[PATCH] cpufreq: powernv: fix missing check of return value in init_powernv_pstates()

[Yangtao Li]

kmalloc() could fail, so insert a check of its return value. And
if it fails, returns -ENOMEM.

And remove (struct pstate_idx_revmap_data *) to fix coccinelle WARNING
by the way.

WARNING: casting value returned by memory allocation function to (struct
pstate_idx_revmap_data *) is useless.

Signed-off-by: Yangtao Li <tiny.win...@gmail.com>
---
 drivers/cpufreq/powernv-cpufreq.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/powernv-cpufreq.c 
b/drivers/cpufreq/powernv-cpufreq.c
index 7e7ad3879c4e..d2230812fa4b 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -244,6 +244,7 @@ static int init_powernv_pstates(void)
        u32 len_ids, len_freqs;
        u32 pstate_min, pstate_max, pstate_nominal;
        u32 pstate_turbo, pstate_ultra_turbo;
+       int rc = -ENODEV;
 
        power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
        if (!power_mgt) {
@@ -327,8 +328,11 @@ static int init_powernv_pstates(void)
                powernv_freqs[i].frequency = freq * 1000; /* kHz */
                powernv_freqs[i].driver_data = id & 0xFF;
 
-               revmap_data = (struct pstate_idx_revmap_data *)
-                             kmalloc(sizeof(*revmap_data), GFP_KERNEL);
+               revmap_data = kmalloc(sizeof(*revmap_data), GFP_KERNEL);
+               if (!revmap_data) {
+                       rc = -ENOMEM;
+                       goto out;
+               }
 
                revmap_data->pstate_id = id & 0xFF;
                revmap_data->cpufreq_table_idx = i;
@@ -357,7 +361,7 @@ static int init_powernv_pstates(void)
        return 0;
 out:
        of_node_put(power_mgt);
-       return -ENODEV;
+       return rc;
 }
 
 /* Returns the CPU frequency corresponding to the pstate_id. */
-- 
2.17.0