On Tue, Jan 7, 2014 at 10:31 AM, Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx> wrote: > On Tue, Jan 07, 2014 at 04:35:01PM +0100, Arnd Bergmann wrote: > >> > >> + 0x00000000 0x0 0xd0000000 0xe0 0xd0000000 0x0 0x00200000 /* cfg */ >> > > >> > > config space is not normally in the ranges property, and I think you will need >> > > it in the pcie node itself as a 'reg' property so the code can access it. >> > >> > pcie-designware.c does it that way. I just followed their implementation. >> >> I don't remember what led to that, it still seems wrong and I can't >> find anything in the PCI binding for host bridges telling their >> config space this way. > > When we discussed the mvebu PCI driver (which is, so far, the most > throughly discussed PCI binding) it was concluded that the config > space ranges like the above was OK only if it exactly described the > standard ECAM layout. > > Idea being that standard/core code should be able to see that ranges, > map the range and issue config accesses via the ECAM rules. Ok. Thanks. > >> > >> + interrupt-map-mask = <0x0 0x0 0x0 0x7>; >> > >> + interrupt-map = <0x0 0x0 0x0 0x1 &gic 0x0 0xc2 0x1>; >> > > >> > > Only one IRQ for all devices? >> > >> > The node represents a port. I believe that Linux framework uses only >> > one of the legacy IRQs per port. Rest all remain unused. Hence I >> > removed them. Please correct me if I am wrong. >> >> Any PCI device can normally have four interrupts (IntA through >> IntD), which are traditionally separate pins on a PCI bus, but get >> emulated on PCIe. While it's not common for any normal device to use >> more than one IRQ, a bridge device will swizzle these (virtual) IRQ >> lines, so a device behind the bridge actually gets a different host >> IRQ. > > Agree, the binding should handle all four INTA,B,C,D assertions > delivered to the port. > > If HW is able to decode the 4 ints into seperate Linux interrupt > numbers then that should be described. If HW routes them all to a > single number then interrupt-map-mask should be all 0. > > Arnd's point about swizzling effects the layout of the > interrupt-map. When it is placed at the pcie-controller node level the > map will incorporate one swizzle of the on-the-wire INTx messages. If > the HW doesn't swizzle the INTx as the TLP passes through the bridge > then it probably makes more sense to put the interrupt-map in the DT > node of the bridge like mvebu does. > Ok. > Jason -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
