diff options
| author | Johannes Berg <johannes.berg@intel.com> | 2020-12-02 20:58:07 +0100 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2020-12-13 22:22:49 +0100 |
| commit | a374b7cb1ea648a27ceaa2dea19aa967725e938b (patch) | |
| tree | 3caccdb36c1cc214f10a2f2d2e267acee1f101a6 /arch/um/include | |
| parent | 92dcd3d31843fbe1a95d880dc912e1f6beac6632 (diff) | |
um: Support suspend to RAM
With all the previous bits in place, we can now also support
suspend to RAM, in the sense that everything is suspended,
not just most, including userspace, processes like in s2idle.
Since um_idle_sleep() now waits forever, we can simply call
that to "suspend" the system.
As before, you can wake it up using SIGUSR1 since we're just
in a pause() call that only needs to return.
In order to implement selective resume from certain devices,
and not have any arbitrary device interrupt wake up, suspend
interrupts by removing SIGIO notification (O_ASYNC) from all
the FDs that are not supposed to wake up the system. However,
swap out the handler so we don't actually handle the SIGIO as
an interrupt.
Since we're in pause(), the mere act of receiving SIGIO wakes
us up, and then after things have been restored enough, re-set
O_ASYNC for all previously suspended FDs, reinstall the proper
SIGIO handler, and send SIGIO to self to process anything that
might now be pending.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/include')
| -rw-r--r-- | arch/um/include/shared/kern_util.h | 1 | ||||
| -rw-r--r-- | arch/um/include/shared/os.h | 3 |
2 files changed, 4 insertions, 0 deletions
diff --git a/arch/um/include/shared/kern_util.h b/arch/um/include/shared/kern_util.h index 9c08e728a675..2888ec812f6e 100644 --- a/arch/um/include/shared/kern_util.h +++ b/arch/um/include/shared/kern_util.h @@ -68,5 +68,6 @@ extern void bus_handler(int sig, struct siginfo *si, struct uml_pt_regs *regs); extern void winch(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs); extern void fatal_sigsegv(void) __attribute__ ((noreturn)); +void um_idle_sleep(void); #endif diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h index 78250a05394a..cd750d4edfb5 100644 --- a/arch/um/include/shared/os.h +++ b/arch/um/include/shared/os.h @@ -233,6 +233,7 @@ extern void timer_set_signal_handler(void); extern void set_sigstack(void *sig_stack, int size); extern void remove_sigstack(void); extern void set_handler(int sig); +extern void send_sigio_to_self(void); extern int change_sig(int signal, int on); extern void block_signals(void); extern void unblock_signals(void); @@ -307,6 +308,8 @@ extern int os_mod_epoll_fd(int events, int fd, void *data); extern int os_del_epoll_fd(int fd); extern void os_set_ioignore(void); extern void os_close_epoll_fd(void); +extern void um_irqs_suspend(void); +extern void um_irqs_resume(void); /* sigio.c */ extern int add_sigio_fd(int fd); |