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/* PPC GNU/Linux native support.

   Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002

   Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 2 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program; if not, write to the Free Software

   Foundation, Inc., 59 Temple Place - Suite 330,

   Boston, MA 02111-1307, USA.  */

#include "defs.h"

#include "frame.h"

#include "inferior.h"

#include "gdbcore.h"

#include "regcache.h"

#include <sys/types.h>

#include <sys/param.h>

#include <signal.h>

#include <sys/user.h>

#include <sys/ioctl.h>

#include <sys/wait.h>

#include <fcntl.h>

#include <sys/procfs.h>

#include <sys/ptrace.h>

/* Prototypes for supply_gregset etc. */

#include "gregset.h"

#include "ppc-tdep.h"

#ifndef PT_READ_U

#define PT_READ_U PTRACE_PEEKUSR

#endif

#ifndef PT_WRITE_U

#define PT_WRITE_U PTRACE_POKEUSR

#endif

/* Default the type of the ptrace transfer to int.  */

#ifndef PTRACE_XFER_TYPE

#define PTRACE_XFER_TYPE int

#endif

/* Glibc's headers don't define PTRACE_GETVRREGS so we cannot use a

   configure time check.  Some older glibc's (for instance 2.2.1)

   don't have a specific powerpc version of ptrace.h, and fall back on

   a generic one.  In such cases, sys/ptrace.h defines

   PTRACE_GETFPXREGS and PTRACE_SETFPXREGS to the same numbers that

   ppc kernel's asm/ptrace.h defines PTRACE_GETVRREGS and

   PTRACE_SETVRREGS to be.  This also makes a configury check pretty

   much useless.  */

/* These definitions should really come from the glibc header files,

   but Glibc doesn't know about the vrregs yet.  */

#ifndef PTRACE_GETVRREGS

#define PTRACE_GETVRREGS 18

#define PTRACE_SETVRREGS 19

#endif

/* This oddity is because the Linux kernel defines elf_vrregset_t as

   an array of 33 16 bytes long elements.  I.e. it leaves out vrsave.

   However the PTRACE_GETVRREGS and PTRACE_SETVRREGS requests return

   the vrsave as an extra 4 bytes at the end.  I opted for creating a

   flat array of chars, so that it is easier to manipulate for gdb.

   There are 32 vector registers 16 bytes longs, plus a VSCR register

   which is only 4 bytes long, but is fetched as a 16 bytes

   quantity. Up to here we have the elf_vrregset_t structure.

   Appended to this there is space for the VRSAVE register: 4 bytes.

   Even though this vrsave register is not included in the regset

   typedef, it is handled by the ptrace requests.

   Note that GNU/Linux doesn't support little endian PPC hardware,

   therefore the offset at which the real value of the VSCR register

   is located will be always 12 bytes.

   The layout is like this (where x is the actual value of the vscr reg): */

/* *INDENT-OFF* */

/*

   |.|.|.|.|.....|.|.|.|.||.|.|.|x||.|

   <------->     <-------><-------><->

     VR0           VR31     VSCR    VRSAVE

*/

/* *INDENT-ON* */

#define SIZEOF_VRREGS 33*16+4

typedef char gdb_vrregset_t[SIZEOF_VRREGS];

/* For runtime check of ptrace support for VRREGS.  */

int have_ptrace_getvrregs = 1;

int

kernel_u_size (void)

{

  return (sizeof (struct user));

}

/* *INDENT-OFF* */

/* registers layout, as presented by the ptrace interface:

PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5, PT_R6, PT_R7,

PT_R8, PT_R9, PT_R10, PT_R11, PT_R12, PT_R13, PT_R14, PT_R15,

PT_R16, PT_R17, PT_R18, PT_R19, PT_R20, PT_R21, PT_R22, PT_R23,

PT_R24, PT_R25, PT_R26, PT_R27, PT_R28, PT_R29, PT_R30, PT_R31,

PT_FPR0, PT_FPR0 + 2, PT_FPR0 + 4, PT_FPR0 + 6, PT_FPR0 + 8, PT_FPR0 + 10, PT_FPR0 + 12, PT_FPR0 + 14,

PT_FPR0 + 16, PT_FPR0 + 18, PT_FPR0 + 20, PT_FPR0 + 22, PT_FPR0 + 24, PT_FPR0 + 26, PT_FPR0 + 28, PT_FPR0 + 30,

PT_FPR0 + 32, PT_FPR0 + 34, PT_FPR0 + 36, PT_FPR0 + 38, PT_FPR0 + 40, PT_FPR0 + 42, PT_FPR0 + 44, PT_FPR0 + 46,

PT_FPR0 + 48, PT_FPR0 + 50, PT_FPR0 + 52, PT_FPR0 + 54, PT_FPR0 + 56, PT_FPR0 + 58, PT_FPR0 + 60, PT_FPR0 + 62,

PT_NIP, PT_MSR, PT_CCR, PT_LNK, PT_CTR, PT_XER, PT_MQ */

/* *INDENT_ON * */

static int

ppc_register_u_addr (int regno)

