[PATCH] s390: channel path measurements

Gather extended measurements for channel paths from the channel subsystem and
expose them to userspace via a sysfs attribute.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/s390/cio/chsc.h

@@ -12,6 +12,16 @@ struct chsc_header {
 	u16 code;
 };
 
+#define NR_MEASUREMENT_CHARS 5
+struct cmg_chars {
+	u32 values[NR_MEASUREMENT_CHARS];
+};
+
+#define NR_MEASUREMENT_ENTRIES 8
+struct cmg_entry {
+	u32 values[NR_MEASUREMENT_ENTRIES];
+};
+
 struct channel_path_desc {
 	u8 flags;
 	u8 lsn;
@@ -27,6 +37,10 @@ struct channel_path {
 	int id;
 	int state;
 	struct channel_path_desc desc;
+	/* Channel-measurement related stuff: */
+	int cmg;
+	int shared;
+	void *cmg_chars;
 	struct device dev;
 };
 
@@ -52,7 +66,11 @@ struct css_general_char {
 
 struct css_chsc_char {
 	u64 res;
-	u64 : 43;
+	u64 : 20;
+	u32 secm : 1; /* bit 84 */
+	u32 : 1;
+	u32 scmc : 1; /* bit 86 */
+	u32 : 20;
 	u32 scssc : 1;  /* bit 107 */
 	u32 scsscf : 1; /* bit 108 */
 	u32 : 19;
@@ -67,6 +85,8 @@ extern int css_characteristics_avail;
 extern void *chsc_get_chp_desc(struct subchannel*, int);
 
 extern int chsc_enable_facility(int);
+struct channel_subsystem;
+extern int chsc_secm(struct channel_subsystem *, int);
 
 #define to_channelpath(device) container_of(device, struct channel_path, dev)
 

drivers/s390/cio/css.c

@@ -452,15 +452,50 @@ channel_subsystem_release(struct device *dev)
 	struct channel_subsystem *css;
 
 	css = to_css(dev);
+	mutex_destroy(&css->mutex);
 	kfree(css);
 }
 
+static ssize_t
+css_cm_enable_show(struct device *dev, struct device_attribute *attr,
+		   char *buf)
+{
+	struct channel_subsystem *css = to_css(dev);
+
+	if (!css)
+		return 0;
+	return sprintf(buf, "%x\n", css->cm_enabled);
+}
+
+static ssize_t
+css_cm_enable_store(struct device *dev, struct device_attribute *attr,
+		    const char *buf, size_t count)
+{
+	struct channel_subsystem *css = to_css(dev);
+	int ret;
+
+	switch (buf[0]) {
+	case '0':
+		ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
+		break;
+	case '1':
+		ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	return ret < 0 ? ret : count;
+}
+
+static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
+
 static inline void __init
 setup_css(int nr)
 {
 	u32 tod_high;
 
 	memset(css[nr], 0, sizeof(struct channel_subsystem));
+	mutex_init(&css[nr]->mutex);
 	css[nr]->valid = 1;
 	css[nr]->cssid = nr;
 	sprintf(css[nr]->device.bus_id, "css%x", nr);
@@ -507,6 +542,9 @@ init_channel_subsystem (void)
 		ret = device_register(&css[i]->device);
 		if (ret)
 			goto out_free;
+		if (css_characteristics_avail && css_chsc_characteristics.secm)
+			device_create_file(&css[i]->device,
+					   &dev_attr_cm_enable);
 	}
 	css_init_done = 1;
 
@@ -519,6 +557,9 @@ init_channel_subsystem (void)
 out_unregister:
 	while (i > 0) {
 		i--;
+		if (css_characteristics_avail && css_chsc_characteristics.secm)
+			device_remove_file(&css[i]->device,
+					   &dev_attr_cm_enable);
 		device_unregister(&css[i]->device);
 	}
 out_bus:

drivers/s390/cio/css.h

 #ifndef _CSS_H
 #define _CSS_H
 
+#include <linux/mutex.h>
 #include <linux/wait.h>
 #include <linux/workqueue.h>
 
@@ -150,6 +151,11 @@ struct channel_subsystem {
 	struct channel_path *chps[__MAX_CHPID + 1];
 	struct device device;
 	struct pgid global_pgid;
+	struct mutex mutex;
+	/* channel measurement related */
+	int cm_enabled;
+	void *cub_addr1;
+	void *cub_addr2;
 };
 #define to_css(dev) container_of(dev, struct channel_subsystem, device)