diff options
Diffstat (limited to 'arch/powerpc/kvm/tm.S')
| -rw-r--r-- | arch/powerpc/kvm/tm.S | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/tm.S b/arch/powerpc/kvm/tm.S new file mode 100644 index 000000000..2158f61e3 --- /dev/null +++ b/arch/powerpc/kvm/tm.S @@ -0,0 +1,398 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * + * Derived from book3s_hv_rmhandlers.S, which is: + * + * Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> + */ + +#include <asm/reg.h> +#include <asm/ppc_asm.h> +#include <asm/asm-offsets.h> +#include <asm/export.h> +#include <asm/tm.h> +#include <asm/cputable.h> + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +#define VCPU_GPRS_TM(reg) (((reg) * ULONG_SIZE) + VCPU_GPR_TM) + +/* + * Save transactional state and TM-related registers. + * Called with: + * - r3 pointing to the vcpu struct + * - r4 containing the MSR with current TS bits: + * (For HV KVM, it is VCPU_MSR ; For PR KVM, it is host MSR). + * - r5 containing a flag indicating that non-volatile registers + * must be preserved. + * If r5 == 0, this can modify all checkpointed registers, but + * restores r1, r2 before exit. If r5 != 0, this restores the + * MSR TM/FP/VEC/VSX bits to their state on entry. + */ +_GLOBAL(__kvmppc_save_tm) + mflr r0 + std r0, PPC_LR_STKOFF(r1) + stdu r1, -SWITCH_FRAME_SIZE(r1) + + mr r9, r3 + cmpdi cr7, r5, 0 + + /* Turn on TM. */ + mfmsr r8 + mr r10, r8 + li r0, 1 + rldimi r8, r0, MSR_TM_LG, 63-MSR_TM_LG + ori r8, r8, MSR_FP + oris r8, r8, (MSR_VEC | MSR_VSX)@h + mtmsrd r8 + + rldicl. r4, r4, 64 - MSR_TS_S_LG, 62 + beq 1f /* TM not active in guest. */ + + std r1, HSTATE_SCRATCH2(r13) + std r3, HSTATE_SCRATCH1(r13) + + /* Save CR on the stack - even if r5 == 0 we need to get cr7 back. */ + mfcr r6 + SAVE_GPR(6, r1) + + /* Save DSCR so we can restore it to avoid running with user value */ + mfspr r7, SPRN_DSCR + SAVE_GPR(7, r1) + + /* + * We are going to do treclaim., which will modify all checkpointed + * registers. Save the non-volatile registers on the stack if + * preservation of non-volatile state has been requested. + */ + beq cr7, 3f + SAVE_NVGPRS(r1) + + /* MSR[TS] will be 0 (non-transactional) once we do treclaim. */ + li r0, 0 + rldimi r10, r0, MSR_TS_S_LG, 63 - MSR_TS_T_LG + SAVE_GPR(10, r1) /* final MSR value */ +3: +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE +BEGIN_FTR_SECTION + /* Emulation of the treclaim instruction needs TEXASR before treclaim */ + mfspr r6, SPRN_TEXASR + std r6, VCPU_ORIG_TEXASR(r3) +END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST) +#endif + + /* Clear the MSR RI since r1, r13 are all going to be foobar. */ + li r5, 0 + mtmsrd r5, 1 + + li r3, TM_CAUSE_KVM_RESCHED + + /* All GPRs are volatile at this point. */ + TRECLAIM(R3) + + /* Temporarily store r13 and r9 so we have some regs to play with */ + SET_SCRATCH0(r13) + GET_PACA(r13) + std r9, PACATMSCRATCH(r13) + ld r9, HSTATE_SCRATCH1(r13) + + /* Save away PPR soon so we don't run with user value. */ + std r0, VCPU_GPRS_TM(0)(r9) + mfspr r0, SPRN_PPR + HMT_MEDIUM + + /* Reload stack pointer. */ + std r1, VCPU_GPRS_TM(1)(r9) + ld r1, HSTATE_SCRATCH2(r13) + + /* Set MSR RI now we have r1 and r13 back. */ + std r2, VCPU_GPRS_TM(2)(r9) + li r2, MSR_RI + mtmsrd r2, 1 + + /* Reload