[RFC PATCH 08/43] powerpc/64s: Keep AMOR SPR a constant ~0 at runtime
Nicholas Piggin
npiggin at gmail.com
Tue Jun 22 20:57:01 AEST 2021
This register controls supervisor SPR modifications, and as such is only
relevant for KVM. KVM always sets AMOR to ~0 on guest entry, and never
restores it coming back out to the host, so it can be kept constant and
avoid the mtSPR in KVM guest entry.
-21 cycles (9116) cycles POWER9 virt-mode NULL hcall
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
arch/powerpc/kernel/cpu_setup_power.c | 8 ++++++++
arch/powerpc/kernel/dt_cpu_ftrs.c | 2 ++
arch/powerpc/kvm/book3s_hv_p9_entry.c | 2 --
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 2 --
arch/powerpc/mm/book3s64/radix_pgtable.c | 15 ---------------
arch/powerpc/platforms/powernv/idle.c | 8 +++-----
6 files changed, 13 insertions(+), 24 deletions(-)
diff --git a/arch/powerpc/kernel/cpu_setup_power.c b/arch/powerpc/kernel/cpu_setup_power.c
index 3cca88ee96d7..a29dc8326622 100644
--- a/arch/powerpc/kernel/cpu_setup_power.c
+++ b/arch/powerpc/kernel/cpu_setup_power.c
@@ -137,6 +137,7 @@ void __setup_cpu_power7(unsigned long offset, struct cpu_spec *t)
return;
mtspr(SPRN_LPID, 0);
+ mtspr(SPRN_AMOR, ~0);
mtspr(SPRN_PCR, PCR_MASK);
init_LPCR_ISA206(mfspr(SPRN_LPCR), LPCR_LPES1 >> LPCR_LPES_SH);
}
@@ -150,6 +151,7 @@ void __restore_cpu_power7(void)
return;
mtspr(SPRN_LPID, 0);
+ mtspr(SPRN_AMOR, ~0);
mtspr(SPRN_PCR, PCR_MASK);
init_LPCR_ISA206(mfspr(SPRN_LPCR), LPCR_LPES1 >> LPCR_LPES_SH);
}
@@ -164,6 +166,7 @@ void __setup_cpu_power8(unsigned long offset, struct cpu_spec *t)
return;
mtspr(SPRN_LPID, 0);
+ mtspr(SPRN_AMOR, ~0);
mtspr(SPRN_PCR, PCR_MASK);
init_LPCR_ISA206(mfspr(SPRN_LPCR) | LPCR_PECEDH, 0); /* LPES = 0 */
init_HFSCR();
@@ -184,6 +187,7 @@ void __restore_cpu_power8(void)
return;
mtspr(SPRN_LPID, 0);
+ mtspr(SPRN_AMOR, ~0);
mtspr(SPRN_PCR, PCR_MASK);
init_LPCR_ISA206(mfspr(SPRN_LPCR) | LPCR_PECEDH, 0); /* LPES = 0 */
init_HFSCR();
@@ -202,6 +206,7 @@ void __setup_cpu_power9(unsigned long offset, struct cpu_spec *t)
mtspr(SPRN_PSSCR, 0);
mtspr(SPRN_LPID, 0);
mtspr(SPRN_PID, 0);
+ mtspr(SPRN_AMOR, ~0);
mtspr(SPRN_PCR, PCR_MASK);
init_LPCR_ISA300((mfspr(SPRN_LPCR) | LPCR_PECEDH | LPCR_PECE_HVEE |\
LPCR_HVICE | LPCR_HEIC) & ~(LPCR_UPRT | LPCR_HR), 0);
@@ -223,6 +228,7 @@ void __restore_cpu_power9(void)
mtspr(SPRN_PSSCR, 0);
mtspr(SPRN_LPID, 0);
mtspr(SPRN_PID, 0);
+ mtspr(SPRN_AMOR, ~0);
mtspr(SPRN_PCR, PCR_MASK);
init_LPCR_ISA300((mfspr(SPRN_LPCR) | LPCR_PECEDH | LPCR_PECE_HVEE |\
LPCR_HVICE | LPCR_HEIC) & ~(LPCR_UPRT | LPCR_HR), 0);
@@ -242,6 +248,7 @@ void __setup_cpu_power10(unsigned long offset, struct cpu_spec *t)
mtspr(SPRN_PSSCR, 0);
mtspr(SPRN_LPID, 0);
mtspr(SPRN_PID, 0);
+ mtspr(SPRN_AMOR, ~0);
mtspr(SPRN_PCR, PCR_MASK);
init_LPCR_ISA300((mfspr(SPRN_LPCR) | LPCR_PECEDH | LPCR_PECE_HVEE |\
LPCR_HVICE | LPCR_HEIC) & ~(LPCR_UPRT | LPCR_HR), 0);
@@ -264,6 +271,7 @@ void __restore_cpu_power10(void)
mtspr(SPRN_PSSCR, 0);
mtspr(SPRN_LPID, 0);
mtspr(SPRN_PID, 0);
+ mtspr(SPRN_AMOR, ~0);
mtspr(SPRN_PCR, PCR_MASK);
init_LPCR_ISA300((mfspr(SPRN_LPCR) | LPCR_PECEDH | LPCR_PECE_HVEE |\
LPCR_HVICE | LPCR_HEIC) & ~(LPCR_UPRT | LPCR_HR), 0);
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c
index 358aee7c2d79..0a6b36b4bda8 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -80,6 +80,7 @@ static void __restore_cpu_cpufeatures(void)
mtspr(SPRN_LPCR, system_registers.lpcr);
if (hv_mode) {
mtspr(SPRN_LPID, 0);
