diff options
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 159 |
1 files changed, 91 insertions, 68 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 3d0dc133a9ae..5381a43e50fe 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -281,7 +281,7 @@ BEGIN_FTR_SECTION mfspr r9,SPRN_PPR END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) HMT_MEDIUM - std r10,IAREA+EX_R10(r13) /* save r10 - r12 */ + std r10,IAREA+EX_R10(r13) /* save r10 */ .if ICFAR BEGIN_FTR_SECTION mfspr r10,SPRN_CFAR @@ -321,7 +321,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) mfctr r10 std r10,IAREA+EX_CTR(r13) mfcr r9 - std r11,IAREA+EX_R11(r13) + std r11,IAREA+EX_R11(r13) /* save r11 - r12 */ std r12,IAREA+EX_R12(r13) /* @@ -580,7 +580,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) std r2,GPR2(r1) /* save r2 in stackframe */ SAVE_GPRS(3, 8, r1) /* save r3 - r8 in stackframe */ mflr r9 /* Get LR, later save to stack */ - ld r2,PACATOC(r13) /* get kernel TOC into r2 */ + LOAD_PACA_TOC() /* get kernel TOC into r2 */ std r9,_LINK(r1) lbz r10,PACAIRQSOFTMASK(r13) mfspr r11,SPRN_XER /* save XER in stackframe */ @@ -589,7 +589,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) li r9,IVEC std r9,_TRAP(r1) /* set trap number */ li r10,0 - ld r11,exception_marker@toc(r2) + LOAD_REG_IMMEDIATE(r11, STACK_FRAME_REGS_MARKER) std r10,RESULT(r1) /* clear regs->result */ std r11,STACK_FRAME_OVERHEAD-16(r1) /* mark the frame */ .endm @@ -610,7 +610,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) .macro SEARCH_RESTART_TABLE #ifdef CONFIG_RELOCATABLE mr r12,r2 - ld r2,PACATOC(r13) + LOAD_PACA_TOC() LOAD_REG_ADDR(r9, __start___restart_table) LOAD_REG_ADDR(r10, __stop___restart_table) mr r2,r12 @@ -640,7 +640,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) .macro SEARCH_SOFT_MASK_TABLE #ifdef CONFIG_RELOCATABLE mr r12,r2 - ld r2,PACATOC(r13) + LOAD_PACA_TOC() LOAD_REG_ADDR(r9, __start___soft_mask_table) LOAD_REG_ADDR(r10, __stop___soft_mask_table) mr r2,r12 @@ -703,6 +703,71 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) .endm /* + * EARLY_BOOT_FIXUP - Fix real-mode interrupt with wrong endian in early boot. + * + * There's a short window during boot where although the kernel is running + * little endian, any exceptions will cause the CPU to switch back to big + * endian. For example a WARN() boils down to a trap instruction, which will + * cause a program check, and we end up here but with the CPU in big endian + * mode. The first instruction of the program check handler (in GEN_INT_ENTRY + * below) is an mtsprg, which when executed in the wrong endian is an lhzu with + * a ~3GB displacement from r3. The content of r3 is random, so that is a load + * from some random location, and depending on the system can easily lead to a + * checkstop, or an infinitely recursive page fault. + * + * So to handle that case we have a trampoline here that can detect we are in + * the wrong endian and flip us back to the correct endian. We can't flip + * MSR[LE] using mtmsr, so we have to use rfid. That requires backing up SRR0/1 + * as well as a GPR. To do that we use SPRG0/2/3, as SPRG1 is already used for + * the paca. SPRG3 is user readable, but this trampoline is only active very + * early in boot, and SPRG3 will be reinitialised in vdso_getcpu_init() before + * userspace starts. + */ +.macro EARLY_BOOT_FIXUP +BEGIN_FTR_SECTION +#ifdef CONFIG_CPU_LITTLE_ENDIAN + tdi 0,0,0x48 // Trap never, or in reverse endian: b . + 8 + b 2f // Skip trampoline if endian is correct + .long 0xa643707d // mtsprg 0, r11 Backup r11 + .long 0xa6027a7d // mfsrr0 r11 + .long 0xa643727d // mtsprg 2, r11 Backup SRR0 in SPRG2 + .long 0xa6027b7d // mfsrr1 r11 + .long 0xa643737d // mtsprg 3, r11 Backup SRR1 in SPRG3 + .long 0xa600607d // mfmsr r11 + .long 0x01006b69 // xori r11, r11, 1 Invert MSR[LE] + .long 0xa6037b7d // mtsrr1 r11 + /* + * This is 'li r11,1f' where 1f is the absolute address of that + * label, byteswapped into the SI field of the instruction. + */ + .long 0x00006039 | \ + ((ABS_ADDR(1f, real_vectors) & 0x00ff) << 24) | \ + ((ABS_ADDR(1f, real_vectors) & 0xff00) << 8) + .long 0xa6037a7d // mtsrr0 r11 + .long 0x2400004c // rfid +1: + mfsprg r11, 3 + mtsrr1 r11 // Restore SRR1 + mfsprg r11, 2 + mtsrr0 r11 // Restore SRR0 + mfsprg r11, 0 // Restore r11 +2: +#endif + /* + * program check could hit at any time, and pseries can not block + * MSR[ME] in early boot. So check if there is anything useful in r13 + * yet, and spin forever if not. + */ + mtsprg 0, r11 + mfcr r11 + cmpdi r13, 0 + beq . + mtcr r11 + mfsprg r11, 0 +END_FTR_SECTION(0, 1) // nop out after boot +.endm + +/* * There are a few constraints to be concerned with. * - Real mode exceptions code/data must be located at