Commit 495a5b45 authored by Cornelia Huck's avatar Cornelia Huck Committed by Linus Torvalds
Browse files

[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: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent dc06010c
Loading
Loading
Loading
Loading
+432 −22
Original line number Diff line number Diff line
@@ -98,10 +98,8 @@ chsc_get_sch_desc_irq(struct subchannel *sch, void *page)

	ssd_area = page;

	ssd_area->request = (struct chsc_header) {
		.length = 0x0010,
		.code   = 0x0004,
	};
	ssd_area->request.length = 0x0010;
	ssd_area->request.code = 0x0004;

	ssd_area->ssid = sch->schid.ssid;
	ssd_area->f_sch = sch->schid.sch_no;
@@ -517,10 +515,8 @@ chsc_process_crw(void)
		struct device *dev;
		memset(sei_area, 0, sizeof(*sei_area));
		memset(&res_data, 0, sizeof(struct res_acc_data));
		sei_area->request = (struct chsc_header) {
			.length = 0x0010,
			.code   = 0x000e,
		};
		sei_area->request.length = 0x0010;
		sei_area->request.code = 0x000e;

		ccode = chsc(sei_area);
		if (ccode > 0)
@@ -874,6 +870,264 @@ s390_vary_chpid( __u8 chpid, int on)
	return 0;
}

/*
 * Channel measurement related functions
 */
static ssize_t
chp_measurement_chars_read(struct kobject *kobj, char *buf, loff_t off,
			   size_t count)
{
	struct channel_path *chp;
	unsigned int size;

	chp = to_channelpath(container_of(kobj, struct device, kobj));
	if (!chp->cmg_chars)
		return 0;

	size = sizeof(struct cmg_chars);

	if (off > size)
		return 0;
	if (off + count > size)
		count = size - off;
	memcpy(buf, chp->cmg_chars + off, count);
	return count;
}

static struct bin_attribute chp_measurement_chars_attr = {
	.attr = {
		.name = "measurement_chars",
		.mode = S_IRUSR,
		.owner = THIS_MODULE,
	},
	.size = sizeof(struct cmg_chars),
	.read = chp_measurement_chars_read,
};

static void
chp_measurement_copy_block(struct cmg_entry *buf,
			   struct channel_subsystem *css, int chpid)
{
	void *area;
	struct cmg_entry *entry, reference_buf;
	int idx;

	if (chpid < 128) {
		area = css->cub_addr1;
		idx = chpid;
	} else {
		area = css->cub_addr2;
		idx = chpid - 128;
	}
	entry = area + (idx * sizeof(struct cmg_entry));
	do {
		memcpy(buf, entry, sizeof(*entry));
		memcpy(&reference_buf, entry, sizeof(*entry));
	} while (reference_buf.values[0] != buf->values[0]);
}

static ssize_t
chp_measurement_read(struct kobject *kobj, char *buf, loff_t off, size_t count)
{
	struct channel_path *chp;
	struct channel_subsystem *css;
	unsigned int size;

	chp = to_channelpath(container_of(kobj, struct device, kobj));
	css = to_css(chp->dev.parent);

	size = sizeof(struct cmg_chars);

	/* Only allow single reads. */
	if (off || count < size)
		return 0;
	chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->id);
	return count;
}

static struct bin_attribute chp_measurement_attr = {
	.attr = {
		.name = "measurement",
		.mode = S_IRUSR,
		.owner = THIS_MODULE,
	},
	.size = sizeof(struct cmg_entry),
	.read = chp_measurement_read,
};

static void
chsc_remove_chp_cmg_attr(struct channel_path *chp)
{
	sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_chars_attr);
	sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_attr);
}

static int
chsc_add_chp_cmg_attr(struct channel_path *chp)
{
	int ret;

	ret = sysfs_create_bin_file(&chp->dev.kobj,
				    &chp_measurement_chars_attr);
	if (ret)
		return ret;
	ret = sysfs_create_bin_file(&chp->dev.kobj, &chp_measurement_attr);
	if (ret)
		sysfs_remove_bin_file(&chp->dev.kobj,
				      &chp_measurement_chars_attr);
	return ret;
}

static void
chsc_remove_cmg_attr(struct channel_subsystem *css)
{
	int i;

	for (i = 0; i <= __MAX_CHPID; i++) {
		if (!css->chps[i])
			continue;
		chsc_remove_chp_cmg_attr(css->chps[i]);
	}
}

static int
chsc_add_cmg_attr(struct channel_subsystem *css)
{
	int i, ret;

	ret = 0;
	for (i = 0; i <= __MAX_CHPID; i++) {
		if (!css->chps[i])
			continue;
		ret = chsc_add_chp_cmg_attr(css->chps[i]);
		if (ret)
			goto cleanup;
	}
	return ret;
cleanup:
	for (--i; i >= 0; i--) {
		if (!css->chps[i])
			continue;
		chsc_remove_chp_cmg_attr(css->chps[i]);
	}
	return ret;
}