+ mtspr(SPRN_AMOR, ~0);
mtspr(SPRN_HFSCR, system_registers.hfscr);
mtspr(SPRN_PCR, system_registers.pcr);
}
@@ -216,6 +217,7 @@ static int __init feat_enable_hv(struct dt_cpu_feature *f)
}
mtspr(SPRN_LPID, 0);
+ mtspr(SPRN_AMOR, ~0);
lpcr = mfspr(SPRN_LPCR);
lpcr &= ~LPCR_LPES0; /* HV external interrupts */
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index c4f3e066fcb4..a3281f0c9214 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -286,8 +286,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
- mtspr(SPRN_AMOR, ~0UL);
-
local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_HV_P9;
/*
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 8dd437d7a2c6..007f87b97184 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -772,10 +772,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
/* Restore AMR and UAMOR, set AMOR to all 1s */
ld r5,VCPU_AMR(r4)
ld r6,VCPU_UAMOR(r4)
- li r7,-1
mtspr SPRN_AMR,r5
mtspr SPRN_UAMOR,r6
- mtspr SPRN_AMOR,r7
/* Restore state of CTRL run bit; assume 1 on entry */
lwz r5,VCPU_CTRL(r4)
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index fe236c38ce00..b985cfead5d7 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -566,18 +566,6 @@ void __init radix__early_init_devtree(void)
return;
}
-static void radix_init_amor(void)
-{
- /*
- * In HV mode, we init AMOR (Authority Mask Override Register) so that
- * the hypervisor and guest can setup IAMR (Instruction Authority Mask
- * Register), enable key 0 and set it to 1.
- *
- * AMOR = 0b1100 .... 0000 (Mask for key 0 is 11)
- */
- mtspr(SPRN_AMOR, (3ul << 62));
-}
-
void __init radix__early_init_mmu(void)
{
unsigned long lpcr;
@@ -638,7 +626,6 @@ void __init radix__early_init_mmu(void)
lpcr = mfspr(SPRN_LPCR);
mtspr(SPRN_LPCR, lpcr | LPCR_UPRT | LPCR_HR);
radix_init_partition_table();
- radix_init_amor();
} else {
radix_init_pseries();
}
@@ -662,8 +649,6 @@ void radix__early_init_mmu_secondary(void)
set_ptcr_when_no_uv(__pa(partition_tb) |
(PATB_SIZE_SHIFT - 12));
-
- radix_init_amor();
}
radix__switch_mmu_context(NULL, &init_mm);
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 180baecad914..f791ca041854 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -306,8 +306,8 @@ struct p7_sprs {
/* per thread SPRs that get lost in shallow states */
u64 amr;
u64 iamr;
- u64 amor;
u64 uamor;
+ /* amor is restored to constant ~0 */
};
static unsigned long power7_idle_insn(unsigned long type)
@@ -378,7 +378,6 @@ static unsigned long power7_idle_insn(unsigned long type)
if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
sprs.amr = mfspr(SPRN_AMR);
sprs.iamr = mfspr(SPRN_IAMR);
- sprs.amor = mfspr(SPRN_AMOR);
sprs.uamor = mfspr(SPRN_UAMOR);
}
@@ -397,7 +396,7 @@ static unsigned long power7_idle_insn(unsigned long type)
*/
mtspr(SPRN_AMR, sprs.amr);
mtspr(SPRN_IAMR, sprs.iamr);
- mtspr(SPRN_AMOR, sprs.amor);
+ mtspr(SPRN_AMOR, ~0);
mtspr(SPRN_UAMOR, sprs.uamor);
}
}
@@ -687,7 +686,6 @@ static unsigned long power9_idle_stop(unsigned long psscr)
sprs.amr = mfspr(SPRN_AMR);
sprs.iamr = mfspr(SPRN_IAMR);
- sprs.amor = mfspr(SPRN_AMOR);
sprs.uamor = mfspr(SPRN_UAMOR);
srr1 = isa300_idle_stop_mayloss(psscr); /* go idle */
@@ -708,7 +706,7 @@ static unsigned long power9_idle_stop(unsigned long psscr)
*/
mtspr(SPRN_AMR, sprs.amr);
mtspr(SPRN_IAMR, sprs.iamr);
- mtspr(SPRN_AMOR, sprs.amor);
+ mtspr(SPRN_AMOR, ~0);
mtspr(SPRN_UAMOR, sprs.uamor);
/*
--
2.23.0
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