sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h

   1 /* Copyright (C) 1998, 1999, 2002, 2004 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #ifndef _SYS_UCONTEXT_H
  20 #define _SYS_UCONTEXT_H 1
  21
  22 #include <features.h>
  23 #include <signal.h>
  24
  25 /* We need the signal context definitions even if they are not used
  26    included in <signal.h>.  */
  27 #include <bits/sigcontext.h>
  28
  29 #if __WORDSIZE == 32
  30
  31 /* Number of general registers.  */
  32 # define NGREG  48
  33
  34 /* Container for all general registers.  */
  35 typedef unsigned long gregset_t[NGREG];
  36
  37 /* Container for floating-point registers and status */
  38 typedef struct _libc_fpstate
  39 {
  40         double fpregs[32];
  41         double fpscr;
  42         unsigned int _pad[2];
  43 } fpregset_t;
  44
  45 /* Container for Altivec/VMX registers and status.
  46    Needs to be aligned on a 16-byte boundary. */
  47 typedef struct _libc_vrstate
  48 {
  49         unsigned int vrregs[32][4];
  50         unsigned int vrsave;
  51         unsigned int _pad[2];
  52         unsigned int vscr;
  53 } vrregset_t;
  54
  55 /* Context to describe whole processor state.  */
  56 typedef struct
  57 {
  58         gregset_t gregs;
  59         fpregset_t fpregs;
  60         vrregset_t vrregs __attribute__((__aligned__(16)));
  61 } mcontext_t;
  62
  63 #else
  64
  65 /* For 64-bit kernels with Altivec support, a machine context is exactly
  66  * a sigcontext.  For older kernel (without Altivec) the sigcontext matches
  67  * the mcontext upto but not including the v_regs field.  For kernels that
  68  * don't AT_HWCAP or return AT_HWCAP without PPC_FEATURE_HAS_ALTIVEC the
  69  * v_regs field may not exit and should not be referenced.  The v_regd field
  70  * can be refernced safely only after verifying that PPC_FEATURE_HAS_ALTIVEC
  71  * is set in AT_HWCAP.  */
  72
  73 # include <asm/types.h>
  74
  75 /* Number of general registers.  */
  76 # define NGREG  48      /* includes r0-r31, nip, msr, lr, etc.   */
  77 # define NFPREG 33      /* includes fp0-fp31 &fpscr.  */
  78 # define NVRREG 34      /* includes v0-v31, vscr, & vrsave in split vectors */
  79
  80 typedef unsigned long gregset_t[NGREG];
  81 typedef double fpregset_t[NFPREG];
  82
  83 /* Container for Altivec/VMX Vector Status and Control Register.  Only 32-bits
  84    but can only be copied to/from a 128-bit vector register.  So we allocated
  85    a whole quadword speedup save/restore.  */
  86 typedef struct _libc_vscr
  87 {
  88         unsigned int __pad[3];
  89         unsigned int vscr_word;
  90 } vscr_t;
  91
  92 /* Container for Altivec/VMX registers and status.
  93    Must to be aligned on a 16-byte boundary. */
  94 typedef struct _libc_vrstate
  95 {
  96         unsigned int    vrregs[32][4];
  97         vscr_t          vscr;
  98         unsigned int    vrsave;
  99         unsigned int    __pad[3];
 100 } vrregset_t  __attribute__((__aligned__(16)));
 101
 102 typedef struct {
 103         unsigned long   __unused[4];
 104         int             signal;
 105         int             __pad0;
 106         unsigned long   handler;
 107         unsigned long   oldmask;
 108         struct pt_regs  *regs;
 109         gregset_t       gp_regs;
 110         fpregset_t      fp_regs;
 111 /*
 112  * To maintain compatibility with current implementations the sigcontext is
 113  * extended by appending a pointer (v_regs) to a quadword type (elf_vrreg_t)
 114  * followed by an unstructured (vmx_reserve) field of 69 doublewords.  This
 115  * allows the array of vector registers to be quadword aligned independent of
 116  * the alignment of the containing sigcontext or ucontext. It is the
 117  * responsibility of the code setting the sigcontext to set this pointer to
 118  * either NULL (if this processor does not support the VMX feature) or the
 119  * address of the first quadword within the allocated (vmx_reserve) area.
 120  *
 121  * The pointer (v_regs) of vector type (elf_vrreg_t) is essentually
 122  * an array of 34 quadword entries.  The entries with
 123  * indexes 0-31 contain the corresponding vector registers.  The entry with
 124  * index 32 contains the vscr as the last word (offset 12) within the
 125  * quadword.  This allows the vscr to be stored as either a quadword (since
 126  * it must be copied via a vector register to/from storage) or as a word.
 127  * The entry with index 33 contains the vrsave as the first word (offset 0)
 128  * within the quadword.
 129  */
 130         vrregset_t      *v_regs;
 131         long            vmx_reserve[NVRREG+NVRREG+1];
 132 } mcontext_t;
 133
 134 #endif
 135
 136 /* Userlevel context.  */
 137 typedef struct ucontext
 138   {
 139     unsigned long int uc_flags;
 140     struct ucontext *uc_link;
 141     stack_t uc_stack;
 142 #if __WORDSIZE == 32
 143     /*
 144      * These fields are set up this way to maximize source and
 145      * binary compatibility with code written for the old
 146      * ucontext_t definition, which didn't include space for the
 147      * registers.
 148      *
 149      * Different versions of the kernel have stored the registers on
 150      * signal delivery at different offsets from the ucontext struct.
 151      * Programs should thus use the uc_mcontext.uc_regs pointer to
 152      * find where the registers are actually stored.  The registers
 153      * will be stored within the ucontext_t struct but not necessarily
 154      * at a fixed address.  As a side-effect, this lets us achieve
 155      * 16-byte alignment for the register storage space if the
 156      * Altivec registers are to be saved, without requiring 16-byte
 157      * alignment on the whole ucontext_t.
 158      *
 159      * The uc_mcontext.regs field is included for source compatibility
 160      * with programs written against the older ucontext_t definition,
 161      * and its name should therefore not change.  The uc_pad field
 162      * is for binary compatibility with programs compiled against the
 163      * old ucontext_t; it ensures that uc_mcontext.regs and uc_sigmask
 164      * are at the same offset as previously.
 165      */
 166     int uc_pad[7];
 167     union uc_regs_ptr {
 168       struct pt_regs *regs;
 169       mcontext_t *uc_regs;
 170     } uc_mcontext;
 171     sigset_t    uc_sigmask;
 172     char uc_reg_space[sizeof(mcontext_t) + 12];  /* last for extensibility */
 173 #else /* 64-bit */
 174     sigset_t    uc_sigmask;
 175     mcontext_t  uc_mcontext;  /* last for extensibility */
 176 #endif
 177   } ucontext_t;
 178
 179 #endif /* sys/ucontext.h */