linux/arch/arm/nwfpe/fpa11_cpdt.c
Richard Purdie f148af2593 [PATCH] ARM: 2837/2: Re: ARM: Make NWFPE preempt safe
Patch from Richard Purdie

NWFPE used global variables which meant it wasn't safe for use with
preemptive kernels. This patch removes them and communicates the
information between functions in a preempt safe manner. Generation
of some exceptions was broken and this has also been corrected.
Tests with glibc's maths test suite show no change in the results
before/after this patch.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-08-03 19:49:17 +01:00

399 lines
8.7 KiB
C

/*
NetWinder Floating Point Emulator
(c) Rebel.com, 1998-1999
(c) Philip Blundell, 1998, 2001
Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
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.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/config.h>
#include "fpa11.h"
#include "softfloat.h"
#include "fpopcode.h"
#include "fpmodule.h"
#include "fpmodule.inl"
#include <asm/uaccess.h>
static inline void loadSingle(const unsigned int Fn, const unsigned int __user *pMem)
{
FPA11 *fpa11 = GET_FPA11();
fpa11->fType[Fn] = typeSingle;
get_user(fpa11->fpreg[Fn].fSingle, pMem);
}
static inline void loadDouble(const unsigned int Fn, const unsigned int __user *pMem)
{
FPA11 *fpa11 = GET_FPA11();
unsigned int *p;
p = (unsigned int *) &fpa11->fpreg[Fn].fDouble;
fpa11->fType[Fn] = typeDouble;
#ifdef __ARMEB__
get_user(p[0], &pMem[0]); /* sign & exponent */
get_user(p[1], &pMem[1]);
#else
get_user(p[0], &pMem[1]);
get_user(p[1], &pMem[0]); /* sign & exponent */
#endif
}
#ifdef CONFIG_FPE_NWFPE_XP
static inline void loadExtended(const unsigned int Fn, const unsigned int __user *pMem)
{
FPA11 *fpa11 = GET_FPA11();
unsigned int *p;
p = (unsigned int *) &fpa11->fpreg[Fn].fExtended;
fpa11->fType[Fn] = typeExtended;
get_user(p[0], &pMem[0]); /* sign & exponent */
get_user(p[1], &pMem[2]); /* ls bits */
get_user(p[2], &pMem[1]); /* ms bits */
}
#endif
static inline void loadMultiple(const unsigned int Fn, const unsigned int __user *pMem)
{
FPA11 *fpa11 = GET_FPA11();
register unsigned int *p;
unsigned long x;
p = (unsigned int *) &(fpa11->fpreg[Fn]);
get_user(x, &pMem[0]);
fpa11->fType[Fn] = (x >> 14) & 0x00000003;
switch (fpa11->fType[Fn]) {
case typeSingle:
case typeDouble:
{
get_user(p[0], &pMem[2]); /* Single */
get_user(p[1], &pMem[1]); /* double msw */
p[2] = 0; /* empty */
}
break;
#ifdef CONFIG_FPE_NWFPE_XP
case typeExtended:
{
get_user(p[1], &pMem[2]);
get_user(p[2], &pMem[1]); /* msw */
p[0] = (x & 0x80003fff);
}
break;
#endif
}
}
static inline void storeSingle(struct roundingData *roundData, const unsigned int Fn, unsigned int __user *pMem)
{
FPA11 *fpa11 = GET_FPA11();
union {
float32 f;
unsigned int i[1];
} val;
switch (fpa11->fType[Fn]) {
case typeDouble:
val.f = float64_to_float32(roundData, fpa11->fpreg[Fn].fDouble);
break;
#ifdef CONFIG_FPE_NWFPE_XP
case typeExtended:
val.f = floatx80_to_float32(roundData, fpa11->fpreg[Fn].fExtended);
break;
#endif
default:
val.f = fpa11->fpreg[Fn].fSingle;
}
put_user(val.i[0], pMem);
}
static inline void storeDouble(struct roundingData *roundData, const unsigned int Fn, unsigned int __user *pMem)
{
FPA11 *fpa11 = GET_FPA11();
union {
float64 f;
unsigned int i[2];
} val;
switch (fpa11->fType[Fn]) {
case typeSingle:
val.f = float32_to_float64(fpa11->fpreg[Fn].fSingle);
break;
#ifdef CONFIG_FPE_NWFPE_XP
case typeExtended:
val.f = floatx80_to_float64(roundData, fpa11->fpreg[Fn].fExtended);
break;
#endif
default:
val.f = fpa11->fpreg[Fn].fDouble;
}
#ifdef __ARMEB__
put_user(val.i[0], &pMem[0]); /* msw */
put_user(val.i[1], &pMem[1]); /* lsw */
#else
put_user(val.i[1], &pMem[0]); /* msw */
put_user(val.i[0], &pMem[1]); /* lsw */
#endif
}
#ifdef CONFIG_FPE_NWFPE_XP
static inline void storeExtended(const unsigned int Fn, unsigned int __user *pMem)
{
FPA11 *fpa11 = GET_FPA11();
union {
floatx80 f;
unsigned int i[3];
} val;
switch (fpa11->fType[Fn]) {
case typeSingle:
val.f = float32_to_floatx80(fpa11->fpreg[Fn].fSingle);
break;
case typeDouble:
val.f = float64_to_floatx80(fpa11->fpreg[Fn].fDouble);
break;
default:
val.f = fpa11->fpreg[Fn].fExtended;
}
put_user(val.i[0], &pMem[0]); /* sign & exp */
put_user(val.i[1], &pMem[2]);
put_user(val.i[2], &pMem[1]); /* msw */
}
#endif
static inline void storeMultiple(const unsigned int Fn, unsigned int __user *pMem)
{
FPA11 *fpa11 = GET_FPA11();
register unsigned int nType, *p;
p = (unsigned int *) &(fpa11->fpreg[Fn]);
nType = fpa11->fType[Fn];
switch (nType) {
case typeSingle:
case typeDouble:
{
put_user(p[0], &pMem[2]); /* single */
put_user(p[1], &pMem[1]); /* double msw */
put_user(nType << 14, &pMem[0]);
}
break;
#ifdef CONFIG_FPE_NWFPE_XP
case typeExtended:
{
put_user(p[2], &pMem[1]); /* msw */
put_user(p[1], &pMem[2]);
put_user((p[0] & 0x80003fff) | (nType << 14), &pMem[0]);
}
break;
#endif
}
}
unsigned int PerformLDF(const unsigned int opcode)
{
unsigned int __user *pBase, *pAddress, *pFinal;
unsigned int nRc = 1, write_back = WRITE_BACK(opcode);
pBase = (unsigned int __user *) readRegister(getRn(opcode));
if (REG_PC == getRn(opcode)) {
pBase += 2;
write_back = 0;
}
pFinal = pBase;
if (BIT_UP_SET(opcode))
pFinal += getOffset(opcode);
else
pFinal -= getOffset(opcode);
if (PREINDEXED(opcode))
pAddress = pFinal;
else
pAddress = pBase;
switch (opcode & MASK_TRANSFER_LENGTH) {
case TRANSFER_SINGLE:
loadSingle(getFd(opcode), pAddress);
break;
case TRANSFER_DOUBLE:
loadDouble(getFd(opcode), pAddress);
break;
#ifdef CONFIG_FPE_NWFPE_XP
case TRANSFER_EXTENDED:
loadExtended(getFd(opcode), pAddress);
break;
#endif
default:
nRc = 0;
}
if (write_back)
writeRegister(getRn(opcode), (unsigned long) pFinal);
return nRc;
}
unsigned int PerformSTF(const unsigned int opcode)
{
unsigned int __user *pBase, *pAddress, *pFinal;
unsigned int nRc = 1, write_back = WRITE_BACK(opcode);
struct roundingData roundData;
roundData.mode = SetRoundingMode(opcode);
roundData.precision = SetRoundingPrecision(opcode);
roundData.exception = 0;
pBase = (unsigned int __user *) readRegister(getRn(opcode));
if (REG_PC == getRn(opcode)) {
pBase += 2;
write_back = 0;
}
pFinal = pBase;
if (BIT_UP_SET(opcode))
pFinal += getOffset(opcode);
else
pFinal -= getOffset(opcode);
if (PREINDEXED(opcode))
pAddress = pFinal;
else
pAddress = pBase;
switch (opcode & MASK_TRANSFER_LENGTH) {
case TRANSFER_SINGLE:
storeSingle(&roundData, getFd(opcode), pAddress);
break;
case TRANSFER_DOUBLE:
storeDouble(&roundData, getFd(opcode), pAddress);
break;
#ifdef CONFIG_FPE_NWFPE_XP
case TRANSFER_EXTENDED:
storeExtended(getFd(opcode), pAddress);
break;
#endif
default:
nRc = 0;
}
if (roundData.exception)
float_raise(roundData.exception);
if (write_back)
writeRegister(getRn(opcode), (unsigned long) pFinal);
return nRc;
}
unsigned int PerformLFM(const unsigned int opcode)
{
unsigned int __user *pBase, *pAddress, *pFinal;
unsigned int i, Fd, write_back = WRITE_BACK(opcode);
pBase = (unsigned int __user *) readRegister(getRn(opcode));
if (REG_PC == getRn(opcode)) {
pBase += 2;
write_back = 0;
}
pFinal = pBase;
if (BIT_UP_SET(opcode))
pFinal += getOffset(opcode);
else
pFinal -= getOffset(opcode);
if (PREINDEXED(opcode))
pAddress = pFinal;
else
pAddress = pBase;
Fd = getFd(opcode);
for (i = getRegisterCount(opcode); i > 0; i--) {
loadMultiple(Fd, pAddress);
pAddress += 3;
Fd++;
if (Fd == 8)
Fd = 0;
}
if (write_back)
writeRegister(getRn(opcode), (unsigned long) pFinal);
return 1;
}
unsigned int PerformSFM(const unsigned int opcode)
{
unsigned int __user *pBase, *pAddress, *pFinal;
unsigned int i, Fd, write_back = WRITE_BACK(opcode);
pBase = (unsigned int __user *) readRegister(getRn(opcode));
if (REG_PC == getRn(opcode)) {
pBase += 2;
write_back = 0;
}
pFinal = pBase;
if (BIT_UP_SET(opcode))
pFinal += getOffset(opcode);
else
pFinal -= getOffset(opcode);
if (PREINDEXED(opcode))
pAddress = pFinal;
else
pAddress = pBase;
Fd = getFd(opcode);
for (i = getRegisterCount(opcode); i > 0; i--) {
storeMultiple(Fd, pAddress);
pAddress += 3;
Fd++;
if (Fd == 8)
Fd = 0;
}
if (write_back)
writeRegister(getRn(opcode), (unsigned long) pFinal);
return 1;
}
unsigned int EmulateCPDT(const unsigned int opcode)
{
unsigned int nRc = 0;
if (LDF_OP(opcode)) {
nRc = PerformLDF(opcode);
} else if (LFM_OP(opcode)) {
nRc = PerformLFM(opcode);
} else if (STF_OP(opcode)) {
nRc = PerformSTF(opcode);
} else if (SFM_OP(opcode)) {
nRc = PerformSFM(opcode);
} else {
nRc = 0;
}
return nRc;
}