On Wed, Aug 10, 2011 at 08:53:16PM +1000, Finn Thain wrote:
On Wed, 10 Aug 2011, Geert Uytterhoeven wrote:
While looking into optimizing interrupts using chain handlers (which
cannot be shared), I noticed several of these cascades are hung on the
same interrupt. Hence we cannot use the optimization of chain handlers
for them.
Knowing which are mutually exclusive helps a lot, but my Mac knowledge
is very limited.
The only simple rules are that OSS only exists on one model, the Mac IIfx,
the PSC only exists on two (three, sort of) models: the Quadra 660AV
(which is also the Centris 660AV) and the Quadra 840AV, and the Baboon
only exists on one m68k model, the Powerbook 190 (it also exists on the
PowerBook 5300, but that is ppc).
What's messy is VIA2/RBV, which gets very complicated. The only simple
thing there is that the Mac IIfx doesn't have any of that because it
has OSS instead.
I derived from the code this list of cascade handlers and the interrupts
they use:
baboon_irq
IRQ_NUBUS_C
oss_irq
OSS_IRQLEV_SCSI = IRQ_AUTO_2 conflict: via2_irq
OSS_IRQLEV_SOUND = IRQ_AUTO_5 conflict: psc_irq
PSC and OSS are mutually exclusive.
VIA2 and OSS are also mutually exlusive.
oss_nubus_irq
OSS_IRQLEV_NUBUS = IRQ_AUTO_3 conflict: psc_irq
psc_irq
IRQ_AUTO_3 conflict: oss_nubus_irq
IRQ_AUTO_4
IRQ_AUTO_5 conflict: oss_irq
IRQ_AUTO_6 conflict: via1_irq
via1_irq
OSS_IRQLEV_VIA1 = IRQ_AUTO_6 (on oss) conflict: psc_irq
IRQ_AUTO_1 conflict: iop_ism_irq
iop_ism_irq is only used with OSS.
Not strictly true, but it's mapped onto IRQ_VIA2_0 in the other case.
IRQ_AUTO_6 (if via_alt_mapping) conflict: psc_irq
via_alt_mapping is not used with PSC.
via2_irq
IRQ_AUTO_2 conflict: oss_irq
via_nubus_irq
IRQ_MAC_NUBUS = IRQ_VIA2_1
These are other interrupts using in the Mac core code, which may use the same
interrupts as some of the cascades above:
iop_ism_irq
OSS_IRQLEV_IOPISM = 1 = IRQ_AUTO_1 (on oss) conflict: via1_irq
via1_irq is remapped to IRQ_AUTO_6 on OSS.
IRQ_VIA2_0 (on !oss)
mac_nmi_handler
IRQ_AUTO_7
timer handler
IRQ_MAC_TIMER_1 = IRQ_VIA1_6
So baboon and PSC are mutually exclusive? But they don't conflict w.r.t. to
interrupt lines anyway, so they're not an issue.
From the code, OSS and VIA are also mutually exclusive (except for via1_irq)?
But PSC can coexist with OSS? That's where most of the conflicts are.
Hope this helps...
More help is always good. Hope I've been helpful as well.
Brad Boyer
flar@xxxxxxxxxxxxx
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