Messages in this thread | | | Subject | Re: [S390] cio: fix stsch_reset. | From | Martin Schwidefsky <> | Date | Sun, 31 Dec 2006 13:07:25 +0100 |
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On Sun, 2006-12-31 at 01:31 -0500, Chuck Ebbert wrote: > > @@ -881,10 +880,18 @@ static void cio_reset_pgm_check_handler( > > static int stsch_reset(struct subchannel_id schid, volatile struct schib *addr) > > { > > int rc; > > + register struct subchannel_id reg1 asm ("1") = schid; > > > > pgm_check_occured = 0; > > s390_reset_pgm_handler = cio_reset_pgm_check_handler; > > - rc = stsch(schid, addr); > > + > > + asm volatile( > > + " stsch 0(%2)\n" > > + " ipm %0\n" > > + " srl %0,28" > > + : "=d" (rc) > > + : "d" (reg1), "a" (addr), "m" (*addr) : "memory", "cc"); > > + > > s390_reset_pgm_handler = NULL; > > if (pgm_check_occured) > > return -EIO; > > > Can't you just put a barrier() before the stsch() call?
You mean after. We have to prevent the sequence 1) load pgm_check_occured, 2) stsch and the execution of cio_reset_pgm_check_handler 3) use of the the value loaded in 1) A barrier before 2) forces a reload of pgm_check_occured but it does not force the reload to be before the stsch call.
But the basic idea is valid. The standard stsch() inline followed by a barrier() is equivalent to the new inline assembly.
-- blue skies, Martin.
Martin Schwidefsky Linux for zSeries Development & Services IBM Deutschland Entwicklung GmbH
"Reality continues to ruin my life." - Calvin.
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