powerpc/powernv: PCI support for p7IOC under OPAL v2

This adds support for p7IOC (and possibly other IODA v1 IO Hubs)
using OPAL v2 interfaces.

We completely take over resource assignment and assign them using an
algorithm that hands out device BARs in a way that makes them fit in
individual segments of the M32 window of the bridge, which enables us
to assign individual PEs to devices and functions.

The current implementation gives out a PE per functions on PCIe, and a
PE for the entire bridge for PCIe to PCI-X bridges.

This can be adjusted / fine tuned later.

We also setup DMA resources (32-bit only for now) and MSIs (both 32-bit
and 64-bit MSI are supported).

The DMA allocation tries to divide the available 256M segments of the
32-bit DMA address space "fairly" among PEs. This is done using a
"weight" heuristic which assigns less value to things like OHCI USB
controllers than, for example SCSI RAID controllers. This algorithm
will probably want some fine tuning for specific devices or device
types.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 16 insertions, 4 deletions

diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index baef772d41f4..c0ed379498a0 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -467,12 +467,24 @@ void __init pnv_pci_init(void)
 		init_pci_config_tokens();
 		find_and_init_phbs();
 #endif /* CONFIG_PPC_POWERNV_RTAS */
-	} else {
-		/* OPAL is here, do our normal stuff */
+	}
+	/* OPAL is here, do our normal stuff */
+	else {
+		int found_ioda = 0;
+
+		/* Look for IODA IO-Hubs. We don't support mixing IODA
+		 * and p5ioc2 due to the need to change some global
+		 * probing flags
+		 */
+		for_each_compatible_node(np, NULL, "ibm,ioda-hub") {
+			pnv_pci_init_ioda_hub(np);
+			found_ioda = 1;
+		}
 
 		/* Look for p5ioc2 IO-Hubs */
-		for_each_compatible_node(np, NULL, "ibm,p5ioc2")
-			pnv_pci_init_p5ioc2_hub(np);
+		if (!found_ioda)
+			for_each_compatible_node(np, NULL, "ibm,p5ioc2")
+				pnv_pci_init_p5ioc2_hub(np);
 	}
 
 	/* Setup the linkage between OF nodes and PHBs */