[2/3] PCI: ARM: add support for virtual PCI host controller

Commit Message

Arnd Bergmann Feb. 11, 2014, 10:42 a.m. UTC

On Monday 10 February 2014 10:34:50 Jason Gunthorpe wrote:

> I noticed this on mvebu as well..
> 
> 3.13 w/ mvebu driver:
> 
> e0001000-e0001fff : /mbus/pex@e0000000/pcie@1,0/fpga@0/fpga_sysmon@1000
> e0006000-e0006fff : /mbus/pex@e0000000/pcie@1,0/fpga@0/qdr2p@6000
> 
> 3.10 w/ old kirkwood driver:
> 
> e0000000-e7ffffff : PCIe 0 MEM
>   e0000000-e001ffff : 0000:00:01.0
>     e0001000-e0001fff : /mbus/pex@e0000000/pcie@1,0/fpga@0/fpga_sysmon@1000
>     e0006000-e0006fff : /mbus/pex@e0000000/pcie@1,0/fpga@0/qdr2p@6000
> 
> The latter is obviously correct and matches x86. I'm not sure where
> the new style host drivers are going wrong, even the resource that
> should be added by the PCI core itself for the BAR is missing..

I looked briefly at the code and found that mach-kirkwood/pcie.c does
both request_resource() and pci_add_resource_offset(), while
drivers/pci/host/pci-mvebu.c only does the latter. Does the patch
below restore the previous behavior?

Since the mvebu_pcie_setup() function seems very generic at this,
we should probably try to factor out that code into a common
helper, at least for arm64, but ideally shared with arm32
as well.

	Arnd


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Comments

Will Deacon Feb. 12, 2014, 7:49 p.m. UTC | #1

On Tue, Feb 11, 2014 at 10:42:52AM +0000, Arnd Bergmann wrote:
> On Monday 10 February 2014 10:34:50 Jason Gunthorpe wrote:
> 
> > I noticed this on mvebu as well..
> > 
> > 3.13 w/ mvebu driver:
> > 
> > e0001000-e0001fff : /mbus/pex@e0000000/pcie@1,0/fpga@0/fpga_sysmon@1000
> > e0006000-e0006fff : /mbus/pex@e0000000/pcie@1,0/fpga@0/qdr2p@6000
> > 
> > 3.10 w/ old kirkwood driver:
> > 
> > e0000000-e7ffffff : PCIe 0 MEM
> >   e0000000-e001ffff : 0000:00:01.0
> >     e0001000-e0001fff : /mbus/pex@e0000000/pcie@1,0/fpga@0/fpga_sysmon@1000
> >     e0006000-e0006fff : /mbus/pex@e0000000/pcie@1,0/fpga@0/qdr2p@6000
> > 
> > The latter is obviously correct and matches x86. I'm not sure where
> > the new style host drivers are going wrong, even the resource that
> > should be added by the PCI core itself for the BAR is missing..
> 
> I looked briefly at the code and found that mach-kirkwood/pcie.c does
> both request_resource() and pci_add_resource_offset(), while
> drivers/pci/host/pci-mvebu.c only does the latter. Does the patch
> below restore the previous behavior?

Making the equivalent changes in my generic driver fixes the issue, cheers
Arnd!

  bash-4.2# cat /proc/ioports
  00000000-0000ffff : /pci
    00006200-000065ff : virtio-pci
    00006600-000069ff : virtio-pci
    00006a00-00006dff : virtio-pci
    00006e00-000071ff : virtio-pci
  bash-4.2# cat /proc/iomem
  41000000-7fffffff : /pci
    41000000-410003ff : virtio-pci
    41000400-410005ff : virtio-pci
    41000800-41000bff : virtio-pci
    41000c00-41000dff : virtio-pci
    41001000-410013ff : virtio-pci
    41001400-410015ff : virtio-pci
    41001800-41001bff : virtio-pci
    41001c00-41001dff : virtio-pci
  80000000-93ffffff : System RAM
    80008000-80697e4f : Kernel code
    806f6000-8077b4c3 : Kernel data

Will
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Patch

diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index 13478ec..b55e9a6 100644
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -680,9 +680,17 @@  static int mvebu_pcie_setup(int nr, struct pci_sys_data *sys)
 	struct mvebu_pcie *pcie = sys_to_pcie(sys);
 	int i;
 
-	if (resource_size(&pcie->realio) != 0)
+	if (request_resource(&iomem_resource, &pcie->mem))
+		return 0;
+
+	if (resource_size(&pcie->realio) != 0) {
+		if (request_resource(&ioport_resource, &pcie->realio)) {
+			release_resource(&pcie->mem);
+			return 0;
+		}
 		pci_add_resource_offset(&sys->resources, &pcie->realio,
 					sys->io_offset);
+	}
 	pci_add_resource_offset(&sys->resources, &pcie->mem, sys->mem_offset);
 	pci_add_resource(&sys->resources, &pcie->busn);