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>
This commit is contained in:
Claudio Imbrenda 2018-01-23 16:50:43 +01:00 committed by Martin Schwidefsky
parent b843563518
commit 0b0d1173d8
3 changed files with 33 additions and 8 deletions

View File

@ -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);

View File

@ -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];

View File

@ -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;