/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* arch/sh64/kernel/fpu.c
*
* Copyright (C) 2001 Manuela Cirronis, Paolo Alberelli
* Copyright (C) 2002 STMicroelectronics Limited
* Author : Stuart Menefy
*
* Started from SH4 version:
* Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
*
*/
#include <linux/sched.h>
#include <linux/signal.h>
#include <asm/processor.h>
#include <asm/user.h>
#include <asm/io.h>
/*
* Initially load the FPU with signalling NANS. This bit pattern
* has the property that no matter whether considered as single or as
* double precision, it still represents a signalling NAN.
*/
#define sNAN64 0xFFFFFFFFFFFFFFFFULL
#define sNAN32 0xFFFFFFFFUL
static union sh_fpu_union init_fpuregs = {
.hard = {
.fp_regs = { [0 ... 63] = sNAN32 },
.fpscr = FPSCR_INIT
}
};
inline void fpsave(struct sh_fpu_hard_struct *fpregs)
{
asm volatile("fst.p %0, (0*8), fp0\n\t"
"fst.p %0, (1*8), fp2\n\t"
"fst.p %0, (2*8), fp4\n\t"
"fst.p %0, (3*8), fp6\n\t"
"fst.p %0, (4*8), fp8\n\t"
"fst.p %0, (5*8), fp10\n\t"
"fst.p %0, (6*8), fp12\n\t"
"fst.p %0, (7*8), fp14\n\t"
"fst.p %0, (8*8), fp16\n\t"
"fst.p %0, (9*8), fp18\n\t"
"fst.p %0, (10*8), fp20\n\t"
"fst.p %0, (11*8), fp22\n\t"
"fst.p %0, (12*8), fp24\n\t"
"fst.p %0, (13*8), fp26\n\t"
"fst.p %0, (14*8), fp28\n\t"
"fst.p %0, (15*8), fp30\n\t"
"fst.p %0, (16*8), fp32\n\t"
"fst.p %0, (17*8), fp34\n\t"
"fst.p %0, (18*8), fp36\n\t"
"fst.p %0, (19*8), fp38\n\t"
"fst.p %0, (20*8), fp40\n\t"
"fst.p %0, (21*8), fp42\n\t"
"fst.p %0, (22*8), fp44\n\t"
"fst.p %0, (23*8), fp46\n\t"
"fst.p %0, (24*8), fp48\n\t"
"fst.p %0, (25*8), fp50\n\t"
"fst.p %0, (26*8), fp52\n\t"
"fst.p %0, (27*8), fp54\n\t"
"fst.p %0, (28*8), fp56\n\t"
"fst.p %0, (29*8), fp58\n\t"
"fst.p %0, (30*8), fp60\n\t"
"fst.p %0, (31*8), fp62\n\t"
"fgetscr fr63\n\t"
"fst.s %0, (32*8), fr63\n\t"
: /* no output */
: "r" (fpregs)
: "memory");
}
static inline void
fpload(struct sh_fpu_hard_struct *fpregs)
{
asm volatile("fld.p %0, (0*8), fp0\n\t"
"fld.p %0, (1*8), fp2\n\t"
"fld.p %0, (2*8), fp4\n\t"
"fld.p %0, (3*8), fp6\n\t"
"fld.p %0, (4*8), fp8\n\t"
"fld.p %0, (5*8), fp10\n\t"
"fld.p %0, (6*8), fp12\n\t"
"fld.p %0, (7*8), fp14\n\t"
"fld.p %0, (8*8), fp16\n\t"
"fld.p %0, (9*8), fp18\n\t"
"fld.p %0, (10*8), fp20\n\t"
"fld.p %0, (11*8), fp22\n\t"
"fld.p %0, (12*8), fp24\n\t"
"fld.p %0, (13*8), fp26\n\t"
"fld.p %0, (14*8), fp28\n\t"
"fld.p %0, (15*8), fp30\n\t"
"fld.p %0, (16*8), fp32\n\t"
"fld.p %0, (17*8), fp34\n\t"
"fld.p %0, (18*8), fp36\n\t"
"fld.p %0, (19*8), fp38\n\t"
"fld.p %0, (20*8), fp40\n\t"
"fld.p %0, (21*8), fp42\n\t"
"fld.p %0, (22*8), fp44\n\t"
"fld.p %0, (23*8), fp46\n\t"
"fld.p %0, (24*8), fp48\n\t"
"fld.p %0, (25*8), fp50\n\t"
"fld.p %0, (26*8), fp52\n\t"
"fld.p %0, (27*8), fp54\n\t"
"fld.p %0, (28*8), fp56\n\t"
"fld.p %0, (29*8), fp58\n\t"
"fld.p %0, (30*8), fp60\n\t"
"fld.s %0, (32*8), fr63\n\t"
"fputscr fr63\n\t"
"fld.p %0, (31*8), fp62\n\t"
: /* no output */
: "r" (fpregs) );
}
void fpinit(struct sh_fpu_hard_struct *fpregs)
{
*fpregs = init_fpuregs.hard;
}
asmlinkage void
do_fpu_error(unsigned long ex, struct pt_regs *regs)
{
struct task_struct *tsk = current;
regs->pc += 4;
tsk->thread.trap_no = 11;
tsk->thread.error_code = 0;
force_sig(SIGFPE, tsk);
}
asmlinkage void
do_fpu_state_restore(unsigned long ex, struct pt_regs *regs)
{
void die(const char *str, struct pt_regs *regs, long err);
if (! user_mode(regs))
die("FPU used in kernel", regs, ex);
regs->sr &= ~SR_FD;
if (last_task_used_math == current)
return;
grab_fpu();
if (last_task_used_math != NULL) {
/* Other processes fpu state, save away */
fpsave(&last_task_used_math->thread.fpu.hard);
}
last_task_used_math = current;
if (used_math()) {
fpload(¤t->thread.fpu.hard);
} else {
/* First time FPU user. */
fpload(&init_fpuregs.hard);
set_used_math();
}
release_fpu();
}
