[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>
diff --git a/arch/arm/nwfpe/fpa11_cprt.c b/arch/arm/nwfpe/fpa11_cprt.c
index db01fbc..adf8d30 100644
--- a/arch/arm/nwfpe/fpa11_cprt.c
+++ b/arch/arm/nwfpe/fpa11_cprt.c
@@ -33,8 +33,6 @@
extern flag float64_is_nan(float64);
extern flag float32_is_nan(float32);
-void SetRoundingMode(const unsigned int opcode);
-
unsigned int PerformFLT(const unsigned int opcode);
unsigned int PerformFIX(const unsigned int opcode);
@@ -77,14 +75,17 @@
unsigned int PerformFLT(const unsigned int opcode)
{
FPA11 *fpa11 = GET_FPA11();
- SetRoundingMode(opcode);
- SetRoundingPrecision(opcode);
+ struct roundingData roundData;
+
+ roundData.mode = SetRoundingMode(opcode);
+ roundData.precision = SetRoundingPrecision(opcode);
+ roundData.exception = 0;
switch (opcode & MASK_ROUNDING_PRECISION) {
case ROUND_SINGLE:
{
fpa11->fType[getFn(opcode)] = typeSingle;
- fpa11->fpreg[getFn(opcode)].fSingle = int32_to_float32(readRegister(getRd(opcode)));
+ fpa11->fpreg[getFn(opcode)].fSingle = int32_to_float32(&roundData, readRegister(getRd(opcode)));
}
break;
@@ -108,6 +109,9 @@
return 0;
}
+ if (roundData.exception)
+ float_raise(roundData.exception);
+
return 1;
}
@@ -115,26 +119,29 @@
{
FPA11 *fpa11 = GET_FPA11();
unsigned int Fn = getFm(opcode);
+ struct roundingData roundData;
- SetRoundingMode(opcode);
+ roundData.mode = SetRoundingMode(opcode);
+ roundData.precision = SetRoundingPrecision(opcode);
+ roundData.exception = 0;
switch (fpa11->fType[Fn]) {
case typeSingle:
{
- writeRegister(getRd(opcode), float32_to_int32(fpa11->fpreg[Fn].fSingle));
+ writeRegister(getRd(opcode), float32_to_int32(&roundData, fpa11->fpreg[Fn].fSingle));
}
break;
case typeDouble:
{
- writeRegister(getRd(opcode), float64_to_int32(fpa11->fpreg[Fn].fDouble));
+ writeRegister(getRd(opcode), float64_to_int32(&roundData, fpa11->fpreg[Fn].fDouble));
}
break;
#ifdef CONFIG_FPE_NWFPE_XP
case typeExtended:
{
- writeRegister(getRd(opcode), floatx80_to_int32(fpa11->fpreg[Fn].fExtended));
+ writeRegister(getRd(opcode), floatx80_to_int32(&roundData, fpa11->fpreg[Fn].fExtended));
}
break;
#endif
@@ -143,6 +150,9 @@
return 0;
}
+ if (roundData.exception)
+ float_raise(roundData.exception);
+
return 1;
}
