From 8aa34ab8b2dc96ca6c4feecfb87ed13f0d40ef98 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 14 Jul 2009 20:52:52 +0000 Subject: powerpc: Rename exception.h to exception-64s.h The file include/asm/exception.h contains definitions that are specific to exception handling on 64-bit server type processors. This renames the file to exception-64s.h to reflect that fact and avoid confusion. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/exception-64s.h | 279 +++++++++++++++++++++++++++++++ 1 file changed, 279 insertions(+) create mode 100644 arch/powerpc/include/asm/exception-64s.h (limited to 'arch/powerpc/include/asm/exception-64s.h') diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h new file mode 100644 index 00000000000..d3d4534e3c7 --- /dev/null +++ b/arch/powerpc/include/asm/exception-64s.h @@ -0,0 +1,279 @@ +#ifndef _ASM_POWERPC_EXCEPTION_H +#define _ASM_POWERPC_EXCEPTION_H +/* + * Extracted from head_64.S + * + * PowerPC version + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP + * Copyright (C) 1996 Cort Dougan + * Adapted for Power Macintosh by Paul Mackerras. + * Low-level exception handlers and MMU support + * rewritten by Paul Mackerras. + * Copyright (C) 1996 Paul Mackerras. + * + * Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and + * Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com + * + * This file contains the low-level support and setup for the + * PowerPC-64 platform, including trap and interrupt dispatch. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +/* + * The following macros define the code that appears as + * the prologue to each of the exception handlers. They + * are split into two parts to allow a single kernel binary + * to be used for pSeries and iSeries. + * + * We make as much of the exception code common between native + * exception handlers (including pSeries LPAR) and iSeries LPAR + * implementations as possible. + */ + +#define EX_R9 0 +#define EX_R10 8 +#define EX_R11 16 +#define EX_R12 24 +#define EX_R13 32 +#define EX_SRR0 40 +#define EX_DAR 48 +#define EX_DSISR 56 +#define EX_CCR 60 +#define EX_R3 64 +#define EX_LR 72 + +/* + * We're short on space and time in the exception prolog, so we can't + * use the normal SET_REG_IMMEDIATE macro. Normally we just need the + * low halfword of the address, but for Kdump we need the whole low + * word. + */ +#define LOAD_HANDLER(reg, label) \ + addi reg,reg,(label)-_stext; /* virt addr of handler ... */ + +#define EXCEPTION_PROLOG_1(area) \ + 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 + +#define EXCEPTION_PROLOG_PSERIES(area, label) \ + EXCEPTION_PROLOG_1(area); \ + ld r12,PACAKBASE(r13); /* get high part of &label */ \ + ld r10,PACAKMSR(r13); /* get MSR value for kernel */ \ + mfspr r11,SPRN_SRR0; /* save SRR0 */ \ + LOAD_HANDLER(r12,label) \ + mtspr SPRN_SRR0,r12; \ + mfspr r12,SPRN_SRR1; /* and SRR1 */ \ + mtspr SPRN_SRR1,r10; \ + rfid; \ + b . /* prevent speculative execution */ + +/* + * The common exception prolog is used for all except a few exceptions + * such as a segment miss on a kernel address. We have to be prepared + * to take another exception from the point where we first touch the + * kernel stack onwards. + * + * On entry r13 points to the paca, r9-r13 are saved in the paca, + * r9 contains the saved CR, r11 and r12 contain the saved SRR0 and + * SRR1, and relocation is on. + */ +#define EXCEPTION_PROLOG_COMMON(n, area) \ + andi. r10,r12,MSR_PR; /* See if coming from user */ \ + mr r10,r1; /* Save