[SPARC64]: Fetch bootup time of day from Hypervisor.

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

diff --git a/arch/sparc64/kernel/time.c b/arch/sparc64/kernel/time.c
index a22930d..24681b9 100644 (file)
--- a/arch/sparc64/kernel/time.c
+++ b/arch/sparc64/kernel/time.c
@@ -683,6 +683,48 @@ static void __init set_system_time(void)
        }
 }
 
+/* davem suggests we keep this within the 4M locked kernel image */
+static u32 starfire_get_time(void)
+{
+       static char obp_gettod[32];
+       static u32 unix_tod;
+
+       sprintf(obp_gettod, "h# %08x unix-gettod",
+               (unsigned int) (long) &unix_tod);
+       prom_feval(obp_gettod);
+
+       return unix_tod;
+}
+
+static u32 hypervisor_get_time(void)
+{
+       register unsigned long func asm("%o5");
+       register unsigned long arg0 asm("%o0");
+       register unsigned long arg1 asm("%o1");
+       int retries = 10000;
+
+retry:
+       func = HV_FAST_TOD_GET;
+       arg0 = 0;
+       arg1 = 0;
+       __asm__ __volatile__("ta        %6"
+                            : "=&r" (func), "=&r" (arg0), "=&r" (arg1)
+                            : "0" (func), "1" (arg0), "2" (arg1),
+                              "i" (HV_FAST_TRAP));
+       if (arg0 == HV_EOK)
+               return arg1;
+       if (arg0 == HV_EWOULDBLOCK) {
+               if (--retries > 0) {
+                       udelay(100);
+                       goto retry;
+               }
+               printk(KERN_WARNING "SUN4V: tod_get() timed out.\n");
+               return 0;
+       }
+       printk(KERN_WARNING "SUN4V: tod_get() not supported.\n");
+       return 0;
+}
+
 void __init clock_probe(void)
 {
        struct linux_prom_registers clk_reg[2];
@@ -702,14 +744,14 @@ void __init clock_probe(void)
 
 
        if (this_is_starfire) {
-               /* davem suggests we keep this within the 4M locked kernel image */
-               static char obp_gettod[256];
-               static u32 unix_tod;
-
-               sprintf(obp_gettod, "h# %08x unix-gettod",
-                       (unsigned int) (long) &unix_tod);
-               prom_feval(obp_gettod);
-               xtime.tv_sec = unix_tod;
+               xtime.tv_sec = starfire_get_time();
+               xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
+               set_normalized_timespec(&wall_to_monotonic,
+                                       -xtime.tv_sec, -xtime.tv_nsec);
+               return;
+       }
+       if (tlb_type == hypervisor) {
+               xtime.tv_sec = hypervisor_get_time();
                xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
                set_normalized_timespec(&wall_to_monotonic,
                                        -xtime.tv_sec, -xtime.tv_nsec);