KVM: arm64: Refactor sys_regs.h,c for nVHE reuse

Refactor sys_regs.h and sys_regs.c to make it easier to reuse
common code. It will be used in nVHE in a later patch.

Note that the refactored code uses __inline_bsearch for find_reg
instead of bsearch to avoid copying the bsearch code for nVHE.

No functional change intended.

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210817081134.2918285-6-tabba@google.com
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 80a6e41..b6a2f8e 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -44,10 +44,6 @@
  * 64bit interface.
  */
 
-#define reg_to_encoding(x)						\
-	sys_reg((u32)(x)->Op0, (u32)(x)->Op1,				\
-		(u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2)
-
 static bool read_from_write_only(struct kvm_vcpu *vcpu,
 				 struct sys_reg_params *params,
 				 const struct sys_reg_desc *r)
@@ -1026,8 +1022,6 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu,
 	return true;
 }
 
-#define FEATURE(x)	(GENMASK_ULL(x##_SHIFT + 3, x##_SHIFT))
-
 /* 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)
@@ -1038,40 +1032,40 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
 	switch (id) {
 	case SYS_ID_AA64PFR0_EL1:
 		if (!vcpu_has_sve(vcpu))
-			val &= ~FEATURE(ID_AA64PFR0_SVE);
-		val &= ~FEATURE(ID_AA64PFR0_AMU);
-		val &= ~FEATURE(ID_AA64PFR0_CSV2);
-		val |= FIELD_PREP(FEATURE(ID_AA64PFR0_CSV2), (u64)vcpu->kvm->arch.pfr0_csv2);
-		val &= ~FEATURE(ID_AA64PFR0_CSV3);
-		val |= FIELD_PREP(FEATURE(ID_AA64PFR0_CSV3), (u64)vcpu->kvm->arch.pfr0_csv3);
+			val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_SVE);
+		val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_AMU);
+		val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_CSV2);
+		val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_CSV2), (u64)vcpu->kvm->arch.pfr0_csv2);
+		val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_CSV3);
+		val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_CSV3), (u64)vcpu->kvm->arch.pfr0_csv3);
 		break;
 	case SYS_ID_AA64PFR1_EL1:
-		val &= ~FEATURE(ID_AA64PFR1_MTE);
+		val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_MTE);
 		if (kvm_has_mte(vcpu->kvm)) {
 			u64 pfr, mte;
 
 			pfr = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1);
 			mte = cpuid_feature_extract_unsigned_field(pfr, ID_AA64PFR1_MTE_SHIFT);
-			val |= FIELD_PREP(FEATURE(ID_AA64PFR1_MTE), mte);
+			val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR1_MTE), mte);
 		}
 		break;
 	case SYS_ID_AA64ISAR1_EL1:
 		if (!vcpu_has_ptrauth(vcpu))
-			val &= ~(FEATURE(ID_AA64ISAR1_APA) |
-				 FEATURE(ID_AA64ISAR1_API) |
-				 FEATURE(ID_AA64ISAR1_GPA) |
-				 FEATURE(ID_AA64ISAR1_GPI));
+			val &= ~(ARM64_FEATURE_MASK(ID_AA64ISAR1_APA) |
+				 ARM64_FEATURE_MASK(ID_AA64ISAR1_API) |
+				 ARM64_FEATURE_MASK(ID_AA64ISAR1_GPA) |
+				 ARM64_FEATURE_MASK(ID_AA64ISAR1_GPI));
 		break;
 	case SYS_ID_AA64DFR0_EL1:
 		/* Limit debug to ARMv8.0 */
-		val &= ~FEATURE(ID_AA64DFR0_DEBUGVER);
-		val |= FIELD_PREP(FEATURE(ID_AA64DFR0_DEBUGVER), 6);
+		val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_DEBUGVER);
+		val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64DFR0_DEBUGVER), 6);
 		/* Limit guests to PMUv3 for ARMv8.4 */
 		val = cpuid_feature_cap_perfmon_field(val,
 						      ID_AA64DFR0_PMUVER_SHIFT,
 						      kvm_vcpu_has_pmu(vcpu) ? ID_AA64DFR0_PMUVER_8_4 : 0);
 		/* Hide SPE from guests */
-		val &= ~FEATURE(ID_AA64DFR0_PMSVER);
+		val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_PMSVER);
 		break;
 	case SYS_ID_DFR0_EL1:
 		/* Limit guests to PMUv3 for ARMv8.4 */
@@ -2106,23 +2100,6 @@ static int check_sysreg_table(const struct sys_reg_desc *table, unsigned int n,
 	return 0;
 }
 
-static int match_sys_reg(const void *key, const void *elt)
-{
-	const unsigned long pval = (unsigned long)key;
-	const struct sys_reg_desc *r = elt;
-
-	return pval - reg_to_encoding(r);
-}
-
-static const struct sys_reg_desc *find_reg(const struct sys_reg_params *params,
-					 const struct sys_reg_desc table[],
-					 unsigned int num)
-{
-	unsigned long pval = reg_to_encoding(params);
-
-	return bsearch((void *)pval, table, num, sizeof(table[0]), match_sys_reg);
-}
-
 int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu)
 {
 	kvm_inject_undefined(vcpu);
@@ -2365,13 +2342,8 @@ int kvm_handle_sys_reg(struct kvm_vcpu *vcpu)
 
 	trace_kvm_handle_sys_reg(esr);
 
-	params.Op0 = (esr >> 20) & 3;
-	params.Op1 = (esr >> 14) & 0x7;
-	params.CRn = (esr >> 10) & 0xf;
-	params.CRm = (esr >> 1) & 0xf;
-	params.Op2 = (esr >> 17) & 0x7;
+	params = esr_sys64_to_params(esr);
 	params.regval = vcpu_get_reg(vcpu, Rt);
-	params.is_write = !(esr & 1);
 
 	ret = emulate_sys_reg(vcpu, &params);