[MIPS] Cleanup memory barriers for weakly ordered systems.

Also the R4000 / R4600 LL/SC instructions imply a sync so no explicit sync
needed.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 7 insertions, 3 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 3947e5daea39..4d64960be035 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1277,6 +1277,7 @@ config CPU_RM9000
         select CPU_SUPPORTS_32BIT_KERNEL
         select CPU_SUPPORTS_64BIT_KERNEL
         select CPU_SUPPORTS_HIGHMEM
+        select WEAK_ORDERING
 
 config CPU_SB1
         bool "SB1"
@@ -1285,6 +1286,7 @@ config CPU_SB1
         select CPU_SUPPORTS_32BIT_KERNEL
         select CPU_SUPPORTS_64BIT_KERNEL
         select CPU_SUPPORTS_HIGHMEM
+        select WEAK_ORDERING
 
 endchoice
 
@@ -1345,6 +1347,8 @@ config SYS_HAS_CPU_RM9000
 config SYS_HAS_CPU_SB1
         bool
 
+config WEAK_ORDERING
+        bool
 endmenu
 
 #
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 49db516789e0..f2a8701e414d 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -172,7 +172,7 @@ int smp_call_function (void (*func) (void *info), void *info, int retry,
 
         spin_lock(&smp_call_lock);
         call_data = &data;
-        mb();
+        smp_mb();
 
         /* Send a message to all other CPUs and wait for them to respond */
         for_each_online_cpu(i)
@@ -204,7 +204,7 @@ void smp_call_function_interrupt(void)
          * Notify initiating CPU that I've grabbed the data and am
          * about to execute the function.
          */
-        mb();
+        smp_mb();
         atomic_inc(&call_data->started);
 
         /*
@@ -215,7 +215,7 @@ void smp_call_function_interrupt(void)
         irq_exit();
 
         if (wait) {
-                mb();
+                smp_mb();
                 atomic_inc(&call_data->finished);
         }
 }