> -----Original Message----- > From: > linuxppc-dev-bounces+tiejun.chen=windriver....@lists.ozlabs.or > g > [mailto:linuxppc-dev-bounces+tiejun.chen=windriver....@lists.o > zlabs.org] On Behalf Of Scott Wood > Sent: Wednesday, September 22, 2010 6:07 AM > To: Anderson, Trevor > Cc: david.hag...@gmail.com; linuxppc-dev@lists.ozlabs.org > Subject: Re: Questions on interrupt vector assignment on MPC8641D > > On Tue, 21 Sep 2010 17:37:15 -0400 > "Anderson, Trevor" <tander...@curtisswright.com> wrote: > > > IRQ assignments for MPC8641D are "virtual", > > This is true for powerpc in general. > > > meaning "made up" and quite difficult to determine by > looking through code. > > But I believe the plan goes something like this: > > > > IRQ > > --------- > > 0 No interrupt > > 1 - 15 External interrupts (only 1..12 would be used) > > 16 - 127 Internal interrupts - see Table 9-2 of > 8641D ref man, > > Add 15 to the numbers shown > > 128 - 255 Yours, or your BSP's, to do with as you like > > 256 - 511 Message Signaled Interrupts > > > > If you look in the sample device trees for 8641 cards > you'll see that > > the interrupt values cited there for various devices match > the 16..127 > > group above. > > There are two different numberspaces involved here. > > The MPIC interrupt numberspace in the device tree (which is > not virtual; it is a private numberspace to MPIC) is based on > the offset of the registers for that interrupt source. > External interrupts start at zero (which is valid), internal > at 16, and special things like MSIs at higher numbers (I > don't think it's quite 256).
Agreed. This should be depend on the given platform. For example 0xe0~0xe7 are ranged for MSI on Freescale targets. And it can avoid easily to conflict those used lower numbers when the special MSI interrupt numbers are higher. Tiejun > > The numberspace for virtual interrupts, which is what you > pass to request_irq(), is dynamically allocated. You > shouldn't need to know anything about it other than that zero > is invalid, and you get the virtual IRQ from > irq_of_parse_and_map() or another such mapping function. > > In neither case is there a range that is set aside for you > "to do with as you like". If you have another interrupt > controller and need a block of virtual interrupts, register > the controller with > irq_alloc_host() and you'll get a block assigned. > > -Scott > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
