Re: [PATCH v2 1/2] PCI: generic: remove dependency on hw_pci

From: Will Deacon <will.deacon@arm.com>
To: Jayachandran C <jchandra@broadcom.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	Arnd Bergmann <arnd@arndb.de>,
	Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
	Liviu Dudau <Liviu.Dudau@arm.com>,
	"suravee.suthikulpanit@amd.com" <suravee.suthikulpanit@amd.com>,
	Ming Lei <ming.lei@canonical.com>
Subject: Re: [PATCH v2 1/2] PCI: generic: remove dependency on hw_pci
Date: Tue, 5 May 2015 16:53:46 +0100	[thread overview]
Message-ID: <20150505155346.GJ1550@arm.com> (raw)
In-Reply-To: <1430791333-26013-1-git-send-email-jchandra@broadcom.com>

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@broadcom.com>
> ---
> 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

Will