[PATCH] PCI Scan all functions

From: Jake Moilanen <moilanen@austin.ibm.com>

On a ppc64 logically partitioned system, there can be a setup where function
0 of a PCI-PCI bridge is assigned to one partition and (for example) function
2 is assigned to a second partition.  On the second partition, it would
appear that function 0 does not exist, but function 2 does.  If all the
functions are not scanned, everything under function 2 would not be detected.

This patch allows devices that don't respond to function 0, but do respond to
other functions to be marked with a quirk and have all of their functions
scanned.

arch/ppc64/kernel/pSeries_pci.c

@@ -721,3 +721,29 @@ pci_find_hose_for_OF_device(struct device_node *node)
 	}
 	return NULL;
 }
+
+/*
+ * ppc64 can have multifunction devices that do not respond to function 0.
+ * In this case we must scan all functions.
+ */
+int
+pcibios_scan_all_fns(struct pci_bus *bus, int devfn)
+{
+       struct device_node *busdn, *dn;
+
+       if (bus->self)
+               busdn = pci_device_to_OF_node(bus->self);
+       else
+               busdn = bus->sysdata;   /* must be a phb */
+
+       /*
+        * Check to see if there is any of the 8 functions are in the
+        * device tree.  If they are then we need to scan all the
+        * functions of this slot.
+        */
+       for (dn = busdn->child; dn; dn = dn->sibling)
+               if ((dn->devfn >> 3) == (devfn >> 3))
+                       return 1;
+
+       return 0;
+}

drivers/pci/probe.c

@@ -620,6 +620,9 @@ pci_scan_single_device(struct pci_bus *bus, int devfn)
 int __devinit pci_scan_slot(struct pci_bus *bus, int devfn)
 {
 	int func, nr = 0;
+	int scan_all_fns;
+
+	scan_all_fns = pcibios_scan_all_fns(bus, devfn);
 
 	for (func = 0; func < 8; func++, devfn++) {
 		struct pci_dev *dev;
@@ -640,7 +643,7 @@ int __devinit pci_scan_slot(struct pci_bus *bus, int devfn)
 				}
 			}
 		} else {
-			if (func == 0)
+			if (func == 0 && !scan_all_fns)
 				break;
 		}
 	}

include/asm-alpha/pci.h

@@ -51,6 +51,7 @@ struct pci_controller {
    bus numbers.  */
 
 #define pcibios_assign_all_busses()	1
+#define pcibios_scan_all_fns(a, b)	0
 
 #define PCIBIOS_MIN_IO		alpha_mv.min_io_address
 #define PCIBIOS_MIN_MEM		alpha_mv.min_mem_address

include/asm-arm/pci.h

@@ -20,6 +20,8 @@
 #endif
 
 
+#define pcibios_scan_all_fns(a, b)	0
+
 static inline void pcibios_set_master(struct pci_dev *dev)
 {
 	/* No special bus mastering setup handling */

include/asm-arm26/pci.h

@@ -2,4 +2,5 @@
 /* JMA 18.05.03 - is kinda needed, if only to tell it we don't have a PCI bus */
 
 #define PCI_DMA_BUS_IS_PHYS  		0
+#define pcibios_scan_all_fns(a, b)	0
 

include/asm-generic/pci.h

@@ -22,4 +22,6 @@ pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
 	region->end = res->end;
 }
 
+#define pcibios_scan_all_fns(a, b)	0
+
 #endif

include/asm-h8300/pci.h

@@ -8,6 +8,7 @@
  */
 
 #define pcibios_assign_all_busses()	0
+#define pcibios_scan_all_fns(a, b)	0
 
 extern inline void pcibios_set_master(struct pci_dev *dev)
 {

include/asm-i386/pci.h

@@ -15,6 +15,7 @@ extern unsigned int pcibios_assign_all_busses(void);
 #else
 #define pcibios_assign_all_busses()	0
 #endif
+#define pcibios_scan_all_fns(a, b)	0
 
 extern unsigned long pci_mem_start;
 #define PCIBIOS_MIN_IO		0x1000

include/asm-ia64/pci.h

@@ -16,6 +16,7 @@
  * loader.
  */
 #define pcibios_assign_all_busses()     0
+#define pcibios_scan_all_fns(a, b)	0
 
