blob: bf6027cbeb5eb7fc6c46c58393d0b40e79633e1e [file] [log] [blame]
/*
* Copyright (c) 2014 Hauke Mehrtens <hauke@hauke-m.de>
*
* Backport functionality introduced in Linux 3.17.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/ktime.h>
#include <linux/jiffies.h>
#include <linux/moduleparam.h>
int bit_wait(void *word)
{
schedule();
return 0;
}
EXPORT_SYMBOL_GPL(bit_wait);
int bit_wait_io(void *word)
{
io_schedule();
return 0;
}
EXPORT_SYMBOL_GPL(bit_wait_io);
/**
* ktime_get_raw - Returns the raw monotonic time in ktime_t format
*/
ktime_t ktime_get_raw(void)
{
struct timespec ts;
getrawmonotonic(&ts);
return timespec_to_ktime(ts);
}
EXPORT_SYMBOL_GPL(ktime_get_raw);
/**
* nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64
*
* @n: nsecs in u64
*
* Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64.
* And this doesn't return MAX_JIFFY_OFFSET since this function is designed
* for scheduler, not for use in device drivers to calculate timeout value.
*
* note:
* NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)
* ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years
*/
static u64 backport_nsecs_to_jiffies64(u64 n)
{
#if (NSEC_PER_SEC % HZ) == 0
/* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */
return div_u64(n, NSEC_PER_SEC / HZ);
#elif (HZ % 512) == 0
/* overflow after 292 years if HZ = 1024 */
return div_u64(n * HZ / 512, NSEC_PER_SEC / 512);
#else
/*
* Generic case - optimized for cases where HZ is a multiple of 3.
* overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc.
*/
return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ);
#endif
}
/**
* nsecs_to_jiffies - Convert nsecs in u64 to jiffies
*
* @n: nsecs in u64
*
* Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64.
* And this doesn't return MAX_JIFFY_OFFSET since this function is designed
* for scheduler, not for use in device drivers to calculate timeout value.
*
* note:
* NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)
* ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years
*/
unsigned long nsecs_to_jiffies(u64 n)
{
return (unsigned long)backport_nsecs_to_jiffies64(n);
}
EXPORT_SYMBOL_GPL(nsecs_to_jiffies);
/**
* devm_kvasprintf - Allocate resource managed space
* for the formatted string.
* @dev: Device to allocate memory for
* @gfp: the GFP mask used in the devm_kmalloc() call when
* allocating memory
* @fmt: the formatted string to duplicate
* @ap: the list of tokens to be placed in the formatted string
* RETURNS:
* Pointer to allocated string on success, NULL on failure.
*/
char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
va_list ap)
{
unsigned int len;
char *p;
va_list aq;
va_copy(aq, ap);
len = vsnprintf(NULL, 0, fmt, aq);
va_end(aq);
p = devm_kmalloc(dev, len+1, gfp);
if (!p)
return NULL;
vsnprintf(p, len+1, fmt, ap);
return p;
}
EXPORT_SYMBOL_GPL(devm_kvasprintf);
/**
* devm_kasprintf - Allocate resource managed space
* and copy an existing formatted string into that
* @dev: Device to allocate memory for
* @gfp: the GFP mask used in the devm_kmalloc() call when
* allocating memory
* @fmt: the string to duplicate
* RETURNS:
* Pointer to allocated string on success, NULL on failure.
*/
char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
{
va_list ap;
char *p;
va_start(ap, fmt);
p = devm_kvasprintf(dev, gfp, fmt, ap);
va_end(ap);
return p;
}
EXPORT_SYMBOL_GPL(devm_kasprintf);
#define STANDARD_PARAM_DEF(name, type, format, strtolfn) \
int param_set_##name(const char *val, const struct kernel_param *kp) \
{ \
return strtolfn(val, 0, (type *)kp->arg); \
} \
int param_get_##name(char *buffer, const struct kernel_param *kp) \
{ \
return scnprintf(buffer, PAGE_SIZE, format, \
*((type *)kp->arg)); \
} \
struct kernel_param_ops param_ops_##name = { \
.set = param_set_##name, \
.get = param_get_##name, \
}; \
EXPORT_SYMBOL(param_set_##name); \
EXPORT_SYMBOL(param_get_##name); \
EXPORT_SYMBOL(param_ops_##name)
STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull);