diff options
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 69 |
1 files changed, 38 insertions, 31 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index c73e909470e3..e5660f3e8331 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -256,7 +256,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) * load KBASE for a slight optimisation. */ #define BRANCH_TO_C000(reg, label) \ - __LOAD_HANDLER(reg, label); \ + __LOAD_FAR_HANDLER(reg, label); \ mtctr reg; \ bctr @@ -822,15 +822,6 @@ EXC_VIRT_NONE(0x4000, 0x100) EXC_REAL_BEGIN(system_reset, 0x100, 0x100) - EXCEPTION_PROLOG_0 PACA_EXNMI - - /* This is EXCEPTION_PROLOG_1 with the idle feature section added */ - OPT_SAVE_REG_TO_PACA(PACA_EXNMI+EX_PPR, r9, CPU_FTR_HAS_PPR) - OPT_SAVE_REG_TO_PACA(PACA_EXNMI+EX_CFAR, r10, CPU_FTR_CFAR) - INTERRUPT_TO_KERNEL - SAVE_CTR(r10, PACA_EXNMI) - mfcr r9 - #ifdef CONFIG_PPC_P7_NAP /* * If running native on arch 2.06 or later, check if we are waking up @@ -838,43 +829,59 @@ EXC_REAL_BEGIN(system_reset, 0x100, 0x100) * bits 46:47. A non-0 value indicates that we are coming from a power * saving state. The idle wakeup handler initially runs in real mode, * but we branch to the 0xc000... address so we can turn on relocation - * with mtmsr. + * with mtmsrd later, after SPRs are restored. + * + * Careful to minimise cost for the fast path (idle wakeup) while + * also avoiding clobbering CFAR for the debug path (non-idle). + * + * For the idle wake case volatile registers can be clobbered, which + * is why we use those initially. If it turns out to not be an idle + * wake, carefully put everything back the way it was, so we can use + * common exception macros to handle it. */ BEGIN_FTR_SECTION - mfspr r10,SPRN_SRR1 - rlwinm. r10,r10,47-31,30,31 - beq- 1f - cmpwi cr1,r10,2 + SET_SCRATCH0(r13) + GET_PACA(r13) + std r3,PACA_EXNMI+0*8(r13) + std r4,PACA_EXNMI+1*8(r13) + std r5,PACA_EXNMI+2*8(r13) mfspr r3,SPRN_SRR1 - bltlr cr1 /* no state loss, return to idle caller */ - BRANCH_TO_C000(r10, system_reset_idle_common) -1: + mfocrf r4,0x80 + rlwinm. r5,r3,47-31,30,31 + bne+ system_reset_idle_wake + /* Not powersave wakeup. Restore regs for regular interrupt handler. */ + mtocrf 0x80,r4 + ld r3,PACA_EXNMI+0*8(r13) + ld r4,PACA_EXNMI+1*8(r13) + ld r5,PACA_EXNMI+2*8(r13) + GET_SCRATCH0(r13) END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206) #endif - KVMTEST EXC_STD 0x100 - std r11,PACA_EXNMI+EX_R11(r13) - std r12,PACA_EXNMI+EX_R12(r13) - GET_SCRATCH0(r10) - std r10,PACA_EXNMI+EX_R13(r13) - + EXCEPTION_PROLOG_0 PACA_EXNMI + EXCEPTION_PROLOG_1 EXC_STD, PACA_EXNMI, 1, 0x100, 0, 0, 0 EXCEPTION_PROLOG_2_REAL system_reset_common, EXC_STD, 0 /* * MSR_RI is not enabled, because PACA_EXNMI and nmi stack is * being used, so a nested NMI exception would corrupt it. + * + * In theory, we should not enable relocation here if it was disabled + * in SRR1, because the MMU may not be configured to support it (e.g., + * SLB may have been cleared). In practice, there should only be a few + * small windows where that's the case, and sreset is considered to + * be dangerous anyway. */ - EXC_REAL_END(system_reset, 0x100, 0x100) + EXC_VIRT_NONE(0x4100, 0x100) TRAMP_KVM(PACA_EXNMI, 0x100) #ifdef CONFIG_PPC_P7_NAP -EXC_COMMON_BEGIN(system_reset_idle_common) - /* - * This must be a direct branch (without linker branch stub) because - * we can not use TOC at this point as r2 may not be restored yet. - */ - b idle_return_gpr_loss +TRAMP_REAL_BEGIN(system_reset_idle_wake) + /* We are waking up from idle, so may clobber any volatile register */ + cmpwi cr1,r5,2 + bltlr cr1 /* no state loss, return to idle caller with r3=SRR1 */ + BRANCH_TO_C000(r12, DOTSYM(idle_return_gpr_loss)) #endif EXC_COMMON_BEGIN(system_reset_common) |