diff options
| -rw-r--r-- | arch/s390/include/asm/delay.h | 1 | ||||
| -rw-r--r-- | arch/s390/lib/delay.c | 13 | ||||
| -rw-r--r-- | drivers/s390/cio/cio.c | 17 |
3 files changed, 16 insertions, 15 deletions
diff --git a/arch/s390/include/asm/delay.h b/arch/s390/include/asm/delay.h index 78357314c45..a356c958e26 100644 --- a/arch/s390/include/asm/delay.h +++ b/arch/s390/include/asm/delay.h @@ -15,6 +15,7 @@ #define _S390_DELAY_H extern void __udelay(unsigned long usecs); +extern void udelay_simple(unsigned long usecs); extern void __delay(unsigned long loops); #define udelay(n) __udelay(n) diff --git a/arch/s390/lib/delay.c b/arch/s390/lib/delay.c index 0953cee05ef..6ccb9fab055 100644 --- a/arch/s390/lib/delay.c +++ b/arch/s390/lib/delay.c @@ -92,3 +92,16 @@ out: local_irq_restore(flags); preempt_enable(); } + +/* + * Simple udelay variant. To be used on startup and reboot + * when the interrupt handler isn't working. + */ +void udelay_simple(unsigned long usecs) +{ + u64 end; + + end = get_clock() + ((u64) usecs << 12); + while (get_clock() < end) + cpu_relax(); +} diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c index c0cb7254725..3db2c386546 100644 --- a/drivers/s390/cio/cio.c +++ b/drivers/s390/cio/cio.c @@ -859,19 +859,6 @@ __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib) return -EBUSY; /* uhm... */ } -/* we can't use the normal udelay here, since it enables external interrupts */ - -static void udelay_reset(unsigned long usecs) -{ - uint64_t start_cc, end_cc; - - asm volatile ("STCK %0" : "=m" (start_cc)); - do { - cpu_relax(); - asm volatile ("STCK %0" : "=m" (end_cc)); - } while (((end_cc - start_cc)/4096) < usecs); -} - static int __clear_io_subchannel_easy(struct subchannel_id schid) { @@ -887,7 +874,7 @@ __clear_io_subchannel_easy(struct subchannel_id schid) if (schid_equal(&ti.schid, &schid)) return 0; } - udelay_reset(100); + udelay_simple(100); } return -EBUSY; } @@ -895,7 +882,7 @@ __clear_io_subchannel_easy(struct subchannel_id schid) static void __clear_chsc_subchannel_easy(void) { /* It seems we can only wait for a bit here :/ */ - udelay_reset(100); + udelay_simple(100); } static int pgm_check_occured; |