diff options
Diffstat (limited to 'arch/powerpc/kernel/head_64.S')
| -rw-r--r-- | arch/powerpc/kernel/head_64.S | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index e16eb2a3317..6ff3cf50608 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -191,6 +191,37 @@ exception_marker: ori reg,reg,(label)@l; /* virt addr of handler ... */ #endif +/* + * Equal to EXCEPTION_PROLOG_PSERIES, except that it forces 64bit mode. + * The firmware calls the registered system_reset_fwnmi and + * machine_check_fwnmi handlers in 32bit mode if the cpu happens to run + * a 32bit application at the time of the event. + * This firmware bug is present on POWER4 and JS20. + */ +#define EXCEPTION_PROLOG_PSERIES_FORCE_64BIT(area, label) \ + mfspr r13,SPRN_SPRG3; /* get paca address into r13 */ \ + std r9,area+EX_R9(r13); /* save r9 - r12 */ \ + std r10,area+EX_R10(r13); \ + std r11,area+EX_R11(r13); \ + std r12,area+EX_R12(r13); \ + mfspr r9,SPRN_SPRG1; \ + std r9,area+EX_R13(r13); \ + mfcr r9; \ + clrrdi r12,r13,32; /* get high part of &label */ \ + mfmsr r10; \ + /* force 64bit mode */ \ + li r11,5; /* MSR_SF_LG|MSR_ISF_LG */ \ + rldimi r10,r11,61,0; /* insert into top 3 bits */ \ + /* done 64bit mode */ \ + mfspr r11,SPRN_SRR0; /* save SRR0 */ \ + LOAD_HANDLER(r12,label) \ + ori r10,r10,MSR_IR|MSR_DR|MSR_RI; \ + mtspr SPRN_SRR0,r12; \ + mfspr r12,SPRN_SRR1; /* and SRR1 */ \ + mtspr SPRN_SRR1,r10; \ + rfid; \ + b . /* prevent speculative execution */ + #define EXCEPTION_PROLOG_PSERIES(area, label) \ mfspr r13,SPRN_SPRG3; /* get paca address into r13 */ \ std r9,area+EX_R9(r13); /* save r9 - r12 */ \ @@ -604,14 +635,14 @@ slb_miss_user_pseries: system_reset_fwnmi: HMT_MEDIUM mtspr SPRN_SPRG1,r13 /* save r13 */ - EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common) + EXCEPTION_PROLOG_PSERIES_FORCE_64BIT(PACA_EXGEN, system_reset_common) .globl machine_check_fwnmi .align 7 machine_check_fwnmi: HMT_MEDIUM mtspr SPRN_SPRG1,r13 /* save r13 */ - EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common) + EXCEPTION_PROLOG_PSERIES_FORCE_64BIT(PACA_EXMC, machine_check_common) #ifdef CONFIG_PPC_ISERIES /*** ISeries-LPAR interrupt handlers ***/ |