diff options
Diffstat (limited to 'arch/powerpc/kernel/tm.S')
| -rw-r--r-- | arch/powerpc/kernel/tm.S | 554 |
1 files changed, 554 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/tm.S b/arch/powerpc/kernel/tm.S new file mode 100644 index 0000000000..a9cd650716 --- /dev/null +++ b/arch/powerpc/kernel/tm.S @@ -0,0 +1,554 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Transactional memory support routines to reclaim and recheckpoint + * transactional process state. + * + * Copyright 2012 Matt Evans & Michael Neuling, IBM Corporation. + */ + +#include <linux/export.h> +#include <asm/asm-offsets.h> +#include <asm/ppc_asm.h> +#include <asm/ppc-opcode.h> +#include <asm/ptrace.h> +#include <asm/reg.h> +#include <asm/bug.h> +#include <asm/feature-fixups.h> + +#ifdef CONFIG_VSX +/* See fpu.S, this is borrowed from there */ +#define __SAVE_32FPRS_VSRS(n,c,base) \ +BEGIN_FTR_SECTION \ + b 2f; \ +END_FTR_SECTION_IFSET(CPU_FTR_VSX); \ + SAVE_32FPRS(n,base); \ + b 3f; \ +2: SAVE_32VSRS(n,c,base); \ +3: +#define __REST_32FPRS_VSRS(n,c,base) \ +BEGIN_FTR_SECTION \ + b 2f; \ +END_FTR_SECTION_IFSET(CPU_FTR_VSX); \ + REST_32FPRS(n,base); \ + b 3f; \ +2: REST_32VSRS(n,c,base); \ +3: +#else +#define __SAVE_32FPRS_VSRS(n,c,base) SAVE_32FPRS(n, base) +#define __REST_32FPRS_VSRS(n,c,base) REST_32FPRS(n, base) +#endif +#define SAVE_32FPRS_VSRS(n,c,base) \ + __SAVE_32FPRS_VSRS(n,__REG_##c,__REG_##base) +#define REST_32FPRS_VSRS(n,c,base) \ + __REST_32FPRS_VSRS(n,__REG_##c,__REG_##base) + +/* Stack frame offsets for local variables. */ +#define TM_FRAME_L0 TM_FRAME_SIZE-16 +#define TM_FRAME_L1 TM_FRAME_SIZE-8 + + +/* In order to access the TM SPRs, TM must be enabled. So, do so: */ +_GLOBAL(tm_enable) + mfmsr r4 + li r3, MSR_TM >> 32 + sldi r3, r3, 32 + and. r0, r4, r3 + bne 1f + or r4, r4, r3 + mtmsrd r4 +1: blr +EXPORT_SYMBOL_GPL(tm_enable); + +_GLOBAL(tm_disable) + mfmsr r4 + li r3, MSR_TM >> 32 + sldi r3, r3, 32 + andc r4, r4, r3 + mtmsrd r4 + blr +EXPORT_SYMBOL_GPL(tm_disable); + +_GLOBAL(tm_save_sprs) + mfspr r0, SPRN_TFHAR + std r0, THREAD_TM_TFHAR(r3) + mfspr r0, SPRN_TEXASR + std r0, THREAD_TM_TEXASR(r3) + mfspr r0, SPRN_TFIAR + std r0, THREAD_TM_TFIAR(r3) + blr + +_GLOBAL(tm_restore_sprs) + ld r0, THREAD_TM_TFHAR(r3) + mtspr SPRN_TFHAR, r0 + ld r0, THREAD_TM_TEXASR(r3) + mtspr SPRN_TEXASR, r0 + ld r0, THREAD_TM_TFIAR(r3) + mtspr SPRN_TFIAR, r0 + blr + + /* Passed an 8-bit failure cause as first argument. */ +_GLOBAL(tm_abort) + TABORT(R3) + blr +EXPORT_SYMBOL_GPL(tm_abort); + +/* + * void tm_reclaim(struct thread_struct *thread, + * uint8_t cause) + * + * - Performs a full reclaim. This destroys outstanding + * transactions and updates thread.ckpt_regs, thread.ckfp_state and + * thread.ckvr_state with the original checkpointed state. Note that + * thread->regs is unchanged. + * + * Purpose is to both abort transactions of, and preserve the state of, + * a transactions at a context switch. We preserve/restore both sets of process + * state to restore them when the thread's scheduled again. We continue in + * userland as though nothing happened, but when the transaction is resumed + * they will abort back to the checkpointed state we save out here. + * + * Call with IRQs off, stacks get all out of sync for some periods in here! + */ +_GLOBAL(tm_reclaim) + mfcr r5 + mflr r0 + stw r5, 8(r1) + std r0, 16(r1) + std r2, STK_GOT(r1) + stdu r1, -TM_FRAME_SIZE(r1) + + /* We've a struct pt_regs at [r1+STACK_INT_FRAME_REGS]. */ + + std r3, STK_PARAM(R3)(r1) + SAVE_NVGPRS(r1) + + /* + * Save kernel live AMR since it will be clobbered by treclaim + * but can be used elsewhere later in kernel space. + */ + mfspr r3, SPRN_AMR + std r3, TM_FRAME_L1(r1) + + /* We need to setup MSR for VSX register save instructions. */ + mfmsr r14 + mr r15, r14 + ori r15, r15, MSR_FP + li r16, 0 + ori r16, r16, MSR_EE /* IRQs hard off */ + andc r15, r15, r16 + oris r15, r15, MSR_VEC@h +#ifdef CONFIG_VSX + BEGIN_FTR_SECTION + oris r15,r15, MSR_VSX@h + END_FTR_SECTION_IFSET(CPU_FTR_VSX) +#endif + mtmsrd r15 + std r14, TM_FRAME_L0(r1) + + /* Do sanity check on MSR to make sure we are suspended */ + li r7, (MSR_TS_S)@higher + srdi r6, r14, 32 + and r6, r6, r7 +1: tdeqi r6, 0 + EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0 + + /* Stash the stack pointer away for use after reclaim */ + std r1, PACAR1(r13) + + /* Clear MSR RI since we are about to use SCRATCH0, EE is already off */ + li r5, 0 + mtmsrd r5, 1 + + /* + * BE CAREFUL HERE: + * At this point we can't take an SLB miss since we have MSR_RI + * off. Load only to/from the stack/paca which are in SLB bolted regions + * until we turn MSR RI back on. + * + * The moment we treclaim, ALL of our GPRs will switch + * to user register state. (FPRs, CCR etc. also!) + * Use an sprg and a tm_scratch in the PACA to shuffle. + */ + TRECLAIM(R4) /* Cause in r4 */ + + /* + * ******************** GPRs ******************** + * Stash the checkpointed r13 in the scratch SPR and get the real paca. + */ + SET_SCRATCH0(r13) + GET_PACA(r13) + + /* + * Stash the checkpointed r1 away in paca->tm_scratch and get the real + * stack pointer back into r1. + */ + std r1, PACATMSCRATCH(r13) + ld r1, PACAR1(r13) + + std r11, GPR11(r1) /* Temporary stash */ + + /* + * Move the saved user r1 to the kernel stack in case PACATMSCRATCH is + * clobbered by an exception once we turn on MSR_RI below. + */ + ld r11, PACATMSCRATCH(r13) + std r11, GPR1(r1) + + /* + * Store r13 away so we can free up the scratch SPR for the SLB fault + * handler (needed once we start accessing the thread_struct). + */ + GET_SCRATCH0(r11) + std r11, GPR13(r1) + + /* Reset MSR RI so we can take SLB faults again */ + li r11, MSR_RI + mtmsrd r11, 1 + + /* Store the PPR in r11 and reset to decent value */ + mfspr r11, SPRN_PPR + HMT_MEDIUM + + /* Now get some more GPRS free */ + std r7, GPR7(r1) /* Temporary stash */ + std r12, GPR12(r1) /* '' '' '' */ + ld r12, STK_PARAM(R3)(r1) /* Param 0, thread_struct * */ + + std r11, THREAD_TM_PPR(r12) /* Store PPR and free r11 */ + + addi r7, r12, PT_CKPT_REGS /* Thread's ckpt_regs */ + + /* + * Make r7 look like an exception frame so that we can use the neat + * GPRx(n) macros. r7 is NOT a pt_regs ptr! + */ + subi r7, r7, STACK_INT_FRAME_REGS + + /* Sync the userland GPRs 2-12, 14-31 to thread->regs: */ + SAVE_GPR(0, r7) /* user r0 */ + SAVE_GPRS(2, 6, r7) /* user r2-r6 */ + SAVE_GPRS(8, 10, r7) /* user r8-r10 */ + ld r3, GPR1(r1) /* user r1 */ + ld r4, GPR7(r1) /* user r7 */ + ld r5, GPR11(r1) /* user r11 */ + ld r6, GPR12(r1) /* user r12 */ + ld r8, GPR13(r1) /* user r13 */ + std r3, GPR1(r7) + std r4, GPR7(r7) + std r5, GPR11(r7) + std r6, GPR12(r7) + std r8, GPR13(r7) + + SAVE_NVGPRS(r7) /* user r14-r31 */ + + /* ******************** NIP ******************** */ + mfspr r3, SPRN_TFHAR + std r3, _NIP(r7) /* Returns to failhandler */ + /* + * The checkpointed NIP is ignored when