Re: [patch 08/18] PS3: Kexec support

Benjamin Herrenschmidt wrote:

On Thu, 2007-06-07 at 12:31 +1000, Michael Ellerman wrote:

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+  pr_debug("%s:%d: cpu %u, virq %d\n", __func__, __LINE__,

pd->cpu, virq);

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+
+  local_irq_save(flags);
+  asm volatile(
+               "1:        ldarx %0,0,%3\n"
+               "andc      %0,%0,%2\n"
+               "stdcx.    %0,0,%3\n"
+               "bne-      1b"
+               : "=&r" (old), "+m" (*p)
+               : "r" (bit), "r" (p)
+               : "cc" );
+
+  lv1_did_update_interrupt_mask(pd->node, pd->cpu);
+  local_irq_restore(flags);

How is this different from set_bit() ?  (asm-powerpc/bitops.h)

ps. now that I see you're just moving this code around someone's
probably already asked that question. 

Actually the above is clear_bit :-)

That would thus be something around the lines of:

 clear_bit(&pd->bmp.mask, 63 - virq);

Geoff, feel free to replace it with the clear_bit if you think it's
nicer that way :-) (and double check I didn't smoke crack when doing
the above conversion).

The other one in unmask would be set_bit() of course.

Almost right.  Needed clear_bit(63 - virq, &pd->bmp.mask).
I added it in.

-Geoff