diff options
| -rw-r--r-- | arch/powerpc/include/asm/exception-64s.h | 13 | ||||
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 6 |
2 files changed, 17 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index 183d73b6ed99..33473cbc0986 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -236,6 +236,19 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) #define kvmppc_interrupt kvmppc_interrupt_pr #endif +/* + * Branch to label using its 0xC000 address. This results in instruction + * address suitable for MSR[IR]=0 or 1, which allows relocation to be turned + * on using mtmsr rather than rfid. + * + * This could set the 0xc bits for !RELOCATABLE as an immediate, rather than + * load KBASE for a slight optimisation. + */ +#define BRANCH_TO_C000(reg, label) \ + __LOAD_HANDLER(reg, label); \ + mtctr reg; \ + bctr + #ifdef CONFIG_RELOCATABLE #define BRANCH_TO_COMMON(reg, label) \ __LOAD_HANDLER(reg, label); \ diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index cad3b4b82813..7807719ca855 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -99,7 +99,9 @@ EXC_VIRT_NONE(0x4000, 0x100) #ifdef CONFIG_PPC_P7_NAP /* * If running native on arch 2.06 or later, check if we are waking up - * from nap/sleep/winkle, and branch to idle handler. + * from nap/sleep/winkle, and branch to idle handler. The idle wakeup + * handler initially runs in real mode, but we branch to the 0xc000... + * address so we can turn on relocation with mtmsr. */ #define IDLETEST(n) \ BEGIN_FTR_SECTION ; \ @@ -107,7 +109,7 @@ EXC_VIRT_NONE(0x4000, 0x100) rlwinm. r10,r10,47-31,30,31 ; \ beq- 1f ; \ cmpwi cr3,r10,2 ; \ - BRANCH_TO_COMMON(r10, system_reset_idle_common) ; \ + BRANCH_TO_C000(r10, system_reset_idle_common) ; \ 1: \ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206) #else |