linux-stable/arch/m68k/include/asm/timex.h
Jason A. Donenfeld 0f392c9539 m68k: use fallback for random_get_entropy() instead of zero
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-05-13 23:59:23 +02:00

43 lines
974 B
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* linux/include/asm-m68k/timex.h
*
* m68k architecture timex specifications
*/
#ifndef _ASMm68K_TIMEX_H
#define _ASMm68K_TIMEX_H
#ifdef CONFIG_COLDFIRE
/*
* CLOCK_TICK_RATE should give the underlying frequency of the tick timer
* to make ntp work best. For Coldfires, that's the main clock.
*/
#include <asm/coldfire.h>
#define CLOCK_TICK_RATE MCF_CLK
#else
/*
* This default CLOCK_TICK_RATE is probably wrong for many 68k boards
* Users of those boards will need to check and modify accordingly
*/
#define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
#endif
typedef unsigned long cycles_t;
static inline cycles_t get_cycles(void)
{
return 0;
}
extern unsigned long (*mach_random_get_entropy)(void);
static inline unsigned long random_get_entropy(void)
{
if (mach_random_get_entropy)
return mach_random_get_entropy();
return random_get_entropy_fallback();
}
#define random_get_entropy random_get_entropy
#endif