static int
__chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
{
	struct {
		struct chsc_header request;
		u32 operation_code : 2;
		u32 : 30;
		u32 key : 4;
		u32 : 28;
		u32 zeroes1;
		u32 cub_addr1;
		u32 zeroes2;
		u32 cub_addr2;
		u32 reserved[13];
		struct chsc_header response;
		u32 status : 8;
		u32 : 4;
		u32 fmt : 4;
		u32 : 16;
	} *secm_area;
	int ret, ccode;

	secm_area = page;
	secm_area->request.length = 0x0050;
	secm_area->request.code = 0x0016;

	secm_area->key = PAGE_DEFAULT_KEY;
	secm_area->cub_addr1 = (u64)(unsigned long)css->cub_addr1;
	secm_area->cub_addr2 = (u64)(unsigned long)css->cub_addr2;

	secm_area->operation_code = enable ? 0 : 1;

	ccode = chsc(secm_area);
	if (ccode > 0)
		return (ccode == 3) ? -ENODEV : -EBUSY;

	switch (secm_area->response.code) {
	case 0x0001: /* Success. */
		ret = 0;
		break;
	case 0x0003: /* Invalid block. */
	case 0x0007: /* Invalid format. */
	case 0x0008: /* Other invalid block. */
		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
		ret = -EINVAL;
		break;
	case 0x0004: /* Command not provided in model. */
		CIO_CRW_EVENT(2, "Model does not provide secm\n");
		ret = -EOPNOTSUPP;
		break;
	case 0x0102: /* cub adresses incorrect */
		CIO_CRW_EVENT(2, "Invalid addresses in chsc request block\n");
		ret = -EINVAL;
		break;
	case 0x0103: /* key error */
		CIO_CRW_EVENT(2, "Access key error in secm\n");
		ret = -EINVAL;
		break;
	case 0x0105: /* error while starting */
		CIO_CRW_EVENT(2, "Error while starting channel measurement\n");
		ret = -EIO;
		break;
	default:
		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
			      secm_area->response.code);
		ret = -EIO;
	}
	return ret;
}

int
chsc_secm(struct channel_subsystem *css, int enable)
{
	void  *secm_area;
	int ret;

	secm_area = (void *)get_zeroed_page(GFP_KERNEL |  GFP_DMA);
	if (!secm_area)
		return -ENOMEM;

	mutex_lock(&css->mutex);
	if (enable && !css->cm_enabled) {
		css->cub_addr1 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
		css->cub_addr2 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
		if (!css->cub_addr1 || !css->cub_addr2) {
			free_page((unsigned long)css->cub_addr1);
			free_page((unsigned long)css->cub_addr2);
			free_page((unsigned long)secm_area);
			mutex_unlock(&css->mutex);
			return -ENOMEM;
		}
	}
	ret = __chsc_do_secm(css, enable, secm_area);
	if (!ret) {
		css->cm_enabled = enable;
		if (css->cm_enabled) {
			ret = chsc_add_cmg_attr(css);
			if (ret) {
				memset(secm_area, 0, PAGE_SIZE);
				__chsc_do_secm(css, 0, secm_area);
				css->cm_enabled = 0;
			}
		} else
			chsc_remove_cmg_attr(css);
	}
	if (enable && !css->cm_enabled) {
		free_page((unsigned long)css->cub_addr1);
		free_page((unsigned long)css->cub_addr2);
	}
	mutex_unlock(&css->mutex);
	free_page((unsigned long)secm_area);
	return ret;
}

/*
 * Files for the channel path entries.
 */
@@ -925,9 +1179,39 @@ chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)

static DEVICE_ATTR(type, 0444, chp_type_show, NULL);

static ssize_t
chp_cmg_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct channel_path *chp = to_channelpath(dev);

	if (!chp)
		return 0;
	if (chp->cmg == -1) /* channel measurements not available */
		return sprintf(buf, "unknown\n");
	return sprintf(buf, "%x\n", chp->cmg);
}

static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);

static ssize_t
chp_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct channel_path *chp = to_channelpath(dev);

	if (!chp)
		return 0;
	if (chp->shared == -1) /* channel measurements not available */
		return sprintf(buf, "unknown\n");
	return sprintf(buf, "%x\n", chp->shared);
}

static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);

static struct attribute * chp_attrs[] = {
	&dev_attr_status.attr,
	&dev_attr_type.attr,
	&dev_attr_cmg.attr,
	&dev_attr_shared.attr,
	NULL,
};

@@ -966,10 +1250,8 @@ chsc_determine_channel_path_description(int chpid,
	if (!scpd_area)
		return -ENOMEM;

	scpd_area->request = (struct chsc_header) {
		.length = 0x0010,
		.code   = 0x0002,
	};
	scpd_area->request.length = 0x0010;
	scpd_area->request.code = 0x0002;

	scpd_area->first_chpid = chpid;
	scpd_area->last_chpid = chpid;
@@ -1006,6 +1288,111 @@ out:
	return ret;
}

static void
chsc_initialize_cmg_chars(struct channel_path *chp, u8 cmcv,
			  struct cmg_chars *chars)
{
	switch (chp->cmg) {
	case 2:
	case 3:
		chp->cmg_chars = kmalloc(sizeof(struct cmg_chars),
					 GFP_KERNEL);
		if (chp->cmg_chars) {
			int i, mask;
			struct cmg_chars *cmg_chars;

