Subject: [RFC PATCH 11/43] KVM: PPC: Book3S HV P9: Implement PMU save/restore in C

From: Nicholas Piggin <[email-masked]>
Date: Tue, 22 Jun 2021 20:57:04 +1000

Implement the P9 path PMU save/restore code in C, and remove the
POWER9/10 code from the P7/8 path assembly.

-449 cycles (8533) POWER9 virt-mode NULL hcall

Signed-off-by: Nicholas Piggin <[email-masked]>
---
 arch/powerpc/include/asm/asm-prototypes.h |   5 -
 arch/powerpc/kvm/book3s_hv.c              | 205 ++++++++++++++++++++--
 arch/powerpc/kvm/book3s_hv_interrupts.S   |  13 +-
 arch/powerpc/kvm/book3s_hv_rmhandlers.S   |  43 +----
 4 files changed, 200 insertions(+), 66 deletions(-)

diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 02ee6f5ac9fe..928db8ef9a5a 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -136,11 +136,6 @@ static inline void kvmppc_restore_tm_hv(struct kvm_vcpu *vcpu, u64 msr,
 					bool preserve_nv) { }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
-void kvmhv_save_host_pmu(void);
-void kvmhv_load_host_pmu(void);
-void kvmhv_save_guest_pmu(struct kvm_vcpu *vcpu, bool pmu_in_use);
-void kvmhv_load_guest_pmu(struct kvm_vcpu *vcpu);
-
 void kvmppc_p9_enter_guest(struct kvm_vcpu *vcpu);
 
 long kvmppc_h_set_dabr(struct kvm_vcpu *vcpu, unsigned long dabr);
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index f7349d150828..b1b94b3563b7 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3635,6 +3635,188 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	trace_kvmppc_run_core(vc, 1);
 }
 
