From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Date: Mon, 09 May 2022 23:32:15 +0000 Subject: [PATCH v8 07/27] kernel/reboot: Add kernel_can_power_off() Message-Id: <20220509233235.995021-8-dmitry.osipenko@collabora.com> List-Id: References: <20220509233235.995021-1-dmitry.osipenko@collabora.com> In-Reply-To: <20220509233235.995021-1-dmitry.osipenko@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Thierry Reding , Jonathan Hunter , Russell King , Catalin Marinas , Will Deacon , Guo Ren , Geert Uytterhoeven , Greg Ungerer , Joshua Thompson , Thomas Bogendoerfer , Sebastian Reichel , Linus Walleij , Philipp Zabel , Greentime Hu , Vincent Chen , "James E.J. Bottomley" , Helge Deller , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Paul Walmsley , Palmer Dabbelt , Albert Ou , Yoshinori Sato , Rich Felker , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , "Rafael J. Wysocki" , Len Brown , Santosh Shilimkar , Krzysztof Kozlowski , Liam Girdwood , Mark Brown , Pavel Machek , Lee Jones , Andrew Morton , Guenter Roeck , Daniel Lezcano , Andy Shevchenko , Ulf Hansson , =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= Cc: linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org Add kernel_can_power_off() helper that replaces open-coded checks of the global pm_power_off variable. This is a necessary step towards supporting chained power-off handlers. Signed-off-by: Dmitry Osipenko --- include/linux/reboot.h | 1 + kernel/reboot.c | 14 +++++++++++++- 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/include/linux/reboot.h b/include/linux/reboot.h index 6b951d68c0c7..c52f77ee4ddd 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -149,6 +149,7 @@ extern void kernel_restart_prepare(char *cmd); extern void kernel_restart(char *cmd); extern void kernel_halt(void); extern void kernel_power_off(void); +extern bool kernel_can_power_off(void); void ctrl_alt_del(void); diff --git a/kernel/reboot.c b/kernel/reboot.c index eaede35f45e2..982e58c11ce8 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -523,6 +523,18 @@ void do_kernel_power_off(void) atomic_notifier_call_chain(&power_off_handler_list, 0, NULL); } +/** + * kernel_can_power_off - check whether system can be powered off + * + * Returns true if power-off handler is registered and system can be + * powered off, false otherwise. + */ +bool kernel_can_power_off(void) +{ + return !atomic_notifier_call_chain_is_empty(&power_off_handler_list); +} +EXPORT_SYMBOL_GPL(kernel_can_power_off); + /** * kernel_power_off - power_off the system * @@ -581,7 +593,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, /* Instead of trying to make the power_off code look like * halt when pm_power_off is not set do it the easy way. */ - if ((cmd = LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) + if ((cmd = LINUX_REBOOT_CMD_POWER_OFF) && !kernel_can_power_off()) cmd = LINUX_REBOOT_CMD_HALT; mutex_lock(&system_transition_mutex); -- 2.35.1