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- Use NULL instead of 0 for fpcurthread.

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- Note the quirk with the interrupt enabled state of the dna handler.
- Use just panic() instead of printf() and panic().  Print tid instead
  of pid, the fpu state is per-thread.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
This commit is contained in:
Konstantin Belousov 2014-09-18 09:13:20 +00:00
parent ea022094f2
commit 6dfc9e44fa
1 changed files with 17 additions and 14 deletions
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31
sys/amd64/amd64/fpu.c
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@ -362,7 +362,7 @@ fpuexit(struct thread *td)
stop_emulating();
fpusave(curpcb->pcb_save);
start_emulating();
PCPU_SET(fpcurthread, 0);
PCPU_SET(fpcurthread, NULL);
}
critical_exit();
}
@ -602,16 +602,21 @@ fputrap_sse(void)
return (fpetable[(mxcsr & (~mxcsr >> 7)) & 0x3f]);
}
/*
* Implement device not available (DNA) exception
*
* It would be better to switch FP context here (if curthread != fpcurthread)
* and not necessarily for every context switch, but it is too hard to
* access foreign pcb's.
*/
static int err_count = 0;
/*
* Device Not Available (DNA, #NM) exception handler.
*
* It would be better to switch FP context here (if curthread !=
* fpcurthread) and not necessarily for every context switch, but it
* is too hard to access foreign pcb's.
*
* The handler is entered with interrupts enabled, which allows the
* context switch to happen before critical enter() is executed, and
* causes restoration of FPU context on CPU other than that caused
* DNA. It is fine, since context switch started emulation on the
* current CPU as well.
*/
void
fpudna(void)
{
@ -625,11 +630,9 @@ fpudna(void)
return;
}
if (PCPU_GET(fpcurthread) != NULL) {
printf("fpudna: fpcurthread = %p (%d), curthread = %p (%d)\n",
PCPU_GET(fpcurthread),
PCPU_GET(fpcurthread)->td_proc->p_pid,
curthread, curthread->td_proc->p_pid);
panic("fpudna");
panic("fpudna: fpcurthread = %p (%d), curthread = %p (%d)\n",
PCPU_GET(fpcurthread), PCPU_GET(fpcurthread)->td_tid,
curthread, curthread->td_tid);
}
stop_emulating();
/*