// Copyright 2016 The Fuchsia Authors
// Copyright (c) 2009 Corey Tabaka
// Copyright (c) 2015 Intel Corporation
// Copyright (c) 2016 Travis Geiselbrecht
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#pragma once

#include <cpuid.h>
#include <stdbool.h>
#include <stdlib.h>
#include <sys/types.h>
#include <zircon/compiler.h>
#include <zircon/types.h>

#include <arch/x86/general_regs.h>
#include <arch/x86/registers.h>
#include <arch/x86/x86intrin.h>
#include <syscalls/syscalls.h>

__BEGIN_CDECLS

#define X86_8BYTE_MASK 0xFFFFFFFF

struct x86_64_iframe {
    uint64_t rdi, rsi, rbp, rbx, rdx, rcx, rax;    // pushed by common handler
    uint64_t r8, r9, r10, r11, r12, r13, r14, r15; // pushed by common handler
    uint64_t vector;                               // pushed by stub
    uint64_t err_code;                             // pushed by interrupt or stub
    uint64_t ip, cs, flags;                        // pushed by interrupt
    uint64_t user_sp, user_ss;                     // pushed by interrupt
};

typedef struct x86_64_iframe x86_iframe_t;
typedef struct x86_64_iframe iframe_t;

void x86_exception_handler(x86_iframe_t* frame);
void platform_irq(x86_iframe_t* frame);

struct arch_exception_context {
    bool is_page_fault;
    x86_iframe_t* frame;
    uint64_t cr2;
};

// Register state layout used by x86_64_context_switch().
struct x86_64_context_switch_frame {
    uint64_t r15, r14, r13, r12;
    uint64_t rbp;
    uint64_t rbx;
    uint64_t rip;
};

void x86_64_context_switch(vaddr_t* oldsp, vaddr_t newsp);
void x86_uspace_entry(uintptr_t arg1, uintptr_t arg2, uintptr_t sp,
                      uintptr_t pc, uint64_t rflags) __NO_RETURN;

void x86_syscall(void);

void x86_syscall_process_pending_signals(x86_syscall_general_regs_t* gregs);

/* @brief Register all of the CPUs in the system
 *
 * Must be called only once.
 *
 * @param apic_ids A list of all APIC IDs in the system.  The BP should be in
 *        the list.
 * @param num_cpus The number of entries in the apic_ids list.
 */
void x86_init_smp(uint32_t* apic_ids, uint32_t num_cpus);

/* @brief Bring all of the specified APs up and hand them over to the kernel
 *
 * This function must not be called before x86_init_smp.
 *
 * May be called by any running CPU.  Due to requiring use of the very limited
 * low 1MB of memory, this function is not re-entrant.  Itshould not be executed
 * more than once concurrently.
 *
 * @param apic_ids A list of all APIC IDs to launch.
 * @param count The number of entries in the apic_ids list.
 *
 * @return ZX_ERR_INVALID_ARGS if an unknown APIC ID was provided.
 * @return ZX_ERR_BAD_STATE if one of the targets is currently online
 * @return ZX_ERR_TIMED_OUT if one of the targets failed to launch
 */
zx_status_t x86_bringup_aps(uint32_t* apic_ids, uint32_t count);

#define IO_BITMAP_BITS 65536
#define IO_BITMAP_BYTES (IO_BITMAP_BITS / 8)
#define IO_BITMAP_LONGS (IO_BITMAP_BITS / sizeof(long))

/*
 * Assignment of Interrupt Stack Table entries
 */
#define NUM_ASSIGNED_IST_ENTRIES 3
#define NMI_IST_INDEX 1
#define MCE_IST_INDEX 2
#define DBF_IST_INDEX 3

/*
 * x86-64 TSS structure
 */
typedef struct {
    uint32_t rsvd0;
    uint64_t rsp0;
    uint64_t rsp1;
    uint64_t rsp2;
    uint32_t rsvd1;
    uint32_t rsvd2;
    uint64_t ist1;
    uint64_t ist2;
    uint64_t ist3;
    uint64_t ist4;
    uint64_t ist5;
    uint64_t ist6;
    uint64_t ist7;
    uint32_t rsvd3;
    uint32_t rsvd4;
    uint16_t rsvd5;
    uint16_t iomap_base;

    uint8_t tss_bitmap[IO_BITMAP_BYTES + 1];
} __PACKED tss_64_t;

typedef tss_64_t tss_t;

static inline void x86_clts(void) {
    __asm__ __volatile__("clts");
}
static inline void x86_hlt(void) {
    __asm__ __volatile__("hlt");
}
static inline void x86_sti(void) {
    __asm__ __volatile__("sti");
}
static inline void x86_cli(void) {
    __asm__ __volatile__("cli");
}
static inline void x86_ltr(uint16_t sel) {
    __asm__ __volatile__("ltr %%ax" ::"a"(sel));
}
static inline void x86_lidt(uintptr_t base) {
    __asm volatile("lidt (%0)" ::"r"(base)
                   : "memory");
}
static inline void x86_lgdt(uintptr_t base)
{
    __asm volatile("lgdt (%0)" :: "r"(base) : "memory");
}

