[S390] cio: fix subchannel channel-path data usage
authorPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Fri, 27 Apr 2007 14:01:35 +0000 (16:01 +0200)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Fri, 27 Apr 2007 14:01:40 +0000 (16:01 +0200)
Ensure that channel-path related subchannel data is only retrieved and
used when it is valid and that it is updated when it may have changed.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
drivers/s390/cio/chsc.c
drivers/s390/cio/chsc.h
drivers/s390/cio/cio.h
drivers/s390/cio/css.c
drivers/s390/cio/css.h
drivers/s390/cio/device.c
drivers/s390/cio/device_fsm.c

index 89a130a62654c472357013699c55fa0bc6d5bb0b..0841e16b6a82ab76cb0d93b63e38e4bb09620280 100644 (file)
 
 static void *sei_page;
 
-/* FIXME: this is _always_ called for every subchannel. shouldn't we
- *       process more than one at a time? */
-static int
-chsc_get_sch_desc_irq(struct subchannel *sch, void *page)
-{
-       int ccode, j;
+struct chsc_ssd_area {
+       struct chsc_header request;
+       u16 :10;
+       u16 ssid:2;
+       u16 :4;
+       u16 f_sch;        /* first subchannel */
+       u16 :16;
+       u16 l_sch;        /* last subchannel */
+       u32 :32;
+       struct chsc_header response;
+       u32 :32;
+       u8 sch_valid : 1;
+       u8 dev_valid : 1;
+       u8 st        : 3; /* subchannel type */
+       u8 zeroes    : 3;
+       u8  unit_addr;    /* unit address */
+       u16 devno;        /* device number */
+       u8 path_mask;
+       u8 fla_valid_mask;
+       u16 sch;          /* subchannel */
+       u8 chpid[8];      /* chpids 0-7 */
+       u16 fla[8];       /* full link addresses 0-7 */
+} __attribute__ ((packed));
 
-       struct {
-               struct chsc_header request;
-               u16 reserved1a:10;
-               u16 ssid:2;
-               u16 reserved1b:4;
-               u16 f_sch;        /* first subchannel */
-               u16 reserved2;
-               u16 l_sch;        /* last subchannel */
-               u32 reserved3;
-               struct chsc_header response;
-               u32 reserved4;
-               u8 sch_valid : 1;
-               u8 dev_valid : 1;
-               u8 st        : 3; /* subchannel type */
-               u8 zeroes    : 3;
-               u8  unit_addr;    /* unit address */
-               u16 devno;        /* device number */
-               u8 path_mask;
-               u8 fla_valid_mask;
-               u16 sch;          /* subchannel */
-               u8 chpid[8];      /* chpids 0-7 */
-               u16 fla[8];       /* full link addresses 0-7 */
-       } __attribute__ ((packed)) *ssd_area;
-
-       ssd_area = page;
+int chsc_get_ssd_info(struct subchannel_id schid, struct chsc_ssd_info *ssd)
+{
+       unsigned long page;
+       struct chsc_ssd_area *ssd_area;
+       int ccode;
+       int ret;
+       int i;
+       int mask;
 
+       page = get_zeroed_page(GFP_KERNEL | GFP_DMA);
+       if (!page)
+               return -ENOMEM;
+       ssd_area = (struct chsc_ssd_area *) page;
        ssd_area->request.length = 0x0010;
        ssd_area->request.code = 0x0004;
-
-       ssd_area->ssid = sch->schid.ssid;
-       ssd_area->f_sch = sch->schid.sch_no;
-       ssd_area->l_sch = sch->schid.sch_no;
+       ssd_area->ssid = schid.ssid;
+       ssd_area->f_sch = schid.sch_no;
+       ssd_area->l_sch = schid.sch_no;
 
