Various drivers implement architecture and/or device specific means to remove power from the system. For the most part, those drivers set the global variable pm_power_off to point to a function within the driver.
This mechanism has a number of drawbacks. Typically only one means to remove power is supported (at least if pm_power_off is used). At least in theory there can be multiple means to remove power, some of which may be less desirable. For example, one mechanism might power off the entire system through an I/O port or gpio pin, while another might power off a board by disabling its power controller. Other mechanisms may really just execute a restart sequence or drop into the ROM monitor, or put the CPU into sleep mode. Using pm_power_off can also be racy if the function pointer is set from a driver built as module, as the driver may be in the process of being unloaded when pm_power_off is called. If there are multiple poweroff handlers in the system, removing a module with such a handler may inadvertently reset the pointer to pm_power_off to NULL, leaving the system with no means to remove power. Introduce a system poweroff handler call chain to solve the described problems. This call chain is expected to be executed from the architecture specific machine_power_off() function. Drivers providing system poweroff functionality are expected to register with this call chain. By using the priority field in the notifier block, callers can control poweroff handler execution sequence and thus ensure that the poweroff handler with the optimal capabilities to remove power for a given system is called first. Patch 01/44 implements the poweroff handler API. Patches 02/44 to 04/44 are cleanup patches to prepare for the move of pm_power_off to a common location. Patches 05/44 to 07/44 remove references to pm_power_off from devicetree bindings descriptions. Patch 08/44 moves the pm_power_off variable from architecture code to kernel/reboot.c. Patches 09/44 to 30/44 convert various drivers to register with the kernel poweroff handler instead of setting pm_power_off directly. Patches 31/44 to 42/44 do the same for architecture code. Patch 43/44 replaces a direct call to pm_power_off from a hwmon driver with a call to kernel_power_off. This patch is part of the series for completeness, but will find its way upstream through the hwmon subsystem. Patch 44/44 removes pm_power_off. For the most part, the individual patches include explanations why specific priorities were chosen, at least if the selected priority is not the default priority. Subsystem and architecture maintainers are encouraged to have a look at the selected priorities and suggest improvements. I ran the final code through my normal build and qemu tests. Results are available at http://server.roeck-us.net:8010/builders in the 'poweroff-handler' column. In addition I build several additional configurations for various architectures. The series is available in branch poweroff-handler of my repository at git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git. It is based on 3.17, with the pending restart handler patches applied. I got a number of Acks from architecture maintainers as response to the RFC. I did not add those since the architecture code changed, and I did not think it was appropriate to retain the Acks. A note on timing: My original plan was to submit this series after 3.18-rc1 was released. However, since the commit window will remain open for three weeks, and the series is, for all practical purposes, ready for review, I decided to submit it now. I plan to rebase it to 3.18-rc1 once available and send another version, hopefully including valuable feedback. Important changes since RFC: - Move API to new file kernel/power/poweroff_handler.c. - Move pm_power_off pointer to kernel/power/poweroff_handler.c. Call pm_power_off from do_kernel_poweroff, and only call do_kernel_poweroff from architecture code instead of calling both pm_power_off and do_kernel_poweroff. - Provide additional API function