rescheduling/rechkpting, + * but is used in signal return to 'wind back' to the abort handler. + */ + + /* ***************** CTR, LR, CR, XER ********** */ + mfctr r3 + mflr r4 + mfcr r5 + mfxer r6 + + std r3, _CTR(r7) + std r4, _LINK(r7) + std r5, _CCR(r7) + std r6, _XER(r7) + + /* ******************** TAR, DSCR ********** */ + mfspr r3, SPRN_TAR + mfspr r4, SPRN_DSCR + + std r3, THREAD_TM_TAR(r12) + std r4, THREAD_TM_DSCR(r12) + + /* ******************** AMR **************** */ + mfspr r3, SPRN_AMR + std r3, THREAD_TM_AMR(r12) + + /* + * MSR and flags: We don't change CRs, and we don't need to alter MSR. + */ + + + /* + * ******************** FPR/VR/VSRs ************ + * After reclaiming, capture the checkpointed FPRs/VRs. + * + * We enabled VEC/FP/VSX in the msr above, so we can execute these + * instructions! + */ + mr r3, r12 + + /* Altivec (VEC/VMX/VR)*/ + addi r7, r3, THREAD_CKVRSTATE + SAVE_32VRS(0, r6, r7) /* r6 scratch, r7 ckvr_state */ + mfvscr v0 + li r6, VRSTATE_VSCR + stvx v0, r7, r6 + + /* VRSAVE */ + mfspr r0, SPRN_VRSAVE + std r0, THREAD_CKVRSAVE(r3) + + /* Floating Point (FP) */ + addi r7, r3, THREAD_CKFPSTATE + SAVE_32FPRS_VSRS(0, R6, R7) /* r6 scratch, r7 ckfp_state */ + mffs fr0 + stfd fr0,FPSTATE_FPSCR(r7) + + + /* + * TM regs, incl TEXASR -- these live in thread_struct. Note they've + * been updated by the treclaim, to explain to userland the failure + * cause (aborted). + */ + mfspr r0, SPRN_TEXASR + mfspr r3, SPRN_TFHAR + mfspr r4, SPRN_TFIAR + std r0, THREAD_TM_TEXASR(r12) + std r3, THREAD_TM_TFHAR(r12) + std r4, THREAD_TM_TFIAR(r12) + + /* Restore kernel live AMR */ + ld r8, TM_FRAME_L1(r1) + mtspr SPRN_AMR, r8 + + /* Restore original MSR/IRQ state & clear TM mode */ + ld r14, TM_FRAME_L0(r1) /* Orig MSR */ + + li r15, 0 + rldimi r14, r15, MSR_TS_LG, (63-MSR_TS_LG)-1 + mtmsrd r14 + + REST_NVGPRS(r1) + + addi r1, r1, TM_FRAME_SIZE + lwz r4, 8(r1) + ld r0, 16(r1) + mtcr r4 + mtlr r0 + ld r2, STK_GOT(r1) + + /* Load CPU's default DSCR */ + ld r0, PACA_DSCR_DEFAULT(r13) + mtspr SPRN_DSCR, r0 + + blr + + + /* + * void __tm_recheckpoint(struct thread_struct *thread) + * - Restore the checkpointed register state saved by tm_reclaim + * when we switch_to a process. + * + * Call with IRQs off, stacks get all out of sync for + * some periods in here! + */ +_GLOBAL(__tm_recheckpoint) + mfcr r5 + mflr r0 + stw r5, 8(r1) + std r0, 16(r1) + std r2, STK_GOT(r1) + stdu r1, -TM_FRAME_SIZE(r1) + + /* + * We've a struct pt_regs at [r1+STACK_INT_FRAME_REGS]. + * This is used for backing up the NVGPRs: + */ + SAVE_NVGPRS(r1) + + /* + * Save kernel live AMR since it will be clobbered for trechkpt + * but can be used elsewhere later in kernel space. + */ + mfspr r8, SPRN_AMR + std r8, TM_FRAME_L0(r1) + + /* Load complete register state from ts_ckpt* registers */ + + addi r7, r3, PT_CKPT_REGS /* Thread's ckpt_regs */ + + /* + * Make r7 look like an exception frame so that we can use the neat + * GPRx(n) macros. r7 is now NOT a pt_regs ptr! + */ + subi r7, r7, STACK_INT_FRAME_REGS + + /* We need to setup MSR for FP/VMX/VSX register save instructions. */ + mfmsr r6 + mr r5, r6 + ori r5, r5, MSR_FP +#ifdef CONFIG_ALTIVEC + oris r5, r5, MSR_VEC@h +#endif +#ifdef CONFIG_VSX + BEGIN_FTR_SECTION + oris r5,r5, MSR_VSX@h + END_FTR_SECTION_IFSET(CPU_FTR_VSX) +#endif + mtmsrd r5 + +#ifdef CONFIG_ALTIVEC + /* + * FP and VEC registers: These are recheckpointed from + * thread.ckfp_state and thread.ckvr_state