powerpc/powernv: Check OPAL RTC calls exists before using

Check that the OPAL_RTC_READ token exists before we use the OPAL RTC.

Refactors the code a little to merge error paths.

This avoids littering the OPAL console with:
  "OPAL: Called with bad token 3".

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/platforms/powernv/opal-rtc.c b/arch/powerpc/platforms/powernv/opal-rtc.c
index b1885db8fdf34bfe068f1712d486f6884dc50d0e..499707ddaa9c79bc94dc900c725d828224209a0d 100644 (file)
--- a/arch/powerpc/platforms/powernv/opal-rtc.c
+++ b/arch/powerpc/platforms/powernv/opal-rtc.c
@@ -42,6 +42,9 @@ unsigned long __init opal_get_boot_time(void)
        __be64 __h_m_s_ms;
        long rc = OPAL_BUSY;
 
+       if (!opal_check_token(OPAL_RTC_READ))
+               goto out;
+
        while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
                rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
                if (rc == OPAL_BUSY_EVENT)
@@ -49,16 +52,18 @@ unsigned long __init opal_get_boot_time(void)
                else
                        mdelay(10);
        }
-       if (rc != OPAL_SUCCESS) {
-               ppc_md.get_rtc_time = NULL;
-               ppc_md.set_rtc_time = NULL;
-               return 0;
-       }
+       if (rc != OPAL_SUCCESS)
+               goto out;
+
        y_m_d = be32_to_cpu(__y_m_d);
        h_m_s_ms = be64_to_cpu(__h_m_s_ms);
        opal_to_tm(y_m_d, h_m_s_ms, &tm);
        return mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
                      tm.tm_hour, tm.tm_min, tm.tm_sec);
+out:
+       ppc_md.get_rtc_time = NULL;
+       ppc_md.set_rtc_time = NULL;
+       return 0;
 }
 
 void opal_get_rtc_time(struct rtc_time *tm)