diff options
Diffstat (limited to 'arch/arm/kernel/swp_emulate.c')
| -rw-r--r-- | arch/arm/kernel/swp_emulate.c | 19 |
1 files changed, 4 insertions, 15 deletions
diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c index b1b89882b113..587fdfe1a72c 100644 --- a/arch/arm/kernel/swp_emulate.c +++ b/arch/arm/kernel/swp_emulate.c @@ -27,6 +27,7 @@ #include <linux/perf_event.h> #include <asm/opcodes.h> +#include <asm/system_info.h> #include <asm/traps.h> #include <asm/uaccess.h> @@ -141,14 +142,6 @@ static int emulate_swpX(unsigned int address, unsigned int *data, while (1) { unsigned long temp; - /* - * Barrier required between accessing protected resource and - * releasing a lock for it. Legacy code might not have done - * this, and we cannot determine that this is not the case - * being emulated, so insert always. - */ - smp_mb(); - if (type == TYPE_SWPB) __user_swpb_asm(*data, address, res, temp); else @@ -161,13 +154,6 @@ static int emulate_swpX(unsigned int address, unsigned int *data, } if (res == 0) { - /* - * Barrier also required between acquiring a lock for a - * protected resource and accessing the resource. Inserted for - * same reason as above. - */ - smp_mb(); - if (type == TYPE_SWPB) swpbcounter++; else @@ -266,6 +252,9 @@ static struct undef_hook swp_hook = { */ static int __init swp_emulation_init(void) { + if (cpu_architecture() < CPU_ARCH_ARMv7) + return 0; + #ifdef CONFIG_PROC_FS if (!proc_create("cpu/swp_emulation", S_IRUGO, NULL, &proc_status_fops)) return -ENOMEM; |