12874c5fdSThomas Gleixner /* SPDX-License-Identifier: GPL-2.0-or-later */ 213363ab9SBenjamin Herrenschmidt /* 313363ab9SBenjamin Herrenschmidt * Definitions for use by exception code on Book3-E 413363ab9SBenjamin Herrenschmidt * 513363ab9SBenjamin Herrenschmidt * Copyright (C) 2008 Ben. Herrenschmidt (benh@kernel.crashing.org), IBM Corp. 613363ab9SBenjamin Herrenschmidt */ 713363ab9SBenjamin Herrenschmidt #ifndef _ASM_POWERPC_EXCEPTION_64E_H 813363ab9SBenjamin Herrenschmidt #define _ASM_POWERPC_EXCEPTION_64E_H 913363ab9SBenjamin Herrenschmidt 1013363ab9SBenjamin Herrenschmidt /* 1113363ab9SBenjamin Herrenschmidt * SPRGs usage an other considerations... 1213363ab9SBenjamin Herrenschmidt * 1313363ab9SBenjamin Herrenschmidt * Since TLB miss and other standard exceptions can be interrupted by 1413363ab9SBenjamin Herrenschmidt * critical exceptions which can themselves be interrupted by machine 1513363ab9SBenjamin Herrenschmidt * checks, and since the two later can themselves cause a TLB miss when 1613363ab9SBenjamin Herrenschmidt * hitting the linear mapping for the kernel stacks, we need to be a bit 1713363ab9SBenjamin Herrenschmidt * creative on how we use SPRGs. 1813363ab9SBenjamin Herrenschmidt * 1913363ab9SBenjamin Herrenschmidt * The base idea is that we have one SRPG reserved for critical and one 2013363ab9SBenjamin Herrenschmidt * for machine check interrupts. Those are used to save a GPR that can 2113363ab9SBenjamin Herrenschmidt * then be used to get the PACA, and store as much context as we need 2213363ab9SBenjamin Herrenschmidt * to save in there. That includes saving the SPRGs used by the TLB miss 2313363ab9SBenjamin Herrenschmidt * handler for linear mapping misses and the associated SRR0/1 due to 2413363ab9SBenjamin Herrenschmidt * the above re-entrancy issue. 2513363ab9SBenjamin Herrenschmidt * 2613363ab9SBenjamin Herrenschmidt * So here's the current usage pattern. It's done regardless of which 2713363ab9SBenjamin Herrenschmidt * SPRGs are user-readable though, thus we might have to change some of 2813363ab9SBenjamin Herrenschmidt * this later. In order to do that more easily, we use special constants 2913363ab9SBenjamin Herrenschmidt * for naming them 3013363ab9SBenjamin Herrenschmidt * 3113363ab9SBenjamin Herrenschmidt * WARNING: Some of these SPRGs are user readable. We need to do something 3213363ab9SBenjamin Herrenschmidt * about it as some point by making sure they can't be used to leak kernel 3313363ab9SBenjamin Herrenschmidt * critical data 3413363ab9SBenjamin Herrenschmidt */ 3513363ab9SBenjamin Herrenschmidt 365473eb1cSMihai Caraman #define PACA_EXGDBELL PACA_EXGEN 3713363ab9SBenjamin Herrenschmidt 3813363ab9SBenjamin Herrenschmidt /* We are out of SPRGs so we save some things in the PACA. The normal 3913363ab9SBenjamin Herrenschmidt * exception frame is smaller than the CRIT or MC one though 4013363ab9SBenjamin Herrenschmidt */ 4113363ab9SBenjamin Herrenschmidt #define EX_R1 (0 * 8) 4213363ab9SBenjamin Herrenschmidt #define EX_CR (1 * 8) 4313363ab9SBenjamin Herrenschmidt #define EX_R10 (2 * 8) 4413363ab9SBenjamin Herrenschmidt #define EX_R11 (3 * 8) 459d378dfaSScott Wood #define EX_R14 (4 * 8) 469d378dfaSScott Wood #define EX_R15 (5 * 8) 4713363ab9SBenjamin Herrenschmidt 48f67f4ef5SScott Wood /* 49f67f4ef5SScott Wood * The TLB miss exception uses different slots. 