diff options
author | Johannes Berg <johannes.berg@intel.com> | 2020-02-13 14:26:48 +0100 |
---|---|---|
committer | Richard Weinberger <richard@nod.at> | 2020-03-29 23:29:52 +0200 |
commit | 0bc8fb4dda2b461491ec567b2333d13897780d8c (patch) | |
tree | ced5713f42b176386f212534ecf07822088d3709 /arch/um | |
parent | 88ce642492339f49a0b391af40e5798c08948e49 (diff) | |
download | linux-0bc8fb4dda2b461491ec567b2333d13897780d8c.tar.bz2 |
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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um')
-rw-r--r-- | arch/um/include/asm/Kbuild | 1 | ||||
-rw-r--r-- | arch/um/include/asm/delay.h | 30 | ||||
-rw-r--r-- | arch/um/include/linux/time-internal.h | 6 | ||||
-rw-r--r-- | arch/um/kernel/time.c | 6 |
4 files changed, 42 insertions, 1 deletions
diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild index db7d9d4e30d8..8d435f8a6dec 100644 --- a/arch/um/include/asm/Kbuild +++ b/arch/um/include/asm/Kbuild @@ -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 diff --git a/arch/um/include/asm/delay.h b/arch/um/include/asm/delay.h new file mode 100644 index 000000000000..56fc2b8f2dd0 --- /dev/null +++ b/arch/um/include/asm/delay.h @@ -0,0 +1,30 @@ +/* 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 */ diff --git a/arch/um/include/linux/time-internal.h b/arch/um/include/linux/time-internal.h index e21655926f08..f3b03d39a854 100644 --- a/arch/um/include/linux/time-internal.h +++ b/arch/um/include/linux/time-internal.h @@ -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__ */ diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c index 15c4825b857e..25eaa6a0c658 100644 --- a/arch/um/kernel/time.c +++ b/arch/um/kernel/time.c @@ -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); |