; i < pad; i++)
-		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
-	VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
-
-	/* emit strings */
-	psrc = &devinfo->infostrs[0];
-	nsrc = sizeof(devinfo->infostrs);
-	x = vbuschannel_sanitize_buffer(p, remain, psrc, nsrc);
-	p += x;
-	remain -= x;
-	chars += x;
-	VBUSCHANNEL_ADDACHAR('\n', p, remain, chars);
-
-	return chars;
+	if (!isprint(devinfo->devtype[0]))
+		return; /* uninitialized vbus device entry */
+
+	if (devix >= 0)
+		seq_printf(seq, "[%d]", devix);
+	else
+		/* vbus device entry is for bus or chipset */
+		seq_puts(seq, "   ");
+
+	/*
+	 * Note: because the s-Par back-end is free to scribble in this area,
+	 * we never assume '\0'-termination.
+	 */
+	seq_printf(seq, "%-*.*s ", (int)sizeof(devinfo->devtype),
+		   (int)sizeof(devinfo->devtype), devinfo->devtype);
+	seq_printf(seq, "%-*.*s ", (int)sizeof(devinfo->drvname),
+		   (int)sizeof(devinfo->drvname), devinfo->drvname);
+	seq_printf(seq, "%.*s\n", (int)sizeof(devinfo->infostrs),
+		   devinfo->infostrs);
 }
 
 struct spar_vbus_headerinfo {
diff --git a/drivers/staging/unisys/visorbus/visorbus_main.c b/drivers/staging/unisys/visorbus/visorbus_main.c
index 2b22515..b7001ed 100644
--- a/drivers/staging/unisys/visorbus/visorbus_main.c
+++ b/drivers/staging/unisys/visorbus/visorbus_main.c
@@ -14,6 +14,7 @@
  * details.
  */
 
+#include <linux/debugfs.h>
 #include <linux/uuid.h>
 
 #include "visorbus.h"
@@ -33,6 +34,7 @@ static int visorbus_forcenomatch;
 #define POLLJIFFIES_NORMALCHANNEL     10
 
 static int busreg_rc = -ENODEV; /* stores the result from bus registration */
+static struct dentry *visorbus_debugfs_dir;
 
 /*
  * DEVICE type attributes
@@ -151,6 +153,8 @@ visorbus_release_busdevice(struct device *xdev)
 {
 	struct visor_device *dev = dev_get_drvdata(xdev);
 
+	debugfs_remove(dev->debugfs_client_bus_info);
+	debugfs_remove_recursive(dev->debugfs_dir);
 	kfree(dev);
 }
 
@@ -349,70 +353,6 @@ static ssize_t channel_id_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(channel_id);
 
-static ssize_t client_bus_info_show(struct device *dev,
-				    struct device_attribute *attr,
-				    char *buf) {
-	struct visor_device *vdev = to_visor_device(dev);
-	struct visorchannel *channel = vdev->visorchannel;
-
-	int i, shift, remain = PAGE_SIZE;
-	unsigned long off;
-	char *pos = buf;
-	u8 *partition_name;
-	struct ultra_vbus_deviceinfo dev_info;
-
-	partition_name = "";
-	if (channel) {
-		if (vdev->name)
-			partition_name = vdev->name;
-		shift = snprintf(pos, remain,
-				 "Client device / client driver info for %s partition (vbus #%u):\n",
-				 partition_name, vdev->chipset_bus_no);
-		pos += shift;
-		remain -= shift;
-		shift = visorchannel_read(channel,
-					  offsetof(struct
-						   spar_vbus_channel_protocol,
-						   chp_info),
-					  &dev_info, sizeof(dev_info));
-		if (shift >= 0) {
-			shift = vbuschannel_devinfo_to_string(&dev_info, pos,
-							      remain, -1);
-			pos += shift;
-			remain -= shift;
-		}
-		shift = visorchannel_read(channel,
-					  offsetof(struct
-						   spar_vbus_channel_protocol,
-						   bus_info),
-					  &dev_info, sizeof(dev_info));
-		if (shift >= 0) {
-			shift = vbuschannel_devinfo_to_string(&dev_info, pos,
-							      remain, -1);
-			pos += shift;
-			remain -= shift;
-		}
-		off = offsetof(struct spar_vbus_channel_protocol, dev_info);
-		i = 0;
-		while (off + sizeof(dev_info) <=
-		       visorchannel_get_nbytes(channel)) {
-			shift = visorchannel_read(channel,
-						  off, &dev_info,
-						  sizeof(dev_info));
-			if (shift >= 0) {
-				shift = vbuschannel_devinfo_to_string
-				    (&dev_info, pos, remain, i);
-				pos += shift;
-				remain -= shift;
-			}
-			off += sizeof(dev_info);
-			i++;
-		}
-	}
-	return PAGE_SIZE - remain;
-}
-static DEVICE_ATTR_RO(client_bus_info);
-
 static struct attribute *dev_attrs[] = {
 		&dev_attr_partition_handle.attr,
 		&dev_attr_partition_guid.attr,
@@ -420,7 +360,6 @@ static struct attribute *dev_attrs[] = {
 		&dev_attr_channel_addr.attr,
 		&dev_attr_channel_bytes.attr,
 		&dev_attr_channel_id.attr,
-		&dev_attr_client_bus_info.attr,
 		NULL
 };
 