static inline uint8_t inp(uint16_t _port) {
    uint8_t rv;
    __asm__ __volatile__("inb %1, %0"
                         : "=a"(rv)
                         : "dN"(_port));
    return (rv);
}

static inline uint16_t inpw(uint16_t _port) {
    uint16_t rv;
    __asm__ __volatile__("inw %1, %0"
                         : "=a"(rv)
                         : "dN"(_port));
    return (rv);
}

static inline uint32_t inpd(uint16_t _port) {
    uint32_t rv;
    __asm__ __volatile__("inl %1, %0"
                         : "=a"(rv)
                         : "dN"(_port));
    return (rv);
}

static inline void outp(uint16_t _port, uint8_t _data) {
    __asm__ __volatile__("outb %1, %0"
                         :
                         : "dN"(_port),
                           "a"(_data));
}

static inline void outpw(uint16_t _port, uint16_t _data) {
    __asm__ __volatile__("outw %1, %0"
                         :
                         : "dN"(_port),
                           "a"(_data));
}

static inline void outpd(uint16_t _port, uint32_t _data) {
    __asm__ __volatile__("outl %1, %0"
                         :
                         : "dN"(_port),
                           "a"(_data));
}

static inline uint64_t rdtsc(void) {
    return __rdtsc();
}

static inline void cpuid(uint32_t sel, uint32_t* a, uint32_t* b, uint32_t* c, uint32_t* d) {
    __cpuid(sel, *a, *b, *c, *d);
}

/* cpuid wrapper with ecx set to a second argument */
static inline void cpuid_c(uint32_t sel, uint32_t sel_c, uint32_t* a, uint32_t* b, uint32_t* c, uint32_t* d) {
    __cpuid_count(sel, sel_c, *a, *b, *c, *d);
}

static inline void set_in_cr0(ulong mask) {
    ulong temp;

    __asm__ __volatile__(
        "mov %%cr0, %0  \n\t"
        "or %1, %0      \n\t"
        "mov %0, %%cr0   \n\t"
        : "=r"(temp)
        : "irg"(mask)
        :);
}

static inline void clear_in_cr0(ulong mask) {
    ulong temp;

    __asm__ __volatile__(
        "mov %%cr0, %0  \n\t"
        "and %1, %0     \n\t"
        "mov %0, %%cr0  \n\t"
        : "=r"(temp)
        : "irg"(~mask)
        :);
}

static inline ulong x86_get_cr2(void) {
    ulong rv;

    __asm__ __volatile__(
        "mov %%cr2, %0"
        : "=r"(rv));

    return rv;
}

static inline ulong x86_get_cr3(void) {
    ulong rv;

    __asm__ __volatile__(
        "mov %%cr3, %0"
        : "=r"(rv));
    return rv;
}

static inline void x86_set_cr3(ulong in_val) {
    __asm__ __volatile__(
        "mov %0,%%cr3 \n\t"
        :
        : "r"(in_val));
}

static inline ulong x86_get_cr0(void) {
    ulong rv;

    __asm__ __volatile__(
        "mov %%cr0, %0 \n\t"
        : "=r"(rv));
    return rv;
}

static inline ulong x86_get_cr4(void) {
    ulong rv;

    __asm__ __volatile__(
        "mov %%cr4, %0 \n\t"
        : "=r"(rv));
    return rv;
}

static inline void x86_set_cr0(ulong in_val) {
    __asm__ __volatile__(
        "mov %0,%%cr0 \n\t"
        :
        : "r"(in_val));
}

static inline void x86_set_cr4(ulong in_val) {
    __asm__ __volatile__(
        "mov %0,%%cr4 \n\t"
        :
        : "r"(in_val));
}

#define DEFINE_REGISTER_ACCESSOR(REG)              \
    static inline void set_##REG(uint16_t value) { \
        __asm__ volatile("mov %0, %%" #REG         \
                         :                         \
                         : "r"(value));            \
    }                                              \
    static inline uint16_t get_##REG(void) {       \
        uint16_t value;                            \
        __asm__ volatile("mov %%" #REG ", %0"      \
                         : "=r"(value));           \
        return value;                              \
    }

DEFINE_REGISTER_ACCESSOR(ds)
DEFINE_REGISTER_ACCESSOR(es)
DEFINE_REGISTER_ACCESSOR(fs)
DEFINE_REGISTER_ACCESSOR(gs)

#undef DEFINE_REGISTER_ACCESSOR

static inline uint64_t read_msr(uint32_t msr_id) {
    uint32_t msr_read_val_lo;
    uint32_t msr_read_val_hi;