        ccode = chsc(ssd_area);
+       /* Check response. */
        if (ccode > 0) {
-               pr_debug("chsc returned with ccode = %d\n", ccode);
-               return (ccode == 3) ? -ENODEV : -EBUSY;
+               ret = (ccode == 3) ? -ENODEV : -EBUSY;
+               goto out_free;
        }
-
-       switch (ssd_area->response.code) {
-       case 0x0001: /* everything ok */
-               break;
-       case 0x0002:
-               CIO_CRW_EVENT(2, "Invalid command!\n");
-               return -EINVAL;
-       case 0x0003:
-               CIO_CRW_EVENT(2, "Error in chsc request block!\n");
-               return -EINVAL;
-       case 0x0004:
-               CIO_CRW_EVENT(2, "Model does not provide ssd\n");
-               return -EOPNOTSUPP;
-       default:
-               CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
+       if (ssd_area->response.code != 0x0001) {
+               CIO_MSG_EVENT(2, "chsc: ssd failed for 0.%x.%04x (rc=%04x)\n",
+                             schid.ssid, schid.sch_no,
                              ssd_area->response.code);
-               return -EIO;
-       }
-
-       /*
-        * ssd_area->st stores the type of the detected
-        * subchannel, with the following definitions:
-        *
-        * 0: I/O subchannel:     All fields have meaning
-        * 1: CHSC subchannel:    Only sch_val, st and sch
-        *                        have meaning
-        * 2: Message subchannel: All fields except unit_addr
-        *                        have meaning
-        * 3: ADM subchannel:     Only sch_val, st and sch
-        *                        have meaning
-        *
-        * Other types are currently undefined.
-        */
-       if (ssd_area->st > 3) { /* uhm, that looks strange... */
-               CIO_CRW_EVENT(0, "Strange subchannel type %d"
-                             " for sch 0.%x.%04x\n", ssd_area->st,
-                             sch->schid.ssid, sch->schid.sch_no);
-               /*
-                * There may have been a new subchannel type defined in the
-                * time since this code was written; since we don't know which
-                * fields have meaning and what to do with it we just jump out
-                */
-               return 0;
-       } else {
-               const char *type[4] = {"I/O", "chsc", "message", "ADM"};
-               CIO_CRW_EVENT(6, "ssd: sch 0.%x.%04x is %s subchannel\n",
-                             sch->schid.ssid, sch->schid.sch_no,
-                             type[ssd_area->st]);
-
-               sch->ssd_info.valid = 1;
-               sch->ssd_info.type = ssd_area->st;
+               ret = -EIO;
+               goto out_free;
        }
-
-       if (ssd_area->st == 0 || ssd_area->st == 2) {
-               for (j = 0; j < 8; j++) {
-                       if (!((0x80 >> j) & ssd_area->path_mask &
-                             ssd_area->fla_valid_mask))
-                               continue;
-                       sch->ssd_info.chpid[j] = ssd_area->chpid[j];
-                       sch->ssd_info.fla[j]   = ssd_area->fla[j];
-               }
+       if (!ssd_area->sch_valid) {
+               ret = -ENODEV;
+               goto out_free;
        }
-       return 0;
-}
-
-int
-css_get_ssd_info(struct subchannel *sch)
-{
-       int ret;
-       void *page;
-
-       page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
-       if (!page)
-               return -ENOMEM;
-       spin_lock_irq(sch->lock);
-       ret = chsc_get_sch_desc_irq(sch, page);
-       if (ret) {
-               static int cio_chsc_err_msg;
-               
-               if (!cio_chsc_err_msg) {
-                       printk(KERN_ERR
-                              "chsc_get_sch_descriptions:"
-                              " Error %d while doing chsc; "
-                              "processing some machine checks may "
-                              "not work\n", ret);
-                       cio_chsc_err_msg = 1;
-               }
-       }
-       spin_unlock_irq(sch->lock);
-       free_page((unsigned long)page);
-       if (!ret) {
-               int j, mask;
-               struct chp_id chpid;
-
-               chp_id_init(&chpid);
-               /* Allocate channel path structures, if needed. */
-               for (j = 0; j < 8; j++) {
-                       mask = 0x80 >> j;
-                       chpid.id = sch->ssd_info.chpid[j];
-                       if ((sch->schib.pmcw.pim & mask) &&
-                           !chp_is_registered(chpid))
-                               chp_new(chpid);
+       /* Copy data */
+       ret = 0;
+       memset(ssd, 0, sizeof(struct chsc_ssd_info));
+       if ((ssd_area->st != 0) && (ssd_area->st != 2))
+               goto out_free;
+       ssd->path_mask = ssd_area->path_mask;
+       ssd->fla_valid_mask = ssd_area->fla_valid_mask;
+       for (i = 0; i < 8; i++) {
+               mask = 0x80 >> i;
+               if (ssd_area->path_mask & mask) {
+                       chp_id_init(&ssd->chpid[i]);
+                       ssd->chpid[i].id = ssd_area->chpid[i];
                }
+               if (ssd_area->fla_valid_mask & mask)
+                       ssd->fla[i] = ssd_area->fla[i];
        }
+out_free:
+       free_page(page);
        return ret;
 }
 
