From 7c151d3d5d7a032e08dbe86ad6088622391bf13e Mon Sep 17 00:00:00 2001 From: Markos Chandras Date: Wed, 3 Dec 2014 12:37:32 +0000 Subject: MIPS: Make use of the ERETNC instruction on MIPS R6 The ERETNC instruction, introduced in MIPS R5, is similar to the ERET one, except it does not clear the LLB bit in the LLADDR register. This feature is necessary to safely emulate R2 LL/SC instructions. However, on context switches, we need to clear the LLAddr/LLB bit in order to make sure that an SC instruction from the new thread will never succeed if it happens to interrupt an LL operation on the same address from the previous thread. Signed-off-by: Markos Chandras --- arch/mips/include/asm/thread_info.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/mips/include/asm/thread_info.h') diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h index 99eea59604e9..fb68fd2714fb 100644 --- a/arch/mips/include/asm/thread_info.h +++ b/arch/mips/include/asm/thread_info.h @@ -28,7 +28,7 @@ struct thread_info { unsigned long tp_value; /* thread pointer */ __u32 cpu; /* current CPU */ int preempt_count; /* 0 => preemptable, <0 => BUG */ - + int r2_emul_return; /* 1 => Returning from R2 emulator */ mm_segment_t addr_limit; /* * thread address space limit: * 0x7fffffff for user-thead -- cgit v1.2.3