their physical location. * - Virtual mode exceptions must be mapped at their 0xc000... location. @@ -1079,6 +1144,7 @@ INT_DEFINE_BEGIN(machine_check) INT_DEFINE_END(machine_check) EXC_REAL_BEGIN(machine_check, 0x200, 0x100) + EARLY_BOOT_FIXUP GEN_INT_ENTRY machine_check_early, virt=0 EXC_REAL_END(machine_check, 0x200, 0x100) EXC_VIRT_NONE(0x4200, 0x100) @@ -1143,6 +1209,9 @@ BEGIN_FTR_SECTION bl enable_machine_check END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) addi r3,r1,STACK_FRAME_OVERHEAD +BEGIN_FTR_SECTION + bl machine_check_early_boot +END_FTR_SECTION(0, 1) // nop out after boot bl machine_check_early std r3,RESULT(r1) /* Save result */ ld r12,_MSR(r1) @@ -1619,51 +1688,7 @@ INT_DEFINE_BEGIN(program_check) INT_DEFINE_END(program_check) EXC_REAL_BEGIN(program_check, 0x700, 0x100) - -#ifdef CONFIG_CPU_LITTLE_ENDIAN - /* - * There's a short window during boot where although the kernel is - * running little endian, any exceptions will cause the CPU to switch - * back to big endian. For example a WARN() boils down to a trap - * instruction, which will cause a program check, and we end up here but - * with the CPU in big endian mode. The first instruction of the program - * check handler (in GEN_INT_ENTRY below) is an mtsprg, which when - * executed in the wrong endian is an lhzu with a ~3GB displacement from - * r3. The content of r3 is random, so that is a load from some random - * location, and depending on the system can easily lead to a checkstop, - * or an infinitely recursive page fault. - * - * So to handle that case we have a trampoline here that can detect we - * are in the wrong endian and flip us back to the correct endian. We - * can't flip MSR[LE] using mtmsr, so we have to use rfid. That requires - * backing up SRR0/1 as well as a GPR. To do that we use SPRG0/2/3, as - * SPRG1 is already used for the paca. SPRG3 is user readable, but this - * trampoline is only active very early in boot, and SPRG3 will be - * reinitialised in vdso_getcpu_init() before userspace starts. - */ -BEGIN_FTR_SECTION - tdi 0,0,0x48 // Trap never, or in reverse endian: b . + 8 - b 1f // Skip trampoline if endian is correct - .long 0xa643707d // mtsprg 0, r11 Backup r11 - .long 0xa6027a7d // mfsrr0 r11 - .long 0xa643727d // mtsprg 2, r11 Backup SRR0 in SPRG2 - .long 0xa6027b7d // mfsrr1 r11 - .long 0xa643737d // mtsprg 3, r11 Backup SRR1 in SPRG3 - .long 0xa600607d // mfmsr r11 - .long 0x01006b69 // xori r11, r11, 1 Invert MSR[LE] - .long 0xa6037b7d // mtsrr1 r11 - .long 0x34076039 // li r11, 0x734 - .long 0xa6037a7d // mtsrr0 r11 - .long 0x2400004c // rfid - mfsprg r11, 3 - mtsrr1 r11 // Restore SRR1 - mfsprg r11, 2 - mtsrr0 r11 // Restore SRR0 - mfsprg r11, 0 // Restore r11 -1: -END_FTR_SECTION(0, 1) // nop out after boot -#endif /* CONFIG_CPU_LITTLE_ENDIAN */ - + EARLY_BOOT_FIXUP GEN_INT_ENTRY program_check, virt=0 EXC_REAL_END(program_check, 0x700, 0x100) EXC_VIRT_BEGIN(program_check, 0x4700, 0x100) @@ -2794,6 +2819,20 @@ masked_Hinterrupt: masked_interrupt: .endif stw r9,PACA_EXGEN+EX_CCR(r13) +#ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG + /* + * Ensure there was no previous MUST_HARD_MASK interrupt or + * HARD_DIS setting. If this does fire, the interrupt is still + * masked and MSR[EE] will be cleared on return, so no need to + * panic, but somebody probably enabled MSR[EE] under + * PACA_IRQ_HARD_DIS, mtmsr(mfmsr() | MSR_x) being a common + * cause. + */ + lbz r9,PACAIRQHAPPENED(r13) + andi. r9,r9,(PACA_IRQ_MUST_HARD_MASK|PACA_IRQ_HARD_DIS) +0: tdnei r9,0 + EMIT_WARN_ENTRY 0b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE) +#endif lbz r9,PACAIRQHAPPENED(r13) or r9,r9,r10 stb r9,PACAIRQHAPPENED(r13) @@ -3034,22 +3073,6 @@ EXPORT_SYMBOL(do_uaccess_flush) MASKED_INTERRUPT MASKED_INTERRUPT hsrr=1 - /* - * Relocation-on interrupts: A subset of the interrupts can be delivered - * with IR=1/DR=1, if AIL==2 and MSR.HV won't be changed by delivering - * it. Addresses are the same as the original interrupt addresses, but - * offset by 0xc000000000004000. - * It's impossible to receive interrupts below 0x300 via this mechanism. - * KVM: None of these traps are from the guest ; anything that escalated - * to HV=1 from HV=0 is delivered via real mode handlers. - */ - - /* - * This uses the standard macro, since the original 0x300 vector - * only has extra guff for STAB-based processors -- which never - * come here. - */ - USE_FIXED_SECTION(virt_trampolines) /* * All code below __end_soft_masked is treated as soft-masked. If @@ -3075,7 +3098,7 @@ CLOSE_FIXED_SECTION(virt_trampolines); USE_TEXT_SECTION() /* MSR[RI] should be clear because this uses SRR[01] */ -enable_machine_check: +_GLOBAL(enable_machine_check) mflr r0 bcl 20,31,$+4 0: mflr r3 |