MIPS: Add LLB bit and related feature for the Config 5 CP0 register
The LLBIT (bit 4) in the Config5 CP0 register indicates the software
availability of the Load-Linked bit. This bit is only set by hardware
and it has the following meaning:
0: LLB functionality is not supported
1: LLB functionality is supported. The following feature are also
supported:
- ERETNC instruction. Similar to ERET but it does not clear the LLB
bit in the LLAddr register.
- CP0 LLAddr/LLB bit must be set
- LLbit is software accessible through the LLAddr[0]
This will be used later on to emulate R2 LL/SC instructions.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index f604523..1568723 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -376,6 +376,7 @@
#define MIPS_CPU_RIXIEX 0x200000000ull /* CPU has unique exception codes for {Read, Execute}-Inhibit exceptions */
#define MIPS_CPU_MAAR 0x400000000ull /* MAAR(I) registers are present */
#define MIPS_CPU_FRE 0x800000000ull /* FRE & UFE bits implemented */
+#define MIPS_CPU_RW_LLB 0x1000000000ull /* LLADDR/LLB writes are allowed */
/*
* CPU ASE encodings