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powerpc: Add SPE/EFP math emulation for E500v1/v2 processors.

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This patch add the handlers of SPE/EFP exceptions.
The code is used to emulate float point arithmetic,
when MSR(SPE) is enabled and receive EFP data interrupt or EFP round interrupt.

This patch has no conflict with or dependence on FP math-emu.

The code has been tested by TestFloat.

Now the code doesn't support SPE/EFP instructions emulation
(it won't be called when receive program interrupt),
but it could be easily added.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This commit is contained in:
Liu Yu
2008-10-28 11:50:21 +08:00
committed by Kumar Gala
parent 033b8a333c
commit 6a800f36ac
6 changed files with 813 additions and 20 deletions
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62
arch/powerpc/kernel/traps.c
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@@ -1160,37 +1160,85 @@ void CacheLockingException(struct pt_regs *regs, unsigned long address,
#ifdef CONFIG_SPE
void SPEFloatingPointException(struct pt_regs *regs)
{
extern int do_spe_mathemu(struct pt_regs *regs);
unsigned long spefscr;
int fpexc_mode;
int code = 0;
int err;
preempt_disable();
if (regs->msr & MSR_SPE)
giveup_spe(current);
preempt_enable();
spefscr = current->thread.spefscr;
fpexc_mode = current->thread.fpexc_mode;
/* Hardware does not neccessarily set sticky
* underflow/overflow/invalid flags */
if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
code = FPE_FLTOVF;
spefscr |= SPEFSCR_FOVFS;
}
else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
code = FPE_FLTUND;
spefscr |= SPEFSCR_FUNFS;
}
else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
code = FPE_FLTDIV;
else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
code = FPE_FLTINV;
spefscr |= SPEFSCR_FINVS;
}
else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
code = FPE_FLTRES;
current->thread.spefscr = spefscr;
err = do_spe_mathemu(regs);
if (err == 0) {
regs->nip += 4; /* skip emulated instruction */
emulate_single_step(regs);
return;
}
if (err == -EFAULT) {
/* got an error reading the instruction */
_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
} else if (err == -EINVAL) {
/* didn't recognize the instruction */
printk(KERN_ERR "unrecognized spe instruction "
"in %s at %lx\n", current->comm, regs->nip);
} else {
_exception(SIGFPE, regs, code, regs->nip);
}
_exception(SIGFPE, regs, code, regs->nip);
return;
}
void SPEFloatingPointRoundException(struct pt_regs *regs)
{
extern int speround_handler(struct pt_regs *regs);
int err;
preempt_disable();
if (regs->msr & MSR_SPE)
giveup_spe(current);
preempt_enable();
regs->nip -= 4;
err = speround_handler(regs);
if (err == 0) {
regs->nip += 4; /* skip emulated instruction */
emulate_single_step(regs);
return;
}
if (err == -EFAULT) {
/* got an error reading the instruction */
_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
} else if (err == -EINVAL) {
/* didn't recognize the instruction */
printk(KERN_ERR "unrecognized spe instruction "
"in %s at %lx\n", current->comm, regs->nip);
} else {
_exception(SIGFPE, regs, 0, regs->nip);
return;
}
}
#endif
/*