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authorGraf Yang <graf.yang@analog.com>2010-01-07 06:57:30 +0000
committerMike Frysinger <vapier@gentoo.org>2011-04-13 19:34:04 -0400
commit943aee0c685d0563228d5a2ad9c8394ad0300fb5 (patch)
tree380d2fab81323a878ab750f573d4476d109e589b /arch
parent85f2e689a5c8fb6ed8fdbee00109e7f6e5fefcb6 (diff)
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Blackfin: SMP: make all barriers handle cache issues
When suspending/resuming, the common task freezing code will run in parallel and freeze processes on each core. This is because the code uses the non-smp version of memory barriers (as well it should). The Blackfin smp barrier logic at the moment contains the cache sync logic, but the non-smp barriers do not. This is incorrect as Rafel summarized: > ... > The existing memory barriers are SMP barriers too, but they are more > than _just_ SMP barriers. At least that's how it is _supposed_ to be > (eg. rmb() is supposed to be stronger than smp_rmb()). > ... > However, looking at the blackfin's definitions of SMP barriers I see > that it uses extra stuff that should _also_ be used in the definitions > of the mandatory barriers. > ... URL: http://lkml.org/lkml/2011/4/13/11 LKML-Reference: <BANLkTi=F-C-vwX4PGGfbkdTBw3OWL-twfg@mail.gmail.com> Signed-off-by: Graf Yang <graf.yang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/blackfin/include/asm/system.h36
1 files changed, 18 insertions, 18 deletions
diff --git a/arch/blackfin/include/asm/system.h b/arch/blackfin/include/asm/system.h
index 19e2c7c..44bd0cc 100644
--- a/arch/blackfin/include/asm/system.h
+++ b/arch/blackfin/include/asm/system.h
@@ -19,11 +19,11 @@
* Force strict CPU ordering.
*/
#define nop() __asm__ __volatile__ ("nop;\n\t" : : )
-#define mb() __asm__ __volatile__ ("" : : : "memory")
-#define rmb() __asm__ __volatile__ ("" : : : "memory")
-#define wmb() __asm__ __volatile__ ("" : : : "memory")
-#define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
-#define read_barrier_depends() do { } while(0)
+#define smp_mb() mb()
+#define smp_rmb() rmb()
+#define smp_wmb() wmb()
+#define set_mb(var, value) do { var = value; mb(); } while (0)
+#define smp_read_barrier_depends() read_barrier_depends()
#ifdef CONFIG_SMP
asmlinkage unsigned long __raw_xchg_1_asm(volatile void *ptr, unsigned long value);
@@ -37,16 +37,16 @@ asmlinkage unsigned long __raw_cmpxchg_4_asm(volatile void *ptr,
unsigned long new, unsigned long old);
#ifdef __ARCH_SYNC_CORE_DCACHE
-# define smp_mb() do { barrier(); smp_check_barrier(); smp_mark_barrier(); } while (0)
-# define smp_rmb() do { barrier(); smp_check_barrier(); } while (0)
-# define smp_wmb() do { barrier(); smp_mark_barrier(); } while (0)
-#define smp_read_barrier_depends() do { barrier(); smp_check_barrier(); } while (0)
-
+/* Force Core data cache coherence */
+# define mb() do { barrier(); smp_check_barrier(); smp_mark_barrier(); } while (0)
+# define rmb() do { barrier(); smp_check_barrier(); } while (0)
+# define wmb() do { barrier(); smp_mark_barrier(); } while (0)
+# define read_barrier_depends() do { barrier(); smp_check_barrier(); } while (0)
#else
-# define smp_mb() barrier()
-# define smp_rmb() barrier()
-# define smp_wmb() barrier()
-#define smp_read_barrier_depends() barrier()
+# define mb() barrier()
+# define rmb() barrier()
+# define wmb() barrier()
+# define read_barrier_depends() do { } while (0)
#endif
static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
@@ -99,10 +99,10 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
#else /* !CONFIG_SMP */
-#define smp_mb() barrier()
-#define smp_rmb() barrier()
-#define smp_wmb() barrier()
-#define smp_read_barrier_depends() do { } while(0)
+#define mb() barrier()
+#define rmb() barrier()
+#define wmb() barrier()
+#define read_barrier_depends() do { } while (0)
struct __xchg_dummy {
unsigned long a[100];