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When trying to figure out which code to return, use the exception enable

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bits to mask out the undesired exceptions.  (Thanks to Todd Whitesel for
the idea).
This commit is contained in:
matt 2004-04-04 22:20:44 +00:00
parent e5795ee03a
commit 15fc41dbb0
1 changed files with 25 additions and 23 deletions
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48
sys/arch/powerpc/powerpc/fpu.c
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@ -1,4 +1,4 @@
/* $NetBSD: fpu.c,v 1.13 2004/04/04 19:21:36 matt Exp $ */
/* $NetBSD: fpu.c,v 1.14 2004/04/04 22:20:44 matt Exp $ */
/*
* Copyright (C) 1996 Wolfgang Solfrank.
@ -32,7 +32,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: fpu.c,v 1.13 2004/04/04 19:21:36 matt Exp $");
__KERNEL_RCSID(0, "$NetBSD: fpu.c,v 1.14 2004/04/04 22:20:44 matt Exp $");
#include "opt_multiprocessor.h"
@ -226,9 +226,9 @@ save_fpu_lwp(struct lwp *l)
}
#define STICKYBITS (FPSCR_VX|FPSCR_OX|FPSCR_UX|FPSCR_ZX|FPSCR_XX)
#if STICKYBITS & (PCB_FE0|PCB_FE1|PCB_VEC|PCB_FPU)
#error PCB flags overlap FPSCR STICKYBITS
#endif
#define STICKYSHIFT 25
#define MASKBITS (FPSCR_VE|FPSCR_OE|FPSCR_UE|FPSCR_ZE|FPSCR_XE)
#define MASKSHIFT 3
int
get_fpu_fault_code(void)
@ -236,21 +236,22 @@ get_fpu_fault_code(void)
#ifdef DIAGNOSTIC
struct cpu_info *ci = curcpu();
#endif
struct lwp *l = curlwp;
struct pcb *pcb = &l->l_addr->u_pcb;
struct pcb *pcb = curpcb;
register_t msr;
uint64_t tmp;
uint32_t fpscr;
uint64_t tmp, fpscr64;
uint32_t fpscr, ofpscr;
int code;
KASSERT(pcb->pcb_fpcpu == ci);
KASSERT(pcb->pcb_flags & PCB_FPU);
KASSERT(ci->ci_fpulwp == l);
KASSERT(ci->ci_fpulwp == curlwp);
msr = mfmsr();
mtmsr((msr & ~PSL_EE) | PSL_FP);
__asm __volatile ("isync");
__asm __volatile (
"stfd 0,0(%0)\n" /* save f0 */
"mffs 0\n" /* get FPSCR */
"stfd 0,0(%2)\n" /* store a temp copy */
"mtfsb0 0\n" /* clear FPSCR_FX */
"mtfsb0 24\n" /* clear FPSCR_VE */
"mtfsb0 25\n" /* clear FPSCR_OE */
@ -260,29 +261,30 @@ get_fpu_fault_code(void)
"mffs 0\n" /* get FPSCR */
"stfd 0,0(%1)\n" /* store it */
"lfd 0,0(%0)\n" /* restore f0 */
:: "b"(&tmp), "b"(&pcb->pcb_fpu.fpscr));
:: "b"(&tmp), "b"(&pcb->pcb_fpu.fpscr), "b"(&fpscr64));
mtmsr(msr);
__asm __volatile ("isync");
/*
* Now determine the fault type. First we see if any of the sticky
* bits have changed since the FP exception. If so, we only want
* to return the code for the new exception. If not, we look at all
* the bits.
* Now determine the fault type. First we test to see if any of sticky
* bits correspond to the enabled exceptions. If so, we only test
* those bits. If not, we look at all the bits. (In reality, we only
* could get an exception if FPSCR_FEX changed state. So we should
* have at least one bit that corresponds).
*/
ofpscr = (uint32_t)fpscr64;
ofpscr &= ofpscr << (STICKYSHIFT - MASKSHIFT);
fpscr = (uint32_t)(*(uint64_t *)&pcb->pcb_fpu.fpscr);
if ((fpscr & ~pcb->pcb_flags) & STICKYBITS)
fpscr &= ~pcb->pcb_flags;
if (fpscr & ofpscr & STICKYBITS)
fpscr &= ofpscr;
/*
* Let's determine what the appropriate code is.
*/
if (fpscr & FPSCR_VX) code = FPE_FLTINV;
else if (fpscr & FPSCR_OX) code = FPE_FLTOVF;
else if (fpscr & FPSCR_UX) code = FPE_FLTUND;
else if (fpscr & FPSCR_ZX) code = FPE_FLTDIV;
else if (fpscr & FPSCR_XX) code = FPE_FLTRES;
else code = 0;
/*
* Now we save the latest set of sticky bits. This is so we can see
* what's changed on the next SIGFPE.
*/
pcb->pcb_flags &= ~STICKYBITS;
pcb->pcb_flags |= fpscr & STICKYBITS;
return code;
}