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 5a4c95905420f39230fa516f9034f0a4cc5777d5..31739c7d66a94930868ed1037bed18df47d3c1e1 100644 (file)
--- 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 a7e7e14cb4307e722b11eab4299e65d9ef61dc28..520a379f4b80490dd9e897d48120d89aef86bc13 100644 (file)
--- 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 cc826e85323f3c1f18eb00a82123e91b76008894..ac96d3804d0c8cea437308d90bb282b28ae058be 100644 (file)
--- a/include/asm-x86/semaphore_32.h
+++ b/include/asm-x86/semaphore_32.h
@@ -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.

diff --git a/include/linux/linkage.h b/include/linux/linkage.h
index ff203dd029191d5b578707ce184655bcc02967da..ceeeb5ea5b152b84c53028da6c21fbcc8c200e82 100644 (file)
--- 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 7d02700a4b0e131ae0dfba2e6da6ecf75b6a8d2c..3e3365e5665eebf950803b34411f386681157533 100644 (file)
--- a/lib/rwsem.c
+++ b/lib/rwsem.c
@@ -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;