register_poweroff_handler_simple to simplify conversion of architecture code. - Provide additional API function have_kernel_poweroff to check if a poweroff handler was installed. - Convert all drivers and architecture code to use the new API. - Remove pm_power_off as last patch of the series. Cc: Alexander Graf <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Aurelien Jacquiot <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Chen Liqin <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Chris Zankel <[email protected]> Cc: Corey Minyard <[email protected]> Cc: David Howells <[email protected]> Cc: David S. Miller <[email protected]> Cc: David Vrabel <[email protected]> Cc: David Woodhouse <[email protected]> Cc: Dmitry Eremin-Solenikov <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Greg Ungerer <[email protected]> Cc: Guan Xuetao <[email protected]> Cc: Haavard Skinnemoen <[email protected]> Cc: Hans-Christian Egtvedt <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Helge Deller <[email protected]> Cc: Hirokazu Takata <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Ivan Kokshaysky <[email protected]> Cc: James E.J. Bottomley <[email protected]> Cc: James Hogan <[email protected]> Cc: Jean Delvare <[email protected]> Cc: Jeff Dike <[email protected]> Cc: Jesper Nilsson <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Jonas Bonn <[email protected]> Cc: Joshua Thompson <[email protected]> Cc: Julian Andres Klode <[email protected]> Cc: Koichi Yasutake <[email protected]> Cc: Konrad Rzeszutek Wilk <[email protected]> Cc: Lee Jones <[email protected]> Cc: Len Brown <[email protected]> Cc: Len Brown <[email protected]> Cc: Lennox Wu <[email protected]> Cc: Linus Walleij <[email protected]> Cc: Maciej W. Rozycki <[email protected]> Cc: Marc Dietrich <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Mark Salter <[email protected]> Cc: Martin Schwidefsky <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Matt Turner <[email protected]> Cc: Max Filippov <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Michal Simek <[email protected]> Cc: Mikael Starvik <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Pavel Machek <[email protected]> Cc: Pawel Moll <[email protected]> Cc: Rafael J. Wysocki <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: Richard Henderson <[email protected]> Cc: Richard Kuo <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Rob Herring <[email protected]> Cc: Romain Perier <[email protected]> Cc: Russell King <[email protected]> Cc: Rusty Russell <[email protected]> Cc: Samuel Ortiz <[email protected]> Cc: Santosh Shilimkar <[email protected]> Cc: Sebastian Reichel <[email protected]> Cc: Steven Miao <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: Vineet Gupta <[email protected]> Cc: Will Deacon <[email protected]> ---------------------------------------------------------------- Guenter Roeck (44): kernel: Add support for poweroff handler call chain memory: emif: Use API function to determine poweroff capability hibernate: Call have_kernel_poweroff instead of checking pm_power_off m68k: Replace mach_power_off with pm_power_off mfd: as3722: Drop reference to pm_power_off from devicetree bindings gpio-poweroff: Drop reference to pm_power_off from devicetree bindings qnap-poweroff: Drop reference to pm_power_off from devicetree bindings kernel: Move pm_power_off to common code mfd: palmas: Register with kernel poweroff handler mfd: axp20x: Register with kernel poweroff handler mfd: retu: Register with kernel poweroff handler mfd: ab8500-sysctrl: Register with kernel poweroff handler mfd: max8907: Register with kernel poweroff handler mfd: tps80031: Register with kernel poweroff handler mfd: dm355evm_msp: Register with kernel poweroff handler mfd: tps6586x: Register with kernel poweroff handler mfd: tps65910: Register with kernel poweroff handler mfd: twl4030-power: Register with kernel poweroff handler ipmi: Register with kernel poweroff handler power/reset: restart-poweroff: Register with kernel poweroff