@@ -276,47 +205,6 @@ void chsc_chp_offline(struct chp_id chpid)
                         s390_subchannel_remove_chpid);
 }
 
-struct res_acc_data {
-       struct chp_id chpid;
-       u32 fla_mask;
-       u16 fla;
-};
-
-static int s390_process_res_acc_sch(struct res_acc_data *res_data,
-                                   struct subchannel *sch)
-{
-       int found;
-       int chp;
-       int ccode;
-
-       found = 0;
-       for (chp = 0; chp <= 7; chp++)
-               /*
-                * check if chpid is in information updated by ssd
-                */
-               if (sch->ssd_info.valid &&
-                   sch->ssd_info.chpid[chp] == res_data->chpid.id &&
-                   (sch->ssd_info.fla[chp] & res_data->fla_mask)
-                   == res_data->fla) {
-                       found = 1;
-                       break;
-               }
-
-       if (found == 0)
-               return 0;
-
-       /*
-        * Do a stsch to update our subchannel structure with the
-        * new path information and eventually check for logically
-        * offline chpids.
-        */
-       ccode = stsch(sch->schid, &sch->schib);
-       if (ccode > 0)
-               return 0;
-
-       return 0x80 >> chp;
-}
-
 static int
 s390_process_res_acc_new_sch(struct subchannel_id schid)
 {
@@ -338,6 +226,32 @@ s390_process_res_acc_new_sch(struct subchannel_id schid)
        return 0;
 }
 
+struct res_acc_data {
+       struct chp_id chpid;
+       u32 fla_mask;
+       u16 fla;
+};
+
+static int get_res_chpid_mask(struct chsc_ssd_info *ssd,
+                             struct res_acc_data *data)
+{
+       int i;
+       int mask;
+
+       for (i = 0; i < 8; i++) {
+               mask = 0x80 >> i;
+               if (!(ssd->path_mask & mask))
+                       continue;
+               if (!chp_id_is_equal(&ssd->chpid[i], &data->chpid))
+                       continue;
+               if ((ssd->fla_valid_mask & mask) &&
+                   ((ssd->fla[i] & data->fla_mask) != data->fla))
+                       continue;
+               return mask;
+       }
+       return 0;
+}
+
 static int
 __s390_process_res_acc(struct subchannel_id schid, void *data)
 {
@@ -352,14 +266,11 @@ __s390_process_res_acc(struct subchannel_id schid, void *data)
                return s390_process_res_acc_new_sch(schid);
 
        spin_lock_irq(sch->lock);
-
-       chp_mask = s390_process_res_acc_sch(res_data, sch);
-
-       if (chp_mask == 0) {
-               spin_unlock_irq(sch->lock);
-               put_device(&sch->dev);
-               return 0;
-       }
+       chp_mask = get_res_chpid_mask(&sch->ssd_info, res_data);
+       if (chp_mask == 0)
+               goto out;
+       if (stsch(sch->schid, &sch->schib))
+               goto out;
        old_lpm = sch->lpm;
        sch->lpm = ((sch->schib.pmcw.pim &
                     sch->schib.pmcw.pam &
@@ -369,13 +280,12 @@ __s390_process_res_acc(struct subchannel_id schid, void *data)
                device_trigger_reprobe(sch);
        else if (sch->driver && sch->driver->verify)
                sch->driver->verify(&sch->dev);
-
+out:
        spin_unlock_irq(sch->lock);
        put_device(&sch->dev);
        return 0;
 }
 