{

  int u_addr = -1;

  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

  /* General purpose registers occupy 1 slot each in the buffer */

  if (regno >= tdep->ppc_gp0_regnum && regno <= tdep->ppc_gplast_regnum )

    u_addr =  ((PT_R0 + regno) * 4);

  /* Floating point regs: 2 slots each */

  if (regno >= FP0_REGNUM && regno <= FPLAST_REGNUM)

    u_addr = ((PT_FPR0 + (regno - FP0_REGNUM) * 2) * 4);

  /* UISA special purpose registers: 1 slot each */

  if (regno == PC_REGNUM)

    u_addr = PT_NIP * 4;

  if (regno == tdep->ppc_lr_regnum)

    u_addr = PT_LNK * 4;

  if (regno == tdep->ppc_cr_regnum)

    u_addr = PT_CCR * 4;

  if (regno == tdep->ppc_xer_regnum)

    u_addr = PT_XER * 4;

  if (regno == tdep->ppc_ctr_regnum)

    u_addr = PT_CTR * 4;

  if (regno == tdep->ppc_mq_regnum)

    u_addr = PT_MQ * 4;

  if (regno == tdep->ppc_ps_regnum)

    u_addr = PT_MSR * 4;

  if (regno == tdep->ppc_fpscr_regnum)

    u_addr = PT_FPSCR * 4;

  return u_addr;

}

static int

ppc_ptrace_cannot_fetch_store_register (int regno)

{

  return (ppc_register_u_addr (regno) == -1);

}

/* The Linux kernel ptrace interface for AltiVec registers uses the

   registers set mechanism, as opposed to the interface for all the

   other registers, that stores/fetches each register individually.  */

static void

fetch_altivec_register (int tid, int regno)

{

  int ret;

  int offset = 0;

  gdb_vrregset_t regs;

  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

  int vrregsize = REGISTER_RAW_SIZE (tdep->ppc_vr0_regnum);

  ret = ptrace (PTRACE_GETVRREGS, tid, 0, &regs);

  if (ret < 0)

    {

      if (errno == EIO)

        {

          have_ptrace_getvrregs = 0;

          return;

        }

      perror_with_name ("Unable to fetch AltiVec register");

    }

  /* VSCR is fetched as a 16 bytes quantity, but it is really 4 bytes

     long on the hardware.  We deal only with the lower 4 bytes of the

     vector.  VRSAVE is at the end of the array in a 4 bytes slot, so

     there is no need to define an offset for it.  */

  if (regno == (tdep->ppc_vrsave_regnum - 1))

    offset = vrregsize - REGISTER_RAW_SIZE (tdep->ppc_vrsave_regnum);

  supply_register (regno,

                   regs + (regno - tdep->ppc_vr0_regnum) * vrregsize + offset);

}

static void

fetch_register (int tid, int regno)

{

  /* This isn't really an address.  But ptrace thinks of it as one.  */

  char mess[128];              /* For messages */

  register int i;

  unsigned int offset;         /* Offset of registers within the u area. */

  char *buf = alloca (MAX_REGISTER_RAW_SIZE);

  CORE_ADDR regaddr = ppc_register_u_addr (regno);

  if (altivec_register_p (regno))

    {

      /* If this is the first time through, or if it is not the first

         time through, and we have comfirmed that there is kernel

         support for such a ptrace request, then go and fetch the

         register.  */

      if (have_ptrace_getvrregs)

       {

         fetch_altivec_register (tid, regno);

         return;

       }

     /* If we have discovered that there is no ptrace support for

        AltiVec registers, fall through and return zeroes, because

        regaddr will be -1 in this case.  */

    }

  if (regaddr == -1)

    {

      memset (buf, '\0', REGISTER_RAW_SIZE (regno));   /* Supply zeroes */

      supply_register (regno, buf);

      return;

    }

  for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE))

    {

      errno = 0;

      *(PTRACE_XFER_TYPE *) & buf[i] = ptrace (PT_READ_U, tid,

                                               (PTRACE_ARG3_TYPE) regaddr, 0);

      regaddr += sizeof (PTRACE_XFER_TYPE);

      if (errno != 0)

        {

          sprintf (mess, "reading register %s (#%d)",

                   REGISTER_NAME (regno), regno);

          perror_with_name (mess);

        }

    }

  supply_register (regno, buf);

}

static void

supply_vrregset (gdb_vrregset_t *vrregsetp)

{

  int i;