handler power/reset: gpio-poweroff: Register with kernel poweroff handler power/reset: as3722-poweroff: Register with kernel poweroff handler power/reset: qnap-poweroff: Register with kernel poweroff handler power/reset: msm-powroff: Register with kernel poweroff handler power/reset: vexpress-poweroff: Register with kernel poweroff handler x86: iris: Register with kernel poweroff handler x86: apm: Register with kernel poweroff handler x86: olpc: Register xo1 poweroff handler with kernel poweroff handler staging: nvec: Register with kernel poweroff handler acpi: Register poweroff handler with kernel poweroff handler arm: Register with kernel poweroff handler arm64: psci: Register with kernel poweroff handler avr32: atngw100: Register with kernel poweroff handler ia64: Register with kernel poweroff handler m68k: Register with kernel poweroff handler mips: Register with kernel poweroff handler sh: Register with kernel poweroff handler x86: lguest: Register with kernel poweroff handler x86: ce4100: Register with kernel poweroff handler x86: intel-mid: Drop registration of dummy poweroff handlers x86: pmc_atom: Register poweroff handler with kernel poweroff handler efi: Register poweroff handler with kernel poweroff handler hwmon: (ab8500) Call kernel_power_off instead of pm_power_off kernel: Remove pm_power_off .../devicetree/bindings/gpio/gpio-poweroff.txt | 10 +- Documentation/devicetree/bindings/mfd/as3722.txt | 3 +- .../bindings/power_supply/qnap-poweroff.txt | 4 +- arch/alpha/kernel/process.c | 9 +- arch/arc/kernel/reset.c | 5 +- arch/arm/kernel/process.c | 5 +- arch/arm/kernel/psci.c | 2 +- arch/arm/mach-at91/board-gsia18s.c | 2 +- arch/arm/mach-at91/setup.c | 4 +- arch/arm/mach-bcm/board_bcm2835.c | 2 +- arch/arm/mach-cns3xxx/cns3420vb.c | 2 +- arch/arm/mach-cns3xxx/core.c | 2 +- arch/arm/mach-highbank/highbank.c | 2 +- arch/arm/mach-imx/mach-mx31moboard.c | 2 +- arch/arm/mach-iop32x/em7210.c | 2 +- arch/arm/mach-iop32x/glantank.c | 2 +- arch/arm/mach-iop32x/iq31244.c | 2 +- arch/arm/mach-iop32x/n2100.c | 2 +- arch/arm/mach-ixp4xx/dsmg600-setup.c | 2 +- arch/arm/mach-ixp4xx/nas100d-setup.c | 2 +- arch/arm/mach-ixp4xx/nslu2-setup.c | 2 +- arch/arm/mach-omap2/board-omap3touchbook.c | 2 +- arch/arm/mach-orion5x/board-mss2.c | 2 +- arch/arm/mach-orion5x/dns323-setup.c | 6 +- arch/arm/mach-orion5x/kurobox_pro-setup.c | 2 +- arch/arm/mach-orion5x/ls-chl-setup.c | 2 +- arch/arm/mach-orion5x/ls_hgl-setup.c | 2 +- arch/arm/mach-orion5x/lsmini-setup.c | 2 +- arch/arm/mach-orion5x/mv2120-setup.c | 2 +- arch/arm/mach-orion5x/net2big-setup.c | 2 +- arch/arm/mach-orion5x/terastation_pro2-setup.c | 2 +- arch/arm/mach-orion5x/ts209-setup.c | 2 +- arch/arm/mach-orion5x/ts409-setup.c | 2 +- arch/arm/mach-pxa/corgi.c | 2 +- arch/arm/mach-pxa/mioa701.c | 2 +- arch/arm/mach-pxa/poodle.c | 2 +- arch/arm/mach-pxa/spitz.c | 2 +- arch/arm/mach-pxa/tosa.c | 2 +- arch/arm/mach-pxa/viper.c | 2 +- arch/arm/mach-pxa/z2.c | 6 +- arch/arm/mach-pxa/zeus.c | 6 +- arch/arm/mach-s3c24xx/mach-gta02.c | 2 +- arch/arm/mach-s3c24xx/mach-jive.c | 2 +- arch/arm/mach-s3c24xx/mach-vr1000.c | 2 +- arch/arm/mach-s3c64xx/mach-smartq.c | 2 +- arch/arm/mach-sa1100/generic.c | 2 +- arch/arm/mach-sa1100/simpad.c | 2 +- arch/arm/mach-u300/regulator.c | 2 +- arch/arm/mach-vt8500/vt8500.c | 2 +- arch/arm/xen/enlighten.c | 2 +- arch/arm64/kernel/process.c | 5 +- arch/arm64/kernel/psci.c | 2 +- arch/avr32/boards/atngw100/mrmt.c | 2 +- arch/avr32/kernel/process.c | 6 +- arch/blackfin/kernel/process.c | 3 - arch/blackfin/kernel/reboot.c | 2 + arch/c6x/kernel/process.c | 9 +- arch/cris/kernel/process.c | 4 +- arch/frv/kernel/process.c | 5 +- arch/hexagon/kernel/reset.c | 5 +- arch/ia64/kernel/process.c | 5 +- arch/ia64/sn/kernel/setup.c | 4 +- arch/m32r/kernel/process.c | 8 +- arch/m68k/emu/natfeat.c | 3 +- arch/m68k/include/asm/machdep.h | 1 - arch/m68k/kernel/process.c | 7 +- arch/m68k/kernel/setup_mm.c | 1 - arch/m68k/kernel/setup_no.c | 1 - arch/m68k/mac/config.c | 3 +- arch/metag/kernel/process.c | 6 +- arch/microblaze/kernel/process.c | 3 - arch/microblaze/kernel/reset.c | 1 + arch/mips/alchemy/board-gpr.c | 2 +- arch/mips/alchemy/board-mtx1.c | 2 +- arch/mips/alchemy/board-xxs1500.c | 2 +- arch/mips/alchemy/devboards/platform.c | 17 +- arch/mips/ar7/setup.c | 2 +- arch/mips/ath79/setup.c | 2 +- arch/mips/bcm47xx/setup.c | 2 +- arch/mips/bcm63xx/setup.c | 2 +- arch/mips/cobalt/setup.c | 2 +- arch/mips/dec/setup.c | 2 +- arch/mips/emma/markeins/setup.c | 2 +- arch/mips/jz4740/reset.c | 2 +- arch/mips/kernel/reset.c | 6 +- arch/mips/lantiq/falcon/reset.c | 2 +- arch/mips/lantiq/xway/reset.c | 2 +- arch/mips/lasat/reset.c | 2 +- arch/mips/loongson/common/reset.c | 2 +- arch/mips/loongson1/common/reset.c | 2 +- arch/mips/mti-malta/malta-reset.c | 2 +- arch/mips/mti-sead3/sead3-reset.c | 2 +- arch/mips/netlogic/xlp/setup.c | 2 +- arch/mips/netlogic/xlr/setup.c | 2 +- arch/mips/pmcs-msp71xx/msp_setup.c | 2 +- arch/mips/pnx833x/common/setup.c | 2 +- arch/mips/ralink/reset.c | 2 +- arch/mips/rb532/setup.c | 2 +- arch/mips/sgi-ip22/ip22-reset.c | 2 +- arch/mips/sgi-ip27/ip27-reset.c | 2 +- arch/mips/sgi-ip32/ip32-reset.c | 2 +- arch/mips/sibyte/common/cfe.c | 2 +- arch/mips/sni/setup.c | 2 +- arch/mips/txx9/generic/setup.c | 2 +- arch/mips/vr41xx/common/pmu.c | 2 +- arch/mn10300/kernel/process.c | 8 +- arch/openrisc/kernel/process.c | 8 +- arch/parisc/kernel/process.c | 8 +- arch/powerpc/kernel/setup-common.c | 6 +- arch/s390/kernel/setup.c | 8 +- arch/score/kernel/process.c | 8 +- arch/sh/boards/board-sh7785lcr.c | 2 +- arch/sh/boards/board-urquell.c | 2 +- arch/sh/boards/mach-highlander/setup.c | 2 +- arch/sh/boards/mach-landisk/setup.c | 2 +- arch/sh/boards/mach-r2d/setup.c | 2 +- arch/sh/boards/mach-sdk7786/setup.c | 2 +- arch/sh/kernel/reboot.c | 6 +- arch/sparc/kernel/process_32.c | 10 +- arch/sparc/kernel/reboot.c | 8 +- arch/tile/kernel/reboot.c | 7 +- arch/um/kernel/reboot.c | 2 - arch/unicore32/kernel/process.c | 9 +- arch/x86/kernel/apm_32.c | 20 ++- arch/x86/kernel/pmc_atom.c | 20 ++- arch/x86/kernel/reboot.c | 11 +- arch/x86/lguest/boot.c | 2 +- arch/x86/platform/ce4100/ce4100.c | 2 +- arch/x86/platform/intel-mid/intel-mid.c | 5 - arch/x86/platform/intel-mid/mfld.c | 5 - arch/x86/platform/iris/iris.c | 25 ++- arch/x86/platform/olpc/olpc-xo1-pm.c | 20 ++- arch/x86/xen/enlighten.c | 3 +- arch/xtensa/kernel/process.c | 4 - drivers/acpi/sleep.c | 15 +- drivers/char/ipmi/ipmi_poweroff.c | 30 ++-- drivers/firmware/efi/reboot.c | 23 ++- drivers/hwmon/ab8500.c | 5 +- drivers/memory/emif.c | 4 +- drivers/mfd/ab8500-sysctrl.c | 26 ++-- drivers/mfd/axp20x.c | 30 ++-- drivers/mfd/dm355evm_msp.c | 18 ++- drivers/mfd/max8907.c | 24 ++- drivers/mfd/palmas.c | 30 ++-- drivers/mfd/retu-mfd.c | 33 ++-- drivers/mfd/tps6586x.c | 31 +++- drivers/mfd/tps65910.c | 27 ++-- drivers/mfd/tps80031.c | 30 ++-- drivers/mfd/twl4030-power.c | 25 ++- drivers/parisc/power.c | 3 +- drivers/power/reset/as3722-poweroff.c | 36 +++-- drivers/power/reset/gpio-poweroff.c | 36 ++--- drivers/power/reset/msm-poweroff.c | 13 +- drivers/power/reset/qnap-poweroff.c | 28 ++-- drivers/power/reset/restart-poweroff.c | 25 ++- drivers/power/reset/vexpress-poweroff.c | 19 ++- drivers/staging/nvec/nvec.c | 24 +-- drivers/staging/nvec/nvec.h | 2 + include/linux/i2c/twl.h | 1 - include/linux/mfd/axp20x.h | 1 + include/linux/mfd/max8907.h | 2 + include/linux/mfd/palmas.h | 3 + include/linux/mfd/tps65910.h | 3 + include/linux/mfd/tps80031.h | 2 + include/linux/pm.h | 14 +- kernel/power/Makefile | 1 + kernel/power/hibernate.c | 2 +- kernel/power/poweroff_handler.c | 173 +++++++++++++++++++++ kernel/reboot.c | 4 +- 169 files changed, 794 insertions(+), 475 deletions(-) create mode 100644 kernel/power/poweroff_handler.c ------------------------------------------------------------------------------ Meet PCI DSS 3.0 Compliance Requirements with EventLog Analyzer Achieve PCI DSS 3.0 Compliant Status with Out-of-the-box PCI DSS Reports Are you Audit-Ready for PCI DSS 3.0 Compliance? 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