cpumask: x86: Introduce cpumask_of_{node,pcibus} to replace {node,pcibus}_to_cpumask

Impact: New APIs

The old node_to_cpumask/node_to_pcibus returned a cpumask_t: these
return a pointer to a struct cpumask.  Part of removing cpumasks from
the stack.

Also makes __pcibus_to_node take a const pointer.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
index 875b38e..52d80d3 100644
--- a/arch/x86/include/asm/pci.h
+++ b/arch/x86/include/asm/pci.h
@@ -98,9 +98,9 @@
 
 #ifdef CONFIG_NUMA
 /* Returns the node based on pci bus */
-static inline int __pcibus_to_node(struct pci_bus *bus)
+static inline int __pcibus_to_node(const struct pci_bus *bus)
 {
-	struct pci_sysdata *sd = bus->sysdata;
+	const struct pci_sysdata *sd = bus->sysdata;
 
 	return sd->node;
 }
@@ -109,6 +109,12 @@
 {
 	return node_to_cpumask(__pcibus_to_node(bus));
 }
+
+static inline const struct cpumask *
+cpumask_of_pcibus(const struct pci_bus *bus)
+{
+	return cpumask_of_node(__pcibus_to_node(bus));
+}
 #endif
 
 #endif /* _ASM_X86_PCI_H */