linux/include/asm-powerpc/sigcontext.h
Michael Neuling ce48b21007 powerpc: Add VSX context save/restore, ptrace and signal support
This patch extends the floating point save and restore code to use the
VSX load/stores when VSX is available.  This will make FP context
save/restore marginally slower on FP only code, when VSX is available,
as it has to load/store 128bits rather than just 64bits.

Mixing FP, VMX and VSX code will get constant architected state.

The signals interface is extended to enable access to VSR 0-31
doubleword 1 after discussions with tool chain maintainers.  Backward
compatibility is maintained.

The ptrace interface is also extended to allow access to VSR 0-31 full
registers.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01 11:28:50 +10:00

88 lines
4.2 KiB
C

#ifndef _ASM_POWERPC_SIGCONTEXT_H
#define _ASM_POWERPC_SIGCONTEXT_H
/*
* 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.
*/
#include <linux/compiler.h>
#include <asm/ptrace.h>
#ifdef __powerpc64__
#include <asm/elf.h>
#endif
struct sigcontext {
unsigned long _unused[4];
int signal;
#ifdef __powerpc64__
int _pad0;
#endif
unsigned long handler;
unsigned long oldmask;
struct pt_regs __user *regs;
#ifdef __powerpc64__
elf_gregset_t gp_regs;
elf_fpregset_t fp_regs;
/*
* To maintain compatibility with current implementations the sigcontext is
* extended by appending a pointer (v_regs) to a quadword type (elf_vrreg_t)
* followed by an unstructured (vmx_reserve) field of 69 doublewords. This
* allows the array of vector registers to be quadword aligned independent of
* the alignment of the containing sigcontext or ucontext. It is the
* responsibility of the code setting the sigcontext to set this pointer to
* either NULL (if this processor does not support the VMX feature) or the
* address of the first quadword within the allocated (vmx_reserve) area.
*
* The pointer (v_regs) of vector type (elf_vrreg_t) is type compatible with
* an array of 34 quadword entries (elf_vrregset_t). The entries with
* indexes 0-31 contain the corresponding vector registers. The entry with
* index 32 contains the vscr as the last word (offset 12) within the
* quadword. This allows the vscr to be stored as either a quadword (since
* it must be copied via a vector register to/from storage) or as a word.
* The entry with index 33 contains the vrsave as the first word (offset 0)
* within the quadword.
*
* Part of the VSX data is stored here also by extending vmx_restore
* by an additional 32 double words. Architecturally the layout of
* the VSR registers and how they overlap on top of the legacy FPR and
* VR registers is shown below:
*
* VSR doubleword 0 VSR doubleword 1
* ----------------------------------------------------------------
* VSR[0] | FPR[0] | |
* ----------------------------------------------------------------
* VSR[1] | FPR[1] | |
* ----------------------------------------------------------------
* | ... | |
* | ... | |
* ----------------------------------------------------------------
* VSR[30] | FPR[30] | |
* ----------------------------------------------------------------
* VSR[31] | FPR[31] | |
* ----------------------------------------------------------------
* VSR[32] | VR[0] |
* ----------------------------------------------------------------
* VSR[33] | VR[1] |
* ----------------------------------------------------------------
* | ... |
* | ... |
* ----------------------------------------------------------------
* VSR[62] | VR[30] |
* ----------------------------------------------------------------
* VSR[63] | VR[31] |
* ----------------------------------------------------------------
*
* FPR/VSR 0-31 doubleword 0 is stored in fp_regs, and VMX/VSR 32-63
* is stored at the start of vmx_reserve. vmx_reserve is extended for
* backwards compatility to store VSR 0-31 doubleword 1 after the VMX
* registers and vscr/vrsave.
*/
elf_vrreg_t __user *v_regs;
long vmx_reserve[ELF_NVRREG+ELF_NVRREG+32+1];
#endif
};
#endif /* _ASM_POWERPC_SIGCONTEXT_H */