/** @file
  GCC inline implementation of BaseLib processor specific functions that use
  privlidged instructions.

  Copyright (c) 2006 - 2021, Intel Corporation. All rights reserved.<BR>
  Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "BaseLibInternals.h"
#include <Library/RegisterFilterLib.h>

/**
  Enables CPU interrupts.

  Enables CPU interrupts.

**/
VOID
EFIAPI
EnableInterrupts (
  VOID
  )
{
  __asm__ __volatile__ ("sti"::: "memory");
}

/**
  Disables CPU interrupts.

  Disables CPU interrupts.

**/
VOID
EFIAPI
DisableInterrupts (
  VOID
  )
{
  __asm__ __volatile__ ("cli"::: "memory");
}

/**
  Returns a 64-bit Machine Specific Register(MSR).

  Reads and returns the 64-bit MSR specified by Index. No parameter checking is
  performed on Index, and some Index values may cause CPU exceptions. The
  caller must either guarantee that Index is valid, or the caller must set up
  exception handlers to catch the exceptions. This function is only available
  on IA-32 and X64.

  @param  Index The 32-bit MSR index to read.

  @return The value of the MSR identified by Index.

**/
UINT64
EFIAPI
AsmReadMsr64 (
  IN      UINT32  Index
  )
{
  UINT64   Data;
  BOOLEAN  Flag;

  Flag = FilterBeforeMsrRead (Index, &Data);
  if (Flag) {
    __asm__ __volatile__ (
      "rdmsr"
      : "=A" (Data)   // %0
      : "c"  (Index)  // %1
    );
  }

  FilterAfterMsrRead (Index, &Data);

  return Data;
}

/**
  Writes a 64-bit value to a Machine Specific Register(MSR), and returns the
  value.

  Writes the 64-bit value specified by Value to the MSR specified by Index. The
  64-bit value written to the MSR is returned. No parameter checking is
  performed on Index or Value, and some of these may cause CPU exceptions. The
  caller must either guarantee that Index and Value are valid, or the caller
  must establish proper exception handlers. This function is only available on
  IA-32 and X64.

  @param  Index The 32-bit MSR index to write.
  @param  Value The 64-bit value to write to the MSR.

  @return Value

**/
UINT64
EFIAPI
AsmWriteMsr64 (
  IN      UINT32  Index,
  IN      UINT64  Value
  )
{
  BOOLEAN  Flag;

  Flag = FilterBeforeMsrWrite (Index, &Value);
  if (Flag) {
    __asm__ __volatile__ (
      "wrmsr"
      :
      : "c" (Index),
        "A" (Value)
    );
  }

  FilterAfterMsrWrite (Index, &Value);

  return Value;
}

/**
  Reads the current value of the Control Register 0 (CR0).

  Reads and returns the current value of CR0. This function is only available
  on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on
  X64.

  @return The value of the Control Register 0 (CR0).

**/
UINTN
EFIAPI
AsmReadCr0 (
  VOID
  )
{
  UINTN  Data;

  __asm__ __volatile__ (
    "movl %%cr0,%0"
    : "=a" (Data)
  );

  return Data;
}

/**
  Reads the current value of the Control Register 2 (CR2).

  Reads and returns the current value of CR2. This function is only available
  on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on
  X64.

  @return The value of the Control Register 2 (CR2).

**/
UINTN
EFIAPI
AsmReadCr2 (
  VOID
  )
{
  UINTN  Data;

  __asm__ __volatile__ (
    "movl %%cr2, %0"
    : "=r" (Data)
  );

  return Data;
}

/**
  Reads the current value of the Control Register 3 (CR3).

  Reads and returns the current value of CR3. This function is only available
  on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on
  X64.

  @return The value of the Control Register 3 (CR3).

**/
UINTN
EFIAPI
AsmReadCr3 (
  VOID
  )
{
  UINTN  Data;

  __asm__ __volatile__ (
    "movl %%cr3, %0"
    : "=r" (Data)
  );

  return Data;
}

/**
  Reads the current value of the Control Register 4 (CR4).

  Reads and returns the current value of CR4. This function is only available
  on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on
  X64.

  @return The value of the Control Register 4 (CR4).

