diff options
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 150 |
1 files changed, 143 insertions, 7 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 446e54c3f71e..f7d748b88705 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -508,8 +508,24 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real) .macro __GEN_COMMON_BODY name .if IMASK + .if ! ISTACK + .error "No support for masked interrupt to use custom stack" + .endif + + /* If coming from user, skip soft-mask tests. */ + andi. r10,r12,MSR_PR + bne 2f + + /* Kernel code running below __end_interrupts is implicitly + * soft-masked */ + LOAD_HANDLER(r10, __end_interrupts) + cmpld r11,r10 + li r10,IMASK + blt- 1f + + /* Test the soft mask state against our interrupt's bit */ lbz r10,PACAIRQSOFTMASK(r13) - andi. r10,r10,IMASK +1: andi. r10,r10,IMASK /* Associate vector numbers with bits in paca->irq_happened */ .if IVEC == 0x500 || IVEC == 0xea0 li r10,PACA_IRQ_EE @@ -540,7 +556,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real) .if ISTACK andi. r10,r12,MSR_PR /* See if coming from user */ - mr r10,r1 /* Save r1 */ +2: mr r10,r1 /* Save r1 */ subi r1,r1,INT_FRAME_SIZE /* alloc frame on kernel stack */ beq- 100f ld r1,PACAKSAVE(r13) /* kernel stack to use */ @@ -740,6 +756,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP) * guarantee they will be delivered virtually. Some conditions (see the ISA) * cause exceptions to be delivered in real mode. * + * The scv instructions are a special case. They get a 0x3000 offset applied. + * scv exceptions have unique reentrancy properties, see below. + * * It's impossible to receive interrupts below 0x300 via AIL. * * KVM: None of the virtual exceptions are from the guest. Anything that @@ -749,8 +768,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP) * We layout physical memory as follows: * 0x0000 - 0x00ff : Secondary processor spin code * 0x0100 - 0x18ff : Real mode pSeries interrupt vectors - * 0x1900 - 0x3fff : Real mode trampolines - * 0x4000 - 0x58ff : Relon (IR=1,DR=1) mode pSeries interrupt vectors + * 0x1900 - 0x2fff : Real mode trampolines + * 0x3000 - 0x58ff : Relon (IR=1,DR=1) mode pSeries interrupt vectors * 0x5900 - 0x6fff : Relon mode trampolines * 0x7000 - 0x7fff : FWNMI data area * 0x8000 - .... : Common interrupt handlers, remaining early @@ -761,8 +780,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP) * vectors there. */ OPEN_FIXED_SECTION(real_vectors, 0x0100, 0x1900) -OPEN_FIXED_SECTION(real_trampolines, 0x1900, 0x4000) -OPEN_FIXED_SECTION(virt_vectors, 0x4000, 0x5900) +OPEN_FIXED_SECTION(real_trampolines, 0x1900, 0x3000) +OPEN_FIXED_SECTION(virt_vectors, 0x3000, 0x5900) OPEN_FIXED_SECTION(virt_trampolines, 0x5900, 0x7000) #ifdef CONFIG_PPC_POWERNV @@ -798,6 +817,77 @@ USE_FIXED_SECTION(real_vectors) .globl __start_interrupts __start_interrupts: +/** + * Interrupt 0x3000 - System Call Vectored Interrupt (syscall). + * This is a synchronous interrupt invoked with the "scv" instruction. The + * system call does not alter the HV bit, so it is directed to the OS. + * + * Handling: + * scv instructions enter the kernel without changing EE, RI, ME, or HV. + * In particular, this means we can take a maskable interrupt at any point + * in the scv handler, which is unlike any other interrupt. This is solved + * by treating the instruction addresses below __end_interrupts as being + * soft-masked. + * + * AIL-0 mode scv exceptions go to 