NetBSD/sys/arch/sparc/include/mcontext.h
manu bba80928a8 setcontext() used to be incompatible with -lpthread since it affected
the TLS pointer, therefore wrecking the pthread environement.

Some ports had _UC_TLSBASE flag or equivalent (_UC_UNIQUE on alpha)
that controlled whether setcontext() would change the TLS pointer.
This change let libpthread override setcontext() with its own version
that unsets _UC_TLSBASE, enabling safe usage of setcontext() with
-lpthread.

We also have the following required changes here:
- rename alpha's _UC_UNIQUE into _UC_TLSBASE
- add _UC_TLSBASE definition in header file for all ports
  (powerpc, sh3, sparc and sparc64 lack the implementation for now)
- introduce a libc stub that can be overriden for setcontext()
- modify MD libcs swapcontext() implementations so that they use the
  setcontext() libc stub instead of doing a plain system call.

While we are there:
- document various MD _UC_* flags in header file
- add libc and libpthread tests for swapcontext() behavior
  (hopefully helpful to spot MD problems introduced with this change)

Future work:
- Deciding whether kernel support or _UC_TLSBASE should be added for
  powerpc, sh3, sparc and sparc64 is left to portmasters
  sparc64

Approved by core@
2012-09-12 02:00:51 +00:00

175 lines
5.1 KiB
C

/* $NetBSD: mcontext.h,v 1.13 2012/09/12 02:00:54 manu Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Klaus Klein.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _SPARC_MCONTEXT_H_
#define _SPARC_MCONTEXT_H_
#define _UC_SETSTACK 0x00010000
#define _UC_CLRSTACK 0x00020000
#define _UC_TLSBASE 0x00080000
/*
* Layout of mcontext_t according the System V Application Binary Interface,
* Edition 4.1, SPARC Processor ABI Supplement and updated for SPARC v9.
*/
#ifdef __arch64__
#define _NGREG 21 /* %ccr, pc, npc, %g1-7, %o0-7, %asi, %fprs */
#else
#define _NGREG 19 /* %psr, pc, npc, %g1-7, %o0-7 */
#endif
typedef long int __greg_t;
typedef __greg_t __gregset_t[_NGREG];
/* Offsets into gregset_t, for convenience. */
#define _REG_CCR 0 /* 64 bit only */
#define _REG_PSR 0 /* 32 bit only */
#define _REG_PC 1
#define _REG_nPC 2
#define _REG_Y 3
#define _REG_G1 4
#define _REG_G2 5
#define _REG_G3 6
#define _REG_G4 7
#define _REG_G5 8
#define _REG_G6 9
#define _REG_G7 10
#define _REG_O0 11
#define _REG_O1 12
#define _REG_O2 13
#define _REG_O3 14
#define _REG_O4 15
#define _REG_O5 16
#define _REG_O6 17
#define _REG_O7 18
#define _REG_ASI 19 /* 64 bit only */
#define _REG_FPRS 20 /* 64 bit only */
#define _SPARC_MAXREGWINDOW 31
/* Layout of a register window. */
typedef struct {
__greg_t __rw_local[8]; /* %l0-7 */
__greg_t __rw_in[8]; /* %i0-7 */
} __rwindow_t;
/* Description of available register windows. */
typedef struct {
int __wbcnt;
__greg_t * __spbuf[_SPARC_MAXREGWINDOW];
__rwindow_t __wbuf[_SPARC_MAXREGWINDOW];
} __gwindows_t;
/* FPU address queue */
struct __fpq {
unsigned int * __fpq_addr; /* address */
unsigned int __fpq_instr; /* instruction */
};
struct __fq {
union {
double __whole;
struct __fpq __fpq;
} _FQu;
};
/* FPU state description */
typedef struct {
union {
unsigned int __fpu_regs[32];
#ifdef __arch64__
double __fpu_dregs[32];
long double __fpu_qregs[16];
#else
double __fpu_dregs[16];
#endif
} __fpu_fr; /* FPR contents */
struct __fq * __fpu_q; /* pointer to FPU insn queue */
unsigned long __fpu_fsr; /* %fsr */
unsigned char __fpu_qcnt; /* # entries in __fpu_q */
unsigned char __fpu_q_entrysize; /* size of a __fpu_q entry */
unsigned char __fpu_en; /* this context valid? */
} __fpregset_t;
/* `Extra Register State'(?) */
typedef struct {
unsigned int __xrs_id; /* See below */
char * __xrs_ptr; /* points into filler area */
} __xrs_t;
#define _XRS_ID 0x78727300 /* 'xrs\0' */
#ifdef __arch64__
/* Ancillary State Registers, 16-31 are available to user programs */
typedef long __asrset_t[16]; /* %asr16-31 */
#endif
typedef struct {
__gregset_t __gregs; /* GPR state */
__gwindows_t * __gwins; /* may point to register windows */
__fpregset_t __fpregs; /* FPU state, if any */
__xrs_t __xrs; /* may indicate extra reg state */
#ifdef __arch64__
__asrset_t __asrs; /* ASR state */
#endif
} mcontext_t;
#ifdef __arch64__
#define _UC_MACHINE_PAD 8 /* Padding appended to ucontext_t */
#define _UC_MACHINE_SP(uc) (((uc)->uc_mcontext.__gregs[_REG_O6])+0x7ff)
#define _UC_MACHINE32_PAD 43 /* compat_netbsd32 variant */
#define _UC_MACHINE32_SP(uc) ((uc)->uc_mcontext.__gregs[_REG_O6])
#else
#define _UC_MACHINE_PAD 43 /* Padding appended to ucontext_t */
#define _UC_MACHINE_SP(uc) ((uc)->uc_mcontext.__gregs[_REG_O6])
#endif
#define _UC_MACHINE_PC(uc) ((uc)->uc_mcontext.__gregs[_REG_PC])
#define _UC_MACHINE_INTRV(uc) ((uc)->uc_mcontext.__gregs[_REG_O0])
#define _UC_MACHINE_SET_PC(uc, pc) \
do { \
(uc)->uc_mcontext.__gregs[_REG_PC] = (pc); \
(uc)->uc_mcontext.__gregs[_REG_nPC] = (pc) + 4; \
} while (/*CONSTCOND*/0)
static __inline void *
__lwp_getprivate_fast(void)
{
register void *__tmp;
__asm volatile("mov %%g7, %0" : "=r" (__tmp));
return __tmp;
}
#endif /* !_SPARC_MCONTEXT_H_ */