respectively. The + * thread.fp_state[] version holds the 'live' (transactional) + * and will be loaded subsequently by any FPUnavailable trap. + */ + addi r8, r3, THREAD_CKVRSTATE + li r5, VRSTATE_VSCR + lvx v0, r8, r5 + mtvscr v0 + REST_32VRS(0, r5, r8) /* r5 scratch, r8 ptr */ + ld r5, THREAD_CKVRSAVE(r3) + mtspr SPRN_VRSAVE, r5 +#endif + + addi r8, r3, THREAD_CKFPSTATE + lfd fr0, FPSTATE_FPSCR(r8) + MTFSF_L(fr0) + REST_32FPRS_VSRS(0, R4, R8) + + mtmsr r6 /* FP/Vec off again! */ + +restore_gprs: + + /* ****************** CTR, LR, XER ************* */ + ld r4, _CTR(r7) + ld r5, _LINK(r7) + ld r8, _XER(r7) + + mtctr r4 + mtlr r5 + mtxer r8 + + /* ******************** TAR ******************** */ + ld r4, THREAD_TM_TAR(r3) + mtspr SPRN_TAR, r4 + + /* ******************** AMR ******************** */ + ld r4, THREAD_TM_AMR(r3) + mtspr SPRN_AMR, r4 + + /* Load up the PPR and DSCR in GPRs only at this stage */ + ld r5, THREAD_TM_DSCR(r3) + ld r6, THREAD_TM_PPR(r3) + + REST_GPR(0, r7) /* GPR0 */ + REST_GPRS(2, 4, r7) /* GPR2-4 */ + REST_GPRS(8, 12, r7) /* GPR8-12 */ + REST_GPRS(14, 31, r7) /* GPR14-31 */ + + /* Load up PPR and DSCR here so we don't run with user values for long */ + mtspr SPRN_DSCR, r5 + mtspr SPRN_PPR, r6 + + /* + * Do final sanity check on TEXASR to make sure FS is set. Do this + * here before we load up the userspace r1 so any bugs we hit will get + * a call chain. + */ + mfspr r5, SPRN_TEXASR + srdi r5, r5, 16 + li r6, (TEXASR_FS)@h + and r6, r6, r5 +1: tdeqi r6, 0 + EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0 + + /* + * Do final sanity check on MSR to make sure we are not transactional + * or suspended. + */ + mfmsr r6 + li r5, (MSR_TS_MASK)@higher + srdi r6, r6, 32 + and r6, r6, r5 +1: tdnei r6, 0 + EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0 + + /* Restore CR */ + ld r6, _CCR(r7) + mtcr r6 + + REST_GPR(6, r7) + + /* + * Store user r1 and r5 and r13 on the stack (in the unused save + * areas / compiler reserved areas), so that we can access them after + * we clear MSR RI. + */ + + REST_GPR(5, r7) + std r5, -8(r1) + ld r5, GPR13(r7) + std r5, -16(r1) + ld r5, GPR1(r7) + std r5, -24(r1) + + REST_GPR(7, r7) + + /* Stash the stack pointer away for use after recheckpoint */ + std r1, PACAR1(r13) + + /* Clear MSR RI since we are about to clobber r13. EE is already off */ + li r5, 0 + mtmsrd r5, 1 + + /* + * BE CAREFUL HERE: + * At this point we can't take an SLB miss since we have MSR_RI + * off. Load only to/from the stack/paca which are in SLB bolted regions + * until we turn MSR RI back on. + */ + + ld r5, -8(r1) + ld r13, -16(r1) + ld r1, -24(r1) + + /* Commit register state as checkpointed state: */ + TRECHKPT + + HMT_MEDIUM + + /* + * Our transactional state has now changed. + * + * Now just get out of here. Transactional (current) state will be + * updated once restore is called on the return path in the _switch-ed + * -to process. + */ + + GET_PACA(r13) + ld r1, PACAR1(r13) + + /* R13, R1 is restored, so we are recoverable again. EE is still off */ + li r4, MSR_RI + mtmsrd r4, 1 + + /* Restore kernel live AMR */ + ld r8, TM_FRAME_L0(r1) + mtspr SPRN_AMR, r8 + + REST_NVGPRS(r1) + + addi r1, r1, TM_FRAME_SIZE + lwz r4, 8(r1) + ld r0, 16(r1) + mtcr r4 + mtlr r0 + ld r2, STK_GOT(r1) + + /* Load CPU's default DSCR */ + ld r0, PACA_DSCR_DEFAULT(r13) + mtspr SPRN_DSCR, r0 + + blr + + /* ****************************************************************** */ |