diff options
author | Paul Mackerras <paulus@ozlabs.org> | 2018-10-08 16:30:53 +1100 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-10-09 16:04:27 +1100 |
commit | 7854f7545bff69567fc3fcd8831752138b892483 (patch) | |
tree | 6560f30a54007e20877a4c9736974dda4493314c /arch/powerpc/kvm/book3s_hv_rmhandlers.S | |
parent | df709a296ef7c493a074609019b0e074cde5c0d0 (diff) | |
download | linux-7854f7545bff69567fc3fcd8831752138b892483.tar.bz2 |
KVM: PPC: Book3S: Rework TM save/restore code and make it C-callable
This adds a parameter to __kvmppc_save_tm and __kvmppc_restore_tm
which allows the caller to indicate whether it wants the nonvolatile
register state to be preserved across the call, as required by the C
calling conventions. This parameter being non-zero also causes the
MSR bits that enable TM, FP, VMX and VSX to be preserved. The
condition register and DSCR are now always preserved.
With this, kvmppc_save_tm_hv and kvmppc_restore_tm_hv can be called
from C code provided the 3rd parameter is non-zero. So that these
functions can be called from modules, they now include code to set
the TOC pointer (r2) on entry, as they can call other built-in C
functions which will assume the TOC to have been set.
Also, the fake suspend code in kvmppc_save_tm_hv is modified here to
assume that treclaim in fake-suspend state does not modify any registers,
which is the case on POWER9. This enables the code to be simplified
quite a bit.
_kvmppc_save_tm_pr and _kvmppc_restore_tm_pr become much simpler with
this change, since they now only need to save and restore TAR and pass
1 for the 3rd argument to __kvmppc_{save,restore}_tm.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_rmhandlers.S')
-rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 49 |
1 files changed, 23 insertions, 26 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index fc360b5ca9b1..45dd637d6b44 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -759,11 +759,13 @@ BEGIN_FTR_SECTION b 91f END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0) /* - * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR + * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR) */ mr r3, r4 ld r4, VCPU_MSR(r3) + li r5, 0 /* don't preserve non-vol regs */ bl kvmppc_restore_tm_hv + nop ld r4, HSTATE_KVM_VCPU(r13) 91: #endif @@ -1603,11 +1605,13 @@ BEGIN_FTR_SECTION b 91f END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0) /* - * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR + * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR) */ mr r3, r9 ld r4, VCPU_MSR(r3) + li r5, 0 /* don't preserve non-vol regs */ bl kvmppc_save_tm_hv + nop ld r9, HSTATE_KVM_VCPU(r13) 91: #endif @@ -2486,11 +2490,13 @@ BEGIN_FTR_SECTION b 91f END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0) /* - * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR + * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR) */ ld r3, HSTATE_KVM_VCPU(r13) ld r4, VCPU_MSR(r3) + li r5, 0 /* don't preserve non-vol regs */ bl kvmppc_save_tm_hv + nop 91: #endif @@ -2606,11 +2612,13 @@ BEGIN_FTR_SECTION b 91f END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0) /* - * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR + * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR) */ mr r3, r4 ld r4, VCPU_MSR(r3) + li r5, 0 /* don't preserve non-vol regs */ bl kvmppc_restore_tm_hv + nop ld r4, HSTATE_KVM_VCPU(r13) 91: #endif @@ -2943,10 +2951,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) * Save transactional state and TM-related registers. * Called with r3 pointing to the vcpu struct and r4 containing * the guest MSR value. - * This can modify all checkpointed registers, but + * r5 is non-zero iff non-volatile register state needs to be maintained. + * If r5 == 0, this can modify all checkpointed registers, but * restores r1 and r2 before exit. */ -kvmppc_save_tm_hv: +_GLOBAL_TOC(kvmppc_save_tm_hv) +EXPORT_SYMBOL_GPL(kvmppc_save_tm_hv) /* See if we need to handle fake suspend mode */ BEGIN_FTR_SECTION b __kvmppc_save_tm @@ -2974,12 +2984,6 @@ BEGIN_FTR_SECTION END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_XER_SO_BUG) nop - std r1, HSTATE_HOST_R1(r13) - - /* Clear the MSR RI since r1, r13 may be foobar. */ - li r5, 0 - mtmsrd r5, 1 - /* We have to treclaim here because that's the only way to do S->N */ li r3, TM_CAUSE_KVM_RESCHED TRECLAIM(R3) @@ -2988,22 +2992,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_XER_SO_BUG) * We were in fake suspend, so we are not going to save the * register state as the guest checkpointed state (since * we already have it), therefore we can now use any volatile GPR. + * In fact treclaim in fake suspend state doesn't modify + * any registers. */ - /* Reload PACA pointer, stack pointer and TOC. */ - GET_PACA(r13) - ld r1, HSTATE_HOST_R1(r13) - ld r2, PACATOC(r13) - /* Set MSR RI now we have r1 and r13 back. */ - li r5, MSR_RI - mtmsrd r5, 1 - - HMT_MEDIUM - ld r6, HSTATE_DSCR(r13) - mtspr SPRN_DSCR, r6 -BEGIN_FTR_SECTION_NESTED(96) +BEGIN_FTR_SECTION bl pnv_power9_force_smt4_release -END_FTR_SECTION_NESTED(CPU_FTR_P9_TM_XER_SO_BUG, CPU_FTR_P9_TM_XER_SO_BUG, 96) +END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_XER_SO_BUG) nop 4: @@ -3029,10 +3024,12 @@ END_FTR_SECTION_NESTED(CPU_FTR_P9_TM_XER_SO_BUG, CPU_FTR_P9_TM_XER_SO_BUG, 96) * Restore transactional state and TM-related registers. * Called with r3 pointing to the vcpu struct * and r4 containing the guest MSR value. + * r5 is non-zero iff non-volatile register state needs to be maintained. * This potentially modifies all checkpointed registers. * It restores r1 and r2 from the PACA. */ -kvmppc_restore_tm_hv: +_GLOBAL_TOC(kvmppc_restore_tm_hv) +EXPORT_SYMBOL_GPL(kvmppc_restore_tm_hv) /* * If we are doing TM emulation for the guest on a POWER9 DD2, * then we don't actually do a trechkpt -- we either set up |