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authorClaudio Imbrenda <imbrenda@linux.vnet.ibm.com>2018-01-23 16:50:43 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2018-02-22 15:31:24 +0100
commit0b0d1173d8aef75e821c0cceedb0e8178834ec1b (patch)
treeeceecae57a15d49a22440434cc3aeb0ed0e97831
parentb843563518c1e06521c446b9a043b7d352df02e0 (diff)
downloadlinux-0b0d1173d8aef75e821c0cceedb0e8178834ec1b.tar.bz2
s390/sclp: 32 bit event mask compatibility mode
Qemu before version 2.11 does not implement the architecture correctly, and does not allow for a mask size of size different than 4. This patch introduces a compatibility mode for such systems, forcing the mask sizes to 4. Since the mask size is currently still 4 anyway, this patch should have no impact whatsoever by itself, but it will be needed when the mask size is increased to 64 bits in the next patch. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r--drivers/s390/char/sclp.c23
-rw-r--r--drivers/s390/char/sclp.h3
-rw-r--r--drivers/s390/char/sclp_early_core.c15
3 files changed, 33 insertions, 8 deletions
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index 59e3219ce5c9..e9aa71cdfc44 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -765,7 +765,10 @@ __sclp_make_init_req(sccb_mask_t receive_mask, sccb_mask_t send_mask)
sclp_init_req.callback_data = NULL;
sclp_init_req.sccb = sccb;
sccb->header.length = sizeof(*sccb);
- sccb->mask_length = sizeof(sccb_mask_t);
+ if (sclp_mask_compat_mode)
+ sccb->mask_length = SCLP_MASK_SIZE_COMPAT;
+ else
+ sccb->mask_length = sizeof(sccb_mask_t);
sccb_set_recv_mask(sccb, receive_mask);
sccb_set_send_mask(sccb, send_mask);
sccb_set_sclp_recv_mask(sccb, 0);
@@ -977,12 +980,18 @@ sclp_check_interface(void)
irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
spin_lock_irqsave(&sclp_lock, flags);
del_timer(&sclp_request_timer);
- if (sclp_init_req.status == SCLP_REQ_DONE &&
- sccb->header.response_code == 0x20) {
- rc = 0;
- break;
- } else
- rc = -EBUSY;
+ rc = -EBUSY;
+ if (sclp_init_req.status == SCLP_REQ_DONE) {
+ if (sccb->header.response_code == 0x20) {
+ rc = 0;
+ break;
+ } else if (sccb->header.response_code == 0x74f0) {
+ if (!sclp_mask_compat_mode) {
+ sclp_mask_compat_mode = true;
+ retry = 0;
+ }
+ }
+ }
}
unregister_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler);
spin_unlock_irqrestore(&sclp_lock, flags);
diff --git a/drivers/s390/char/sclp.h b/drivers/s390/char/sclp.h
index ee44d169f10f..45e6ffdc7f08 100644
--- a/drivers/s390/char/sclp.h
+++ b/drivers/s390/char/sclp.h
@@ -109,6 +109,8 @@ struct init_sccb {
*/
} __attribute__((packed));
+#define SCLP_MASK_SIZE_COMPAT 4
+
static inline sccb_mask_t sccb_get_mask(u8 *masks, size_t len, int i)
{
sccb_mask_t res = 0;
@@ -262,6 +264,7 @@ extern int sclp_init_state;
extern int sclp_console_pages;
extern int sclp_console_drop;
extern unsigned long sclp_console_full;
+extern bool sclp_mask_compat_mode;
extern char sclp_early_sccb[PAGE_SIZE];
diff --git a/drivers/s390/char/sclp_early_core.c b/drivers/s390/char/sclp_early_core.c
index c8c53260f4b7..5f8d9ea69ebd 100644
--- a/drivers/s390/char/sclp_early_core.c
+++ b/drivers/s390/char/sclp_early_core.c
@@ -14,6 +14,11 @@
char sclp_early_sccb[PAGE_SIZE] __aligned(PAGE_SIZE) __section(.data);
int sclp_init_state __section(.data) = sclp_init_state_uninitialized;
+/*
+ * Used to keep track of the size of the event masks. Qemu until version 2.11
+ * only supports 4 and needs a workaround.
+ */
+bool sclp_mask_compat_mode;
void sclp_early_wait_irq(void)
{
@@ -145,13 +150,21 @@ int sclp_early_set_event_mask(struct init_sccb *sccb,
sccb_mask_t receive_mask,
sccb_mask_t send_mask)
{
+retry:
memset(sccb, 0, sizeof(*sccb));
sccb->header.length = sizeof(*sccb);
- sccb->mask_length = sizeof(sccb_mask_t);
+ if (sclp_mask_compat_mode)
+ sccb->mask_length = SCLP_MASK_SIZE_COMPAT;
+ else
+ sccb->mask_length = sizeof(sccb_mask_t);
sccb_set_recv_mask(sccb, receive_mask);
sccb_set_send_mask(sccb, send_mask);
if (sclp_early_cmd(SCLP_CMDW_WRITE_EVENT_MASK, sccb))
return -EIO;
+ if ((sccb->header.response_code == 0x74f0) && !sclp_mask_compat_mode) {
+ sclp_mask_compat_mode = true;
+ goto retry;
+ }
if (sccb->header.response_code != 0x20)
return -EIO;
return 0;