of/pci: move of_irq_map_pci() into generic code
There is a tiny difference between PPC32 and PPC64. Microblaze uses the
PPC32 variant.
Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
[grant.likely@secretlab.ca: Added comment to #endif, moved documentation
block to function implementation, fixed for non ppc and microblaze
compiles]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
new file mode 100644
index 0000000..314535f
--- /dev/null
+++ b/drivers/of/of_pci.c
@@ -0,0 +1,91 @@
+#include <linux/kernel.h>
+#include <linux/of_pci.h>
+#include <asm/prom.h>
+
+/**
+ * of_irq_map_pci - Resolve the interrupt for a PCI device
+ * @pdev: the device whose interrupt is to be resolved
+ * @out_irq: structure of_irq filled by this function
+ *
+ * This function resolves the PCI interrupt for a given PCI device. If a
+ * device-node exists for a given pci_dev, it will use normal OF tree
+ * walking. If not, it will implement standard swizzling and walk up the
+ * PCI tree until an device-node is found, at which point it will finish
+ * resolving using the OF tree walking.
+ */
+int of_irq_map_pci(struct pci_dev *pdev, struct of_irq *out_irq)
+{
+ struct device_node *dn, *ppnode;
+ struct pci_dev *ppdev;
+ u32 lspec;
+ __be32 lspec_be;
+ __be32 laddr[3];
+ u8 pin;
+ int rc;
+
+ /* Check if we have a device node, if yes, fallback to standard
+ * device tree parsing
+ */
+ dn = pci_device_to_OF_node(pdev);
+ if (dn) {
+ rc = of_irq_map_one(dn, 0, out_irq);
+ if (!rc)
+ return rc;
+ }
+
+ /* Ok, we don't, time to have fun. Let's start by building up an
+ * interrupt spec. we assume #interrupt-cells is 1, which is standard
+ * for PCI. If you do different, then don't use that routine.
+ */
+ rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
+ if (rc != 0)
+ return rc;
+ /* No pin, exit */
+ if (pin == 0)
+ return -ENODEV;
+
+ /* Now we walk up the PCI tree */
+ lspec = pin;
+ for (;;) {
+ /* Get the pci_dev of our parent */
+ ppdev = pdev->bus->self;
+
+ /* Ouch, it's a host bridge... */
+ if (ppdev == NULL) {
+ ppnode = pci_bus_to_OF_node(pdev->bus);
+
+ /* No node for host bridge ? give up */
+ if (ppnode == NULL)
+ return -EINVAL;
+ } else {
+ /* We found a P2P bridge, check if it has a node */
+ ppnode = pci_device_to_OF_node(ppdev);
+ }
+
+ /* Ok, we have found a parent with a device-node, hand over to
+ * the OF parsing code.
+ * We build a unit address from the linux device to be used for
+ * resolution. Note that we use the linux bus number which may
+ * not match your firmware bus numbering.
+ * Fortunately, in most cases, interrupt-map-mask doesn't
+ * include the bus number as part of the matching.
+ * You should still be careful about that though if you intend
+ * to rely on this function (you ship a firmware that doesn't
+ * create device nodes for all PCI devices).
+ */
+ if (ppnode)
+ break;
+
+ /* We can only get here if we hit a P2P bridge with no node,
+ * let's do standard swizzling and try again
+ */
+ lspec = pci_swizzle_interrupt_pin(pdev, lspec);
+ pdev = ppdev;
+ }
+
+ lspec_be = cpu_to_be32(lspec);
+ laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
+ laddr[1] = laddr[2] = cpu_to_be32(0);
+ return of_irq_map_raw(ppnode, &lspec_be, 1, laddr, out_irq);
+}
+EXPORT_SYMBOL_GPL(of_irq_map_pci);