diff options
| author | Nicholas Piggin | 2021-11-23 19:51:55 +1000 |
|---|---|---|
| committer | Michael Ellerman | 2021-11-24 21:08:58 +1100 |
| commit | a1a19e1154e4e9c6c1136474cb040657b1c17817 (patch) | |
| tree | e28f6b021e6c4eb1fc3bdea755a5ab46c313e62c | |
| parent | b1adcf57ceca7eab9bfdafc754802e05e634bfcc (diff) | |
KVM: PPC: Book3S HV: CTRL SPR does not require read-modify-write
Processors that support KVM HV do not require read-modify-write of
the CTRL SPR to set/clear their thread's runlatch. Just write 1 or 0
to it.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-18-npiggin@gmail.com
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 15 |
2 files changed, 7 insertions, 10 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index bbaf018dcb67..e4fb36871ce4 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4071,7 +4071,7 @@ static void load_spr_state(struct kvm_vcpu *vcpu) */ if (!(vcpu->arch.ctrl & 1)) - mtspr(SPRN_CTRLT, mfspr(SPRN_CTRLF) & ~1); + mtspr(SPRN_CTRLT, 0); } static void store_spr_state(struct kvm_vcpu *vcpu) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index a454d65e6353..be79ae7afdf5 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -781,12 +781,11 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) mtspr SPRN_AMR,r5 mtspr SPRN_UAMOR,r6 - /* Restore state of CTRL run bit; assume 1 on entry */ + /* Restore state of CTRL run bit; the host currently has it set to 1 */ lwz r5,VCPU_CTRL(r4) andi. r5,r5,1 bne 4f - mfspr r6,SPRN_CTRLF - clrrdi r6,r6,1 + li r6,0 mtspr SPRN_CTRLT,r6 4: /* Secondary threads wait for primary to have done partition switch */ @@ -1209,12 +1208,12 @@ guest_bypass: stw r0, VCPU_CPU(r9) stw r0, VCPU_THREAD_CPU(r9) - /* Save guest CTRL register, set runlatch to 1 */ + /* Save guest CTRL register, set runlatch to 1 if it was clear */ mfspr r6,SPRN_CTRLF stw r6,VCPU_CTRL(r9) andi. r0,r6,1 bne 4f - ori r6,r6,1 + li r6,1 mtspr SPRN_CTRLT,r6 4: /* @@ -2184,8 +2183,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_TM) * Also clear the runlatch bit before napping. */ kvm_do_nap: - mfspr r0, SPRN_CTRLF - clrrdi r0, r0, 1 + li r0,0 mtspr SPRN_CTRLT, r0 li r0,1 @@ -2204,8 +2202,7 @@ kvm_nap_sequence: /* desired LPCR value in r5 */ bl isa206_idle_insn_mayloss - mfspr r0, SPRN_CTRLF - ori r0, r0, 1 + li r0,1 mtspr SPRN_CTRLT, r0 mtspr SPRN_SRR1, r3 |