/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2012,2013 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * Derived from arch/arm/kvm/coproc.h
 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 * Authors: Christoffer Dall <c.dall@virtualopensystems.com>
 */

#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;
        u8      CRn;
        u8      CRm;
        u8      Op2;
        u64     regval;
        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;

        enum {
                AA32_ZEROHIGH,
                AA32_LO,
                AA32_HI,
        } aarch32_map;

        /* MRS/MSR instruction which accesses it. */
        u8      Op0;
        u8      Op1;
        u8      CRn;
        u8      CRm;
        u8      Op2;

        /* Trapped access from guest, if non-NULL. */
        bool (*access)(struct kvm_vcpu *,
                       struct sys_reg_params *,
                       const struct sys_reg_desc *);

        /* Initialization for vcpu. */
        void (*reset)(struct kvm_vcpu *, const struct sys_reg_desc *);

        /* Index into sys_reg[], or 0 if we don't need to save it. */
        int reg;

        /* Value (usually reset value) */
        u64 val;

        /* Custom get/set_user functions, fallback to generic if NULL */
        int (*get_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
                        const struct kvm_one_reg *reg, void __user *uaddr);
        int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
                        const struct kvm_one_reg *reg, void __user *uaddr);

        /* Return mask of REG_* runtime visibility overrides */
        unsigned int (*visibility)(const struct kvm_vcpu *vcpu,
                                   const struct sys_reg_desc *rd);
};

#define REG_HIDDEN              (1 << 0) /* hidden from userspace and guest */
#define REG_RAZ                 (1 << 1) /* RAZ from userspace and guest */

static __printf(2, 3)
inline void print_sys_reg_msg(const struct sys_reg_params *p,
                                       char *fmt, ...)
{
        va_list va;

        va_start(va, fmt);
        /* Look, we even formatted it for you to paste into the table! */
        kvm_pr_unimpl("%pV { Op0(%2u), Op1(%2u), CRn(%2u), CRm(%2u), Op2(%2u), func_%s },\n",
                      &(struct va_format){ fmt, &va },
                      p->Op0, p->Op1, p->CRn, p->CRm, p->Op2, p->is_write ? "write" : "read");
        va_end(va);
}

static inline void print_sys_reg_instr(const struct sys_reg_params *p)
{
        /* GCC warns on an empty format string */
        print_sys_reg_msg(p, "%s", "");
}

static inline bool ignore_write(struct kvm_vcpu *vcpu,
                                const struct sys_reg_params *p)
{
        return true;
}

static inline bool read_zero(struct kvm_vcpu *vcpu,
                             struct sys_reg_params *p)
{
        p->regval = 0;
        return true;
}

/* Reset functions */
static inline void reset_unknown(struct kvm_vcpu *vcpu,
                                 const struct sys_reg_desc *r)
{
        BUG_ON(!r->reg);
        BUG_ON(r->reg >= NR_SYS_REGS);
        __vcpu_sys_reg(vcpu, r->reg) = 0x1de7ec7edbadc0deULL;
}

static inline void reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
        BUG_ON(!r->reg);
        BUG_ON(r->reg >= NR_SYS_REGS);
        __vcpu_sys_reg(vcpu, r->reg) = r->val;
}

static inline bool sysreg_hidden(const struct kvm_vcpu *vcpu,
                                 const struct sys_reg_desc *r)
{
        if (likely(!r->visibility))
                return false;

        return r->visibility(vcpu, r) & REG_HIDDEN;
}

static inline bool sysreg_visible_as_raz(const struct kvm_vcpu *vcpu,
                                         const struct sys_reg_desc *r)
{
        if (likely(!r->visibility))
                return false;

        return r->visibility(vcpu, r) & REG_RAZ;
}

static inline int cmp_sys_reg(const struct sys_reg_desc *i1,
                              const struct sys_reg_desc *i2)
{
        BUG_ON(i1 == i2);
        if (!i1)
                return 1;
        else if (!i2)
                return -1;
        if (i1->Op0 != i2->Op0)
                return i1->Op0 - i2->Op0;
        if (i1->Op1 != i2->Op1)
                return i1->Op1 - i2->Op1;
        if (i1->CRn != i2->CRn)
                return i1->CRn - i2->CRn;
        if (i1->CRm != i2->CRm)
                return i1->CRm - i2->CRm;
        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[],
                                          unsigned int num);

#define AA32(_x)        .aarch32_map = AA32_##_x
#define Op0(_x)         .Op0 = _x
#define Op1(_x)         .Op1 = _x
#define CRn(_x)         .CRn = _x
#define CRm(_x)         .CRm = _x
#define Op2(_x)         .Op2 = _x

#define SYS_DESC(reg)                                   \
        .name = #reg,                                   \
        Op0(sys_reg_Op0(reg)), Op1(sys_reg_Op1(reg)),   \
        CRn(sys_reg_CRn(reg)), CRm(sys_reg_CRm(reg)),   \
        Op2(sys_reg_Op2(reg))

#endif /* __ARM64_KVM_SYS_REGS_LOCAL_H__ */