diff options
| author | Lennert Buytenhek <buytenh@wantstofly.org> | 2007-03-31 12:03:20 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2007-04-01 22:38:36 +0100 |
| commit | 398e692fd5cecdd25d311b47bbae69f7bac3a3cb (patch) | |
| tree | f1852c28d9f9c47c4763607630ac3db1c91930d6 | |
| parent | 9a4d93d49d140c196020a1bae339efcf211cac03 (diff) | |
[ARM] 4298/1: fix memory barriers for DMA coherent and SMP platforms
This patch:
- Switches mb/rmb/wmb back to being full-blown DMBs on ARM SMP systems,
since mb/rmb/wmb are required to order Normal memory accesses as well.
- Enables the use of DMB and ISB on XSC3 (which is an ARMv5TE ISA core
but conforms to the ARMv6 memory ordering model and supports the
various ARMv6 barriers.)
- Makes DMA coherent platforms (only ixp23xx at the moment) map
mb/rmb/wmb to dmb(), as on DMA coherent platforms, DMA consistent
mappings are done as Normal mappings, which are weakly ordered.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | include/asm-arm/system.h | 34 |
1 files changed, 18 insertions, 16 deletions
diff --git a/include/asm-arm/system.h b/include/asm-arm/system.h index f06d8a43fde..69134c7518c 100644 --- a/include/asm-arm/system.h +++ b/include/asm-arm/system.h @@ -3,6 +3,7 @@ #ifdef __KERNEL__ +#include <asm/memory.h> #define CPU_ARCH_UNKNOWN 0 #define CPU_ARCH_ARMv3 1 @@ -154,7 +155,7 @@ extern unsigned int user_debug; #define vectors_high() (0) #endif -#if __LINUX_ARM_ARCH__ >= 6 +#if defined(CONFIG_CPU_XSC3) || __LINUX_ARM_ARCH__ >= 6 #define isb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c5, 4" \ : : "r" (0) : "memory") #define dsb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \ @@ -168,22 +169,23 @@ extern unsigned int user_debug; #define dmb() __asm__ __volatile__ ("" : : : "memory") #endif -#define mb() barrier() -#define rmb() barrier() -#define wmb() barrier() -#define read_barrier_depends() do { } while(0) - -#ifdef CONFIG_SMP -#define smp_mb() dmb() -#define smp_rmb() dmb() -#define smp_wmb() dmb() -#define smp_read_barrier_depends() read_barrier_depends() +#ifndef CONFIG_SMP +#define mb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0) +#define rmb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0) +#define wmb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0) +#define smp_mb() barrier() +#define smp_rmb() barrier() +#define smp_wmb() barrier() #else -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() -#define smp_read_barrier_depends() read_barrier_depends() -#endif /* CONFIG_SMP */ +#define mb() dmb() +#define rmb() dmb() +#define wmb() dmb() +#define smp_mb() dmb() +#define smp_rmb() dmb() +#define smp_wmb() dmb() +#endif +#define read_barrier_depends() do { } while(0) +#define smp_read_barrier_depends() do { } while(0) #define set_mb(var, value) do { var = value; smp_mb(); } while (0) #define nop() __asm__ __volatile__("mov\tr0,r0\t@ nop\n\t"); |