50f67f4ef5SScott Wood * 51f67f4ef5SScott Wood * The bolted variant uses only the first six fields, 52f67f4ef5SScott Wood * which in combination with pgd and kernel_pgd fits in 53f67f4ef5SScott Wood * one 64-byte cache line. 54f67f4ef5SScott Wood */ 5513363ab9SBenjamin Herrenschmidt 5613363ab9SBenjamin Herrenschmidt #define EX_TLB_R10 ( 0 * 8) 5713363ab9SBenjamin Herrenschmidt #define EX_TLB_R11 ( 1 * 8) 58f67f4ef5SScott Wood #define EX_TLB_R14 ( 2 * 8) 59f67f4ef5SScott Wood #define EX_TLB_R15 ( 3 * 8) 60f67f4ef5SScott Wood #define EX_TLB_R16 ( 4 * 8) 61f67f4ef5SScott Wood #define EX_TLB_CR ( 5 * 8) 62f67f4ef5SScott Wood #define EX_TLB_R12 ( 6 * 8) 63f67f4ef5SScott Wood #define EX_TLB_R13 ( 7 * 8) 6413363ab9SBenjamin Herrenschmidt #define EX_TLB_DEAR ( 8 * 8) /* Level 0 and 2 only */ 6513363ab9SBenjamin Herrenschmidt #define EX_TLB_ESR ( 9 * 8) /* Level 0 and 2 only */ 6613363ab9SBenjamin Herrenschmidt #define EX_TLB_SRR0 (10 * 8) 6713363ab9SBenjamin Herrenschmidt #define EX_TLB_SRR1 (11 * 8) 68e1f580e8SKevin Hao #define EX_TLB_R7 (12 * 8) 69e1f580e8SKevin Hao #define EX_TLB_SIZE (13 * 8) 7013363ab9SBenjamin Herrenschmidt 7113363ab9SBenjamin Herrenschmidt #define START_EXCEPTION(label) \ 7213363ab9SBenjamin Herrenschmidt .globl exc_##label##_book3e; \ 7313363ab9SBenjamin Herrenschmidt exc_##label##_book3e: 7413363ab9SBenjamin Herrenschmidt 7513363ab9SBenjamin Herrenschmidt /* TLB miss exception prolog 7613363ab9SBenjamin Herrenschmidt * 7713363ab9SBenjamin Herrenschmidt * This prolog handles re-entrancy (up to 3 levels supported in the PACA 7813363ab9SBenjamin Herrenschmidt * though we currently don't test for overflow). It provides you with a 7913363ab9SBenjamin Herrenschmidt * re-entrancy safe working space of r10...r16 and CR with r12 being used 8013363ab9SBenjamin Herrenschmidt * as the exception area pointer in the PACA for that level of re-entrancy 8113363ab9SBenjamin Herrenschmidt * and r13 containing the PACA pointer. 8213363ab9SBenjamin Herrenschmidt * 8313363ab9SBenjamin Herrenschmidt * SRR0 and SRR1 are saved, but DEAR and ESR are not, since they don't apply 8413363ab9SBenjamin Herrenschmidt * as-is for instruction exceptions. It's up to the actual exception code 8513363ab9SBenjamin Herrenschmidt * to save them as well if required. 8613363ab9SBenjamin Herrenschmidt */ 8713363ab9SBenjamin Herrenschmidt #define TLB_MISS_PROLOG \ 8813363ab9SBenjamin Herrenschmidt mtspr SPRN_SPRG_TLB_SCRATCH,r12; \ 8913363ab9SBenjamin Herrenschmidt mfspr r12,SPRN_SPRG_TLB_EXFRAME; \ 9013363ab9SBenjamin Herrenschmidt std r10,EX_TLB_R10(r12); \ 9113363ab9SBenjamin Herrenschmidt mfcr r10; \ 9213363ab9SBenjamin Herrenschmidt std r11,EX_TLB_R11(r12); \ 9313363ab9SBenjamin Herrenschmidt mfspr r11,SPRN_SPRG_TLB_SCRATCH; \ 9413363ab9SBenjamin Herrenschmidt std r13,EX_TLB_R13(r12); \ 9513363ab9SBenjamin Herrenschmidt mfspr r13,SPRN_SPRG_PACA; \ 9613363ab9SBenjamin Herrenschmidt std r14,EX_TLB_R14(r12); \ 9713363ab9SBenjamin Herrenschmidt addi r14,r12,EX_TLB_SIZE; \ 9813363ab9SBenjamin Herrenschmidt std r15,EX_TLB_R15(r12); \ 9913363ab9SBenjamin Herrenschmidt mfspr r15,SPRN_SRR1; \ 10013363ab9SBenjamin Herrenschmidt std r16,EX_TLB_R16(r12); \ 10113363ab9SBenjamin Herrenschmidt mfspr r16,SPRN_SRR0; \ 10213363ab9SBenjamin Herrenschmidt std r10,EX_TLB_CR(r12); \ 10313363ab9SBenjamin Herrenschmidt std r11,EX_TLB_R12(r12); \ 10413363ab9SBenjamin Herrenschmidt mtspr SPRN_SPRG_TLB_EXFRAME,r14; \ 10513363ab9SBenjamin Herrenschmidt std r15,EX_TLB_SRR1(r12); \ 10607e571eaSMichael Ellerman std r16,EX_TLB_SRR0(r12); 10713363ab9SBenjamin Herrenschmidt 10813363ab9SBenjamin Herrenschmidt /* And these are the matching epilogs that restores things 10913363ab9SBenjamin Herrenschmidt * 11013363ab9SBenjamin Herrenschmidt * There are 3 epilogs: 11113363ab9SBenjamin Herrenschmidt * 11213363ab9SBenjamin Herrenschmidt * - SUCCESS : Unwinds one level 11313363ab9SBenjamin Herrenschmidt * - ERROR : restore from level 0 and reset 11413363ab9SBenjamin Herrenschmidt * - ERROR_SPECIAL : restore from current level and reset 11513363ab9SBenjamin Herrenschmidt * 11613363ab9SBenjamin Herrenschmidt * Normal errors use ERROR, that is, they restore the initial fault context 11713363ab9SBenjamin Herrenschmidt * and trigger a fault. However, there is a special case for linear mapping 11813363ab9SBenjamin Herrenschmidt * errors. Those should basically never happen, but if they do happen, we 11913363ab9SBenjamin Herrenschmidt * want the error to point out the context that did that linear mapping 12013363ab9SBenjamin Herrenschmidt * fault, not the initial level 0 (basically, we got a bogus PGF or something 12113363ab9SBenjamin Herrenschmidt * like that). For userland errors on the linear mapping, there is no 12213363ab9SBenjamin Herrenschmidt * difference since those are always level 0 anyway 12313363ab9SBenjamin Herrenschmidt */ 12413363ab9SBenjamin Herrenschmidt 12513363ab9SBenjamin Herrenschmidt #define TLB_MISS_RESTORE(freg) \ 12613363ab9SBenjamin Herrenschmidt ld r14,EX_TLB_CR(r12); \ 12713363ab9SBenjamin Herrenschmidt ld r10,EX_TLB_R10(r12); \ 12813363ab9SBenjamin Herrenschmidt ld r15,EX_TLB_SRR0(r12); \ 12913363ab9SBenjamin Herrenschmidt ld r16,EX_TLB_SRR1(r12); \ 13013363ab9SBenjamin Herrenschmidt mtspr SPRN_SPRG_TLB_EXFRAME,freg; \ 13113363ab9SBenjamin Herrenschmidt ld r11,EX_TLB_R11(r12); \ 13213363ab9SBenjamin Herrenschmidt mtcr r14; \ 13313363ab9SBenjamin Herrenschmidt ld r13,EX_TLB_R13(r12); \ 13413363ab9SBenjamin Herrenschmidt ld r14,EX_TLB_R14(r12); \ 13513363ab9SBenjamin Herrenschmidt mtspr SPRN_SRR0,r15; \ 13613363ab9SBenjamin Herrenschmidt ld r15,EX_TLB_R15(r12); \ 13713363ab9SBenjamin Herrenschmidt mtspr SPRN_SRR1,r16; \ 13813363ab9SBenjamin Herrenschmidt ld r16,EX_TLB_R16(r12); \ 13913363ab9SBenjamin Herrenschmidt ld r12,EX_TLB_R12(r12); \ 14013363ab9SBenjamin Herrenschmidt 14113363ab9SBenjamin Herrenschmidt #define TLB_MISS_EPILOG_SUCCESS \ 14213363ab9SBenjamin Herrenschmidt TLB_MISS_RESTORE(r12) 14313363ab9SBenjamin Herrenschmidt 14413363ab9SBenjamin Herrenschmidt #define TLB_MISS_EPILOG_ERROR \ 14513363ab9SBenjamin Herrenschmidt addi r12,r13,PACA_EXTLB; \ 14613363ab9SBenjamin Herrenschmidt TLB_MISS_RESTORE(r12) 14713363ab9SBenjamin Herrenschmidt 14813363ab9SBenjamin Herrenschmidt #define TLB_MISS_EPILOG_ERROR_SPECIAL \ 14913363ab9SBenjamin Herrenschmidt addi r11,r13,PACA_EXTLB; \ 15013363ab9SBenjamin Herrenschmidt TLB_MISS_RESTORE(r11) 15113363ab9SBenjamin Herrenschmidt 152*29562a9dSChristophe Leroy #ifndef __ASSEMBLY__ 153*29562a9dSChristophe Leroy extern unsigned int interrupt_base_book3e; 154*29562a9dSChristophe Leroy #endif 155*29562a9dSChristophe Leroy 1564b98d9e7SKumar Gala #define SET_IVOR(vector_number, vector_offset) \ 1571cb6e064STiejun Chen LOAD_REG_ADDR(r3,interrupt_base_book3e);\ 1581cb6e064STiejun Chen ori r3,r3,vector_offset@l; \ 1594b98d9e7SKumar Gala mtspr SPRN_IVOR##vector_number,r3; 1602384b36fSNicholas Piggin /* 1612384b36fSNicholas Piggin * powerpc relies on return from interrupt/syscall being context synchronising 1622384b36fSNicholas Piggin * (which rfi is) to support ARCH_HAS_MEMBARRIER_SYNC_CORE without additional 1632384b36fSNicholas Piggin * synchronisation instructions. 1642384b36fSNicholas Piggin */ 16550e51c13SNicholas Piggin #define RFI_TO_KERNEL \ 16650e51c13SNicholas Piggin rfi 16750e51c13SNicholas Piggin 16850e51c13SNicholas Piggin #define RFI_TO_USER \ 16950e51c13SNicholas Piggin rfi 17050e51c13SNicholas Piggin 17113363ab9SBenjamin Herrenschmidt #endif /* _ASM_POWERPC_EXCEPTION_64E_H */ 17213363ab9SBenjamin Herrenschmidt 173