On Wed, May 20, 2015 at 12:29 PM, Will Deacon <will.deacon@xxxxxxx> wrote: > On Wed, May 20, 2015 at 12:09:18AM +0100, Bjorn Helgaas wrote: >> On Tue, May 12, 2015 at 05:37:47AM +0530, Jayachandran C. wrote: >> > On Tue, May 05, 2015 at 04:53:46PM +0100, Will Deacon wrote: >> > > On Tue, May 05, 2015 at 03:02:12AM +0100, Jayachandran C wrote: >> > > > The current code in pci-host-generic.c uses pci_common_init_dev() >> > > > from the arch/arm/ to do a part of the PCI initialization, and this >> > > > prevents it from being used on arm64. >> > > > >> > > > The initialization done by pci_common_init_dev() that is really >> > > > needed by pci-host-generic.c can be done in the same file without >> > > > using the hw_pci API of ARM. >> > > > >> > > > The ARM platform requires a pci_sys_data as sysdata for the PCI bus, >> > > > this is be handled by setting up 'struct gen_pci' to embed a >> > > > pci_sys_data variable as the first element on the ARM platform. >> > > > >> > > > Signed-off-by: Jayachandran C <jchandra@xxxxxxxxxxxx> >> > > > --- >> > > > Here's v2 of the patches, this enables use of pci-host-generic on >> > > > arm64. >> > > > >> > > > This has been tested on both qemu and fast model for arm64, and on >> > > > qemu for arm32. >> > > > >> > > > v1->v2 >> > > > - Address comments from Arnd Bergmann and Lorenzo Pieralisi >> > > > - move contents of gen_pci_init to gen_pci_probe >> > > > - assign resources only when !probe_only >> > > > - tested on ARM32 with qemu option -M virt >> > > >> > > I tried this with an arm64 kernel running under kvmtool, but I get the >> > > following errors (a 32-bit ARM kernel does seem to work): >> > > >> > > PCI host bridge /pci ranges: >> > > IO 0x00000000..0x0000ffff -> 0x00000000 >> > > MEM 0x41000000..0x7fffffff -> 0x41000000 >> > > pci-host-generic 40000000.pci: PCI host bridge to bus 0000:00 >> > > pci_bus 0000:00: root bus resource [bus 00-01] >> > > pci_bus 0000:00: root bus resource [io 0x0000-0xffff] >> > > pci_bus 0000:00: root bus resource [mem 0x41000000-0x7fffffff] >> > > pci_bus 0000:00: scanning bus >> > > pci 0000:00:00.0: [1af4:1009] type 00 class 0xff0000 >> > > pci 0000:00:00.0: reg 0x10: [mem 0x41000000-0x410003ff] >> > > pci 0000:00:00.0: reg 0x14: [io 0x6200-0x65ff] >> > > pci 0000:00:00.0: reg 0x18: [mem 0x41000400-0x410005ff] >> > > pci 0000:00:01.0: [1af4:1009] type 00 class 0xff0000 >> > > pci 0000:00:01.0: reg 0x10: [mem 0x41000800-0x41000bff] >> > > pci 0000:00:01.0: reg 0x14: [io 0x6600-0x69ff] >> > > pci 0000:00:01.0: reg 0x18: [mem 0x41000c00-0x41000dff] >> > > pci_bus 0000:00: fixups for bus >> > > pci_bus 0000:00: bus scan returning with max=00 >> > > pci 0000:00:00.0: fixup irq: got 10 >> > > pci 0000:00:00.0: assigning IRQ 10 >> > > pci 0000:00:01.0: fixup irq: got 11 >> > > pci 0000:00:01.0: assigning IRQ 11 >> > > virtio-pci 0000:00:00.0: can't enable device: BAR 0 [mem 0x41000000-0x410003ff] not claimed >> > > virtio-pci: probe of 0000:00:00.0 failed with error -22 >> > > virtio-pci 0000:00:01.0: can't enable device: BAR 0 [mem 0x41000800-0x41000bff] not claimed >> > > virtio-pci: probe of 0000:00:01.0 failed with error -22 >> > >> > PCI_PROBE_ONLY does not work yet for arm64, this will need further changes >> > in either arm64 or pci as noted by Lorenzo. This is not due to a problem with >> > this patch per se. >> > >> > More importantly, this does not change the current arm32 behavior and adds >> > support for arm64 for two very useful cases >> > - we can use "pci-host-ecam-generic" for a host bridge controller that is >> > initialized by firmware, without adding a custom driver. >> > - qemu virt platform works on arm64 >> > >> > If you think there are any furhter changes needed in this patchset please >> > let me know. >> >> I'm waiting for at least an ack from Will. > > I'm not too keen on the current state of this patch. Firstly, I'd really > like to see the PROBE_ONLY case addressed at the same time as this port > (Lorenzo and Suravee are working on this). Secondly, the hack to put > pci_sys_data as the first member of gen_pci is ugly at best and probably > makes it difficult to support MSIs on ARM. Thanks, Will. I'll wait for another iteration that addresses these. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