 #define PCIBIOS_MIN_IO		0x1000
 #define PCIBIOS_MIN_MEM		0x10000000

include/asm-m68k/pci.h

@@ -36,6 +36,7 @@ struct pci_bus_info
 };
 
 #define pcibios_assign_all_busses()	0
+#define pcibios_scan_all_fns(a, b)	0
 
 static inline void pcibios_set_master(struct pci_dev *dev)
 {

include/asm-m68knommu/pci.h

@@ -11,6 +11,8 @@
 #define PCIBIOS_MIN_IO		0x100
 #define PCIBIOS_MIN_MEM		0x00010000
 
+#define pcibios_scan_all_fns(a, b)	0
+
 /*
  * Return whether the given PCI device DMA address mask can
  * be supported properly.  For example, if your device can

include/asm-mips/pci.h

@@ -20,6 +20,7 @@ extern unsigned int pcibios_assign_all_busses(void);
 #else
 #define pcibios_assign_all_busses()	0
 #endif
+#define pcibios_scan_all_fns(a, b)	0
 
 #define PCIBIOS_MIN_IO		0x1000
 #define PCIBIOS_MIN_MEM		0x10000000

include/asm-parisc/pci.h

@@ -174,6 +174,7 @@ extern inline void pcibios_register_hba(struct pci_hba_data *x)
 **   to zero for legacy platforms and one for PAT platforms.
 */
 #define pcibios_assign_all_busses()     (pdc_type == PDC_TYPE_PAT)
+#define pcibios_scan_all_fns(a, b)	0
 
 #define PCIBIOS_MIN_IO          0x10
 #define PCIBIOS_MIN_MEM         0x1000 /* NBPG - but pci/setup-res.c dies */

include/asm-ppc/pci.h

@@ -26,6 +26,7 @@ struct pci_dev;
 extern int pci_assign_all_busses;
 
 #define pcibios_assign_all_busses()	(pci_assign_all_busses)
+#define pcibios_scan_all_fns(a, b)	0
 
 #define PCIBIOS_MIN_IO		0x1000
 #define PCIBIOS_MIN_MEM		0x10000000

include/asm-ppc64/pci.h

@@ -19,6 +19,8 @@
 #define PCIBIOS_MIN_IO		0x1000
 #define PCIBIOS_MIN_MEM		0x10000000
 
+extern int pcibios_scan_all_fns(struct pci_bus *bus, int devfn);
+
 static inline void pcibios_set_master(struct pci_dev *dev)
 {
 	/* No special bus mastering setup handling */

include/asm-sh/pci.h

@@ -12,6 +12,7 @@
    or architectures with incomplete PCI setup by the loader */
 
 #define pcibios_assign_all_busses()	1
+#define pcibios_scan_all_fns(a, b)	0
 
 /*
  * A board can define one or more PCI channels that represent built-in (or

include/asm-sparc/pci.h

@@ -8,6 +8,7 @@
  * or architectures with incomplete PCI setup by the loader.
  */
 #define pcibios_assign_all_busses()	0
+#define pcibios_scan_all_fns(a, b)	0
 
 #define PCIBIOS_MIN_IO		0UL
 #define PCIBIOS_MIN_MEM		0UL

include/asm-sparc64/pci.h

@@ -11,6 +11,7 @@
  * or architectures with incomplete PCI setup by the loader.
  */
 #define pcibios_assign_all_busses()	0
+#define pcibios_scan_all_fns(a, b)	0
 
 #define PCIBIOS_MIN_IO		0UL
 #define PCIBIOS_MIN_MEM		0UL

include/asm-um/pci.h

@@ -2,5 +2,6 @@
 #define __UM_PCI_H
 
 #define PCI_DMA_BUS_IS_PHYS     (1)
+#define pcibios_scan_all_fns(a, b)	0
 
 #endif

include/asm-v850/pci.h

@@ -17,6 +17,8 @@
 /* Get any platform-dependent definitions.  */
 #include <asm/machdep.h>
 
+#define pcibios_scan_all_fns(a, b)	0
+
 /* Generic declarations.  */
 
 struct scatterlist;

include/asm-x86_64/pci.h

@@ -17,6 +17,7 @@ extern unsigned int pcibios_assign_all_busses(void);
 #else
 #define pcibios_assign_all_busses()	0
 #endif
+#define pcibios_scan_all_fns(a, b)	0
 
 extern int no_iommu, force_iommu;