include/asm-powerpc/sigcontext.h

   1 #ifndef _ASM_POWERPC_SIGCONTEXT_H
   2 #define _ASM_POWERPC_SIGCONTEXT_H
   3
   4 /*
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version
   8  * 2 of the License, or (at your option) any later version.
   9  */
  10 #include <linux/compiler.h>
  11 #include <asm/ptrace.h>
  12 #ifdef __powerpc64__
  13 #include <asm/elf.h>
  14 #endif
  15
  16 struct sigcontext {
  17         unsigned long   _unused[4];
  18         int             signal;
  19 #ifdef __powerpc64__
  20         int             _pad0;
  21 #endif
  22         unsigned long   handler;
  23         unsigned long   oldmask;
  24         struct pt_regs  __user *regs;
  25 #ifdef __powerpc64__
  26         elf_gregset_t   gp_regs;
  27         elf_fpregset_t  fp_regs;
  28 /*
  29  * To maintain compatibility with current implementations the sigcontext is
  30  * extended by appending a pointer (v_regs) to a quadword type (elf_vrreg_t)
  31  * followed by an unstructured (vmx_reserve) field of 69 doublewords.  This
  32  * allows the array of vector registers to be quadword aligned independent of
  33  * the alignment of the containing sigcontext or ucontext. It is the
  34  * responsibility of the code setting the sigcontext to set this pointer to
  35  * either NULL (if this processor does not support the VMX feature) or the
  36  * address of the first quadword within the allocated (vmx_reserve) area.
  37  *
  38  * The pointer (v_regs) of vector type (elf_vrreg_t) is type compatible with
  39  * an array of 34 quadword entries (elf_vrregset_t).  The entries with
  40  * indexes 0-31 contain the corresponding vector registers.  The entry with
  41  * index 32 contains the vscr as the last word (offset 12) within the
  42  * quadword.  This allows the vscr to be stored as either a quadword (since
  43  * it must be copied via a vector register to/from storage) or as a word.
  44  * The entry with index 33 contains the vrsave as the first word (offset 0)
  45  * within the quadword.
  46  *
  47  * Part of the VSX data is stored here also by extending vmx_restore
  48  * by an additional 32 double words.  Architecturally the layout of
  49  * the VSR registers and how they overlap on top of the legacy FPR and
  50  * VR registers is shown below:
  51  *
  52  *                    VSR doubleword 0               VSR doubleword 1
  53  *           ----------------------------------------------------------------
  54  *   VSR[0]  |             FPR[0]            |                              |
  55  *           ----------------------------------------------------------------
  56  *   VSR[1]  |             FPR[1]            |                              |
  57  *           ----------------------------------------------------------------
  58  *           |              ...              |                              |
  59  *           |              ...              |                              |
  60  *           ----------------------------------------------------------------
  61  *   VSR[30] |             FPR[30]           |                              |
  62  *           ----------------------------------------------------------------
  63  *   VSR[31] |             FPR[31]           |                              |
  64  *           ----------------------------------------------------------------
  65  *   VSR[32] |                             VR[0]                            |
  66  *           ----------------------------------------------------------------
  67  *   VSR[33] |                             VR[1]                            |
  68  *           ----------------------------------------------------------------
  69  *           |                              ...                             |
  70  *           |                              ...                             |
  71  *           ----------------------------------------------------------------
  72  *   VSR[62] |                             VR[30]                           |
  73  *           ----------------------------------------------------------------
  74  *   VSR[63] |                             VR[31]                           |
  75  *           ----------------------------------------------------------------
  76  *
  77  * FPR/VSR 0-31 doubleword 0 is stored in fp_regs, and VMX/VSR 32-63
  78  * is stored at the start of vmx_reserve.  vmx_reserve is extended for
  79  * backwards compatility to store VSR 0-31 doubleword 1 after the VMX
  80  * registers and vscr/vrsave.
  81  */
  82         elf_vrreg_t     __user *v_regs;
  83         long            vmx_reserve[ELF_NVRREG+ELF_NVRREG+32+1];
  84 #endif
  85 };
  86
  87 #endif /* _ASM_POWERPC_SIGCONTEXT_H */