Kernel Sysfs Param Storage function - Get calling parameter - Nexus 6 Developer Discussion [Developers Only]

So, I hate to ask because I'm sure this is really simple...
I have this function that is storing a sysfs value. To save space, I have 4 different parameters sharing the function as it's basically the same function for each. I'd like to check which parameter is calling the function so that I can perform some checks depending on the parameter (ie, that each is in a logical order compared to it's neighboring values). How would I get the name of parameter that called it?
https://gist.github.com/yoinx/6a3ff00945f3ec1db230
embedded to avoid the link:
Code:
/* Frequency limit storage */
static int set_freq_limit(const char *val, const struct kernel_param *kp)
{
int ret = 0;
int i, cnt;
int valid = 0;
struct cpufreq_policy *policy;
static struct cpufreq_frequency_table *tbl = NULL;
ret = kstrtouint(val, 10, &i);
if (ret)
return -EINVAL;
policy = cpufreq_cpu_get(0);
tbl = cpufreq_frequency_get_table(0);
for (cnt = 0; (tbl[cnt].frequency != CPUFREQ_TABLE_END); cnt++) {
if (cnt > 0)
if (tbl[cnt].frequency == i)
valid = 1;
}
if (!valid)
return -EINVAL;
ret = param_set_int(val, kp);
return ret;
}
static struct kernel_param_ops freq_limit_ops = {
.set = set_freq_limit,
.get = param_get_int,
};
module_param_cb(freq_hell, &freq_limit_ops, &FREQ_HELL, 0644);
module_param_cb(freq_very_hot, &freq_limit_ops, &FREQ_VERY_HOT, 0644);
module_param_cb(freq_hot, &freq_limit_ops, &FREQ_HOT, 0644);
module_param_cb(freq_warm, &freq_limit_ops, &FREQ_WARM, 0644);
I could go even more sloppy and just duplicate this function repeatedly... But I'd rather not.
I thought kp would hold the kernel parameter... but it's a structure, not a variable... So I'm not positive what value in the structure would hold the name.
Thanks for the help.
Edit:
Would it be kp->name?

---

Ok, so not sure why it wouldn't work for me the other day... Which is what lead me to this post.
It was indeed kp->name, like I expected it to be. When I was trying to test it in a printk, it was causing a kernel panic though. Whatever, it worked now.
It prints out as module.param, just in case this helps anyone in the future.
*Edit*
Here's how I ended up doing this. Again, in case it helps anyone in the future.
Code:
/* Frequency limit storage */
static int set_freq_limit(const char *val, const struct kernel_param *kp)
{
int ret = 0;
int i, cnt;
int valid = 0;
struct cpufreq_policy *policy;
static struct cpufreq_frequency_table *tbl = NULL;
ret = kstrtouint(val, 10, &i);
if (ret)
return -EINVAL;
policy = cpufreq_cpu_get(0);
tbl = cpufreq_frequency_get_table(0);
for (cnt = 0; (tbl[cnt].frequency != CPUFREQ_TABLE_END); cnt++) {
if (cnt > 0)
if (tbl[cnt].frequency == i)
valid = 1;
}
if (!valid)
return -EINVAL;
/* Perform some sanity checks on the values that we're storing
* to make sure that they're scaling linearly */
if (strcmp( kp->name, "msm_thermal.freq_warm") == 0 && i <= FREQ_HOT)
return -EINVAL;
if ( strcmp( kp->name, "msm_thermal.freq_hot") == 0 && ( i >= FREQ_WARM || i <= FREQ_VERY_HOT ))
return -EINVAL;
if ( strcmp( kp->name, "msm_thermal.freq_very_hot") == 0 && ( i >= FREQ_HOT || i <= FREQ_HELL ))
return -EINVAL;
if ( strcmp( kp->name, "msm_thermal.freq_hell") == 0 && i >= FREQ_VERY_HOT )
return -EINVAL;
/* End Sanity Checks */
ret = param_set_int(val, kp);
return ret;
}
static struct kernel_param_ops freq_limit_ops = {
.set = set_freq_limit,
.get = param_get_int,
};
module_param_cb(freq_hell, &freq_limit_ops, &FREQ_HELL, 0644);
module_param_cb(freq_very_hot, &freq_limit_ops, &FREQ_VERY_HOT, 0644);
module_param_cb(freq_hot, &freq_limit_ops, &FREQ_HOT, 0644);
module_param_cb(freq_warm, &freq_limit_ops, &FREQ_WARM, 0644);