**/
UINTN
EFIAPI
AsmReadCr4 (
  VOID
  )
{
  UINTN  Data;

  __asm__ __volatile__ (
    "movl %%cr4, %0"
    : "=a" (Data)
  );

  return Data;
}

/**
  Writes a value to Control Register 0 (CR0).

  Writes and returns a new value to CR0. This function is only available on
  IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.

  @param  Cr0 The value to write to CR0.

  @return The value written to CR0.

**/
UINTN
EFIAPI
AsmWriteCr0 (
  UINTN  Cr0
  )
{
  __asm__ __volatile__ (
    "movl %0, %%cr0"
    :
    : "r" (Cr0)
  );
  return Cr0;
}

/**
  Writes a value to Control Register 2 (CR2).

  Writes and returns a new value to CR2. This function is only available on
  IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.

  @param  Cr2 The value to write to CR2.

  @return The value written to CR2.

**/
UINTN
EFIAPI
AsmWriteCr2 (
  UINTN  Cr2
  )
{
  __asm__ __volatile__ (
    "movl %0, %%cr2"
    :
    : "r" (Cr2)
  );
  return Cr2;
}

/**
  Writes a value to Control Register 3 (CR3).

  Writes and returns a new value to CR3. This function is only available on
  IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.

  @param  Cr3 The value to write to CR3.

  @return The value written to CR3.

**/
UINTN
EFIAPI
AsmWriteCr3 (
  UINTN  Cr3
  )
{
  __asm__ __volatile__ (
    "movl %0, %%cr3"
    :
    : "r" (Cr3)
  );
  return Cr3;
}

/**
  Writes a value to Control Register 4 (CR4).

  Writes and returns a new value to CR4. This function is only available on
  IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.

  @param  Cr4 The value to write to CR4.

  @return The value written to CR4.

**/
UINTN
EFIAPI
AsmWriteCr4 (
  UINTN  Cr4
  )
{
  __asm__ __volatile__ (
    "movl %0, %%cr4"
    :
    : "r" (Cr4)
  );
  return Cr4;
}

/**
  Reads the current value of Debug Register 0 (DR0).

  Reads and returns the current value of DR0. This function is only available
  on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on
  X64.

  @return The value of Debug Register 0 (DR0).

**/
UINTN
EFIAPI
AsmReadDr0 (
  VOID
  )
{
  UINTN  Data;

  __asm__ __volatile__ (
    "movl %%dr0, %0"
    : "=r" (Data)
  );

  return Data;
}

/**
  Reads the current value of Debug Register 1 (DR1).

  Reads and returns the current value of DR1. This function is only available
  on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on
  X64.

  @return The value of Debug Register 1 (DR1).

**/
UINTN
EFIAPI
AsmReadDr1 (
  VOID
  )
{
  UINTN  Data;

  __asm__ __volatile__ (
    "movl %%dr1, %0"
    : "=r" (Data)
  );

  return Data;
}

/**
  Reads the current value of Debug Register 2 (DR2).

  Reads and returns the current value of DR2. This function is only available
  on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on
  X64.

  @return The value of Debug Register 2 (DR2).

**/
UINTN
EFIAPI
AsmReadDr2 (
  VOID
  )
{
  UINTN  Data;

  __asm__ __volatile__ (
    "movl %%dr2, %0"
    : "=r" (Data)
  );

  return Data;
}

/**
  Reads the current value of Debug Register 3 (DR3).

  Reads and returns the current value of DR3. This function is only available
  on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on
  X64.

  @return The value of Debug Register 3 (DR3).

**/
UINTN
EFIAPI
AsmReadDr3 (
  VOID
  )
{
  UINTN  Data;

  __asm__ __volatile__ (
    "movl %%dr3, %0"
    : "=r" (Data)
  );

  return Data;
}

/**
  Reads the current value of Debug Register 4 (DR4).

  Reads and returns the current value of DR4. This function is only available
  on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on
  X64.

  @return The value of Debug Register 4 (DR4).

**/
UINTN
EFIAPI
AsmReadDr4 (
  VOID
  )
{
  UINTN  Data;

  __asm__ __volatile__ (
    "movl %%dr4, %0"
    : "=r" (Data)
  );

  return Data;
}

/**
  Reads the current value of Debug Register 5 (DR5).

  Reads and returns the current value of DR5. This function is only available
  on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on
  X64.

  @return The value of Debug Register 5 (DR5).

