powerpc: Update page-in counter for CMM

A new field has been added to the VPA as a method for the client OS to
communicate to firmware the number of page-ins it is performing when
running collaborative memory overcommit.  The hypervisor will use this
information to better determine if a partition is experiencing memory
pressure and needs more memory allocated to it.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 565b7a2..b18bc0f 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -30,6 +30,7 @@
 #include <linux/kprobes.h>
 #include <linux/kdebug.h>
 
+#include <asm/firmware.h>
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include <asm/mmu.h>
@@ -318,9 +319,16 @@
 			goto do_sigbus;
 		BUG();
 	}
-	if (ret & VM_FAULT_MAJOR)
+	if (ret & VM_FAULT_MAJOR) {
 		current->maj_flt++;
-	else
+#ifdef CONFIG_PPC_SMLPAR
+		if (firmware_has_feature(FW_FEATURE_CMO)) {
+			preempt_disable();
+			get_lppaca()->page_ins++;
+			preempt_enable();
+		}
+#endif
+	} else
 		current->min_flt++;
 	up_read(&mm->mmap_sem);
 	return 0;