mei: Convert to use DEFINE_SHOW_ATTRIBUTE macro

Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
Signed-off-by: Vitaly Lubart <vitaly.lubart@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/debugfs.c

@@ -8,6 +8,7 @@
 #include <linux/kernel.h>
 #include <linux/device.h>
 #include <linux/debugfs.h>
+#include <linux/seq_file.h>
 
 #include <linux/mei.h>
 
@@ -15,104 +16,56 @@
 #include "client.h"
 #include "hw.h"
 
-static ssize_t mei_dbgfs_read_meclients(struct file *fp, char __user *ubuf,
-					size_t cnt, loff_t *ppos)
+static int mei_dbgfs_meclients_show(struct seq_file *m, void *unused)
 {
-	struct mei_device *dev = fp->private_data;
+	struct mei_device *dev = m->private;
 	struct mei_me_client *me_cl;
-	size_t bufsz = 1;
-	char *buf;
 	int i = 0;
-	int pos = 0;
-	int ret;
 
-#define HDR \
-"  |id|fix|         UUID                       |con|msg len|sb|refc|\n"
+	if (!dev)
+		return -ENODEV;
 
 	down_read(&dev->me_clients_rwsem);
-	list_for_each_entry(me_cl, &dev->me_clients, list)
-		bufsz++;
 
-	bufsz *= sizeof(HDR) + 1;
-	buf = kzalloc(bufsz, GFP_KERNEL);
-	if (!buf) {
-		up_read(&dev->me_clients_rwsem);
-		return -ENOMEM;
-	}
-
-	pos += scnprintf(buf + pos, bufsz - pos, HDR);
-#undef HDR
+	seq_puts(m, "  |id|fix|         UUID                       |con|msg len|sb|refc|\n");
 
 	/*  if the driver is not enabled the list won't be consistent */
 	if (dev->dev_state != MEI_DEV_ENABLED)
 		goto out;
 
 	list_for_each_entry(me_cl, &dev->me_clients, list) {
-
-		if (mei_me_cl_get(me_cl)) {
-			pos += scnprintf(buf + pos, bufsz - pos,
-				"%2d|%2d|%3d|%pUl|%3d|%7d|%2d|%4d|\n",
-				i++, me_cl->client_id,
-				me_cl->props.fixed_address,
-				&me_cl->props.protocol_name,
-				me_cl->props.max_number_of_connections,
-				me_cl->props.max_msg_length,
-				me_cl->props.single_recv_buf,
-				kref_read(&me_cl->refcnt));
-
-			mei_me_cl_put(me_cl);
-		}
+		if (!mei_me_cl_get(me_cl))
+			continue;
+
+		seq_printf(m, "%2d|%2d|%3d|%pUl|%3d|%7d|%2d|%4d|\n",
+			   i++, me_cl->client_id,
+			   me_cl->props.fixed_address,
+			   &me_cl->props.protocol_name,
+			   me_cl->props.max_number_of_connections,
+			   me_cl->props.max_msg_length,
+			   me_cl->props.single_recv_buf,
+			   kref_read(&me_cl->refcnt));
+		mei_me_cl_put(me_cl);
 	}
 
 out:
 	up_read(&dev->me_clients_rwsem);
-	ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, pos);
-	kfree(buf);
-	return ret;
+	return 0;
 }
+DEFINE_SHOW_ATTRIBUTE(mei_dbgfs_meclients);
 
-static const struct file_operations mei_dbgfs_fops_meclients = {
-	.open = simple_open,
-	.read = mei_dbgfs_read_meclients,
-	.llseek = generic_file_llseek,
-};
-
-static ssize_t mei_dbgfs_read_active(struct file *fp, char __user *ubuf,
-					size_t cnt, loff_t *ppos)
+static int mei_dbgfs_active_show(struct seq_file *m, void *unused)
 {
-	struct mei_device *dev = fp->private_data;
+	struct mei_device *dev = m->private;
 	struct mei_cl *cl;
-	size_t bufsz = 1;
-	char *buf;
 	int i = 0;
-	int pos = 0;
-	int ret;
-
-#define HDR "   |me|host|state|rd|wr|wrq\n"
 
 	if (!dev)
 		return -ENODEV;
 
 	mutex_lock(&dev->device_lock);
 
