thermal/drivers/int340x/processor_thermal: Fix tcc setting

The following fixes are done for tcc sysfs interface:
- TCC is 6 bits only from bit 29-24
- TCC of 0 is valid
- When BIT(31) is set, this register is read only
- Check for invalid tcc value
- Error for negative values

Fixes: fdf4f2fb8e899 ("drivers: thermal: processor_thermal_device: Export sysfs interface for TCC offset")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: stable@vger.kernel.org
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210628215803.75038-1-srinivas.pandruvada@linux.intel.com

diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c
index de4fc64..0f0038a 100644 (file)
--- a/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c
+++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c
@@ -78,24 +78,27 @@ static ssize_t tcc_offset_degree_celsius_show(struct device *dev,
        if (err)
                return err;
 
-       val = (val >> 24) & 0xff;
+       val = (val >> 24) & 0x3f;
        return sprintf(buf, "%d\n", (int)val);
 }
 
-static int tcc_offset_update(int tcc)
+static int tcc_offset_update(unsigned int tcc)
 {
        u64 val;
        int err;
 
-       if (!tcc)
+       if (tcc > 63)
                return -EINVAL;
 
        err = rdmsrl_safe(MSR_IA32_TEMPERATURE_TARGET, &val);
        if (err)
                return err;
 
-       val &= ~GENMASK_ULL(31, 24);
-       val |= (tcc & 0xff) << 24;
+       if (val & BIT(31))
+               return -EPERM;
+
+       val &= ~GENMASK_ULL(29, 24);
+       val |= (tcc & 0x3f) << 24;
 
        err = wrmsrl_safe(MSR_IA32_TEMPERATURE_TARGET, val);
        if (err)
@@ -104,14 +107,15 @@ static int tcc_offset_update(int tcc)
        return 0;
 }
 
-static int tcc_offset_save;
+static unsigned int tcc_offset_save;
 
 static ssize_t tcc_offset_degree_celsius_store(struct device *dev,
                                struct device_attribute *attr, const char *buf,
                                size_t count)
 {
+       unsigned int tcc;
        u64 val;
-       int tcc, err;
+       int err;
 
        err = rdmsrl_safe(MSR_PLATFORM_INFO, &val);
        if (err)
@@ -120,7 +124,7 @@ static ssize_t tcc_offset_degree_celsius_store(struct device *dev,
        if (!(val & BIT(30)))
                return -EACCES;
 
-       if (kstrtoint(buf, 0, &tcc))
+       if (kstrtouint(buf, 0, &tcc))
                return -EINVAL;
 
        err = tcc_offset_update(tcc);