[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>

4 files changed, 500 insertions, 23 deletions

diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index f4183d660258..8b57fe62a9f9 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -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)
@@ -875,6 +871,264 @@ s390_vary_chpid( __u8 chpid, int on)
 }
 
 /*
+ * 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.
  */
 static ssize_t
@@ -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
-                css[0]->chps[chpid] = chp;
+        }
+        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) {
diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h
index 3e75095f35d0..a259245780ae 100644
--- a/drivers/s390/cio/chsc.h
+++ b/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)
 
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 3c77d65960db..5b304dbacaeb 100644
--- a/drivers/s390/cio/css.c
+++ b/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 @@ 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:
diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
index b6375861cb37..74a257b23383 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -1,6 +1,7 @@
 #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)