x86: fix UML and -regparm=3
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>
diff --git a/include/asm-x86/linkage.h b/include/asm-x86/linkage.h
index 5a4c959..31739c7 100644
--- a/include/asm-x86/linkage.h
+++ b/include/asm-x86/linkage.h
@@ -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
diff --git a/include/asm-x86/rwsem.h b/include/asm-x86/rwsem.h
index a7e7e14..520a379 100644
--- a/include/asm-x86/rwsem.h
+++ b/include/asm-x86/rwsem.h
@@ -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
diff --git a/include/asm-x86/semaphore_32.h b/include/asm-x86/semaphore_32.h
index cc826e8..ac96d38 100644
--- a/include/asm-x86/semaphore_32.h
+++ b/include/asm-x86/semaphore_32.h
@@ -83,10 +83,10 @@
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.
diff --git a/include/linux/linkage.h b/include/linux/linkage.h
index ff203dd..ceeeb5e 100644
--- a/include/linux/linkage.h
+++ b/include/linux/linkage.h
@@ -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
diff --git a/lib/rwsem.c b/lib/rwsem.c
index 7d02700..3e3365e 100644
--- a/lib/rwsem.c
+++ b/lib/rwsem.c
@@ -187,7 +187,7 @@
/*
* 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 @@
/*
* 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 @@
* 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 @@
* - 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;