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x86: fix UML and -regparm=3

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introduce the "asmregparm" calling convention: for functions
implemented in assembly with a fixed regparm input parameters
calling convention.

mark the semaphore and rwsem slowpath functions with that.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Ingo Molnar 2008-01-30 13:33:00 +01:00
parent 3a556b26a2
commit d50efc6c40
5 changed files with 25 additions and 12 deletions
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5
include/asm-x86/linkage.h
View file

@ -9,6 +9,11 @@
#ifdef CONFIG_X86_32
#define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0)))
#define prevent_tail_call(ret) __asm__ ("" : "=r" (ret) : "0" (ret))
/*
* For 32-bit UML - mark functions implemented in assembly that use
* regparm input parameters:
*/
#define asmregparm __attribute__((regparm(3)))
#endif
#ifdef CONFIG_X86_ALIGNMENT_16

12
include/asm-x86/rwsem.h
View file

@ -44,10 +44,14 @@
struct rwsem_waiter;
extern struct rw_semaphore *FASTCALL(rwsem_down_read_failed(struct rw_semaphore *sem));
extern struct rw_semaphore *FASTCALL(rwsem_down_write_failed(struct rw_semaphore *sem));
extern struct rw_semaphore *FASTCALL(rwsem_wake(struct rw_semaphore *));
extern struct rw_semaphore *FASTCALL(rwsem_downgrade_wake(struct rw_semaphore *sem));
extern asmregparm struct rw_semaphore *
rwsem_down_read_failed(struct rw_semaphore *sem);
extern asmregparm struct rw_semaphore *
rwsem_down_write_failed(struct rw_semaphore *sem);
extern asmregparm struct rw_semaphore *
rwsem_wake(struct rw_semaphore *);
extern asmregparm struct rw_semaphore *
rwsem_downgrade_wake(struct rw_semaphore *sem);
/*
* the semaphore definition

8
include/asm-x86/semaphore_32.h
View file

@ -83,10 +83,10 @@ static inline void init_MUTEX_LOCKED (struct semaphore *sem)
sema_init(sem, 0);
}
void __down_failed(void /* special register calling convention */);
int __down_failed_interruptible(void /* params in registers */);
int __down_failed_trylock(void /* params in registers */);
void __up_wakeup(void /* special register calling convention */);
extern asmregparm void __down_failed(atomic_t *count_ptr);
extern asmregparm int __down_failed_interruptible(atomic_t *count_ptr);
extern asmregparm int __down_failed_trylock(atomic_t *count_ptr);
extern asmregparm void __up_wakeup(atomic_t *count_ptr);
/*
* This is ugly, but we want the default case to fall through.

4
include/linux/linkage.h
View file

@ -13,6 +13,10 @@
#define asmlinkage CPP_ASMLINKAGE
#endif
#ifndef asmregparm
# define asmregparm
#endif
#ifndef prevent_tail_call
# define prevent_tail_call(ret) do { } while (0)
#endif

8
lib/rwsem.c
View file

@ -187,7 +187,7 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
/*
* wait for the read lock to be granted
*/
struct rw_semaphore fastcall __sched *
asmregparm struct rw_semaphore __sched *
rwsem_down_read_failed(struct rw_semaphore *sem)
{
struct rwsem_waiter waiter;
@ -201,7 +201,7 @@ rwsem_down_read_failed(struct rw_semaphore *sem)
/*
* wait for the write lock to be granted
*/
struct rw_semaphore fastcall __sched *
asmregparm struct rw_semaphore __sched *
rwsem_down_write_failed(struct rw_semaphore *sem)
{
struct rwsem_waiter waiter;
@ -216,7 +216,7 @@ rwsem_down_write_failed(struct rw_semaphore *sem)
* handle waking up a waiter on the semaphore
* - up_read/up_write has decremented the active part of count if we come here
*/
struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem)
asmregparm struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
{
unsigned long flags;
@ -236,7 +236,7 @@ struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem)
* - caller incremented waiting part of count and discovered it still negative
* - just wake up any readers at the front of the queue
*/
struct rw_semaphore fastcall *rwsem_downgrade_wake(struct rw_semaphore *sem)
asmregparm struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
{
unsigned long flags;