@@ -433,6 +372,66 @@ static const struct attribute_group *visorbus_groups[] = {
 		NULL
 };
 
+/*
+ *  BUS debugfs entries
+ *
+ *  define & implement display of debugfs attributes under
+ *  /sys/kernel/debug/visorbus/visorbus<n>.
+ */
+
+static int client_bus_info_debugfs_show(struct seq_file *seq, void *v)
+{
+	struct visor_device *vdev = seq->private;
+	struct visorchannel *channel = vdev->visorchannel;
+
+	int i;
+	unsigned long off;
+	struct ultra_vbus_deviceinfo dev_info;
+
+	if (!channel)
+		return 0;
+
+	seq_printf(seq,
+		   "Client device / client driver info for %s partition (vbus #%u):\n",
+		   ((vdev->name) ? (char *)(vdev->name) : ""),
+		   vdev->chipset_bus_no);
+	if (visorchannel_read(channel,
+			      offsetof(struct spar_vbus_channel_protocol,
+				       chp_info),
+			      &dev_info, sizeof(dev_info)) >= 0)
+		vbuschannel_print_devinfo(&dev_info, seq, -1);
+	if (visorchannel_read(channel,
+			      offsetof(struct spar_vbus_channel_protocol,
+				       bus_info),
+			      &dev_info, sizeof(dev_info)) >= 0)
+		vbuschannel_print_devinfo(&dev_info, seq, -1);
+	off = offsetof(struct spar_vbus_channel_protocol, dev_info);
+	i = 0;
+	while (off + sizeof(dev_info) <= visorchannel_get_nbytes(channel)) {
+		if (visorchannel_read(channel, off, &dev_info,
+				      sizeof(dev_info)) >= 0)
+			vbuschannel_print_devinfo(&dev_info, seq, i);
+		off += sizeof(dev_info);
+		i++;
+	}
+
+	return 0;
+}
+
+static int client_bus_info_debugfs_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, client_bus_info_debugfs_show,
+			   inode->i_private);
+}
+
+static const struct file_operations client_bus_info_debugfs_fops = {
+	.owner = THIS_MODULE,
+	.open = client_bus_info_debugfs_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
 static void
 dev_periodic_work(unsigned long __opaque)
 {
@@ -964,6 +963,7 @@ static int
 create_bus_instance(struct visor_device *dev)
 {
 	int id = dev->chipset_bus_no;
+	int err;
 	struct spar_vbus_headerinfo *hdr_info;
 
 	POSTCODE_LINUX_2(BUS_CREATE_ENTRY_PC, POSTCODE_SEVERITY_INFO);
@@ -977,11 +977,26 @@ create_bus_instance(struct visor_device *dev)
 	dev->device.groups = visorbus_groups;
 	dev->device.release = visorbus_release_busdevice;
 
+	dev->debugfs_dir = debugfs_create_dir(dev_name(&dev->device),
+					      visorbus_debugfs_dir);
+	if (!dev->debugfs_dir) {
+		err = -ENOMEM;
+		goto err_hdr_info;
+	}
+	dev->debugfs_client_bus_info =
+		debugfs_create_file("client_bus_info", S_IRUSR | S_IRGRP,
+				    dev->debugfs_dir, dev,
+				    &client_bus_info_debugfs_fops);
+	if (!dev->debugfs_client_bus_info) {
+		err = -ENOMEM;
+		goto err_debugfs_dir;
+	}
+
 	if (device_register(&dev->device) < 0) {
 		POSTCODE_LINUX_3(DEVICE_CREATE_FAILURE_PC, id,
 				 POSTCODE_SEVERITY_ERR);
-		kfree(hdr_info);
-		return -ENODEV;
+		err = -ENODEV;
+		goto err_debugfs_created;
 	}
 
 	if (get_vbus_header_info(dev->visorchannel, hdr_info) >= 0) {
@@ -996,6 +1011,16 @@ create_bus_instance(struct visor_device *dev)
 	list_add_tail(&dev->list_all, &list_all_bus_instances);
 	dev_set_drvdata(&dev->device, dev);
 	return 0;
+
+err_debugfs_created:
+	debugfs_remove(dev->debugfs_client_bus_info);
+
+err_debugfs_dir:
+	debugfs_remove_recursive(dev->debugfs_dir);
+
+err_hdr_info:
+	kfree(hdr_info);
+	return err;
 }
 
 /**
@@ -1273,6 +1298,11 @@ visorbus_init(void)
 	int err;
 
 	POSTCODE_LINUX_3(DRIVER_ENTRY_PC, 0, POSTCODE_SEVERITY_INFO);
+
+	visorbus_debugfs_dir = debugfs_create_dir("visorbus", NULL);
+	if (!visorbus_debugfs_dir)
+		return -ENOMEM;
+
 	bus_device_info_init(&clientbus_driverinfo, "clientbus", "visorbus");
 
 	err = create_bus_type();
@@ -1304,6 +1334,7 @@ visorbus_exit(void)
 		remove_bus_instance(dev);
 	}
 	remove_bus_type();
+	debugfs_remove_recursive(visorbus_debugfs_dir);
 }
 
 module_param_named(forcematch, visorbus_forcematch, int, S_IRUGO);