2 files changed, 23 insertions, 8 deletions

diff --git a/arch/x86/kernel/uv_time.c b/arch/x86/kernel/uv_time.c
index 3c84aa001c11..2b75ef638dbc 100644
--- a/arch/x86/kernel/uv_time.c
+++ b/arch/x86/kernel/uv_time.c
@@ -282,10 +282,21 @@ static int uv_rtc_unset_timer(int cpu, int force)
 
 /*
  * Read the RTC.
+ *
+ * Starting with HUB rev 2.0, the UV RTC register is replicated across all
+ * cachelines of it's own page.  This allows faster simultaneous reads
+ * from a given socket.
  */
 static cycle_t uv_read_rtc(struct clocksource *cs)
 {
-        return (cycle_t)uv_read_local_mmr(UVH_RTC);
+        unsigned long offset;
+
+        if (uv_get_min_hub_revision_id() == 1)
+                offset = 0;
+        else
+                offset = (uv_blade_processor_id() * L1_CACHE_BYTES) % PAGE_SIZE;
+
+        return (cycle_t)uv_read_local_mmr(UVH_RTC | offset);
 }
 
 /*
diff --git a/drivers/char/uv_mmtimer.c b/drivers/char/uv_mmtimer.c
index 867b67be9f0a..c7072ba14f48 100644
--- a/drivers/char/uv_mmtimer.c
+++ b/drivers/char/uv_mmtimer.c
@@ -89,13 +89,17 @@ static long uv_mmtimer_ioctl(struct file *file, unsigned int cmd,
         switch (cmd) {
         case MMTIMER_GETOFFSET: /* offset of the counter */
                 /*
-                 * UV RTC register is on its own page
+                 * Starting with HUB rev 2.0, the UV RTC register is
+                 * replicated across all cachelines of it's own page.
+                 * This allows faster simultaneous reads from a given socket.
+                 *
+                 * The offset returned is in 64 bit units.
                  */
-                if (PAGE_SIZE <= (1 << 16))
-                        ret = ((UV_LOCAL_MMR_BASE | UVH_RTC) & (PAGE_SIZE-1))
-                                / 8;
+                if (uv_get_min_hub_revision_id() == 1)
+                        ret = 0;
                 else
-                        ret = -ENOSYS;
+                        ret = ((uv_blade_processor_id() * L1_CACHE_BYTES) %
+                                        PAGE_SIZE) / 8;
                 break;
 
         case MMTIMER_GETRES: /* resolution of the clock in 10^-15 s */
@@ -115,8 +119,8 @@ static long uv_mmtimer_ioctl(struct file *file, unsigned int cmd,
                 ret = hweight64(UVH_RTC_REAL_TIME_CLOCK_MASK);
                 break;
 
-        case MMTIMER_MMAPAVAIL: /* can we mmap the clock into userspace? */
-                ret = (PAGE_SIZE <= (1 << 16)) ? 1 : 0;
+        case MMTIMER_MMAPAVAIL:
+                ret = 1;
                 break;
 
         case MMTIMER_GETCOUNTER: