Subject: [PATCH v1 06/55] powerpc/64s: Remove WORT SPR from POWER9/10

From: Nicholas Piggin <[email-masked]>
Date: Mon, 26 Jul 2021 13:49:47 +1000

This register is not architected and not implemented in POWER9 or 10,
it just reads back zeroes for compatibility.

-78 cycles (9255) cycles POWER9 virt-mode NULL hcall

Reviewed-by: Fabiano Rosas <[email-masked]>
Signed-off-by: Nicholas Piggin <[email-masked]>
---
 arch/powerpc/kvm/book3s_hv.c          | 3 ---
 arch/powerpc/platforms/powernv/idle.c | 2 --
 2 files changed, 5 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index c743020837e7..905bf29940ea 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3740,7 +3740,6 @@ static void load_spr_state(struct kvm_vcpu *vcpu)
 	mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
 	mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
 	mtspr(SPRN_BESCR, vcpu->arch.bescr);
-	mtspr(SPRN_WORT, vcpu->arch.wort);
 	mtspr(SPRN_TIDR, vcpu->arch.tid);
 	mtspr(SPRN_AMR, vcpu->arch.amr);
 	mtspr(SPRN_UAMOR, vcpu->arch.uamor);
@@ -3767,7 +3766,6 @@ static void store_spr_state(struct kvm_vcpu *vcpu)
 	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
 	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
 	vcpu->arch.bescr = mfspr(SPRN_BESCR);
-	vcpu->arch.wort = mfspr(SPRN_WORT);
 	vcpu->arch.tid = mfspr(SPRN_TIDR);
 	vcpu->arch.amr = mfspr(SPRN_AMR);
 	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
@@ -3799,7 +3797,6 @@ static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
 				    struct p9_host_os_sprs *host_os_sprs)
 {
 	mtspr(SPRN_PSPB, 0);
-	mtspr(SPRN_WORT, 0);
 	mtspr(SPRN_UAMOR, 0);
 
 	mtspr(SPRN_DSCR, host_os_sprs->dscr);
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 1e908536890b..df19e2ff9d3c 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -667,7 +667,6 @@ static unsigned long power9_idle_stop(unsigned long psscr)
 		sprs.purr	= mfspr(SPRN_PURR);
 		sprs.spurr	= mfspr(SPRN_SPURR);
 		sprs.dscr	= mfspr(SPRN_DSCR);
-		sprs.wort	= mfspr(SPRN_WORT);
 		sprs.ciabr	= mfspr(SPRN_CIABR);
 
 		sprs.mmcra	= mfspr(SPRN_MMCRA);
@@ -785,7 +784,6 @@ static unsigned long power9_idle_stop(unsigned long psscr)
 	mtspr(SPRN_PURR,	sprs.purr);
 	mtspr(SPRN_SPURR,	sprs.spurr);
 	mtspr(SPRN_DSCR,	sprs.dscr);
-	mtspr(SPRN_WORT,	sprs.wort);
 	mtspr(SPRN_CIABR,	sprs.ciabr);
 
 	mtspr(SPRN_MMCRA,	sprs.mmcra);
-- 
2.23.0