a0da3772c0
commit e10e2f58030c5c211d49042a8c2a1b93d40b2ffb upstream. 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. This is accomplished by just including the asm-generic code like on other architectures, which means we can get rid of the empty stub function here. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
71 lines
1.8 KiB
C
71 lines
1.8 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2001 - 2013 Tensilica Inc.
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*/
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#ifndef _XTENSA_TIMEX_H
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#define _XTENSA_TIMEX_H
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#include <asm/processor.h>
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#include <linux/stringify.h>
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#if XCHAL_NUM_TIMERS > 0 && \
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XTENSA_INT_LEVEL(XCHAL_TIMER0_INTERRUPT) <= XCHAL_EXCM_LEVEL
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# define LINUX_TIMER 0
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# define LINUX_TIMER_INT XCHAL_TIMER0_INTERRUPT
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#elif XCHAL_NUM_TIMERS > 1 && \
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XTENSA_INT_LEVEL(XCHAL_TIMER1_INTERRUPT) <= XCHAL_EXCM_LEVEL
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# define LINUX_TIMER 1
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# define LINUX_TIMER_INT XCHAL_TIMER1_INTERRUPT
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#elif XCHAL_NUM_TIMERS > 2 && \
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XTENSA_INT_LEVEL(XCHAL_TIMER2_INTERRUPT) <= XCHAL_EXCM_LEVEL
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# define LINUX_TIMER 2
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# define LINUX_TIMER_INT XCHAL_TIMER2_INTERRUPT
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#else
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# error "Bad timer number for Linux configurations!"
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#endif
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extern unsigned long ccount_freq;
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void local_timer_setup(unsigned cpu);
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/*
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* Register access.
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*/
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#define WSR_CCOUNT(r) asm volatile ("wsr %0, ccount" :: "a" (r))
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#define RSR_CCOUNT(r) asm volatile ("rsr %0, ccount" : "=a" (r))
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#define WSR_CCOMPARE(x,r) asm volatile ("wsr %0,"__stringify(SREG_CCOMPARE)"+"__stringify(x) :: "a"(r))
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#define RSR_CCOMPARE(x,r) asm volatile ("rsr %0,"__stringify(SREG_CCOMPARE)"+"__stringify(x) : "=a"(r))
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static inline unsigned long get_ccount (void)
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{
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unsigned long ccount;
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RSR_CCOUNT(ccount);
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return ccount;
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}
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static inline void set_ccount (unsigned long ccount)
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{
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WSR_CCOUNT(ccount);
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}
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static inline unsigned long get_linux_timer (void)
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{
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unsigned ccompare;
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RSR_CCOMPARE(LINUX_TIMER, ccompare);
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return ccompare;
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}
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static inline void set_linux_timer (unsigned long ccompare)
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{
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WSR_CCOMPARE(LINUX_TIMER, ccompare);
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}
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#include <asm-generic/timex.h>
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#endif /* _XTENSA_TIMEX_H */
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