-	/*
-	 * if the driver is not enabled the list won't be consistent,
-	 * we output empty table
-	 */
-	if (dev->dev_state == MEI_DEV_ENABLED)
-		list_for_each_entry(cl, &dev->file_list, link)
-			bufsz++;
-
-	bufsz *= sizeof(HDR) + 1;
-
-	buf = kzalloc(bufsz, GFP_KERNEL);
-	if  (!buf) {
-		mutex_unlock(&dev->device_lock);
-		return -ENOMEM;
-	}
-
-	pos += scnprintf(buf + pos, bufsz - pos, HDR);
-#undef HDR
+	seq_puts(m, "   |me|host|state|rd|wr|wrq\n");
 
 	/*  if the driver is not enabled the list won't be consistent */
 	if (dev->dev_state != MEI_DEV_ENABLED)
@@ -120,76 +73,44 @@ static ssize_t mei_dbgfs_read_active(struct file *fp, char __user *ubuf,
 
 	list_for_each_entry(cl, &dev->file_list, link) {
 
-		pos += scnprintf(buf + pos, bufsz - pos,
-			"%3d|%2d|%4d|%5d|%2d|%2d|%3u\n",
-			i, mei_cl_me_id(cl), cl->host_client_id, cl->state,
-			!list_empty(&cl->rd_completed), cl->writing_state,
-			cl->tx_cb_queued);
+		seq_printf(m, "%3d|%2d|%4d|%5d|%2d|%2d|%3u\n",
+			   i, mei_cl_me_id(cl), cl->host_client_id, cl->state,
+			   !list_empty(&cl->rd_completed), cl->writing_state,
+			   cl->tx_cb_queued);
 		i++;
 	}
 out:
 	mutex_unlock(&dev->device_lock);
-	ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, pos);
-	kfree(buf);
-	return ret;
+	return 0;
 }
+DEFINE_SHOW_ATTRIBUTE(mei_dbgfs_active);
 
-static const struct file_operations mei_dbgfs_fops_active = {
-	.open = simple_open,
-	.read = mei_dbgfs_read_active,
-	.llseek = generic_file_llseek,
-};
-
-static ssize_t mei_dbgfs_read_devstate(struct file *fp, char __user *ubuf,
-					size_t cnt, loff_t *ppos)
+static int mei_dbgfs_devstate_show(struct seq_file *m, void *unused)
 {
-	struct mei_device *dev = fp->private_data;
-	const size_t bufsz = 1024;
-	char *buf = kzalloc(bufsz, GFP_KERNEL);
-	int pos = 0;
-	int ret;
-
-	if  (!buf)
-		return -ENOMEM;
+	struct mei_device *dev = m->private;
 
-	pos += scnprintf(buf + pos, bufsz - pos, "dev: %s\n",
-			mei_dev_state_str(dev->dev_state));
-	pos += scnprintf(buf + pos, bufsz - pos, "hbm: %s\n",
-			mei_hbm_state_str(dev->hbm_state));
+	seq_printf(m, "dev: %s\n", mei_dev_state_str(dev->dev_state));
+	seq_printf(m, "hbm: %s\n", mei_hbm_state_str(dev->hbm_state));
 
