From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Move cio's private simple udelay function to lib/delay.c and turn it
into something much more readable. So we have all implementations
at one place.
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---
arch/s390/include/asm/delay.h | 1 +
arch/s390/lib/delay.c | 13 +++++++++++++
drivers/s390/cio/cio.c | 17 ++---------------
3 files changed, 16 insertions(+), 15 deletions(-)
Index: quilt-2.6/arch/s390/include/asm/delay.h
===================================================================
--- quilt-2.6.orig/arch/s390/include/asm/delay.h
+++ quilt-2.6/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)
Index: quilt-2.6/arch/s390/lib/delay.c
===================================================================
--- quilt-2.6.orig/arch/s390/lib/delay.c
+++ quilt-2.6/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();
+}
Index: quilt-2.6/drivers/s390/cio/cio.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/cio.c
+++ quilt-2.6/drivers/s390/cio/cio.c
@@ -855,19 +855,6 @@ __disable_subchannel_easy(struct subchan
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)
{
@@ -883,7 +870,7 @@ __clear_io_subchannel_easy(struct subcha
if (schid_equal(&ti.schid, &schid))
return 0;
}
- udelay_reset(100);
+ udelay_simple(100);
}
return -EBUSY;
}
@@ -891,7 +878,7 @@ __clear_io_subchannel_easy(struct subcha
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;
--
blue skies,
Martin.
"Reality continues to ruin my life." - Calvin.
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