[SPARC64]: Do not try to write to %tick or %stick on SUN4V.

Writes by privileged code are disallowed.  The hypervisor manages
the non-privileged bit.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 10 deletions

diff --git a/arch/sparc64/kernel/time.c b/arch/sparc64/kernel/time.c
index 24681b9b4426..7041146f86f0 100644
--- a/arch/sparc64/kernel/time.c
+++ b/arch/sparc64/kernel/time.c
@@ -193,16 +193,22 @@ struct sparc64_tick_ops *tick_ops __read_mostly = &tick_operations;
 
 static void stick_init_tick(unsigned long offset)
 {
-        tick_disable_protection();
-
-        /* Let the user get at STICK too. */
-        __asm__ __volatile__(
-        "       rd      %%asr24, %%g2\n"
-        "       andn    %%g2, %0, %%g2\n"
-        "       wr      %%g2, 0, %%asr24"
-        : /* no outputs */
-        : "r" (TICK_PRIV_BIT)
-        : "g1", "g2");
+        /* Writes to the %tick and %stick register are not
+         * allowed on sun4v.  The Hypervisor controls that
+         * bit, per-strand.
+         */
+        if (tlb_type != hypervisor) {
+                tick_disable_protection();
+
+                /* Let the user get at STICK too. */
+                __asm__ __volatile__(
+                "       rd      %%asr24, %%g2\n"
+                "       andn    %%g2, %0, %%g2\n"
+                "       wr      %%g2, 0, %%asr24"
+                : /* no outputs */
+                : "r" (TICK_PRIV_BIT)
+                : "g1", "g2");
+        }
 
         __asm__ __volatile__(
         "       rd      %%asr24, %%g1\n"