			cmg_chars = chp->cmg_chars;
			for (i = 0; i < NR_MEASUREMENT_CHARS; i++) {
				mask = 0x80 >> (i + 3);
				if (cmcv & mask)
					cmg_chars->values[i] = chars->values[i];
				else
					cmg_chars->values[i] = 0;
			}
		}
		break;
	default:
		/* No cmg-dependent data. */
		break;
	}
}

static int
chsc_get_channel_measurement_chars(struct channel_path *chp)
{
	int ccode, ret;

	struct {
		struct chsc_header request;
		u32 : 24;
		u32 first_chpid : 8;
		u32 : 24;
		u32 last_chpid : 8;
		u32 zeroes1;
		struct chsc_header response;
		u32 zeroes2;
		u32 not_valid : 1;
		u32 shared : 1;
		u32 : 22;
		u32 chpid : 8;
		u32 cmcv : 5;
		u32 : 11;
		u32 cmgq : 8;
		u32 cmg : 8;
		u32 zeroes3;
		u32 data[NR_MEASUREMENT_CHARS];
	} *scmc_area;

	scmc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
	if (!scmc_area)
		return -ENOMEM;

	scmc_area->request.length = 0x0010;
	scmc_area->request.code = 0x0022;

	scmc_area->first_chpid = chp->id;
	scmc_area->last_chpid = chp->id;

	ccode = chsc(scmc_area);
	if (ccode > 0) {
		ret = (ccode == 3) ? -ENODEV : -EBUSY;
		goto out;
	}

	switch (scmc_area->response.code) {
	case 0x0001: /* Success. */
		if (!scmc_area->not_valid) {
			chp->cmg = scmc_area->cmg;
			chp->shared = scmc_area->shared;
			chsc_initialize_cmg_chars(chp, scmc_area->cmcv,
						  (struct cmg_chars *)
						  &scmc_area->data);
		} else {
			chp->cmg = -1;
			chp->shared = -1;
		}
		ret = 0;
		break;
	case 0x0003: /* Invalid block. */
	case 0x0007: /* Invalid format. */
	case 0x0008: /* Invalid bit combination. */
		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
		ret = -EINVAL;
		break;
	case 0x0004: /* Command not provided. */
		CIO_CRW_EVENT(2, "Model does not provide scmc\n");
		ret = -EOPNOTSUPP;
		break;
	default:
		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
			      scmc_area->response.code);
		ret = -EIO;
	}
out:
	free_page((unsigned long)scmc_area);
	return ret;
}

/*
 * Entries for chpids on the system bus.
 * This replaces /proc/chpids.
@@ -1034,6 +1421,22 @@ new_channel_path(int chpid)
	ret = chsc_determine_channel_path_description(chpid, &chp->desc);
	if (ret)
		goto out_free;
	/* Get channel-measurement characteristics. */
	if (css_characteristics_avail && css_chsc_characteristics.scmc
	    && css_chsc_characteristics.secm) {
		ret = chsc_get_channel_measurement_chars(chp);
		if (ret)
			goto out_free;
	} else {
		static int msg_done;

		if (!msg_done) {
			printk(KERN_WARNING "cio: Channel measurements not "
			       "available, continuing.\n");
			msg_done = 1;
		}
		chp->cmg = -1;
	}

	/* make it known to the system */
	ret = device_register(&chp->dev);
@@ -1046,8 +1449,19 @@ new_channel_path(int chpid)
	if (ret) {
		device_unregister(&chp->dev);
		goto out_free;
	} else
	}
	mutex_lock(&css[0]->mutex);
	if (css[0]->cm_enabled) {
		ret = chsc_add_chp_cmg_attr(chp);
		if (ret) {
			sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
			device_unregister(&chp->dev);
			mutex_unlock(&css[0]->mutex);
			goto out_free;
		}
	}
	css[0]->chps[chpid] = chp;
	mutex_unlock(&css[0]->mutex);
	return ret;
out_free:
	kfree(chp);
@@ -1103,10 +1517,8 @@ chsc_enable_facility(int operation_code)
	sda_area = (void *)get_zeroed_page(GFP_KERNEL|GFP_DMA);
	if (!sda_area)
		return -ENOMEM;
	sda_area->request = (struct chsc_header) {
		.length = 0x0400,
		.code = 0x0031,
	};
	sda_area->request.length = 0x0400;
	sda_area->request.code = 0x0031;
	sda_area->operation_code = operation_code;

	ret = chsc(sda_area);
@@ -1161,10 +1573,8 @@ chsc_determine_css_characteristics(void)
		return -ENOMEM;
	}

	scsc_area->request = (struct chsc_header) {
		.length = 0x0010,
		.code   = 0x0010,
	};
	scsc_area->request.length = 0x0010;
	scsc_area->request.code = 0x0010;

	result = chsc(scsc_area);
	if (result) {
+21 −1
Original line number Diff line number Diff line
@@ -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)

+41 −0
Original line number Diff line number Diff line
@@ -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 @@ out_free:
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:
+6 −0
Original line number Diff line number Diff line
#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)