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>

arch/powerpc/include/asm/pci-bridge.h

@@ -153,8 +153,8 @@ struct pci_dn {
 
 	int	pci_ext_config_space;	/* for pci devices */
 
-#ifdef CONFIG_EEH
 	struct	pci_dev *pcidev;	/* back-pointer to the pci device */
+#ifdef CONFIG_EEH
 	int	class_code;		/* pci device class */
 	int	eeh_mode;		/* See eeh.h for possible EEH_MODEs */
 	int	eeh_config_addr;
@@ -164,6 +164,10 @@ struct pci_dn {
 	int	eeh_false_positives;	/* # times this device reported #ff's */
 	u32	config_space[16];	/* saved PCI config space */
 #endif
+#define IODA_INVALID_PE		(-1)
+#ifdef CONFIG_PPC_POWERNV
+	int	pe_number;
+#endif
 };
 
 /* Get the pointer to a device_node's pci_dn */

arch/powerpc/kernel/pci_dn.c

@@ -50,6 +50,9 @@ void * __devinit update_dn_pci_info(struct device_node *dn, void *data)
 	dn->data = pdn;
 	pdn->node = dn;
 	pdn->phb = phb;
+#ifdef CONFIG_PPC_POWERNV
+	pdn->pe_number = IODA_INVALID_PE;
+#endif
 	regs = of_get_property(dn, "reg", NULL);
 	if (regs) {
 		/* First register entry is addr (00BBSS00)  */

arch/powerpc/platforms/powernv/Makefile

@@ -2,4 +2,4 @@ obj-y			+= setup.o opal-takeover.o opal-wrappers.o opal.o
 obj-y			+= opal-rtc.o opal-nvram.o
 
 obj-$(CONFIG_SMP)	+= smp.o
-obj-$(CONFIG_PCI)	+= pci.o pci-p5ioc2.o
+obj-$(CONFIG_PCI)	+= pci.o pci-p5ioc2.o pci-ioda.o