linux-kernel - [PATCH v3 3/7] KVM: arm64: Drop raz parameter from read_id

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Date:   Tue, 13 Sep 2022 09:44:36 +0000
From:   Oliver Upton <oliver.upton@...ux.dev>
To:     Marc Zyngier <maz@...nel.org>, James Morse <james.morse@....com>,
        Alexandru Elisei <alexandru.elisei@....com>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Oliver Upton <oliver.upton@...ux.dev>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>
Cc:     linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.cs.columbia.edu,
        kvm@...r.kernel.org, Reiji Watanabe <reijiw@...gle.com>,
        Andrew Jones <andrew.jones@...ux.dev>,
        linux-kernel@...r.kernel.org
Subject: [PATCH v3 3/7] KVM: arm64: Drop raz parameter from read_id_reg()

There is no longer a need for caller-specified RAZ visibility. Hoist the
call to sysreg_visible_as_raz() into read_id_reg() and drop the
parameter.

No functional change intended.

Suggested-by: Reiji Watanabe <reijiw@...gle.com>
Signed-off-by: Oliver Upton <oliver.upton@...ux.dev>
Reviewed-by: Reiji Watanabe <reijiw@...gle.com>
---
 arch/arm64/kvm/sys_regs.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 26210f3a0b27..0e20a311ea20 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1063,13 +1063,12 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu,
 }
 
 /* Read a sanitised cpufeature ID register by sys_reg_desc */
-static u64 read_id_reg(const struct kvm_vcpu *vcpu,
-		struct sys_reg_desc const *r, bool raz)
+static u64 read_id_reg(const struct kvm_vcpu *vcpu, struct sys_reg_desc const *r)
 {
 	u32 id = reg_to_encoding(r);
 	u64 val;
 
-	if (raz)
+	if (sysreg_visible_as_raz(vcpu, r))
 		return 0;
 
 	val = read_sanitised_ftr_reg(id);
@@ -1157,12 +1156,10 @@ static bool access_id_reg(struct kvm_vcpu *vcpu,
 			  struct sys_reg_params *p,
 			  const struct sys_reg_desc *r)
 {
-	bool raz = sysreg_visible_as_raz(vcpu, r);
-
 	if (p->is_write)
 		return write_to_read_only(vcpu, p, r);
 
-	p->regval = read_id_reg(vcpu, r, raz);
+	p->regval = read_id_reg(vcpu, r);
 	return true;
 }
 
@@ -1199,7 +1196,7 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
 		return -EINVAL;
 
 	/* We can only differ with CSV[23], and anything else is an error */
-	val ^= read_id_reg(vcpu, rd, false);
+	val ^= read_id_reg(vcpu, rd);
 	val &= ~((0xFUL << ID_AA64PFR0_CSV2_SHIFT) |
 		 (0xFUL << ID_AA64PFR0_CSV3_SHIFT));
 	if (val)
@@ -1221,19 +1218,15 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
 static int get_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 		      u64 *val)
 {
-	bool raz = sysreg_visible_as_raz(vcpu, rd);
-
-	*val = read_id_reg(vcpu, rd, raz);
+	*val = read_id_reg(vcpu, rd);
 	return 0;
 }
 
 static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 		      u64 val)
 {
-	bool raz = sysreg_visible_as_raz(vcpu, rd);
-
 	/* This is what we mean by invariant: you can't change it. */
-	if (val != read_id_reg(vcpu, rd, raz))
+	if (val != read_id_reg(vcpu, rd))
 		return -EINVAL;
 
 	return 0;
-- 
2.37.2.789.g6183377224-goog