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asmlinkage unsigned long
osf_setsysinfo(unsigned long op, void __user *buffer, unsigned long nbytes,
int __user *start, void __user *arg)
{
switch (op) {
case SSI_IEEE_FP_CONTROL: {
unsigned long swcr, fpcr;
unsigned int *state;
/*
* Alpha Architecture Handbook 4.7.7.3:
* To be fully IEEE compiant, we must track the current IEEE
* exception state in software, because spurrious bits can be
* set in the trap shadow of a software-complete insn.
*/
if (get_user(swcr, (unsigned long __user *)buffer))
return -EFAULT;
state = ¤t_thread_info()->ieee_state;
/* Update softare trap enable bits. */
*state = (*state & ~IEEE_SW_MASK) | (swcr & IEEE_SW_MASK);
/* Update the real fpcr. */
fpcr = rdfpcr() & FPCR_DYN_MASK;
fpcr |= ieee_swcr_to_fpcr(swcr);
wrfpcr(fpcr);
return 0;
}
case SSI_IEEE_RAISE_EXCEPTION: {
unsigned long exc, swcr, fpcr, fex;
unsigned int *state;
if (get_user(exc, (unsigned long __user *)buffer))
return -EFAULT;
state = ¤t_thread_info()->ieee_state;
exc &= IEEE_STATUS_MASK;
/* Update softare trap enable bits. */
swcr = (*state & IEEE_SW_MASK) | exc;
*state |= exc;
/* Update the real fpcr. */
fpcr = rdfpcr();
fpcr |= ieee_swcr_to_fpcr(swcr);
wrfpcr(fpcr);
/* If any exceptions set by this call, and are unmasked,
send a signal. Old exceptions are not signaled. */
fex = (exc >> IEEE_STATUS_TO_EXCSUM_SHIFT) & swcr;
if (fex) {
siginfo_t info;
int si_code = 0;
if (fex & IEEE_TRAP_ENABLE_DNO) si_code = FPE_FLTUND;
if (fex & IEEE_TRAP_ENABLE_INE) si_code = FPE_FLTRES;
if (fex & IEEE_TRAP_ENABLE_UNF) si_code = FPE_FLTUND;
if (fex & IEEE_TRAP_ENABLE_OVF) si_code = FPE_FLTOVF;
if (fex & IEEE_TRAP_ENABLE_DZE) si_code = FPE_FLTDIV;
if (fex & IEEE_TRAP_ENABLE_INV) si_code = FPE_FLTINV;
info.si_signo = SIGFPE;
info.si_errno = 0;
info.si_code = si_code;
info.si_addr = NULL; /* FIXME */
send_sig_info(SIGFPE, &info, current);
}
return 0;
}
case SSI_IEEE_STATE_AT_SIGNAL:
case SSI_IEEE_IGNORE_STATE_AT_SIGNAL:
/*
* Not sure anybody will ever use this weird stuff. These
* ops can be used (under OSF/1) to set the fpcr that should
* be used when a signal handler starts executing.
*/
break;
case SSI_NVPAIRS: {
unsigned long v, w, i;
unsigned int old, new;
for (i = 0; i < nbytes; ++i) {
if (get_user(v, 2*i + (unsigned int __user *)buffer))
return -EFAULT;
if (get_user(w, 2*i + 1 + (unsigned int __user *)buffer))
return -EFAULT;
switch (v) {
case SSIN_UACPROC:
again:
old = current_thread_info()->flags;
new = old & ~(UAC_BITMASK << UAC_SHIFT);
new = new | (w & UAC_BITMASK) << UAC_SHIFT;
if (cmpxchg(¤t_thread_info()->flags,
old, new) != old)
goto again;
break;
default:
return -EOPNOTSUPP;
}
}
return 0;
}
default:
break;
}
return -EOPNOTSUPP;
}
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