Thread (19 messages) 19 messages, 5 authors, 2014-02-04

Re: [RFC PATCH V3 1/4] pci: APM X-Gene PCIe controller driver

From: Arnd Bergmann <hidden>
Date: 2014-01-30 14:16:38
Also in: linux-arm-kernel, linux-pci, lkml

On Friday 24 January 2014, Tanmay Inamdar wrote:
+static void xgene_pcie_fixup_bridge(struct pci_dev *dev)
+{
+	int i;
+
+	/* Hide the PCI host BARs from the kernel as their content doesn't
+	 * fit well in the resource management
+	 */
+	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
+		dev->resource[i].start = dev->resource[i].end = 0;
+		dev->resource[i].flags = 0;
+	}
+	dev_info(&dev->dev, "Hiding X-Gene pci host bridge resources %s\n",
+		 pci_name(dev));
+}
+DECLARE_PCI_FIXUP_HEADER(XGENE_PCIE_VENDORID, XGENE_PCIE_DEVICEID,
+			 xgene_pcie_fixup_bridge);
Shouldn't this be gone now that the host bridge is correctly shown
at the domain root?
+static int xgene_pcie_setup(int nr, struct pci_sys_data *sys)
+{
+	struct xgene_pcie_port *pp = sys->private_data;
+	struct resource *io = &pp->realio;
+
+	io->start = sys->domain * SZ_64K;
+	io->end = io->start + SZ_64K;
+	io->flags = pp->io.res.flags;
+	io->name = "PCI IO";
+	pci_ioremap_io(io->start, pp->io.res.start);
+
+	pci_add_resource_offset(&sys->resources, io, sys->io_offset);
+	sys->mem_offset = pp->mem.res.start - pp->mem.pci_addr;
+	pci_add_resource_offset(&sys->resources, &pp->mem.res,
+				sys->mem_offset);
+	return 1;
+}
Thanks for bringing back the I/O space handling.

You don't seem to set sys->io_offset anywhere, but each of the
ports listed in your DT starts a local bus I/O register range
at port 0.

AFAICT, you need to add (somewhere)

	sys->io_offset = pp->realio.start - pp->io.pci_addr;

but there could be something else missing. You clearly haven't
tested if the I/O space actually works.

If you want to try out the I/O space, I'd suggest using an Intel
e1000 network card, which has both memory and i/o space. There
is a patch at http://www.spinics.net/lists/linux-pci/msg27684.html
that lets you check the I/O registers on it, or you can go
through /dev/port from user space.

I also haven't seen your patch that adds pci_ioremap_io() for
arm64. It would be helpful to keep it in the same patch
series, since it won't build without this patch.

	Arnd
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