0x17000-0x17fff, but we set AIL-3 and + * ensure scv is never executed with relocation off, which means AIL-0 + * should never happen. + * + * Before leaving the below __end_interrupts text, at least of the following + * must be true: + * - MSR[PR]=1 (i.e., return to userspace) + * - MSR_EE|MSR_RI is set (no reentrant exceptions) + * - Standard kernel environment is set up (stack, paca, etc) + * + * Call convention: + * + * syscall register convention is in Documentation/powerpc/syscall64-abi.rst + */ +EXC_VIRT_BEGIN(system_call_vectored, 0x3000, 0x1000) + /* SCV 0 */ + mr r9,r13 + GET_PACA(r13) + mflr r11 + mfctr r12 + li r10,IRQS_ALL_DISABLED + stb r10,PACAIRQSOFTMASK(r13) +#ifdef CONFIG_RELOCATABLE + b system_call_vectored_tramp +#else + b system_call_vectored_common +#endif + nop + + /* SCV 1 - 127 */ + .rept 127 + mr r9,r13 + GET_PACA(r13) + mflr r11 + mfctr r12 + li r10,IRQS_ALL_DISABLED + stb r10,PACAIRQSOFTMASK(r13) + li r0,-1 /* cause failure */ +#ifdef CONFIG_RELOCATABLE + b system_call_vectored_sigill_tramp +#else + b system_call_vectored_sigill +#endif + .endr +EXC_VIRT_END(system_call_vectored, 0x3000, 0x1000) + +#ifdef CONFIG_RELOCATABLE +TRAMP_VIRT_BEGIN(system_call_vectored_tramp) + __LOAD_HANDLER(r10, system_call_vectored_common) + mtctr r10 + bctr + +TRAMP_VIRT_BEGIN(system_call_vectored_sigill_tramp) + __LOAD_HANDLER(r10, system_call_vectored_sigill) + mtctr r10 + bctr +#endif + + /* No virt vectors corresponding with 0x0..0x100 */ EXC_VIRT_NONE(0x4000, 0x100) @@ -2838,7 +2928,8 @@ masked_interrupt: ld r10,PACA_EXGEN+EX_R10(r13) ld r11,PACA_EXGEN+EX_R11(r13) ld r12,PACA_EXGEN+EX_R12(r13) - /* returns to kernel where r13 must be set up, so don't restore it */ + ld r13,PACA_EXGEN+EX_R13(r13) + /* May return to masked low address where r13 is not set up */ .if \hsrr HRFI_TO_KERNEL .else @@ -2946,6 +3037,47 @@ TRAMP_REAL_BEGIN(hrfi_flush_fallback) GET_SCRATCH0(r13); hrfid +TRAMP_REAL_BEGIN(rfscv_flush_fallback) + /* system call volatile */ + mr r7,r13 + GET_PACA(r13); + mr r8,r1 + ld r1,PACAKSAVE(r13) + mfctr r9 + ld r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13) + ld r11,PACA_L1D_FLUSH_SIZE(r13) + srdi r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */ + mtctr r11 + DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */ + + /* order ld/st prior to dcbt stop all streams with flushing */ + sync + + /* + * The load adresses are at staggered offsets within cachelines, + * which suits some pipelines better (on others it should not + * hurt). + */ +1: + ld r11,(0x80 + 8)*0(r10) + ld r11,(0x80 + 8)*1(r10) + ld r11,(0x80 + 8)*2(r10) + ld r11,(0x80 + 8)*3(r10) + ld r11,(0x80 + 8)*4(r10) + ld r11,(0x80 + 8)*5(r10) + ld r11,(0x80 + 8)*6(r10) + ld r11,(0x80 + 8)*7(r10) + addi r10,r10,0x80*8 + bdnz 1b + + mtctr r9 + li r9,0 + li r10,0 + li r11,0 + mr r1,r8 + mr r13,r7 + RFSCV + USE_TEXT_SECTION() MASKED_INTERRUPT MASKED_INTERRUPT hsrr=1 @@ -2997,6 +3129,10 @@ EXC_COMMON_BEGIN(ppc64_runlatch_on_trampoline) USE_FIXED_SECTION(virt_trampolines) /* + * All code below __end_interrupts is treated as soft-masked. If + * any code runs here with MSR[EE]=1, it must then cope with pending + * soft interrupt being raised (i.e., by ensuring it is replayed). + * * The __end_interrupts marker must be past the out-of-line (OOL) * handlers, so that they are copied to real address 0x100 when running * a relocatable kernel. This ensures they can be reached from the short |