+/*
+ * Privileged (non-hypervisor) host registers to save.
+ */
+struct p9_host_os_sprs {
+	unsigned long dscr;
+	unsigned long tidr;
+	unsigned long iamr;
+	unsigned long amr;
+	unsigned long fscr;
+
+	unsigned int pmc1;
+	unsigned int pmc2;
+	unsigned int pmc3;
+	unsigned int pmc4;
+	unsigned int pmc5;
+	unsigned int pmc6;
+	unsigned long mmcr0;
+	unsigned long mmcr1;
+	unsigned long mmcr2;
+	unsigned long mmcr3;
+	unsigned long mmcra;
+	unsigned long siar;
+	unsigned long sier1;
+	unsigned long sier2;
+	unsigned long sier3;
+	unsigned long sdar;
+};
+
+static void freeze_pmu(unsigned long mmcr0, unsigned long mmcra)
+{
+	if (!(mmcr0 & MMCR0_FC))
+		goto do_freeze;
+	if (mmcra & MMCRA_SAMPLE_ENABLE)
+		goto do_freeze;
+	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+		if (!(mmcr0 & MMCR0_PMCCEXT))
+			goto do_freeze;
+		if (!(mmcra & MMCRA_BHRB_DISABLE))
+			goto do_freeze;
+	}
+	return;
+
+do_freeze:
+	mmcr0 = MMCR0_FC;
+	mmcra = 0;
+	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+		mmcr0 |= MMCR0_PMCCEXT;
+		mmcra = MMCRA_BHRB_DISABLE;
+	}
+
+	mtspr(SPRN_MMCR0, mmcr0);
+	mtspr(SPRN_MMCRA, mmcra);
+	isync();
+}
+
+static void save_p9_host_pmu(struct p9_host_os_sprs *host_os_sprs)
+{
+	if (ppc_get_pmu_inuse()) {
+		/*
+		 * It might be better to put PMU handling (at least for the
+		 * host) in the perf subsystem because it knows more about what
+		 * is being used.
+		 */
+
+		/* POWER9, POWER10 do not implement HPMC or SPMC */
+
+		host_os_sprs->mmcr0 = mfspr(SPRN_MMCR0);
+		host_os_sprs->mmcra = mfspr(SPRN_MMCRA);
+
+		freeze_pmu(host_os_sprs->mmcr0, host_os_sprs->mmcra);
+
+		host_os_sprs->pmc1 = mfspr(SPRN_PMC1);
+		host_os_sprs->pmc2 = mfspr(SPRN_PMC2);
+		host_os_sprs->pmc3 = mfspr(SPRN_PMC3);
+		host_os_sprs->pmc4 = mfspr(SPRN_PMC4);
+		host_os_sprs->pmc5 = mfspr(SPRN_PMC5);
+		host_os_sprs->pmc6 = mfspr(SPRN_PMC6);
+		host_os_sprs->mmcr1 = mfspr(SPRN_MMCR1);
+		host_os_sprs->mmcr2 = mfspr(SPRN_MMCR2);
+		host_os_sprs->sdar = mfspr(SPRN_SDAR);
+		host_os_sprs->siar = mfspr(SPRN_SIAR);
+		host_os_sprs->sier1 = mfspr(SPRN_SIER);
+
+		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+			host_os_sprs->mmcr3 = mfspr(SPRN_MMCR3);
+			host_os_sprs->sier2 = mfspr(SPRN_SIER2);
+			host_os_sprs->sier3 = mfspr(SPRN_SIER3);
+		}
+	}
+}
+
+static void load_p9_guest_pmu(struct kvm_vcpu *vcpu)
+{
+	mtspr(SPRN_PMC1, vcpu->arch.pmc[0]);
+	mtspr(SPRN_PMC2, vcpu->arch.pmc[1]);
+	mtspr(SPRN_PMC3, vcpu->arch.pmc[2]);
+	mtspr(SPRN_PMC4, vcpu->arch.pmc[3]);
+	mtspr(SPRN_PMC5, vcpu->arch.pmc[4]);
+	mtspr(SPRN_PMC6, vcpu->arch.pmc[5]);
+	mtspr(SPRN_MMCR1, vcpu->arch.mmcr[1]);
+	mtspr(SPRN_MMCR2, vcpu->arch.mmcr[2]);