-
 static void s390_process_res_acc (struct res_acc_data *res_data)
 {
        char dbf_txt[15];
@@ -661,29 +571,30 @@ static void __s390_subchannel_vary_chpid(struct subchannel *sch,
                                         struct chp_id chpid, int on)
 {
        int chp, old_lpm;
+       int mask;
        unsigned long flags;
 
-       if (!sch->ssd_info.valid)
-               return;
-       
        spin_lock_irqsave(sch->lock, flags);
        old_lpm = sch->lpm;
        for (chp = 0; chp < 8; chp++) {
-               if (sch->ssd_info.chpid[chp] != chpid.id)
+               mask = 0x80 >> chp;
+               if (!(sch->ssd_info.path_mask & mask))
+                       continue;
+               if (!chp_id_is_equal(&sch->ssd_info.chpid[chp], &chpid))
                        continue;
 
                if (on) {
-                       sch->opm |= (0x80 >> chp);
-                       sch->lpm |= (0x80 >> chp);
+                       sch->opm |= mask;
+                       sch->lpm |= mask;
                        if (!old_lpm)
                                device_trigger_reprobe(sch);
                        else if (sch->driver && sch->driver->verify)
                                sch->driver->verify(&sch->dev);
                        break;
                }
-               sch->opm &= ~(0x80 >> chp);
-               sch->lpm &= ~(0x80 >> chp);
-               if (check_for_io_on_path(sch, (0x80 >> chp))) {
+               sch->opm &= ~mask;
+               sch->lpm &= ~mask;
+               if (check_for_io_on_path(sch, mask)) {
                        if (device_is_online(sch))
                                /* Path verification is done after killing. */
                                device_kill_io(sch);
index 742ef57d2c5851953586f5af0624079c4ce8457f..2ad81d11cf7bfa564bdebe1d65085f0e054e3f7f 100644 (file)
@@ -4,6 +4,7 @@
 #include <linux/types.h>
 #include <linux/device.h>
 #include <asm/chpid.h>
+#include "schid.h"
 
 #define CHSC_SDA_OC_MSS   0x2
 
@@ -35,7 +36,6 @@ struct channel_path_desc {
 
 struct channel_path;
 
-extern int css_get_ssd_info(struct subchannel *);
 extern void chsc_process_crw(void);
 
 struct css_general_char {
@@ -69,6 +69,14 @@ struct css_chsc_char {
 extern struct css_general_char css_general_characteristics;
 extern struct css_chsc_char css_chsc_characteristics;
 
+struct chsc_ssd_info {
+       u8 path_mask;
+       u8 fla_valid_mask;
+       struct chp_id chpid[8];
+       u16 fla[8];
+};
+extern int chsc_get_ssd_info(struct subchannel_id schid,
+                            struct chsc_ssd_info *ssd);
 extern int chsc_determine_css_characteristics(void);
 extern int css_characteristics_avail;
 
index e62ab5c52863c0e535200d1677bc9309c7be51ea..7446c39951a716c88ad5c1f8cf4fc699aff9d050 100644 (file)
@@ -1,19 +1,11 @@
 #ifndef S390_CIO_H
 #define S390_CIO_H
 
-#include "schid.h"
 #include <linux/mutex.h>
 #include <linux/device.h>
-
-/*
- * where we put the ssd info
- */
-struct ssd_info {
-       __u8  valid:1;
-       __u8  type:7;           /* subchannel type */
-       __u8  chpid[8];         /* chpids */
-       __u16 fla[8];           /* full link addresses */
-} __attribute__ ((packed));
+#include <asm/chpid.h>
+#include "chsc.h"
+#include "schid.h"
 
 /*
  * path management control word
@@ -109,7 +101,7 @@ struct subchannel {
        struct schib schib;     /* subchannel information block */
        struct orb orb;         /* operation request block */
        struct ccw1 sense_ccw;  /* static ccw for sense command */
-       struct ssd_info ssd_info;       /* subchannel description */
+       struct chsc_ssd_info ssd_info;  /* subchannel description */
        struct device dev;      /* entry in device tree */
        struct css_driver *driver;
 } __attribute__ ((aligned(8)));
index fcc641e578f4e990517508facc3ba033229cf8e6..27c6d9e55b23e41142309750fbd3afb799a2a8c3 100644 (file)
@@ -21,6 +21,7 @@
 #include "chsc.h"
 #include "device.h"
 #include "idset.h"
+#include "chp.h"
 
 int css_init_done = 0;
 static int need_reprobe = 0;
@@ -125,8 +126,52 @@ void css_sch_device_unregister(struct subchannel *sch)
        mutex_unlock(&sch->reg_mutex);
 }
 
