/* libunwind - a platform-independent unwind library
   Copyright (C) 2008 CodeSourcery
   Copyright (C) 2012 Tommi Rantala <tt.rantala@gmail.com>
   Copyright (C) 2013 Linaro Limited

This file is part of libunwind.

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */

#include "dwarf_i.h"
#include "unwind_i.h"

HIDDEN int
tdep_access_reg (struct cursor *c, unw_regnum_t reg, unw_word_t *valp,
                 int write)
{
  dwarf_loc_t loc = DWARF_NULL_LOC;
  unsigned int mask;

  switch (reg)
    {
    case UNW_AARCH64_X0:
    case UNW_AARCH64_X1:
    case UNW_AARCH64_X2:
    case UNW_AARCH64_X3:
      mask = 1 << reg;
      if (write)
        {
          c->dwarf.eh_args[reg] = *valp;
          c->dwarf.eh_valid_mask |= mask;
          return 0;
        }
      else if ((c->dwarf.eh_valid_mask & mask) != 0)
        {
          *valp = c->dwarf.eh_args[reg];
          return 0;
        }
      else
        loc = c->dwarf.loc[reg];
      break;

    case UNW_AARCH64_X30:
      if (write)
        c->dwarf.ip = *valp;            /* update the IP cache */
    case UNW_AARCH64_X4:
    case UNW_AARCH64_X5:
    case UNW_AARCH64_X6:
    case UNW_AARCH64_X7:
    case UNW_AARCH64_X8:
    case UNW_AARCH64_X9:
    case UNW_AARCH64_X10:
    case UNW_AARCH64_X11:
    case UNW_AARCH64_X12:
    case UNW_AARCH64_X13:
    case UNW_AARCH64_X14:
    case UNW_AARCH64_X15:
    case UNW_AARCH64_X16:
    case UNW_AARCH64_X17:
    case UNW_AARCH64_X18:
    case UNW_AARCH64_X19:
    case UNW_AARCH64_X20:
    case UNW_AARCH64_X21:
    case UNW_AARCH64_X22:
    case UNW_AARCH64_X23:
    case UNW_AARCH64_X24:
    case UNW_AARCH64_X25:
    case UNW_AARCH64_X26:
    case UNW_AARCH64_X27:
    case UNW_AARCH64_X28:
    case UNW_AARCH64_X29:
    case UNW_AARCH64_PC:
    case UNW_AARCH64_PSTATE:
      loc = c->dwarf.loc[reg];
      break;
    case UNW_AARCH64_RA_SIGN_STATE:
      Debug (1, "Reading from ra sign state not supported: %u\n", reg);
      return -UNW_EBADREG;

    case UNW_AARCH64_VG:
      if (write)
       {
         Debug (1, "Writing to VG pseudo register not supported\n");
         return -UNW_EBADREG;
       }

      if (DWARF_IS_REG_LOC(c->dwarf.loc[reg]))
        loc = c->dwarf.loc[reg];
      else
        {
          unw_addr_space_t as = c->dwarf.as;
          unw_accessors_t *a = unw_get_accessors_int (as);
          void *arg = c->dwarf.as_arg;
          unw_word_t addr = DWARF_GET_LOC (c->dwarf.loc[reg]);
          uint16_t val16;

          /*
           * If it's a memory location it means it must be in the signal context
           * and it's saved as VL rather than VG so it needs to be scaled.
           *
           * linux/Documentation/arm64/sve.rst:
           *  * Vector length (VL) = size of a Z-register in bytes
           *
           * https://github.com/ARM-software/abi-aa/blob/main/aadwarf64/aadwarf64.rst:
           *  * Vector granule (VG) = Size in bits of the SVE vector registers
           *    in the current call frame divided by 64.
           */
          int ret = dwarf_readu16 (as, a, &addr, &val16, arg);
          if (!ret)
            *valp = (val16 * 8) / 64;
          return ret;
        }
      break;

    case UNW_AARCH64_SP:
      if (write)
        return -UNW_EREADONLYREG;
      *valp = c->dwarf.cfa;
      return 0;

    default:
      Debug (1, "bad register number %u\n", reg);
      return -UNW_EBADREG;
    }

  if (write)
    return dwarf_put (&c->dwarf, loc, *valp);
  else
    {
      int ret = dwarf_get (&c->dwarf, loc, valp);
      if (reg == UNW_AARCH64_X30)
        {
          *valp = tdep_strip_ptrauth_insn_mask((unw_cursor_t*)c, *valp);
        }
      return ret;
    }
}

HIDDEN int
tdep_access_fpreg (struct cursor *c, unw_regnum_t reg, unw_fpreg_t *valp,
                   int write)
{
  dwarf_loc_t loc = c->dwarf.loc[reg];
  if (write)
    return dwarf_putfp (&c->dwarf, loc, *valp);
  else
    return dwarf_getfp (&c->dwarf, loc, valp);
}