+	mtspr(SPRN_SDAR, vcpu->arch.sdar);
+	mtspr(SPRN_SIAR, vcpu->arch.siar);
+	mtspr(SPRN_SIER, vcpu->arch.sier[0]);
+
+	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+		mtspr(SPRN_MMCR3, vcpu->arch.mmcr[4]);
+		mtspr(SPRN_SIER2, vcpu->arch.sier[1]);
+		mtspr(SPRN_SIER3, vcpu->arch.sier[2]);
+	}
+
+	/* Set MMCRA then MMCR0 last */
+	mtspr(SPRN_MMCRA, vcpu->arch.mmcra);
+	mtspr(SPRN_MMCR0, vcpu->arch.mmcr[0]);
+	/* No isync necessary because we're starting counters */
+}
+
+static void save_p9_guest_pmu(struct kvm_vcpu *vcpu)
+{
+	struct lppaca *lp;
+	int save_pmu = 1;
+
+	lp = vcpu->arch.vpa.pinned_addr;
+	if (lp)
+		save_pmu = lp->pmcregs_in_use;
+
+	if (save_pmu) {
+		vcpu->arch.mmcr[0] = mfspr(SPRN_MMCR0);
+		vcpu->arch.mmcra = mfspr(SPRN_MMCRA);
+
+		freeze_pmu(vcpu->arch.mmcr[0], vcpu->arch.mmcra);
+
+		vcpu->arch.pmc[0] = mfspr(SPRN_PMC1);
+		vcpu->arch.pmc[1] = mfspr(SPRN_PMC2);
+		vcpu->arch.pmc[2] = mfspr(SPRN_PMC3);
+		vcpu->arch.pmc[3] = mfspr(SPRN_PMC4);
+		vcpu->arch.pmc[4] = mfspr(SPRN_PMC5);
+		vcpu->arch.pmc[5] = mfspr(SPRN_PMC6);
+		vcpu->arch.mmcr[1] = mfspr(SPRN_MMCR1);
+		vcpu->arch.mmcr[2] = mfspr(SPRN_MMCR2);
+		vcpu->arch.sdar = mfspr(SPRN_SDAR);
+		vcpu->arch.siar = mfspr(SPRN_SIAR);
+		vcpu->arch.sier[0] = mfspr(SPRN_SIER);
+
+		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+			vcpu->arch.mmcr[3] = mfspr(SPRN_MMCR3);
+			vcpu->arch.sier[1] = mfspr(SPRN_SIER2);
+			vcpu->arch.sier[2] = mfspr(SPRN_SIER3);
+		}
+	} else {
+		freeze_pmu(mfspr(SPRN_MMCR0), mfspr(SPRN_MMCRA));
+	}
+}
+
+static void load_p9_host_pmu(struct p9_host_os_sprs *host_os_sprs)
+{
+	if (ppc_get_pmu_inuse()) {
+		mtspr(SPRN_PMC1, host_os_sprs->pmc1);
+		mtspr(SPRN_PMC2, host_os_sprs->pmc2);
+		mtspr(SPRN_PMC3, host_os_sprs->pmc3);
+		mtspr(SPRN_PMC4, host_os_sprs->pmc4);
+		mtspr(SPRN_PMC5, host_os_sprs->pmc5);
+		mtspr(SPRN_PMC6, host_os_sprs->pmc6);
+		mtspr(SPRN_MMCR1, host_os_sprs->mmcr1);
+		mtspr(SPRN_MMCR2, host_os_sprs->mmcr2);
+		mtspr(SPRN_SDAR, host_os_sprs->sdar);
+		mtspr(SPRN_SIAR, host_os_sprs->siar);
+		mtspr(SPRN_SIER, host_os_sprs->sier1);
+
+		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+			mtspr(SPRN_MMCR3, host_os_sprs->mmcr3);
+			mtspr(SPRN_SIER2, host_os_sprs->sier2);
+			mtspr(SPRN_SIER3, host_os_sprs->sier3);
+		}
+
+		/* Set MMCRA then MMCR0 last */
+		mtspr(SPRN_MMCRA, host_os_sprs->mmcra);
+		mtspr(SPRN_MMCR0, host_os_sprs->mmcr0);
+		isync();
+	}
+}
+
 static void load_spr_state(struct kvm_vcpu *vcpu)
 {
 	mtspr(SPRN_DSCR, vcpu->arch.dscr);
@@ -3677,17 +3859,6 @@ static void store_spr_state(struct kvm_vcpu *vcpu)
 	vcpu->arch.dscr = mfspr(SPRN_DSCR);
 }
 
