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

1 files changed, 31 insertions, 0 deletions

diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
index 9d0621417c2a..cc0cc95a0280 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 +166,23 @@ 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[],