r1 */ \ + subi r1,r1,INT_FRAME_SIZE; /* alloc frame on kernel stack */ \ + beq- 1f; \ + ld r1,PACAKSAVE(r13); /* kernel stack to use */ \ +1: cmpdi cr1,r1,0; /* check if r1 is in userspace */ \ + bge- cr1,2f; /* abort if it is */ \ + b 3f; \ +2: li r1,(n); /* will be reloaded later */ \ + sth r1,PACA_TRAP_SAVE(r13); \ + b bad_stack; \ +3: std r9,_CCR(r1); /* save CR in stackframe */ \ + std r11,_NIP(r1); /* save SRR0 in stackframe */ \ + std r12,_MSR(r1); /* save SRR1 in stackframe */ \ + std r10,0(r1); /* make stack chain pointer */ \ + std r0,GPR0(r1); /* save r0 in stackframe */ \ + std r10,GPR1(r1); /* save r1 in stackframe */ \ + ACCOUNT_CPU_USER_ENTRY(r9, r10); \ + std r2,GPR2(r1); /* save r2 in stackframe */ \ + SAVE_4GPRS(3, r1); /* save r3 - r6 in stackframe */ \ + SAVE_2GPRS(7, r1); /* save r7, r8 in stackframe */ \ + ld r9,area+EX_R9(r13); /* move r9, r10 to stackframe */ \ + ld r10,area+EX_R10(r13); \ + std r9,GPR9(r1); \ + std r10,GPR10(r1); \ + ld r9,area+EX_R11(r13); /* move r11 - r13 to stackframe */ \ + ld r10,area+EX_R12(r13); \ + ld r11,area+EX_R13(r13); \ + std r9,GPR11(r1); \ + std r10,GPR12(r1); \ + std r11,GPR13(r1); \ + ld r2,PACATOC(r13); /* get kernel TOC into r2 */ \ + mflr r9; /* save LR in stackframe */ \ + std r9,_LINK(r1); \ + mfctr r10; /* save CTR in stackframe */ \ + std r10,_CTR(r1); \ + lbz r10,PACASOFTIRQEN(r13); \ + mfspr r11,SPRN_XER; /* save XER in stackframe */ \ + std r10,SOFTE(r1); \ + std r11,_XER(r1); \ + li r9,(n)+1; \ + std r9,_TRAP(r1); /* set trap number */ \ + li r10,0; \ + ld r11,exception_marker@toc(r2); \ + std r10,RESULT(r1); /* clear regs->result */ \ + std r11,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame */ + +/* + * Exception vectors. + */ +#define STD_EXCEPTION_PSERIES(n, label) \ + . = n; \ + .globl label##_pSeries; \ +label##_pSeries: \ + HMT_MEDIUM; \ + mtspr SPRN_SPRG1,r13; /* save r13 */ \ + EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common) + +#define HSTD_EXCEPTION_PSERIES(n, label) \ + . = n; \ + .globl label##_pSeries; \ +label##_pSeries: \ + HMT_MEDIUM; \ + mtspr SPRN_SPRG1,r20; /* save r20 */ \ + mfspr r20,SPRN_HSRR0; /* copy HSRR0 to SRR0 */ \ + mtspr SPRN_SRR0,r20; \ + mfspr r20,SPRN_HSRR1; /* copy HSRR0 to SRR0 */ \ + mtspr SPRN_SRR1,r20; \ + mfspr r20,SPRN_SPRG1; /* restore r20 */ \ + mtspr SPRN_SPRG1,r13; /* save r13 */ \ + EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common) + + +#define MASKABLE_EXCEPTION_PSERIES(n, label) \ + . = n; \ + .globl label##_pSeries; \ +label##_pSeries: \ + HMT_MEDIUM; \ + mtspr SPRN_SPRG1,r13; /* save r13 */ \ + mfspr r13,SPRN_SPRG3; /* get paca address into r13 */ \ + std r9,PACA_EXGEN+EX_R9(r13); /* save r9, r10 */ \ + std r10,PACA_EXGEN+EX_R10(r13); \ + lbz r10,PACASOFTIRQEN(r13); \ + mfcr r9; \ + cmpwi r10,0; \ + beq masked_interrupt; \ + mfspr r10,SPRN_SPRG1; \ + std r10,PACA_EXGEN+EX_R13(r13); \ + std r11,PACA_EXGEN+EX_R11(r13); \ + std r12,PACA_EXGEN+EX_R12(r13); \ + ld r12,PACAKBASE(r13); /* get high part of &label */ \ + ld r10,PACAKMSR(r13); /* get MSR value for kernel */ \ + mfspr r11,SPRN_SRR0; /* save SRR0 */ \ + LOAD_HANDLER(r12,label##_common) \ + mtspr SPRN_SRR0,r12; \ + mfspr r12,SPRN_SRR1; /* and SRR1 */ \ + mtspr SPRN_SRR1,r10; \ + rfid; \ + b . /* prevent speculative execution */ + +#ifdef CONFIG_PPC_ISERIES +#define DISABLE_INTS \ + li r11,0; \ + stb r11,PACASOFTIRQEN(r13); \ +BEGIN_FW_FTR_SECTION; \ + stb r11,PACAHARDIRQEN(r13); \ +END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES); \ + TRACE_DISABLE_INTS; \ +BEGIN_FW_FTR_SECTION; \ + mfmsr r10; \ + ori r10,r10,MSR_EE; \ + mtmsrd r10,1; \ +END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES) +#else +#define DISABLE_INTS \ + li r11,0; \ + stb r11,PACASOFTIRQEN(r13); \ + stb r11,PACAHARDIRQEN(r13); \ + TRACE_DISABLE_INTS +#endif /* CONFIG_PPC_ISERIES */ + +#define ENABLE_INTS \ + ld r12,_MSR(r1); \ + mfmsr r11; \ + rlwimi r11,r12,0,MSR_EE; \ + mtmsrd r11,1 + +#define STD_EXCEPTION_COMMON(trap, label, hdlr) \ + .align 7; \ + .globl label##_common; \ +label##_common: \ + EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \ + DISABLE_INTS; \ + bl .save_nvgprs; \ + addi r3,r1,STACK_FRAME_OVERHEAD; \ + bl hdlr; \ + b .ret_from_except + +/* + * Like STD_EXCEPTION_COMMON, but for exceptions that can occur + * in the idle task and therefore need the special idle handling. + */ +#define STD_EXCEPTION_COMMON_IDLE(trap, label, hdlr) \ + .align 7; \ + .globl label##_common; \ +label##_common: \ + EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \ + FINISH_NAP; \ + DISABLE_INTS; \ + bl .save_nvgprs; \ + addi r3,r1,STACK_FRAME_OVERHEAD; \ + bl hdlr; \ + b .ret_from_except + +#define STD_EXCEPTION_COMMON_LITE(trap, label, hdlr) \ + .align 7; \ + .globl label##_common; \ +label##_common: \ + EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \ + FINISH_NAP; \ + DISABLE_INTS; \ +BEGIN_FTR_SECTION \ + bl .ppc64_runlatch_on; \ +END_FTR_SECTION_IFSET(CPU_FTR_CTRL) \ + addi r3,r1,STACK_FRAME_OVERHEAD; \ + bl hdlr; \ + b .ret_from_except_lite + +/* + * When the idle code in power4_idle puts the CPU into NAP mode, + * it has to do so in a loop, and relies on the external interrupt + * and decrementer interrupt entry code to get it out of the loop. + * It sets the _TLF_NAPPING bit in current_thread_info()->local_flags + * to signal that it is in the loop and needs help to get out. + */ +#ifdef CONFIG_PPC_970_NAP +#define FINISH_NAP \ +BEGIN_FTR_SECTION \ + clrrdi r11,r1,THREAD_SHIFT; \ + ld r9,TI_LOCAL_FLAGS(r11); \ + andi. r10,r9,_TLF_NAPPING; \ + bnel power4_fixup_nap; \ +END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP) +#else +#define FINISH_NAP +#endif + +#endif /* _ASM_POWERPC_EXCEPTION_H */ -- cgit v1.2.3 From ee43eb788b3a06425fffb912677e2e1c8b00dd3b Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 14 Jul 2009 20:52:54 +0000 Subject: powerpc: Use names rather than numbers for SPRGs (v2) The kernel uses SPRG registers for various purposes, typically in low level assembly code as scratch registers or to hold per-cpu global infos such as the PACA or the current thread_info pointer. We want to be able to easily shuffle the usage of those registers as some implementations have specific constraints realted to some of them, for example, some have userspace readable aliases, etc.. and the current choice isn't always the best. This patch should not change any code generation, and replaces the usage of SPRN_SPRGn everywhere in the kernel with a named replacement and adds documentation next to the definition of the names as to what those are used for on each processor family. The only parts that still use the original numbers are bits of KVM or suspend/resume code that just blindly needs to save/restore all the SPRGs. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/exception-64s.h | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'arch/powerpc/include/asm/exception-64s.h') diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index d3d4534e3c7..773e380b5fe 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -57,12 +57,12 @@ addi reg,reg,(label)-_stext; /* virt addr of handler ... */ #define EXCEPTION_PROLOG_1(area) \ - mfspr r13,SPRN_SPRG3; /* get paca address into r13 */ \ + mfspr r13,SPRN_SPRG_PACA; /* 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; \ + mfspr r9,SPRN_SPRG_SCRATCH0; \ std r9,area+EX_R13(r13); \ mfcr r9 @@ -144,7 +144,7 @@ .globl label##_pSeries; \ label##_pSeries: \ HMT_MEDIUM; \ - mtspr SPRN_SPRG1,r13; /* save r13 */ \ + mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \ EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common) #define HSTD_EXCEPTION_PSERIES(n, label) \ @@ -152,13 +152,13 @@ label##_pSeries: \ .globl label##_pSeries; \ label##_pSeries: \ HMT_MEDIUM; \ - mtspr SPRN_SPRG1,r20; /* save r20 */ \ + mtspr SPRN_SPRG_SCRATCH0,r20; /* save r20 */ \ mfspr r20,SPRN_HSRR0; /* copy HSRR0 to SRR0 */ \ mtspr SPRN_SRR0,r20; \ mfspr r20,SPRN_HSRR1; /* copy HSRR0 to SRR0 */ \ mtspr SPRN_SRR1,r20; \ - mfspr r20,SPRN_SPRG1; /* restore r20 */ \ - mtspr SPRN_SPRG1,r13; /* save r13 */ \ + mfspr r20,SPRN_SPRG_SCRATCH0; /* restore r20 */ \ + mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \ EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common) @@ -167,15 +167,15 @@ label##_pSeries: \ .globl label##_pSeries; \ label##_pSeries: \ HMT_MEDIUM; \ - mtspr SPRN_SPRG1,r13; /* save r13 */ \ - mfspr r13,SPRN_SPRG3; /* get paca address into r13 */ \ + mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \ + mfspr r13,SPRN_SPRG_PACA; /* get paca address into r13 */ \ std r9,PACA_EXGEN+EX_R9(r13); /* save r9, r10 */ \ std r10,PACA_EXGEN+EX_R10(r13); \ lbz r10,PACASOFTIRQEN(r13); \ mfcr r9; \ cmpwi r10,0; \ beq masked_interrupt; \ - mfspr r10,SPRN_SPRG1; \ + mfspr r10,SPRN_SPRG_SCRATCH0; \ std r10,PACA_EXGEN+EX_R13(r13); \ std r11,PACA_EXGEN+EX_R11(r13); \ std r12,PACA_EXGEN+EX_R12(r13); \ -- cgit v1.2.3 From c5a8c0c99f67ae8a784faafbaaea1529825796e2 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Thu, 16 Jul 2009 19:36:57 +0000 Subject: powerpc: Remove use of a second scratch SPRG in STAB code The STAB code used on Power3 and RS/64 uses a second scratch SPRG to save a GPR in order to decide whether to go to do_stab_bolted_* or to handle a normal data access exception. This prevents our scheme of freeing SPRG3 which is user visible for user uses since we cannot use SPRG0 which, on RS/64, seems to be read-only for supervisor mode (like POWER4). This reworks the STAB exception entry to use the PACA as temporary storage instead. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/exception-64s.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/include/asm/exception-64s.h') diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index 773e380b5fe..a98653b2623 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -66,8 +66,7 @@ std r9,area+EX_R13(r13); \ mfcr r9 -#define EXCEPTION_PROLOG_PSERIES(area, label) \ - EXCEPTION_PROLOG_1(area); \ +#define EXCEPTION_PROLOG_PSERIES_1(label) \ ld r12,PACAKBASE(r13); /* get high part of &label */ \ ld r10,PACAKMSR(r13); /* get MSR value for kernel */ \ mfspr r11,SPRN_SRR0; /* save SRR0 */ \ @@ -78,6 +77,10 @@ rfid; \ b . /* prevent speculative execution */ +#define EXCEPTION_PROLOG_PSERIES(area, label) \ + EXCEPTION_PROLOG_1(area); \ + EXCEPTION_PROLOG_PSERIES_1(label); + /* * The common exception prolog is used for all except a few exceptions * such as a segment miss on a kernel address. We have to be prepared -- cgit v1.2.3