powerpc/pseries: Poll VPA for topology changes and update NUMA maps

This patch sets a timer during boot that will periodically poll the
associativity change counters in the VPA. When a change in
associativity is detected, it retrieves the new associativity domain
information via the H_HOME_NODE_ASSOCIATIVITY hcall and updates the
NUMA node maps and sysfs entries accordingly. Note that since the
ibm,associativity device tree property does not exist on configurations
with both NUMA and SPLPAR enabled, no device tree updates are necessary.

Signed-off-by: Jesse Larrew <jlarrew@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/lppaca.h b/arch/powerpc/include/asm/lppaca.h
index 7f5e0fe..380d48b 100644
--- a/arch/powerpc/include/asm/lppaca.h
+++ b/arch/powerpc/include/asm/lppaca.h
@@ -62,7 +62,10 @@
 	volatile u32 dyn_pir;		// Dynamic ProcIdReg value	x20-x23
 	u32	dsei_data;           	// DSEI data                  	x24-x27
 	u64	sprg3;               	// SPRG3 value                	x28-x2F
-	u8	reserved3[80];		// Reserved			x30-x7F
+	u8	reserved3[40];		// Reserved			x30-x57
+	volatile u8 vphn_assoc_counts[8]; // Virtual processor home node
+					// associativity change counters x58-x5F
+	u8	reserved4[32];		// Reserved			x60-x7F
 
 //=============================================================================
 // CACHE_LINE_2 0x0080 - 0x00FF Contains local read-write data