Commit 0bc8fb4d authored by Johannes Berg's avatar Johannes Berg Committed by Richard Weinberger
Browse files

um: Implement ndelay/udelay in time-travel mode 



In external or inf-cpu time-travel mode, ndelay/udelay currently
just waste CPU time since the simulation time doesn't advance.
Implement them properly in this case.

Note that the "if (time_travel_mode == ...)" parts compile out
if CONFIG_UML_TIME_TRAVEL_SUPPORT isn't set, time_travel_mode is
defined to TT_MODE_OFF in that case.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent 88ce6424

arch/um/include/asm/Kbuild

+0 −1
Original line number Diff line number Diff line
@@ -3,7 +3,6 @@ generic-y += bpf_perf_event.h 
generic-y += bug.h

generic-y += compat.h

generic-y += current.h

generic-y += delay.h

generic-y += device.h

generic-y += emergency-restart.h

generic-y += exec.h

arch/um/include/asm/delay.h

0 → 100644
+30 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef __UM_DELAY_H

#define __UM_DELAY_H

#include <asm-generic/delay.h>

#include <linux/time-internal.h>



static inline void um_ndelay(unsigned long nsecs)

{

	if (time_travel_mode == TT_MODE_INFCPU ||

	    time_travel_mode == TT_MODE_EXTERNAL) {

		time_travel_ndelay(nsecs);

		return;

	}

	ndelay(nsecs);

}

#undef ndelay

#define ndelay um_ndelay



static inline void um_udelay(unsigned long usecs)

{

	if (time_travel_mode == TT_MODE_INFCPU ||

	    time_travel_mode == TT_MODE_EXTERNAL) {

		time_travel_ndelay(1000 * usecs);

		return;

	}

	udelay(usecs);

}

#undef udelay

#define udelay um_udelay

#endif /* __UM_DELAY_H */

arch/um/include/linux/time-internal.h

+6 −0
Original line number Diff line number Diff line
@@ -75,4 +75,10 @@ static inline void time_travel_wait_readable(int fd) 
{

}

#endif /* CONFIG_UML_TIME_TRAVEL_SUPPORT */



/*

 * Without CONFIG_UML_TIME_TRAVEL_SUPPORT this is a linker error if used,

 * which is intentional since we really shouldn't link it in that case.

 */

void time_travel_ndelay(unsigned long nsec);

#endif /* __TIMER_INTERNAL_H__ */

arch/um/kernel/time.c

+6 −0
Original line number Diff line number Diff line
@@ -374,6 +374,12 @@ static void time_travel_update_time(unsigned long long next, bool idle) 
	time_travel_del_event(&ne);

}



void time_travel_ndelay(unsigned long nsec)

{

	time_travel_update_time(time_travel_time + nsec, false);

}

EXPORT_SYMBOL(time_travel_ndelay);



void time_travel_add_irq_event(struct time_travel_event *e)

{

	BUG_ON(time_travel_mode != TT_MODE_EXTERNAL);

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