TOC pointer. */ + LOAD_PACA_TOC() + + /* Save all but r0-r2, r9 & r13 */ + reg = 3 + .rept 29 + .if (reg != 9) && (reg != 13) + std reg, VCPU_GPRS_TM(reg)(r9) + .endif + reg = reg + 1 + .endr + /* ... now save r13 */ + GET_SCRATCH0(r4) + std r4, VCPU_GPRS_TM(13)(r9) + /* ... and save r9 */ + ld r4, PACATMSCRATCH(r13) + std r4, VCPU_GPRS_TM(9)(r9) + + /* Restore host DSCR and CR values, after saving guest values */ + mfcr r6 + mfspr r7, SPRN_DSCR + stw r6, VCPU_CR_TM(r9) + std r7, VCPU_DSCR_TM(r9) + REST_GPR(6, r1) + REST_GPR(7, r1) + mtcr r6 + mtspr SPRN_DSCR, r7 + + /* Save away checkpointed SPRs. */ + std r0, VCPU_PPR_TM(r9) + mflr r5 + mfctr r7 + mfspr r8, SPRN_AMR + mfspr r10, SPRN_TAR + mfxer r11 + std r5, VCPU_LR_TM(r9) + std r7, VCPU_CTR_TM(r9) + std r8, VCPU_AMR_TM(r9) + std r10, VCPU_TAR_TM(r9) + std r11, VCPU_XER_TM(r9) + + /* Save FP/VSX. */ + addi r3, r9, VCPU_FPRS_TM + bl store_fp_state + addi r3, r9, VCPU_VRS_TM + bl store_vr_state + mfspr r6, SPRN_VRSAVE + stw r6, VCPU_VRSAVE_TM(r9) + + /* Restore non-volatile registers if requested to */ + beq cr7, 1f + REST_NVGPRS(r1) + REST_GPR(10, r1) +1: + /* + * We need to save these SPRs after the treclaim so that the software + * error code is recorded correctly in the TEXASR. Also the user may + * change these outside of a transaction, so they must always be + * context switched. + */ + mfspr r7, SPRN_TEXASR + std r7, VCPU_TEXASR(r9) + mfspr r5, SPRN_TFHAR + mfspr r6, SPRN_TFIAR + std r5, VCPU_TFHAR(r9) + std r6, VCPU_TFIAR(r9) + + /* Restore MSR state if requested */ + beq cr7, 2f + mtmsrd r10, 0 +2: + addi r1, r1, SWITCH_FRAME_SIZE + ld r0, PPC_LR_STKOFF(r1) + mtlr r0 + blr + +/* + * _kvmppc_save_tm_pr() is a wrapper around __kvmppc_save_tm(), so that it can + * be invoked from C function by PR KVM only. + */ +_GLOBAL(_kvmppc_save_tm_pr) + mflr r0 + std r0, PPC_LR_STKOFF(r1) + stdu r1, -PPC_MIN_STKFRM(r1) + + mfspr r8, SPRN_TAR + std r8, PPC_MIN_STKFRM-8(r1) + + li r5, 1 /* preserve non-volatile registers */ + bl __kvmppc_save_tm + + ld r8, PPC_MIN_STKFRM-8(r1) + mtspr SPRN_TAR, r8 + + addi r1, r1, PPC_MIN_STKFRM + ld r0, PPC_LR_STKOFF(r1) + mtlr r0 + blr + +EXPORT_SYMBOL_GPL(_kvmppc_save_tm_pr); + +/* + * Restore transactional state and TM-related registers. + * Called with: + * - r3 pointing to the vcpu struct. + * - r4 is the guest MSR with desired TS bits: + * For HV KVM, it is VCPU_MSR + * For PR KVM, it is provided by caller + * - r5 containing a flag indicating that non-volatile registers + * must be preserved. + * If r5 == 0, this potentially modifies all checkpointed registers, but + * restores r1, r2 from the PACA before exit. + * If r5 != 0, this restores the MSR TM/FP/VEC/VSX bits to their state on entry. + */ +_GLOBAL(__kvmppc_restore_tm) + mflr r0 + std r0, PPC_LR_STKOFF(r1) + + cmpdi cr7, r5, 0 + + /* Turn on TM/FP/VSX/VMX so we can restore them. */ + mfmsr r5 + mr r10, r5 + li r6, MSR_TM >> 32 + sldi r6, r6, 32 + or r5, r5, r6 + ori r5, r5, MSR_FP + oris r5, r5, (MSR_VEC | MSR_VSX)@h + mtmsrd r5 + + /* + * The user may change these outside of a transaction, so they must + * always be context switched. + */ + ld r5, VCPU_TFHAR(r3) + ld r6, VCPU_TFIAR(r3) + ld r7, VCPU_TEXASR(r3) + mtspr SPRN_TFHAR, r5 + mtspr SPRN_TFIAR, r6 + mtspr SPRN_TEXASR, r7 + + mr r5, r4 + rldicl. r5, r5, 64 - MSR_TS_S_LG, 62 + beq 9f /* TM not active in guest */ + + /* Make sure the failure summary is set, otherwise we'll program check + * when we trechkpt. It's possible that this might have been not set + * on a kvmppc_set_one_reg() call but we shouldn't let this crash the + * host. + */ + oris r7, r7, (TEXASR_FS)@h + mtspr SPRN_TEXASR, r7 + + /* + * Make a stack frame and save non-volatile registers if requested. + */ + stdu r1, -SWITCH_FRAME_SIZE(r1) + std r1, HSTATE_SCRATCH2(r13) + + mfcr r6 + mfspr r7, SPRN_DSCR + SAVE_GPR(2, r1) + SAVE_GPR(6, r1) + SAVE_GPR(7, r1) + + beq cr7, 4f + SAVE_NVGPRS(r1) + + /* MSR[TS] will be 1 (suspended) once we do trechkpt */ + li r0, 1 + rldimi r10, r0, MSR_TS_S_LG, 63 - MSR_TS_T_LG + SAVE_GPR(10, r1) /* final MSR value */ +4: + /* + * We need to load up the checkpointed state for the guest. + * We need to do this early as it will blow away any GPRs, VSRs and + * some SPRs. + */ + + mr r31, r3 + addi r3, r31, VCPU_FPRS_TM + bl load_fp_state + addi r3, r31, VCPU_VRS_TM + bl load_vr_state + mr r3, r31 + lwz r7, VCPU_VRSAVE_TM(r3) + mtspr SPRN_VRSAVE, r7 + + ld r5, VCPU_LR_TM(r3) + lwz r6, VCPU_CR_TM(r3) + ld r7, VCPU_CTR_TM(r3) + ld r8, VCPU_AMR_TM(r3) + ld r9, VCPU_TAR_TM(r3) + ld r10, VCPU_XER_TM(r3) + mtlr r5 + mtcr r6 + mtctr r7 + mtspr SPRN_AMR, r8 + mtspr SPRN_TAR, r9 + mtxer r10 + + /* + * Load up PPR and DSCR values but don't put them in the actual SPRs + * till the last moment to avoid running with userspace PPR and DSCR for + * too long. + */ + ld r29, VCPU_DSCR_TM(r3) + ld r30, VCPU_PPR_TM(r3) + + /* Clear the MSR RI since r1, r13 are all going to be foobar. */ + li r5, 0 + mtmsrd r5, 1 + + /* Load GPRs r0-r28 */ + reg = 0 + .rept 29 + ld reg, VCPU_GPRS_TM(reg)(r31) + reg = reg + 1 + .endr + + mtspr SPRN_DSCR, r29 + mtspr SPRN_PPR, r30 + + /* Load final GPRs */ + ld 29, VCPU_GPRS_TM(29)(r31) + ld 30, VCPU_GPRS_TM(30)(r31) + ld 31, VCPU_GPRS_TM(31)(r31) + + /* TM checkpointed state is now setup. All GPRs are now volatile. */ + TRECHKPT + + /* Now let's get back the state we need. */ + HMT_MEDIUM + GET_PACA(r13) + ld r1, HSTATE_SCRATCH2(r13) + REST_GPR(7, r1) + mtspr SPRN_DSCR, r7 + + /* Set the MSR RI since we have our registers back. */ + li r5, MSR_RI + mtmsrd r5, 1 + + /* Restore TOC pointer and CR */ + REST_GPR(2, r1) + REST_GPR(6, r1) + mtcr r6 + + /* Restore non-volatile registers if requested to. */ + beq cr7, 5f + REST_GPR(10, r1) + REST_NVGPRS(r1) + +5: addi r1, r1, SWITCH_FRAME_SIZE + ld r0, PPC_LR_STKOFF(r1) + mtlr r0 + +9: /* Restore MSR bits if requested */ + beqlr cr7 + mtmsrd r10, 0 + blr + +/* + * _kvmppc_restore_tm_pr() is a wrapper around __kvmppc_restore_tm(), so that it + * can be invoked from C function by PR KVM only. + */ +_GLOBAL(_kvmppc_restore_tm_pr) + mflr r0 + std r0, PPC_LR_STKOFF(r1) + stdu r1, -PPC_MIN_STKFRM(r1) + + /* save TAR so that it can be recovered later */ + mfspr r8, SPRN_TAR + std r8, PPC_MIN_STKFRM-8(r1) + + li r5, 1 + bl __kvmppc_restore_tm + + ld r8, PPC_MIN_STKFRM-8(r1) + mtspr SPRN_TAR, r8 + + addi r1, r1, PPC_MIN_STKFRM + ld r0, PPC_LR_STKOFF(r1) + mtlr r0 + blr + +EXPORT_SYMBOL_GPL(_kvmppc_restore_tm_pr); +#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ |