On Wed, Feb 28, 2018 at 01:37:14AM +0800, wei.guo.si...@gmail.com wrote: > From: Simon Guo <wei.guo.si...@gmail.com> > > Currently _kvmppc_save/restore_tm() APIs can only be invoked from > assembly function. This patch adds C function wrappers for them so > that they can be safely called from C function. > > Signed-off-by: Simon Guo <wei.guo.si...@gmail.com>
Some relatively minor comments below: > diff --git a/arch/powerpc/kvm/tm.S b/arch/powerpc/kvm/tm.S > index 2d6fe5b..269dd11 100644 > --- a/arch/powerpc/kvm/tm.S > +++ b/arch/powerpc/kvm/tm.S > @@ -35,7 +35,7 @@ > * This can modify all checkpointed registers, but > * restores r1, r2 before exit. > */ > -_GLOBAL(kvmppc_save_tm) > +_GLOBAL(__kvmppc_save_tm) > mflr r0 > std r0, PPC_LR_STKOFF(r1) > > @@ -149,6 +149,52 @@ _GLOBAL(kvmppc_save_tm) > blr > > /* > + * _kvmppc_save_tm() 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) The comment doesn't match the actual function name. > + mflr r5 > + std r5, PPC_LR_STKOFF(r1) > + stdu r1, -SWITCH_FRAME_SIZE(r1) > + SAVE_NVGPRS(r1) > + > + /* save MSR since TM/math bits might be impacted > + * by __kvmppc_save_tm(). > + */ > + mfmsr r5 > + SAVE_GPR(5, r1) > + > + /* also save DSCR/CR so that it can be recovered later */ > + mfspr r6, SPRN_DSCR > + SAVE_GPR(6, r1) > + > + mfcr r7 > + stw r7, _CCR(r1) > + > + bl __kvmppc_save_tm > + > + ld r7, _CCR(r1) > + mtcr r7 > + > + REST_GPR(6, r1) > + mtspr SPRN_DSCR, r6 > + > + /* need preserve current MSR's MSR_TS bits */ > + REST_GPR(5, r1) > + mfmsr r6 > + rldicl r6, r6, 64 - MSR_TS_S_LG, 62 > + rldimi r5, r6, MSR_TS_S_LG, 63 - MSR_TS_T_LG > + mtmsrd r5 > + > + REST_NVGPRS(r1) > + addi r1, r1, SWITCH_FRAME_SIZE > + ld r5, PPC_LR_STKOFF(r1) > + mtlr r5 > + blr > + > +EXPORT_SYMBOL_GPL(_kvmppc_save_tm_pr); > + > +/* > * Restore transactional state and TM-related registers. > * Called with: > * - r3 pointing to the vcpu struct. > @@ -158,7 +204,7 @@ _GLOBAL(kvmppc_save_tm) > * This potentially modifies all checkpointed registers. > * It restores r1, r2 from the PACA. > */ > -_GLOBAL(kvmppc_restore_tm) > +_GLOBAL(__kvmppc_restore_tm) > mflr r0 > std r0, PPC_LR_STKOFF(r1) > > @@ -186,6 +232,7 @@ _GLOBAL(kvmppc_restore_tm) > rldicl. r5, r5, 64 - MSR_TS_S_LG, 62 > beqlr /* TM not active in guest */ > std r1, HSTATE_SCRATCH2(r13) > + std r3, HSTATE_SCRATCH1(r13) Why do we need to save r3 here and restore it below? > > /* 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 > @@ -262,6 +309,7 @@ _GLOBAL(kvmppc_restore_tm) > ld r29, HSTATE_DSCR(r13) > mtspr SPRN_DSCR, r29 > #endif > + ld r3, HSTATE_SCRATCH1(r13) > ld r1, HSTATE_SCRATCH2(r13) > ld r2, PACATMSCRATCH(r13) > > @@ -273,4 +321,47 @@ _GLOBAL(kvmppc_restore_tm) > mtlr r0 > blr > > +/* > + * _kvmppc_restore_tm() 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) Again, comment doesn't match the actual function name. > + mflr r5 > + std r5, PPC_LR_STKOFF(r1) > + stdu r1, -SWITCH_FRAME_SIZE(r1) > + SAVE_NVGPRS(r1) > + > + /* save MSR to avoid TM/math bits change */ > + mfmsr r5 > + SAVE_GPR(5, r1) > + > + /* also save DSCR/CR so that it can be recovered later */ > + mfspr r6, SPRN_DSCR > + SAVE_GPR(6, r1) > + > + mfcr r7 > + stw r7, _CCR(r1) > + > + bl __kvmppc_restore_tm > + > + ld r7, _CCR(r1) > + mtcr r7 > + > + REST_GPR(6, r1) > + mtspr SPRN_DSCR, r6 > + > + /* need preserve current MSR's MSR_TS bits */ > + REST_GPR(5, r1) > + mfmsr r6 > + rldicl r6, r6, 64 - MSR_TS_S_LG, 62 > + rldimi r5, r6, MSR_TS_S_LG, 63 - MSR_TS_T_LG > + mtmsrd r5 > + > + REST_NVGPRS(r1) > + addi r1, r1, SWITCH_FRAME_SIZE > + ld r5, PPC_LR_STKOFF(r1) > + mtlr r5 > + blr > + > +EXPORT_SYMBOL_GPL(_kvmppc_restore_tm_pr); > #endif > -- > 1.8.3.1 Paul.