-static int
-css_register_subchannel(struct subchannel *sch)
+static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
+{
+       int i;
+       int mask;
+
+       memset(ssd, 0, sizeof(struct chsc_ssd_info));
+       ssd->path_mask = pmcw->pim;
+       for (i = 0; i < 8; i++) {
+               mask = 0x80 >> i;
+               if (pmcw->pim & mask) {
+                       chp_id_init(&ssd->chpid[i]);
+                       ssd->chpid[i].id = pmcw->chpid[i];
+               }
+       }
+}
+
+static void ssd_register_chpids(struct chsc_ssd_info *ssd)
+{
+       int i;
+       int mask;
+
+       for (i = 0; i < 8; i++) {
+               mask = 0x80 >> i;
+               if (ssd->path_mask & mask)
+                       if (!chp_is_registered(ssd->chpid[i]))
+                               chp_new(ssd->chpid[i]);
+       }
+}
+
+void css_update_ssd_info(struct subchannel *sch)
+{
+       int ret;
+
+       if (cio_is_console(sch->schid)) {
+               /* Console is initialized too early for functions requiring
+                * memory allocation. */
+               ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
+       } else {
+               ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
+               if (ret)
+                       ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
+               ssd_register_chpids(&sch->ssd_info);
+       }
+}
+
+static int css_register_subchannel(struct subchannel *sch)
 {
        int ret;
 
@@ -135,9 +180,7 @@ css_register_subchannel(struct subchannel *sch)
        sch->dev.bus = &css_bus_type;
        sch->dev.release = &css_subchannel_release;
        sch->dev.groups = subch_attr_groups;
-
-       css_get_ssd_info(sch);
-
+       css_update_ssd_info(sch);
        /* make it known to the system */
        ret = css_sch_device_register(sch);
        if (ret) {
index 4b3133a7bae18327640534be3fea23eab60f1065..71fcfdc42800d39d0433d51cbf1e6f30be521f37 100644 (file)
@@ -148,6 +148,7 @@ extern int css_init_done;
 extern int for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *);
 extern void css_process_crw(int, int);
 extern void css_reiterate_subchannels(void);
+void css_update_ssd_info(struct subchannel *sch);
 
 #define __MAX_SUBCHANNEL 65535
 #define __MAX_SSID 3
index 34e7d77b997d844c300f9b76419df757443c39a4..7bb44e73ea9d8af83728e3bee3119c1314c053bd 100644 (file)
@@ -216,12 +216,18 @@ static ssize_t
 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 {
        struct subchannel *sch = to_subchannel(dev);
-       struct ssd_info *ssd = &sch->ssd_info;
+       struct chsc_ssd_info *ssd = &sch->ssd_info;
        ssize_t ret = 0;
        int chp;
+       int mask;
 
-       for (chp = 0; chp < 8; chp++)
-               ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
+       for (chp = 0; chp < 8; chp++) {
+               mask = 0x80 >> chp;
+               if (ssd->path_mask & mask)
+                       ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
+               else
+                       ret += sprintf(buf + ret, "00 ");
+       }
        ret += sprintf (buf+ret, "\n");
        return min((ssize_t)PAGE_SIZE, ret);
 }
index 898ec3b2bebb5092c123030504c69aae89b89886..aadd2fd4a86ce367404b02c9c7225eae0e5b5eae 100644 (file)
@@ -246,6 +246,7 @@ ccw_device_recog_done(struct ccw_device *cdev, int state)
         */
        old_lpm = sch->lpm;
        stsch(sch->schid, &sch->schib);
+       css_update_ssd_info(sch);
        sch->lpm = sch->schib.pmcw.pam & sch->opm;
        /* Check since device may again have become not operational. */
        if (!sch->schib.pmcw.dnv)