**/
UINTN
EFIAPI
AsmReadDr5 (
  VOID
  )
{
  UINTN  Data;

  __asm__ __volatile__ (
    "movl %%dr5, %0"
    : "=r" (Data)
  );

  return Data;
}

/**
  Reads the current value of Debug Register 6 (DR6).

  Reads and returns the current value of DR6. This function is only available
  on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on
  X64.

  @return The value of Debug Register 6 (DR6).

**/
UINTN
EFIAPI
AsmReadDr6 (
  VOID
  )
{
  UINTN  Data;

  __asm__ __volatile__ (
    "movl %%dr6, %0"
    : "=r" (Data)
  );

  return Data;
}

/**
  Reads the current value of Debug Register 7 (DR7).

  Reads and returns the current value of DR7. This function is only available
  on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on
  X64.

  @return The value of Debug Register 7 (DR7).

**/
UINTN
EFIAPI
AsmReadDr7 (
  VOID
  )
{
  UINTN  Data;

  __asm__ __volatile__ (
    "movl %%dr7, %0"
    : "=r" (Data)
  );

  return Data;
}

/**
  Writes a value to Debug Register 0 (DR0).

  Writes and returns a new value to DR0. This function is only available on
  IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.

  @param  Dr0 The value to write to Dr0.

  @return The value written to Debug Register 0 (DR0).

**/
UINTN
EFIAPI
AsmWriteDr0 (
  UINTN  Dr0
  )
{
  __asm__ __volatile__ (
    "movl %0, %%dr0"
    :
    : "r" (Dr0)
  );
  return Dr0;
}

/**
  Writes a value to Debug Register 1 (DR1).

  Writes and returns a new value to DR1. This function is only available on
  IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.

  @param  Dr1 The value to write to Dr1.

  @return The value written to Debug Register 1 (DR1).

**/
UINTN
EFIAPI
AsmWriteDr1 (
  UINTN  Dr1
  )
{
  __asm__ __volatile__ (
    "movl %0, %%dr1"
    :
    : "r" (Dr1)
  );
  return Dr1;
}

/**
  Writes a value to Debug Register 2 (DR2).

  Writes and returns a new value to DR2. This function is only available on
  IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.

  @param  Dr2 The value to write to Dr2.

  @return The value written to Debug Register 2 (DR2).

**/
UINTN
EFIAPI
AsmWriteDr2 (
  UINTN  Dr2
  )
{
  __asm__ __volatile__ (
    "movl %0, %%dr2"
    :
    : "r" (Dr2)
  );
  return Dr2;
}

/**
  Writes a value to Debug Register 3 (DR3).

  Writes and returns a new value to DR3. This function is only available on
  IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.

  @param  Dr3 The value to write to Dr3.

  @return The value written to Debug Register 3 (DR3).

**/
UINTN
EFIAPI
AsmWriteDr3 (
  UINTN  Dr3
  )
{
  __asm__ __volatile__ (
    "movl %0, %%dr3"
    :
    : "r" (Dr3)
  );
  return Dr3;
}

/**
  Writes a value to Debug Register 4 (DR4).

  Writes and returns a new value to DR4. This function is only available on
  IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.

  @param  Dr4 The value to write to Dr4.

  @return The value written to Debug Register 4 (DR4).

**/
UINTN
EFIAPI
AsmWriteDr4 (
  UINTN  Dr4
  )
{
  __asm__ __volatile__ (
    "movl %0, %%dr4"
    :
    : "r" (Dr4)
  );
  return Dr4;
}

/**
  Writes a value to Debug Register 5 (DR5).

  Writes and returns a new value to DR5. This function is only available on
  IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.

  @param  Dr5 The value to write to Dr5.

  @return The value written to Debug Register 5 (DR5).

**/
UINTN
EFIAPI
AsmWriteDr5 (
  UINTN  Dr5
  )
{
  __asm__ __volatile__ (
    "movl %0, %%dr5"
    :
    : "r" (Dr5)
  );
  return Dr5;
}

/**
  Writes a value to Debug Register 6 (DR6).

  Writes and returns a new value to DR6. This function is only available on
  IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.

  @param  Dr6 The value to write to Dr6.

  @return The value written to Debug Register 6 (DR6).

**/
UINTN
EFIAPI
AsmWriteDr6 (
  UINTN  Dr6
  )
{
  __asm__ __volatile__ (
    "movl %0, %%dr6"
    :
    : "r" (Dr6)
  );
  return Dr6;
}

/**
  Writes a value to Debug Register 7 (DR7).

  Writes and returns a new value to DR7. This function is only available on
  IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.

  @param  Dr7 The value to write to Dr7.

  @return The value written to Debug Register 7 (DR7).

**/
UINTN
EFIAPI
AsmWriteDr7 (
  UINTN  Dr7
  )
{
  __asm__ __volatile__ (
    "movl %0, %%dr7"
    :
    : "r" (Dr7)
  );
  return Dr7;
}

/**
  Reads the current value of Code Segment Register (CS).

  Reads and returns the current value of CS. This function is only available on
  IA-32 and X64.

  @return The current value of CS.

**/
UINT16
EFIAPI
AsmReadCs (
  VOID
  )
{
  UINT16  Data;

  __asm__ __volatile__ (
    "mov   %%cs, %0"
    :"=a" (Data)
  );

  return Data;
}

/**
  Reads the current value of Data Segment Register (DS).

  Reads and returns the current value of DS. This function is only available on
  IA-32 and X64.

  @return The current value of DS.

**/
UINT16
EFIAPI
AsmReadDs (
  VOID
  )
{
  UINT16  Data;

  __asm__ __volatile__ (
    "mov  %%ds, %0"
    :"=a" (Data)
  );

  return Data;
}

/**
  Reads the current value of Extra Segment Register (ES).

  Reads and returns the current value of ES. This function is only available on
  IA-32 and X64.

  @return The current value of ES.

**/
UINT16
EFIAPI
AsmReadEs (
  VOID
  )
{
  UINT16  Data;

  __asm__ __volatile__ (
    "mov  %%es, %0"
    :"=a" (Data)
  );

  return Data;
}

/**
  Reads the current value of FS Data Segment Register (FS).

  Reads and returns the current value of FS. This function is only available on
  IA-32 and X64.

  @return The current value of FS.

**/
UINT16
EFIAPI
AsmReadFs (
  VOID
  )
{
  UINT16  Data;

  __asm__ __volatile__ (
    "mov  %%fs, %0"
    :"=a" (Data)
  );

  return Data;
}

/**
  Reads the current value of GS Data Segment Register (GS).

  Reads and returns the current value of GS. This function is only available on
  IA-32 and X64.

  @return The current value of GS.

**/
UINT16
EFIAPI
AsmReadGs (
  VOID
  )
{
  UINT16  Data;

  __asm__ __volatile__ (
    "mov  %%gs, %0"
    :"=a" (Data)
  );

  return Data;
}

/**
  Reads the current value of Stack Segment Register (SS).

  Reads and returns the current value of SS. This function is only available on
  IA-32 and X64.

  @return The current value of SS.

**/
UINT16
EFIAPI
AsmReadSs (
  VOID
  )
{
  UINT16  Data;

  __asm__ __volatile__ (
    "mov  %%ss, %0"
    :"=a" (Data)
  );

  return Data;
}

/**
  Reads the current value of Task Register (TR).

  Reads and returns the current value of TR. This function is only available on
  IA-32 and X64.

  @return The current value of TR.

**/
UINT16
EFIAPI
AsmReadTr (
  VOID
  )
{
  UINT16  Data;

  __asm__ __volatile__ (
    "str  %0"
    : "=a" (Data)
  );

  return Data;
}

/**
  Reads the current Global Descriptor Table Register(GDTR) descriptor.

  Reads and returns the current GDTR descriptor and returns it in Gdtr. This
  function is only available on IA-32 and X64.

  @param  Gdtr  The pointer to a GDTR descriptor.

**/
VOID
EFIAPI
InternalX86ReadGdtr (
  OUT     IA32_DESCRIPTOR  *Gdtr
  )
{
  __asm__ __volatile__ (
    "sgdt %0"
    : "=m" (*Gdtr)
  );
}

/**
  Writes the current Global Descriptor Table Register (GDTR) descriptor.

  Writes and the current GDTR descriptor specified by Gdtr. This function is
  only available on IA-32 and X64.

  @param  Gdtr  The pointer to a GDTR descriptor.