  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

  int num_of_vrregs = tdep->ppc_vrsave_regnum - tdep->ppc_vr0_regnum + 1;

  int vrregsize = REGISTER_RAW_SIZE (tdep->ppc_vr0_regnum);

  int offset = vrregsize - REGISTER_RAW_SIZE (tdep->ppc_vrsave_regnum);

  for (i = 0; i < num_of_vrregs; i++)

    {

      /* The last 2 registers of this set are only 32 bit long, not

         128.  However an offset is necessary only for VSCR because it

         occupies a whole vector, while VRSAVE occupies a full 4 bytes

         slot.  */

      if (i == (num_of_vrregs - 2))

        supply_register (tdep->ppc_vr0_regnum + i,

                         *vrregsetp + i * vrregsize + offset);

      else

        supply_register (tdep->ppc_vr0_regnum + i, *vrregsetp + i * vrregsize);

    }

}

static void

fetch_altivec_registers (int tid)

{

  int ret;

  gdb_vrregset_t regs;

  ret = ptrace (PTRACE_GETVRREGS, tid, 0, &regs);

  if (ret < 0)

    {

      if (errno == EIO)

        {

          have_ptrace_getvrregs = 0;

          return;

        }

      perror_with_name ("Unable to fetch AltiVec registers");

    }

  supply_vrregset (&regs);

}

static void

fetch_ppc_registers (int tid)

{

  int i;

  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

  for (i = 0; i <= tdep->ppc_fpscr_regnum; i++)

    fetch_register (tid, i);

  if (tdep->ppc_mq_regnum != -1)

    fetch_register (tid, tdep->ppc_mq_regnum);

  if (have_ptrace_getvrregs)

    if (tdep->ppc_vr0_regnum != -1 && tdep->ppc_vrsave_regnum != -1)

      fetch_altivec_registers (tid);

}

/* Fetch registers from the child process.  Fetch all registers if

   regno == -1, otherwise fetch all general registers or all floating

   point registers depending upon the value of regno.  */

void

fetch_inferior_registers (int regno)

{

  /* Overload thread id onto process id */

  int tid = TIDGET (inferior_ptid);

  /* No thread id, just use process id */

  if (tid == 0)

    tid = PIDGET (inferior_ptid);

  if (regno == -1)

    fetch_ppc_registers (tid);

  else

    fetch_register (tid, regno);

}

/* Store one register. */

static void

store_altivec_register (int tid, int regno)

{

  int ret;

  int offset = 0;

  gdb_vrregset_t regs;

  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

  int vrregsize = REGISTER_RAW_SIZE (tdep->ppc_vr0_regnum);

  ret = ptrace (PTRACE_GETVRREGS, tid, 0, &regs);

  if (ret < 0)

    {

      if (errno == EIO)

        {

          have_ptrace_getvrregs = 0;

          return;

        }

      perror_with_name ("Unable to fetch AltiVec register");

    }

  /* VSCR is fetched as a 16 bytes quantity, but it is really 4 bytes

     long on the hardware.  */

  if (regno == (tdep->ppc_vrsave_regnum - 1))

    offset = vrregsize - REGISTER_RAW_SIZE (tdep->ppc_vrsave_regnum);

  regcache_collect (regno,

                    regs + (regno - tdep->ppc_vr0_regnum) * vrregsize + offset);

  ret = ptrace (PTRACE_SETVRREGS, tid, 0, &regs);

  if (ret < 0)

    perror_with_name ("Unable to store AltiVec register");

}

static void

store_register (int tid, int regno)

{

  /* This isn't really an address.  But ptrace thinks of it as one.  */

  CORE_ADDR regaddr = ppc_register_u_addr (regno);

  char mess[128];              /* For messages */

  register int i;

  unsigned int offset;         /* Offset of registers within the u area.  */

  char *buf = alloca (MAX_REGISTER_RAW_SIZE);

  if (altivec_register_p (regno))

    {

      store_altivec_register (tid, regno);

      return;

    }

  if (regaddr == -1)

    return;

  regcache_collect (regno, buf);

  for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE))

    {

      errno = 0;

      ptrace (PT_WRITE_U, tid, (PTRACE_ARG3_TYPE) regaddr,

              *(PTRACE_XFER_TYPE *) & buf[i]);

      regaddr += sizeof (PTRACE_XFER_TYPE);

      if (errno == EIO

          && regno == gdbarch_tdep (current_gdbarch)->ppc_fpscr_regnum)

        {

          /* Some older kernel versions don't allow fpscr to be written.  */

          continue;

        }

      if (errno != 0)

        {

          sprintf (mess, "writing register %s (#%d)",

                   REGISTER_NAME (regno), regno);

          perror_with_name (mess);

        }

    }

}

static void

fill_vrregset (gdb_vrregset_t *vrregsetp)

{

  int i;

