sh: Support for SH-4A memory barriers.

SH-4A supports 'synco' as a barrier, sprinkle it around
the cache ops as necessary..

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 12 insertions, 0 deletions

diff --git a/arch/sh/mm/cache-sh4.c b/arch/sh/mm/cache-sh4.c
index 94c05d09c3f7..846b63d6f5e8 100644
--- a/arch/sh/mm/cache-sh4.c
+++ b/arch/sh/mm/cache-sh4.c
@@ -184,6 +184,7 @@ void flush_cache_sigtramp(unsigned long addr)
              i++, index += cpu_data->icache.way_incr)
                 ctrl_outl(0, index);    /* Clear out Valid-bit */
         back_to_P1();
+        wmb();
         local_irq_restore(flags);
 }
 
@@ -223,6 +224,8 @@ void flush_dcache_page(struct page *page)
                 flush_cache_4096(CACHE_OC_ADDRESS_ARRAY | 0x2000, phys);
                 flush_cache_4096(CACHE_OC_ADDRESS_ARRAY | 0x3000, phys);
         }
+
+        wmb();
 }
 
 static inline void flush_icache_all(void)
@@ -247,6 +250,7 @@ void flush_dcache_all(void)
                 __flush_dcache_all();
         else
                 __flush_dcache_all_ex();
+        wmb();
 }
 
 void flush_cache_all(void)
@@ -377,5 +381,6 @@ void flush_icache_user_range(struct vm_area_struct *vma,
                              struct page *page, unsigned long addr, int len)
 {
         flush_cache_page(vma, addr, page_to_pfn(page));
+        mb();
 }
 
diff --git a/include/asm-sh/system.h b/include/asm-sh/system.h
index e89728d405d8..eb4902ed920a 100644
--- a/include/asm-sh/system.h
+++ b/include/asm-sh/system.h
@@ -84,10 +84,17 @@ static __inline__ unsigned long tas(volatile int *m)
 
 extern void __xchg_called_with_bad_pointer(void);
 
+#ifdef CONFIG_CPU_SH4A
+#define mb()    __asm__ __volatile__ ("synco": : :"memory")
+#define rmb()   mb()
+#define wmb()   __asm__ __volatile__ ("synco": : :"memory")
+#define read_barrier_depends()  do { } while(0)
+#else
 #define mb()    __asm__ __volatile__ ("": : :"memory")
 #define rmb()   mb()
 #define wmb()   __asm__ __volatile__ ("": : :"memory")
 #define read_barrier_depends()  do { } while(0)
+#endif
 
 #ifdef CONFIG_SMP
 #define smp_mb()        mb()