From: Martin Schwidefsky <schwidefsky@de.ibm.com>
To: hch@lst.df
Cc: akpm@osdl.org, spyro@f2s.com, rmk@arm.linux.org.uk,
linux390@de.ibm.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] irq_enter/irq_exit consolidation
Date: Mon, 13 Sep 2004 15:02:40 +0200 [thread overview]
Message-ID: <20040913130239.GA3086@mschwid3.boeblingen.de.ibm.com> (raw)
Hi Christoph,
> s390 has an assembly wrapper around do_softirq.
>
> I've extended the invoke_softirq mechanism used by s390 (also called
> by ksoftirqd) to the two arm variants, but the right thing to do is
> probably to use the normal do_softirq call in arm and set
> __ARCH_HAS_DO_SOFTIRQ + providing a per-arch do_softirq for all callers
> for s390 and maybe arm26.
do_call_softirq switches to the asynchronous interrupt stack,
just what i386 does now as well. Trouble is that on s390 it is
non-trivial to do the switch in C with inline assembly. We need
a bit of assembly. But we could get rid of invoke_softirq, define
__ARCH_HAS_DO_SOFTIRQ and use do_softirq to call the assembly
wrapper.
blue skies,
Martin.
---
From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Replace invoke_softirq mechanism by __ARCH_HAS_DO_SOFTIRQ
mechanism for s390.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diffstat:
arch/s390/kernel/entry.S | 4 +---
arch/s390/kernel/entry64.S | 4 +---
arch/s390/kernel/s390_ext.c | 1 +
arch/s390/kernel/s390_ksyms.c | 1 -
arch/s390/kernel/setup.c | 20 ++++++++++++++++++++
include/asm-s390/hardirq.h | 3 +--
6 files changed, 24 insertions(+), 9 deletions(-)
diff -urN linux-2.6/arch/s390/kernel/entry64.S linux-2.6-s390/arch/s390/kernel/entry64.S
--- linux-2.6/arch/s390/kernel/entry64.S 2004-09-13 14:30:42.000000000 +0200
+++ linux-2.6-s390/arch/s390/kernel/entry64.S 2004-09-13 14:21:29.000000000 +0200
@@ -153,7 +153,6 @@
*/
.global do_call_softirq
do_call_softirq:
- stnsm __SF_EMPTY(%r15),0xfc
stmg %r12,%r15,__SF_GPRS(%r15)
lgr %r12,%r15
lg %r0,__LC_ASYNC_STACK
@@ -163,9 +162,8 @@
lg %r15,__LC_ASYNC_STACK
0: aghi %r15,-STACK_FRAME_OVERHEAD
stg %r12,__SF_BACKCHAIN(%r15) # store back chain
- brasl %r14,do_softirq
+ brasl %r14,__do_softirq
lmg %r12,%r15,__SF_GPRS(%r12)
- ssm __SF_EMPTY(%r15)
br %r14
__critical_start:
diff -urN linux-2.6/arch/s390/kernel/entry.S linux-2.6-s390/arch/s390/kernel/entry.S
--- linux-2.6/arch/s390/kernel/entry.S 2004-09-13 14:30:42.000000000 +0200
+++ linux-2.6-s390/arch/s390/kernel/entry.S 2004-09-13 14:21:29.000000000 +0200
@@ -156,7 +156,6 @@
*/
.global do_call_softirq
do_call_softirq:
- stnsm __SF_EMPTY(%r15),0xfc
stm %r12,%r15,__SF_GPRS(%r15)
lr %r12,%r15
basr %r13,0
@@ -171,7 +170,6 @@
l %r1,.Ldo_softirq-do_call_base(%r13)
basr %r14,%r1
lm %r12,%r15,__SF_GPRS(%r12)
- ssm __SF_EMPTY(%r15)
br %r14
__critical_start:
@@ -733,7 +731,7 @@
.Ldo_IRQ: .long do_IRQ
.Ldo_extint: .long do_extint
.Ldo_signal: .long do_signal
-.Ldo_softirq: .long do_softirq
+.Ldo_softirq: .long __do_softirq
.Lhandle_per: .long do_single_step
.Ljump_table: .long pgm_check_table
.Lschedule: .long schedule
diff -urN linux-2.6/arch/s390/kernel/s390_ext.c linux-2.6-s390/arch/s390/kernel/s390_ext.c
--- linux-2.6/arch/s390/kernel/s390_ext.c 2004-08-14 12:55:32.000000000 +0200
+++ linux-2.6-s390/arch/s390/kernel/s390_ext.c 2004-09-13 14:34:14.000000000 +0200
@@ -12,6 +12,7 @@
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
+#include <linux/interrupt.h>
#include <asm/lowcore.h>
#include <asm/s390_ext.h>
diff -urN linux-2.6/arch/s390/kernel/s390_ksyms.c linux-2.6-s390/arch/s390/kernel/s390_ksyms.c
--- linux-2.6/arch/s390/kernel/s390_ksyms.c 2004-09-13 14:03:55.000000000 +0200
+++ linux-2.6-s390/arch/s390/kernel/s390_ksyms.c 2004-09-13 14:33:34.000000000 +0200
@@ -61,6 +61,5 @@
EXPORT_SYMBOL(console_mode);
EXPORT_SYMBOL(console_devno);
EXPORT_SYMBOL(console_irq);
-EXPORT_SYMBOL(do_call_softirq);
EXPORT_SYMBOL(sys_wait4);
EXPORT_SYMBOL(cpcmd);
diff -urN linux-2.6/arch/s390/kernel/setup.c linux-2.6-s390/arch/s390/kernel/setup.c
--- linux-2.6/arch/s390/kernel/setup.c 2004-09-13 14:30:42.000000000 +0200
+++ linux-2.6-s390/arch/s390/kernel/setup.c 2004-09-13 14:31:53.000000000 +0200
@@ -654,3 +654,23 @@
{
/* nothing... */
}
+
+extern void do_call_softirq(void);
+
+asmlinkage void do_softirq(void)
+{
+ unsigned long flags;
+
+ if (in_interrupt())
+ return;
+
+ local_irq_save(flags);
+
+ if (local_softirq_pending())
+ /* Call __do_softirq on asynchromous interrupt stack. */
+ do_call_softirq();
+
+ local_irq_restore(flags);
+}
+
+EXPORT_SYMBOL(do_softirq);
diff -urN linux-2.6/include/asm-s390/hardirq.h linux-2.6-s390/include/asm-s390/hardirq.h
--- linux-2.6/include/asm-s390/hardirq.h 2004-09-13 14:30:42.000000000 +0200
+++ linux-2.6-s390/include/asm-s390/hardirq.h 2004-09-13 14:31:42.000000000 +0200
@@ -61,9 +61,8 @@
#define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
#define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
-extern void do_call_softirq(void);
extern void account_ticks(struct pt_regs *);
-#define invoke_softirq() do_call_softirq()
+#define __ARCH_HAS_DO_SOFTIRQ
#endif /* __ASM_HARDIRQ_H */
next reply other threads:[~2004-09-13 13:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-13 13:02 Martin Schwidefsky [this message]
2004-09-14 18:31 ` [PATCH] irq_enter/irq_exit consolidation Christoph Hellwig
-- strict thread matches above, loose matches on Subject: below --
2004-09-12 11:25 Christoph Hellwig
2004-09-12 11:44 ` Russell King
2004-09-12 22:57 ` David S. Miller
2004-09-13 8:10 ` Russell King
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