    __asm__ __volatile__(
        "rdmsr \n\t"
        : "=a"(msr_read_val_lo), "=d"(msr_read_val_hi)
        : "c"(msr_id));

    return ((uint64_t)msr_read_val_hi << 32) | msr_read_val_lo;
}

static inline uint32_t read_msr32(uint32_t msr_id) {
    uint32_t msr_read_val;

    __asm__ __volatile__(
        "rdmsr \n\t"
        : "=a"(msr_read_val)
        : "c"(msr_id)
        : "rdx");

    return msr_read_val;
}

zx_status_t read_msr_safe(uint32_t msr_id, uint64_t* val);

static inline void write_msr(uint32_t msr_id, uint64_t msr_write_val) {
    __asm__ __volatile__(
        "wrmsr \n\t"
        :
        : "c"(msr_id), "a"(msr_write_val & 0xffffffff), "d"(msr_write_val >> 32));
}

static inline bool x86_is_paging_enabled(void) {
    if (x86_get_cr0() & X86_CR0_PG)
        return true;

    return false;
}

static inline bool x86_is_PAE_enabled(void) {
    if (x86_is_paging_enabled() == false)
        return false;

    if (!(x86_get_cr4() & X86_CR4_PAE))
        return false;

    return true;
}

static inline uint64_t x86_read_gs_offset64(uintptr_t offset) {
    uint64_t ret;
    __asm__("movq  %%gs:%1, %0"
            : "=r"(ret)
            : "m"(*(uint64_t*)(offset)));
    return ret;
}

static inline void x86_write_gs_offset64(uintptr_t offset, uint64_t val) {
    __asm__("movq  %0, %%gs:%1"
            :
            : "ir"(val), "m"(*(uint64_t*)(offset))
            : "memory");
}

static inline uint32_t x86_read_gs_offset32(uintptr_t offset) {
    uint32_t ret;
    __asm__("movl  %%gs:%1, %0"
            : "=r"(ret)
            : "m"(*(uint32_t*)(offset)));
    return ret;
}

static inline void x86_write_gs_offset32(uintptr_t offset, uint32_t val) {
    __asm__("movl   %0, %%gs:%1"
            :
            : "ir"(val), "m"(*(uint32_t*)(offset))
            : "memory");
}

typedef uint64_t x86_flags_t;

static inline uint64_t x86_save_flags(void) {
    uint64_t state;

    __asm__ volatile(
        "pushfq;"
        "popq %0"
        : "=rm"(state)::"memory");

    return state;
}

static inline void x86_restore_flags(uint64_t flags) {
    __asm__ volatile(
        "pushq %0;"
        "popfq" ::"g"(flags)
        : "memory", "cc");
}

static inline void inprep(uint16_t _port, uint8_t* _buffer, uint32_t _reads) {
    __asm__ __volatile__("pushfq \n\t"
                         "cli \n\t"
                         "cld \n\t"
                         "rep insb \n\t"
                         "popfq \n\t"
                         :
                         : "d"(_port),
                           "D"(_buffer),
                           "c"(_reads));
}

static inline void outprep(uint16_t _port, uint8_t* _buffer, uint32_t _writes) {
    __asm__ __volatile__("pushfq \n\t"
                         "cli \n\t"
                         "cld \n\t"
                         "rep outsb \n\t"
                         "popfq \n\t"
                         :
                         : "d"(_port),
                           "S"(_buffer),
                           "c"(_writes));
}

static inline void inpwrep(uint16_t _port, uint16_t* _buffer, uint32_t _reads) {
    __asm__ __volatile__("pushfq \n\t"
                         "cli \n\t"
                         "cld \n\t"
                         "rep insw \n\t"
                         "popfq \n\t"
                         :
                         : "d"(_port),
                           "D"(_buffer),
                           "c"(_reads));
}

static inline void outpwrep(uint16_t _port, uint16_t* _buffer,
                            uint32_t _writes) {
    __asm__ __volatile__("pushfq \n\t"
                         "cli \n\t"
                         "cld \n\t"
                         "rep outsw \n\t"
                         "popfq \n\t"
                         :
                         : "d"(_port),
                           "S"(_buffer),
                           "c"(_writes));
}

static inline void inpdrep(uint16_t _port, uint32_t* _buffer,
                           uint32_t _reads) {
    __asm__ __volatile__("pushfq \n\t"
                         "cli \n\t"
                         "cld \n\t"
                         "rep insl \n\t"
                         "popfq \n\t"
                         :
                         : "d"(_port),
                           "D"(_buffer),
                           "c"(_reads));
}

static inline void outpdrep(uint16_t _port, uint32_t* _buffer,
                            uint32_t _writes) {
    __asm__ __volatile__("pushfq \n\t"
                         "cli \n\t"
                         "cld \n\t"
                         "rep outsl \n\t"
                         "popfq \n\t"
                         :
                         : "d"(_port),
                           "S"(_buffer),
                           "c"(_writes));
}

void x86_monitor(volatile void* addr);
void x86_mwait(void);
void x86_idle(void);

__END_CDECLS