  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

  int num_of_vrregs = tdep->ppc_vrsave_regnum - tdep->ppc_vr0_regnum + 1;

  int vrregsize = REGISTER_RAW_SIZE (tdep->ppc_vr0_regnum);

  int offset = vrregsize - REGISTER_RAW_SIZE (tdep->ppc_vrsave_regnum);

  for (i = 0; i < num_of_vrregs; i++)

    {

      /* The last 2 registers of this set are only 32 bit long, not

         128, but only VSCR is fetched as a 16 bytes quantity.  */

      if (i == (num_of_vrregs - 2))

        regcache_collect (tdep->ppc_vr0_regnum + i,

                          *vrregsetp + i * vrregsize + offset);

      else

        regcache_collect (tdep->ppc_vr0_regnum + i, *vrregsetp + i * vrregsize);

    }

}

static void

store_altivec_registers (int tid)

{

  int ret;

  gdb_vrregset_t regs;

  ret = ptrace (PTRACE_GETVRREGS, tid, 0, (int) &regs);

  if (ret < 0)

    {

      if (errno == EIO)

        {

          have_ptrace_getvrregs = 0;

          return;

        }

      perror_with_name ("Couldn't get AltiVec registers");

    }

  fill_vrregset (&regs);

  if (ptrace (PTRACE_SETVRREGS, tid, 0, (int) &regs) < 0)

    perror_with_name ("Couldn't write AltiVec registers");

}

static void

store_ppc_registers (int tid)

{

  int i;

  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

  for (i = 0; i <= tdep->ppc_fpscr_regnum; i++)

    store_register (tid, i);

  if (tdep->ppc_mq_regnum != -1)

    store_register (tid, tdep->ppc_mq_regnum);

  if (have_ptrace_getvrregs)

    if (tdep->ppc_vr0_regnum != -1 && tdep->ppc_vrsave_regnum != -1)

      store_altivec_registers (tid);

}

void

store_inferior_registers (int regno)

{

  /* Overload thread id onto process id */

  int tid = TIDGET (inferior_ptid);

  /* No thread id, just use process id */

  if (tid == 0)

    tid = PIDGET (inferior_ptid);

  if (regno >= 0)

    store_register (tid, regno);

  else

    store_ppc_registers (tid);

}

void

supply_gregset (gdb_gregset_t *gregsetp)

{

  ppc_linux_supply_gregset ((char *) gregsetp);

}

void

fill_gregset (gdb_gregset_t *gregsetp, int regno)

{

  int regi;

  elf_greg_t *regp = (elf_greg_t *) gregsetp;

  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

  for (regi = 0; regi < 32; regi++)

    {

      if ((regno == -1) || regno == regi)

        regcache_collect (regi, regp + PT_R0 + regi);

    }

  if ((regno == -1) || regno == PC_REGNUM)

    regcache_collect (PC_REGNUM, regp + PT_NIP);

  if ((regno == -1) || regno == tdep->ppc_lr_regnum)

    regcache_collect (tdep->ppc_lr_regnum, regp + PT_LNK);

  if ((regno == -1) || regno == tdep->ppc_cr_regnum)

    regcache_collect (tdep->ppc_cr_regnum, regp + PT_CCR);

  if ((regno == -1) || regno == tdep->ppc_xer_regnum)

    regcache_collect (tdep->ppc_xer_regnum, regp + PT_XER);

  if ((regno == -1) || regno == tdep->ppc_ctr_regnum)

    regcache_collect (tdep->ppc_ctr_regnum, regp + PT_CTR);

  if (((regno == -1) || regno == tdep->ppc_mq_regnum)

      && (tdep->ppc_mq_regnum != -1))

    regcache_collect (tdep->ppc_mq_regnum, regp + PT_MQ);

  if ((regno == -1) || regno == tdep->ppc_ps_regnum)

    regcache_collect (tdep->ppc_ps_regnum, regp + PT_MSR);

}

void

supply_fpregset (gdb_fpregset_t * fpregsetp)

{

  ppc_linux_supply_fpregset ((char *) fpregsetp);

}

/* Given a pointer to a floating point register set in /proc format

   (fpregset_t *), update the register specified by REGNO from gdb's

   idea of the current floating point register set.  If REGNO is -1,

   update them all.  */

void

fill_fpregset (gdb_fpregset_t *fpregsetp, int regno)

{

  int regi;

  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

  for (regi = 0; regi < 32; regi++)

    {

      if ((regno == -1) || (regno == FP0_REGNUM + regi))

        regcache_collect (FP0_REGNUM + regi, (char *) (*fpregsetp + regi));

    }

  if ((regno == -1) || regno == tdep->ppc_fpscr_regnum)

    regcache_collect (tdep->ppc_fpscr_regnum, (char *) (*fpregsetp + regi));

}