 	if (dev->hbm_state >= MEI_HBM_ENUM_CLIENTS &&
 	    dev->hbm_state <= MEI_HBM_STARTED) {
-		pos += scnprintf(buf + pos, bufsz - pos, "hbm features:\n");
-		pos += scnprintf(buf + pos, bufsz - pos, "\tPG: %01d\n",
-				 dev->hbm_f_pg_supported);
-		pos += scnprintf(buf + pos, bufsz - pos, "\tDC: %01d\n",
-				 dev->hbm_f_dc_supported);
-		pos += scnprintf(buf + pos, bufsz - pos, "\tIE: %01d\n",
-				 dev->hbm_f_ie_supported);
-		pos += scnprintf(buf + pos, bufsz - pos, "\tDOT: %01d\n",
-				 dev->hbm_f_dot_supported);
-		pos += scnprintf(buf + pos, bufsz - pos, "\tEV: %01d\n",
-				 dev->hbm_f_ev_supported);
-		pos += scnprintf(buf + pos, bufsz - pos, "\tFA: %01d\n",
-				 dev->hbm_f_fa_supported);
-		pos += scnprintf(buf + pos, bufsz - pos, "\tOS: %01d\n",
-				 dev->hbm_f_os_supported);
-		pos += scnprintf(buf + pos, bufsz - pos, "\tDR: %01d\n",
-				 dev->hbm_f_dr_supported);
+		seq_puts(m, "hbm features:\n");
+		seq_printf(m, "\tPG: %01d\n", dev->hbm_f_pg_supported);
+		seq_printf(m, "\tDC: %01d\n", dev->hbm_f_dc_supported);
+		seq_printf(m, "\tIE: %01d\n", dev->hbm_f_ie_supported);
+		seq_printf(m, "\tDOT: %01d\n", dev->hbm_f_dot_supported);
+		seq_printf(m, "\tEV: %01d\n", dev->hbm_f_ev_supported);
+		seq_printf(m, "\tFA: %01d\n", dev->hbm_f_fa_supported);
+		seq_printf(m, "\tOS: %01d\n", dev->hbm_f_os_supported);
+		seq_printf(m, "\tDR: %01d\n", dev->hbm_f_dr_supported);
 	}
 
-	pos += scnprintf(buf + pos, bufsz - pos, "pg:  %s, %s\n",
-			mei_pg_is_enabled(dev) ? "ENABLED" : "DISABLED",
-			mei_pg_state_str(mei_pg_state(dev)));
-	ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, pos);
-	kfree(buf);
-	return ret;
+	seq_printf(m, "pg:  %s, %s\n",
+		   mei_pg_is_enabled(dev) ? "ENABLED" : "DISABLED",
+		   mei_pg_state_str(mei_pg_state(dev)));
+	return 0;
 }
-static const struct file_operations mei_dbgfs_fops_devstate = {
-	.open = simple_open,
-	.read = mei_dbgfs_read_devstate,
-	.llseek = generic_file_llseek,
-};
+DEFINE_SHOW_ATTRIBUTE(mei_dbgfs_devstate);
 
 static ssize_t mei_dbgfs_write_allow_fa(struct file *file,
 					const char __user *user_buf,
@@ -208,7 +129,7 @@ static ssize_t mei_dbgfs_write_allow_fa(struct file *file,
 	return ret;
 }
 
-static const struct file_operations mei_dbgfs_fops_allow_fa = {
+static const struct file_operations mei_dbgfs_allow_fa_fops = {
 	.open = simple_open,
 	.read = debugfs_read_file_bool,
 	.write = mei_dbgfs_write_allow_fa,
@@ -247,26 +168,26 @@ int mei_dbgfs_register(struct mei_device *dev, const char *name)
 	dev->dbgfs_dir = dir;
 
 	f = debugfs_create_file("meclients", S_IRUSR, dir,
-				dev, &mei_dbgfs_fops_meclients);
+				dev, &mei_dbgfs_meclients_fops);
 	if (!f) {
 		dev_err(dev->dev, "meclients: registration failed\n");
 		goto err;
 	}
 	f = debugfs_create_file("active", S_IRUSR, dir,
-				dev, &mei_dbgfs_fops_active);
+				dev, &mei_dbgfs_active_fops);
 	if (!f) {
 		dev_err(dev->dev, "active: registration failed\n");
 		goto err;
 	}
 	f = debugfs_create_file("devstate", S_IRUSR, dir,
-				dev, &mei_dbgfs_fops_devstate);
+				dev, &mei_dbgfs_devstate_fops);
 	if (!f) {
 		dev_err(dev->dev, "devstate: registration failed\n");
 		goto err;
 	}
 	f = debugfs_create_file("allow_fixed_address", S_IRUSR | S_IWUSR, dir,
 				&dev->allow_fixed_address,
-				&mei_dbgfs_fops_allow_fa);
+				&mei_dbgfs_allow_fa_fops);
 	if (!f) {
 		dev_err(dev->dev, "allow_fixed_address: registration failed\n");
 		goto err;
@@ -276,4 +197,3 @@ int mei_dbgfs_register(struct mei_device *dev, const char *name)
 	mei_dbgfs_deregister(dev);
 	return -ENODEV;
 }
-