[S390] cio: fix subchannel channel-path data usage
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>
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 89a130a..0841e16 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -26,155 +26,84 @@
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)
+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));
+
+int chsc_get_ssd_info(struct subchannel_id schid, struct chsc_ssd_info *ssd)
{
- int ccode, j;
-
- 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;
-
- 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;
-
- ccode = chsc(ssd_area);
- if (ccode > 0) {
- pr_debug("chsc returned with ccode = %d\n", ccode);
- return (ccode == 3) ? -ENODEV : -EBUSY;
- }
-
- 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",
- 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;
- }
-
- 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];
- }
- }
- return 0;
-}
-
-int
-css_get_ssd_info(struct subchannel *sch)
-{
+ unsigned long page;
+ struct chsc_ssd_area *ssd_area;
+ int ccode;
int ret;
- void *page;
+ int i;
+ int mask;
- page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
+ page = 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;
+ ssd_area = (struct chsc_ssd_area *) page;
+ ssd_area->request.length = 0x0010;
+ ssd_area->request.code = 0x0004;
+ ssd_area->ssid = schid.ssid;
+ ssd_area->f_sch = schid.sch_no;
+ ssd_area->l_sch = schid.sch_no;
- 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);
- }
+ ccode = chsc(ssd_area);
+ /* Check response. */
+ if (ccode > 0) {
+ ret = (ccode == 3) ? -ENODEV : -EBUSY;
+ goto out_free;
}
+ 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);
+ ret = -EIO;
+ goto out_free;
+ }
+ if (!ssd_area->sch_valid) {
+ ret = -ENODEV;
+ goto out_free;
+ }
+ /* 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 @@
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 @@
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 @@
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 @@
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 @@
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);