[PATCH v1 04/13] KVM: arm64: Refactor sys_regs.h,c for nVHE reuse

[Fuad Tabba <tabba@google.com>]

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.

No functional change intended.

Signed-off-by: Fuad Tabba <tabba@google.com>
---
 arch/arm64/kvm/sys_regs.c | 58 ++++++++++-----------------------------
 arch/arm64/kvm/sys_regs.h | 35 +++++++++++++++++++++++
 2 files changed, 50 insertions(+), 43 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 15c247fc9f0c..73d09bbd173c 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)
@@ -1038,33 +1032,33 @@ 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 &= ~SYS_FEATURE(ID_AA64PFR0_SVE);
+		val &= ~SYS_FEATURE(ID_AA64PFR0_AMU);
+		val &= ~SYS_FEATURE(ID_AA64PFR0_CSV2);
+		val |= FIELD_PREP(SYS_FEATURE(ID_AA64PFR0_CSV2), (u64)vcpu->kvm->arch.pfr0_csv2);
+		val &= ~SYS_FEATURE(ID_AA64PFR0_CSV3);
+		val |= FIELD_PREP(SYS_FEATURE(ID_AA64PFR0_CSV3), (u64)vcpu->kvm->arch.pfr0_csv3);
 		break;
 	case SYS_ID_AA64PFR1_EL1:
-		val &= ~FEATURE(ID_AA64PFR1_MTE);
+		val &= ~SYS_FEATURE(ID_AA64PFR1_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 &= ~(SYS_FEATURE(ID_AA64ISAR1_APA) |
+				 SYS_FEATURE(ID_AA64ISAR1_API) |
+				 SYS_FEATURE(ID_AA64ISAR1_GPA) |
+				 SYS_FEATURE(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 &= ~SYS_FEATURE(ID_AA64DFR0_DEBUGVER);
+		val |= FIELD_PREP(SYS_FEATURE(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 &= ~SYS_FEATURE(ID_AA64DFR0_PMSVER);
 		break;
 	case SYS_ID_DFR0_EL1:
 		/* Limit guests to PMUv3 for ARMv8.4 */
@@ -2082,23 +2076,6 @@ 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);
@@ -2341,13 +2318,8 @@ 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);
 
diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
index 9d0621417c2a..f7cde4436f32 100644
--- a/arch/arm64/kvm/sys_regs.h
+++ b/arch/arm64/kvm/sys_regs.h
@@ -11,6 +11,12 @@
 #ifndef __ARM64_KVM_SYS_REGS_LOCAL_H__
 #define __ARM64_KVM_SYS_REGS_LOCAL_H__
 
+#include <linux/bsearch.h>
+
+#define reg_to_encoding(x)						\
+	sys_reg((u32)(x)->Op0, (u32)(x)->Op1,				\
+		(u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2)
+
 struct sys_reg_params {
 	u8	Op0;
 	u8	Op1;
@@ -21,6 +27,14 @@ struct sys_reg_params {
 	bool	is_write;
 };
 
+#define esr_sys64_to_params(esr)                                               \
+	((struct sys_reg_params){ .Op0 = ((esr) >> 20) & 3,                    \
+				  .Op1 = ((esr) >> 14) & 0x7,                  \
+				  .CRn = ((esr) >> 10) & 0xf,                  \
+				  .CRm = ((esr) >> 1) & 0xf,                   \
+				  .Op2 = ((esr) >> 17) & 0x7,                  \
+				  .is_write = !((esr)&1) })
+
 struct sys_reg_desc {
 	/* Sysreg string for debug */
 	const char *name;
@@ -152,6 +166,24 @@ static inline int cmp_sys_reg(const struct sys_reg_desc *i1,
 	return i1->Op2 - i2->Op2;
 }
 
+static inline 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 inline 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 __inline_bsearch((void *)pval, table, num, sizeof(table[0]),
+				match_sys_reg);
+}
+
 const struct sys_reg_desc *find_reg_by_id(u64 id,
 					  struct sys_reg_params *params,
 					  const struct sys_reg_desc table[],
@@ -170,4 +202,7 @@ const struct sys_reg_desc *find_reg_by_id(u64 id,
 	CRn(sys_reg_CRn(reg)), CRm(sys_reg_CRm(reg)),	\
 	Op2(sys_reg_Op2(reg))
 
+/* Extract the feature specified from the feature id register. */
+#define SYS_FEATURE(x)	(GENMASK_ULL(x##_SHIFT + 3, x##_SHIFT))
+
 #endif /* __ARM64_KVM_SYS_REGS_LOCAL_H__ */
-- 
2.32.0.rc1.229.g3e70b5a671-goog