-/*
- * Privileged (non-hypervisor) host registers to save.
- */
-struct p9_host_os_sprs {
-	unsigned long dscr;
-	unsigned long tidr;
-	unsigned long iamr;
-	unsigned long amr;
-	unsigned long fscr;
-};
-
 static void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
 {
 	host_os_sprs->dscr = mfspr(SPRN_DSCR);
@@ -3735,7 +3906,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	struct p9_host_os_sprs host_os_sprs;
 	s64 dec;
 	u64 tb, next_timer;
-	int trap, save_pmu;
+	int trap;
 
 	WARN_ON_ONCE(vcpu->arch.ceded);
 
@@ -3748,7 +3919,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	save_p9_host_os_sprs(&host_os_sprs);
 
-	kvmhv_save_host_pmu();		/* saves it to PACA kvm_hstate */
+	save_p9_host_pmu(&host_os_sprs);
 
 	kvmppc_subcore_enter_guest();
 
@@ -3776,7 +3947,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		}
 	}
 #endif
-	kvmhv_load_guest_pmu(vcpu);
+	load_p9_guest_pmu(vcpu);
 
 	msr_check_and_set(MSR_FP | MSR_VEC | MSR_VSX);
 	load_fp_state(&vcpu->arch.fp);
@@ -3898,16 +4069,14 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
 		kvmppc_save_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
 
-	save_pmu = 1;
 	if (vcpu->arch.vpa.pinned_addr) {
 		struct lppaca *lp = vcpu->arch.vpa.pinned_addr;
 		u32 yield_count = be32_to_cpu(lp->yield_count) + 1;
 		lp->yield_count = cpu_to_be32(yield_count);
 		vcpu->arch.vpa.dirty = 1;
-		save_pmu = lp->pmcregs_in_use;
 	}
 
-	kvmhv_save_guest_pmu(vcpu, save_pmu);
+	save_p9_guest_pmu(vcpu);
 #ifdef CONFIG_PPC_PSERIES
 	if (kvmhv_on_pseries())
 		get_lppaca()->pmcregs_in_use = ppc_get_pmu_inuse();
@@ -3920,7 +4089,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
 
-	kvmhv_load_host_pmu();
+	load_p9_host_pmu(&host_os_sprs);
 
 	kvmppc_subcore_exit_guest();
 
diff --git a/arch/powerpc/kvm/book3s_hv_interrupts.S b/arch/powerpc/kvm/book3s_hv_interrupts.S
index 4444f83cb133..59d89e4b154a 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupts.S
+++ b/arch/powerpc/kvm/book3s_hv_interrupts.S
@@ -104,7 +104,10 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	mtlr	r0
 	blr
 
-_GLOBAL(kvmhv_save_host_pmu)
+/*
+ * void kvmhv_save_host_pmu(void)
+ */
+kvmhv_save_host_pmu:
 BEGIN_FTR_SECTION
 	/* Work around P8 PMAE bug */
 	li	r3, -1
@@ -138,14 +141,6 @@ BEGIN_FTR_SECTION
 	std	r8, HSTATE_MMCR2(r13)
 	std	r9, HSTATE_SIER(r13)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
-BEGIN_FTR_SECTION
-	mfspr	r5, SPRN_MMCR3
-	mfspr	r6, SPRN_SIER2
-	mfspr	r7, SPRN_SIER3
-	std	r5, HSTATE_MMCR3(r13)
-	std	r6, HSTATE_SIER2(r13)
-	std	r7, HSTATE_SIER3(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31)
 	mfspr	r3, SPRN_PMC1
 	mfspr	r5, SPRN_PMC2
 	mfspr	r6, SPRN_PMC3
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 007f87b97184..0eb06734bc26 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -2780,10 +2780,11 @@ kvmppc_msr_interrupt:
 	blr
 
 /*
+ * void kvmhv_load_guest_pmu(struct kvm_vcpu *vcpu)
+ *
  * Load up guest PMU state.  R3 points to the vcpu struct.
  */
-_GLOBAL(kvmhv_load_guest_pmu)
-EXPORT_SYMBOL_GPL(kvmhv_load_guest_pmu)
+kvmhv_load_guest_pmu:
 	mr	r4, r3
 	mflr	r0
 	li	r3, 1
@@ -2817,27 +2818,17 @@ END_FTR_SECTION_IFSET(CPU_FTR_PMAO_BUG)
 	mtspr	SPRN_MMCRA, r6
 	mtspr	SPRN_SIAR, r7
 	mtspr	SPRN_SDAR, r8
-BEGIN_FTR_SECTION
-	ld      r5, VCPU_MMCR + 24(r4)
-	ld      r6, VCPU_SIER + 8(r4)
-	ld      r7, VCPU_SIER + 16(r4)
-	mtspr   SPRN_MMCR3, r5
-	mtspr   SPRN_SIER2, r6
-	mtspr   SPRN_SIER3, r7
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31)
 BEGIN_FTR_SECTION
 	ld	r5, VCPU_MMCR + 16(r4)
 	ld	r6, VCPU_SIER(r4)
 	mtspr	SPRN_MMCR2, r5
 	mtspr	SPRN_SIER, r6
-BEGIN_FTR_SECTION_NESTED(96)
 	lwz	r7, VCPU_PMC + 24(r4)
 	lwz	r8, VCPU_PMC + 28(r4)
 	ld	r9, VCPU_MMCRS(r4)
 	mtspr	SPRN_SPMC1, r7
 	mtspr	SPRN_SPMC2, r8
 	mtspr	SPRN_MMCRS, r9
-END_FTR_SECTION_NESTED(CPU_FTR_ARCH_300, 0, 96)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 	mtspr	SPRN_MMCR0, r3
 	isync
@@ -2845,10 +2836,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 	blr
 
