/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef X86_CPU_USER_REGS_H
#define X86_CPU_USER_REGS_H

#include <xen/stdint.h>

/*
 * cpu_user_regs represents the interrupted GPR state at the point of an
 * interrupt, exception or syscall.  The layout is dictated by the hardware
 * format for the event frame, with software filling in the rest.
 */
struct cpu_user_regs
{
    union { uint64_t r15;    uint32_t r15d;   uint16_t r15w;  uint8_t r15b; };
    union { uint64_t r14;    uint32_t r14d;   uint16_t r14w;  uint8_t r14b; };
    union { uint64_t r13;    uint32_t r13d;   uint16_t r13w;  uint8_t r13b; };
    union { uint64_t r12;    uint32_t r12d;   uint16_t r12w;  uint8_t r12b; };
    union { uint64_t rbp;    uint32_t ebp;    uint16_t bp;    uint8_t bpl;  };
    union { uint64_t rbx;    uint32_t ebx;    uint16_t bx;    struct { uint8_t bl, bh; }; };
    union { uint64_t r11;    uint32_t r11d;   uint16_t r11w;  uint8_t r11b; };
    union { uint64_t r10;    uint32_t r10d;   uint16_t r10w;  uint8_t r10b; };
    union { uint64_t r9;     uint32_t r9d;    uint16_t r9w;   uint8_t r9b;  };
    union { uint64_t r8;     uint32_t r8d;    uint16_t r8w;   uint8_t r8b;  };
    union { uint64_t rax;    uint32_t eax;    uint16_t ax;    struct { uint8_t al, ah; }; };
    union { uint64_t rcx;    uint32_t ecx;    uint16_t cx;    struct { uint8_t cl, ch; }; };
    union { uint64_t rdx;    uint32_t edx;    uint16_t dx;    struct { uint8_t dl, dh; }; };
    union { uint64_t rsi;    uint32_t esi;    uint16_t si;    uint8_t sil;  };
    union { uint64_t rdi;    uint32_t edi;    uint16_t di;    uint8_t dil;  };

    /*
     * During IDT delivery for exceptions with an error code, hardware pushes
     * to this point.  Entry_vector is filled in by software.
     */

    uint32_t error_code;
    uint32_t entry_vector;

    /*
     * During IDT delivery for interrupts or exceptions without an error code,
     * hardware pushes to this point.  Both error_code and entry_vector are
     * filled in by software.
     */

    union { uint64_t rip;    uint32_t eip;    uint16_t ip; };
    uint16_t cs, _pad0[1];
    uint8_t  saved_upcall_mask; /* PV (v)rflags.IF == !saved_upcall_mask */
    uint8_t  _pad1[3];
    union { uint64_t rflags; uint32_t eflags; uint16_t flags; };
    union { uint64_t rsp;    uint32_t esp;    uint16_t sp;    uint8_t spl; };
    uint16_t ss, _pad2[3];

    /*
     * For IDT delivery, tss->rsp0 points to this boundary as embedded within
     * struct cpu_info.  It must be 16-byte aligned.
     */
};

static inline uint64_t msr_fold(const struct cpu_user_regs *regs)
{
    return (regs->rdx << 32) | regs->eax;
}

static inline void msr_split(struct cpu_user_regs *regs, uint64_t val)
{
    regs->rdx = val >> 32;
    regs->rax = (uint32_t)val;
}

#endif /* X86_CPU_USER_REGS_H */