Blackfin/ipipe: prepare status bitops for SMP support

Signed-off-by: Philippe Gerum <rpm@xenomai.org>
Signed-off-by: Li Yi <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

3 files changed, 76 insertions, 27 deletions

diff --git a/arch/blackfin/include/asm/ipipe.h b/arch/blackfin/include/asm/ipipe.h
index 4617ba66278f..07bd2e65ab5b 100644
--- a/arch/blackfin/include/asm/ipipe.h
+++ b/arch/blackfin/include/asm/ipipe.h
@@ -124,16 +124,6 @@ static inline int __ipipe_check_tickdev(const char *devname)
         return 1;
 }
 
-static inline void __ipipe_lock_root(void)
-{
-        set_bit(IPIPE_SYNCDEFER_FLAG, &ipipe_root_cpudom_var(status));
-}
-
-static inline void __ipipe_unlock_root(void)
-{
-        clear_bit(IPIPE_SYNCDEFER_FLAG, &ipipe_root_cpudom_var(status));
-}
-
 void __ipipe_enable_pipeline(void);
 
 #define __ipipe_hook_critical_ipi(ipd) do { } while (0)
diff --git a/arch/blackfin/include/asm/ipipe_base.h b/arch/blackfin/include/asm/ipipe_base.h
index 490098f532a7..00409201d9ed 100644
--- a/arch/blackfin/include/asm/ipipe_base.h
+++ b/arch/blackfin/include/asm/ipipe_base.h
@@ -51,23 +51,15 @@
 
 extern unsigned long __ipipe_root_status; /* Alias to ipipe_root_cpudom_var(status) */
 
-#define __ipipe_stall_root()                                            \
-        do {                                                            \
-                volatile unsigned long *p = &__ipipe_root_status;       \
-                set_bit(0, p);                                          \
-        } while (0)
-
-#define __ipipe_test_and_stall_root()                                   \
-        ({                                                              \
-                volatile unsigned long *p = &__ipipe_root_status;       \
-                test_and_set_bit(0, p);                                 \
-        })
-
-#define __ipipe_test_root()                                     \
-        ({                                                      \
-                const unsigned long *p = &__ipipe_root_status;  \
-                test_bit(0, p);                                 \
-        })
+void __ipipe_stall_root(void);
+
+unsigned long __ipipe_test_and_stall_root(void);
+
+unsigned long __ipipe_test_root(void);
+
+void __ipipe_lock_root(void);
+
+void __ipipe_unlock_root(void);
 
 #endif /* !__ASSEMBLY__ */
 
diff --git a/arch/blackfin/kernel/ipipe.c b/arch/blackfin/kernel/ipipe.c
index 5d7382396dc0..a77307a4473b 100644
--- a/arch/blackfin/kernel/ipipe.c
+++ b/arch/blackfin/kernel/ipipe.c
@@ -335,3 +335,70 @@ void __ipipe_enable_root_irqs_hw(void)
         __clear_bit(IPIPE_STALL_FLAG, &ipipe_root_cpudom_var(status));
         bfin_sti(bfin_irq_flags);
 }
+
+/*
+ * We could use standard atomic bitops in the following root status
+ * manipulation routines, but let's prepare for SMP support in the
+ * same move, preventing CPU migration as required.
+ */
+void __ipipe_stall_root(void)
+{
+        unsigned long *p, flags;
+
+        local_irq_save_hw(flags);
+        p = &__ipipe_root_status;
+        __set_bit(IPIPE_STALL_FLAG, p);
+        local_irq_restore_hw(flags);
+}
+EXPORT_SYMBOL(__ipipe_stall_root);
+
+unsigned long __ipipe_test_and_stall_root(void)
+{
+        unsigned long *p, flags;
+        int x;
+
+        local_irq_save_hw(flags);
+        p = &__ipipe_root_status;
+        x = __test_and_set_bit(IPIPE_STALL_FLAG, p);
+        local_irq_restore_hw(flags);
+
+        return x;
+}
+EXPORT_SYMBOL(__ipipe_test_and_stall_root);
+
+unsigned long __ipipe_test_root(void)
+{
+        const unsigned long *p;
+        unsigned long flags;
+        int x;
+
+        local_irq_save_hw_smp(flags);
+        p = &__ipipe_root_status;
+        x = test_bit(IPIPE_STALL_FLAG, p);
+        local_irq_restore_hw_smp(flags);
+
+        return x;
+}
+EXPORT_SYMBOL(__ipipe_test_root);
+
+void __ipipe_lock_root(void)
+{
+        unsigned long *p, flags;
+
+        local_irq_save_hw(flags);
+        p = &__ipipe_root_status;
+        __set_bit(IPIPE_SYNCDEFER_FLAG, p);
+        local_irq_restore_hw(flags);
+}
+EXPORT_SYMBOL(__ipipe_lock_root);
+
+void __ipipe_unlock_root(void)
+{
+        unsigned long *p, flags;
+
+        local_irq_save_hw(flags);
+        p = &__ipipe_root_status;
+        __clear_bit(IPIPE_SYNCDEFER_FLAG, p);
+        local_irq_restore_hw(flags);
+}
+EXPORT_SYMBOL(__ipipe_unlock_root);