 /*
+ * void kvmhv_load_host_pmu(void)
+ *
  * Reload host PMU state saved in the PACA by kvmhv_save_host_pmu.
  */
-_GLOBAL(kvmhv_load_host_pmu)
-EXPORT_SYMBOL_GPL(kvmhv_load_host_pmu)
+kvmhv_load_host_pmu:
 	mflr	r0
 	lbz	r4, PACA_PMCINUSE(r13) /* is the host using the PMU? */
 	cmpwi	r4, 0
@@ -2886,25 +2878,18 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_MMCR2, r8
 	mtspr	SPRN_SIER, r9
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
-BEGIN_FTR_SECTION
-	ld      r5, HSTATE_MMCR3(r13)
-	ld      r6, HSTATE_SIER2(r13)
-	ld      r7, HSTATE_SIER3(r13)
-	mtspr   SPRN_MMCR3, r5
-	mtspr   SPRN_SIER2, r6
-	mtspr   SPRN_SIER3, r7
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31)
 	mtspr	SPRN_MMCR0, r3
 	isync
 	mtlr	r0
 23:	blr
 
 /*
+ * void kvmhv_save_guest_pmu(struct kvm_vcpu *vcpu, bool pmu_in_use)
+ *
  * Save guest PMU state into the vcpu struct.
  * r3 = vcpu, r4 = full save flag (PMU in use flag set in VPA)
  */
-_GLOBAL(kvmhv_save_guest_pmu)
-EXPORT_SYMBOL_GPL(kvmhv_save_guest_pmu)
+kvmhv_save_guest_pmu:
 	mr	r9, r3
 	mr	r8, r4
 BEGIN_FTR_SECTION
@@ -2953,14 +2938,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 BEGIN_FTR_SECTION
 	std	r10, VCPU_MMCR + 16(r9)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
-BEGIN_FTR_SECTION
-	mfspr   r5, SPRN_MMCR3
-	mfspr   r6, SPRN_SIER2
-	mfspr   r7, SPRN_SIER3
-	std     r5, VCPU_MMCR + 24(r9)
-	std     r6, VCPU_SIER + 8(r9)
-	std     r7, VCPU_SIER + 16(r9)
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31)
 	std	r7, VCPU_SIAR(r9)
 	std	r8, VCPU_SDAR(r9)
 	mfspr	r3, SPRN_PMC1
@@ -2978,7 +2955,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31)
 BEGIN_FTR_SECTION
 	mfspr	r5, SPRN_SIER
 	std	r5, VCPU_SIER(r9)
-BEGIN_FTR_SECTION_NESTED(96)
 	mfspr	r6, SPRN_SPMC1
 	mfspr	r7, SPRN_SPMC2
 	mfspr	r8, SPRN_MMCRS
@@ -2987,7 +2963,6 @@ BEGIN_FTR_SECTION_NESTED(96)
 	std	r8, VCPU_MMCRS(r9)
 	lis	r4, 0x8000
 	mtspr	SPRN_MMCRS, r4
-END_FTR_SECTION_NESTED(CPU_FTR_ARCH_300, 0, 96)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 22:	blr
 
-- 
2.23.0