**/
VOID
EFIAPI
InternalX86WriteGdtr (
  IN      CONST IA32_DESCRIPTOR  *Gdtr
  )
{
  __asm__ __volatile__ (
    "lgdt %0"
    :
    : "m" (*Gdtr)
  );
}

/**
  Reads the current Interrupt Descriptor Table Register(GDTR) descriptor.

  Reads and returns the current IDTR descriptor and returns it in Idtr. This
  function is only available on IA-32 and X64.

  @param  Idtr  The pointer to a IDTR descriptor.

**/
VOID
EFIAPI
InternalX86ReadIdtr (
  OUT     IA32_DESCRIPTOR  *Idtr
  )
{
  __asm__ __volatile__ (
    "sidt  %0"
    : "=m" (*Idtr)
  );
}

/**
  Writes the current Interrupt Descriptor Table Register(GDTR) descriptor.

  Writes the current IDTR descriptor and returns it in Idtr. This function is
  only available on IA-32 and X64.

  @param  Idtr  The pointer to a IDTR descriptor.

**/
VOID
EFIAPI
InternalX86WriteIdtr (
  IN      CONST IA32_DESCRIPTOR  *Idtr
  )
{
  __asm__ __volatile__ (
    "lidt %0"
    :
    : "m" (*Idtr)
  );
}

/**
  Reads the current Local Descriptor Table Register(LDTR) selector.

  Reads and returns the current 16-bit LDTR descriptor value. This function is
  only available on IA-32 and X64.

  @return The current selector of LDT.

**/
UINT16
EFIAPI
AsmReadLdtr (
  VOID
  )
{
  UINT16  Data;

  __asm__ __volatile__ (
    "sldt  %0"
    : "=g" (Data)   // %0
  );

  return Data;
}

/**
  Writes the current Local Descriptor Table Register (GDTR) selector.

  Writes and the current LDTR descriptor specified by Ldtr. This function is
  only available on IA-32 and X64.

  @param  Ldtr  16-bit LDTR selector value.

**/
VOID
EFIAPI
AsmWriteLdtr (
  IN      UINT16  Ldtr
  )
{
  __asm__ __volatile__ (
    "lldtw  %0"
    :
    : "g" (Ldtr)   // %0
  );
}

/**
  Reads the current value of a Performance Counter (PMC).

  Reads and returns the current value of performance counter specified by
  Index. This function is only available on IA-32 and X64.

  @param  Index The 32-bit Performance Counter index to read.

  @return The value of the PMC specified by Index.

**/
UINT64
EFIAPI
AsmReadPmc (
  IN      UINT32  Index
  )
{
  UINT64  Data;

  __asm__ __volatile__ (
    "rdpmc"
    : "=A" (Data)
    : "c"  (Index)
  );

  return Data;
}

/**
  Executes a WBINVD instruction.

  Executes a WBINVD instruction. This function is only available on IA-32 and
  X64.

**/
VOID
EFIAPI
AsmWbinvd (
  VOID
  )
{
  __asm__ __volatile__ ("wbinvd":::"memory");
}

/**
  Executes a INVD instruction.

  Executes a INVD instruction. This function is only available on IA-32 and
  X64.

**/
VOID
EFIAPI
AsmInvd (
  VOID
  )
{
  __asm__ __volatile__ ("invd":::"memory");
}

/**
  Flushes a cache line from all the instruction and data caches within the
  coherency domain of the CPU.

  Flushed the cache line specified by LinearAddress, and returns LinearAddress.
  This function is only available on IA-32 and X64.

  @param  LinearAddress The address of the cache line to flush. If the CPU is
                        in a physical addressing mode, then LinearAddress is a
                        physical address. If the CPU is in a virtual
                        addressing mode, then LinearAddress is a virtual
                        address.

  @return LinearAddress
**/
VOID *
EFIAPI
AsmFlushCacheLine (
  IN      VOID  *LinearAddress
  )
{
  UINT32  RegEdx;

  //
  // If the CPU does not support CLFLUSH instruction,
  // then promote flush range to flush entire cache.
  //
  AsmCpuid (0x01, NULL, NULL, NULL, &RegEdx);
  if ((RegEdx & BIT19) == 0) {
    __asm__ __volatile__ ("wbinvd":::"memory");
    return LinearAddress;
  }

  __asm__ __volatile__ (
    "clflush (%0)"
    : "+a" (LinearAddress)
    :
    : "memory"
  );

  return LinearAddress;
}