[PATCH V2 5/5] Microblaze: Modifying microblaze PCI subsytem to support generic Xilinx AXI PCIe Host Bridge IP driver

On Thu, Feb 04, 2016 at 05:49:20AM +0000, Bharat Kumar Gogada wrote:

quoted

Subject: Re: [PATCH V2 5/5] Microblaze: Modifying microblaze PCI subsytem
to support generic Xilinx AXI PCIe Host Bridge IP driver

[+cc Ben for real this time]

On Wed, Feb 03, 2016 at 10:32:07AM -0600, Bjorn Helgaas wrote:

quoted

[+cc Ben, pcibios_get_phb_of_node() question]

On Tue, Jan 12, 2016 at 11:06:13PM +0530, Bharat Kumar Gogada wrote:

quoted

This patch does required modifications to microblaze PCI subsystem,
to work with generic driver (drivers/pci/host/pcie-xilinx.c) on
Microblaze and Zynq.

Signed-off-by: Bharat Kumar Gogada <redacted>
Signed-off-by: Ravi Kiran Gummaluri <redacted> ...

quoted

 resource_size_t pcibios_align_resource(void *data, const struct resource

*res,

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 				resource_size_t size, resource_size_t align)  {
-	struct pci_dev *dev = data;
 	resource_size_t start = res->start;

-	if (res->flags & IORESOURCE_IO) {
-		if (skip_isa_ioresource_align(dev))
-			return start;
-		if (start & 0x300)
-			start = (start + 0x3ff) & ~0x3ff;
-	}
-
 	return start;

"return res->start;" is sufficient; no need for a temporary variable.

Agreed will address in next patch.

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 }
 EXPORT_SYMBOL(pcibios_align_resource);

+int pcibios_add_device(struct pci_dev *dev) {
+	dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
+
+	return 0;
+}
+EXPORT_SYMBOL(pcibios_add_device);
+
 /*
  * Reparent resource children of pr that conflict with res
  * under res, and make res replace those children.

@@ -1335,9 +1308,21 @@ static void

pcibios_setup_phb_resources(struct pci_controller *hose,

 struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus)  {
-	struct pci_controller *hose = bus->sysdata;
+	struct device_node *np;
+
+	for_each_node_by_type(np, "pci") {
+		const void *prop;
+		unsigned int bus_min;
+
+		prop = of_get_property(np, "bus-range", NULL);
+		if (!prop)
+			continue;
+		bus_min = be32_to_cpup(prop);
+		if (bus->number == bus_min)
+			return np;
+	}

-	return of_node_get(hose->dn);
+	return NULL;

Hmmm.  The old microblaze code ("return of_node_get(hose->dn);") is
basically the same as the mips and powerpc versions.  The new code is
basically the same as the x86 version.

I like the generic weak version in drivers/pci/of.c because it doesn't
use any arch-specific data, and it looks like if we just set the
struct device.of_node members correctly, everything should Just Work.

But Ben added both the generic and the x86 versions the same day, so
there must be some complication:

  98d9f30c820d ("pci/of: Match PCI devices to OF nodes dynamically")
  3d5fe5a65af9 ("x86/devicetree: Use generic PCI <-> OF matching")

So I guess my question is, why do we need a microblaze-specific
version at all?

I did not notice the weak version in /pci/of.c, I have tested with
weak version also and it is working.  We might not need this
microblaze specific version, but will wait for ben's reply.  

If the generic version works, and you don't need the microblaze-
specific version, just remove it and we'll get this wrapped up.  No
need to wait for Ben.

Bjorn