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>

3 files changed, 13 insertions, 3 deletions

diff --git a/arch/powerpc/include/asm/lppaca.h b/arch/powerpc/include/asm/lppaca.h
index 2fe268b10333..25aaa97facd8 100644
--- a/arch/powerpc/include/asm/lppaca.h
+++ b/arch/powerpc/include/asm/lppaca.h
@@ -133,7 +133,8 @@ struct lppaca {
 //=============================================================================
 // CACHE_LINE_4-5 0x0180 - 0x027F Contains PMC interrupt data
 //=============================================================================
-        u8      pmc_save_area[256];     // PMC interrupt Area           x00-xFF
+        u32     page_ins;                       // CMO Hint - # page ins by OS  x00-x04
+        u8      pmc_save_area[252];     // PMC interrupt Area           x04-xFF
 } __attribute__((__aligned__(0x400)));
 
 extern struct lppaca lppaca[];
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index 48a347133f41..c744b327bcab 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -37,6 +37,7 @@ struct lppaca lppaca[] = {
                 .end_of_quantum = 0xfffffffffffffffful,
                 .slb_count = 64,
                 .vmxregs_in_use = 0,
+                .page_ins = 0,
         },
 };
 
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 565b7a237c84..b18bc0f023c8 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 @@ good_area:
                         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;