powerpc/rtas: Fix watchdog driver temperature read functionality

Using the RTAS watchdog driver to read out the temperature crashes
on a PXCAB:

Unable to handle kernel paging request for data at address 0xfe347b50
Faulting instruction address: 0xc00000000001af64
Oops: Kernel access of bad area, sig: 11 [#1]

The wrong usage of "(void *)__pa(&temperature)" in rtas_call() is
removed by using the function rtas_get_sensor() which does the
right thing.

Signed-off-by: Adrian Reber <adrian@lisas.de>
Acked-by: Utz Bacher <utz.bacher@de.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 3 insertions, 5 deletions

diff --git a/drivers/watchdog/wdrtas.c b/drivers/watchdog/wdrtas.c
index a4fe7a38d9b0..3bde56bce63a 100644
--- a/drivers/watchdog/wdrtas.c
+++ b/drivers/watchdog/wdrtas.c
@@ -218,16 +218,14 @@ static void wdrtas_timer_keepalive(void)
  */
 static int wdrtas_get_temperature(void)
 {
-        long result;
+        int result;
         int temperature = 0;
 
-        result = rtas_call(wdrtas_token_get_sensor_state, 2, 2,
-                           (void *)__pa(&temperature),
-                           WDRTAS_THERMAL_SENSOR, 0);
+        result = rtas_get_sensor(WDRTAS_THERMAL_SENSOR, 0, &temperature);
 
         if (result < 0)
                 printk(KERN_WARNING "wdrtas: reading the thermal sensor "
-                       "faild: %li\n", result);
+                       "failed: %i\n", result);
         else
                 temperature = ((temperature * 9) / 5) + 32; /* fahrenheit */