|From:||Jiang Liu <firstname.lastname@example.org>|
|To:||Len Brown <email@example.com>, Tony Luck <firstname.lastname@example.org>, Bob Moore <email@example.com>, Huang Ying <firstname.lastname@example.org>, Yinghai Lu <email@example.com>, Yasuaki Ishimatsu <firstname.lastname@example.org>, Kenji Kaneshige <email@example.com>, Wen Congyang <firstname.lastname@example.org>, Taku Izumi <email@example.com>|
|Subject:||[RFC PATCH 0/3] ACPI based system device hotplug framework|
|Date:||Sat, 28 Jul 2012 19:42:49 +0800|
|Cc:||Jiang Liu <firstname.lastname@example.org>, Bjorn Helgaas <email@example.com>, Hanjun Guo <firstname.lastname@example.org>, email@example.com, firstname.lastname@example.org, email@example.com|
From: Jiang Liu <firstname.lastname@example.org> The patchset is based on v3.5-rc6 and you may pull them from: git://github.com/jiangliu/linux.git acpihp Modern high-end server may support advanced hotplug features for system devices, including physical processor, memory board, IO extension board and/or computer node. The ACPI specifications have provided standard interfaces between firmware and OS to support device hotplug at runtime. This patch series provide an ACPI based hotplug framework to support system device hotplug at runtime, which will replace current existing ACPI device driver based CPU/memory/CONTAINER hotplug mechanism. The new ACPI based hotplug framework is modelled after PCI hotplug architecture and target to achieve following goals: 1) Provide a mechanism to detect hotplug slots by checking ACPI _EJ0 method, ACPI PRCT (platform RAS capabilities table) and other platform specific mechanisms. 2) Unify the way to enumerate ACPI based hotplug slots. All hotplug slots will be enumerated by the enumeration driver, instead of by ACPI device drivers. 3) Dynamically create/destroy ACPI hotplug slots. For example, new ACPI hotplug slots may be created when hot-adding a computer node if the node contains some memory hotplug slots. 4) Unify the way to handle ACPI hotplug events. All ACPI hotplug events for system devices will be handled by a generic ACPI hotplug driver, instead of handled by ACPI device drivers. 5) Solve dependencies among hotplug slots. You need first to remove the memory device before removing a physical processor if a hotpluggable memory device is connected to a hotpluggable physical processor. 6) Provide better error handling and recover. 7) Provide interface to cancel ongoing hotplug operations. It may take a very long time to remove a memory device, so provide interface to cancel the operation. 8) Support new RAS features, such as socket/memory migration. 9) Provide better user interfaces to the hotplug functionalities. The new hotplug framework includes four logical components. The first is an ACPI hotplug slot enumerator, which enumerates ACPI hotplug slots on load and provides callbacks to manage those hotplug slots. An ACPI hotplug slot is an abstraction of receptacles, where a group of system devices could be connected to. The second is a device class for ACPI hotplug slots, named acpihp_slot_class. All ACPI hotplug slot devices will be associated with acpihp_slot_class. The third is a platform independent class driver for ACPI hotplug slots, which registers itself onto acpihp_slot_class and manages all ACPI hotplug slots in system. This hotplug driver handles ACPI hotplug events, processes user requests and manages slot state machine accoring to user requests. The fourth is a series of ACPI device drivers, for CPU, memory, PCI host bridge, IOAPIC and ACPI CONTAINER. These ACPI device drivers provide device specific callbacks for the hotplug driver to add/remove system devices at runtime. This patch set implements the first and second parts, which enumerates hotplug slots and creates sysfs entries for each slot as below. linux-drf:/sys/devices/LNXSYSTM:00/acpihp # ll drwxr-xr-x 4 root root 0 Jul 28 16:00 NODE00 drwxr-xr-x 3 root root 0 Jul 28 16:00 NODE01 drwxr-xr-x 3 root root 0 Jul 28 16:00 NODE02 linux-drf:/sys/devices/LNXSYSTM:00/acpihp/NODE00 # ll drwxr-xr-x 3 root root 0 Jul 28 16:00 IOX01 -r--r--r-- 1 root root 65536 Jul 28 16:01 capabilities lrwxrwxrwx 1 root root 0 Jul 28 16:00 device -> ../../../LNXSYSTM:00 -r--r--r-- 1 root root 65536 Jul 28 16:01 object drwxr-xr-x 2 root root 0 Jul 28 16:01 power -r--r--r-- 1 root root 65536 Jul 28 16:01 state -r--r--r-- 1 root root 65536 Jul 28 16:01 status lrwxrwxrwx 1 root root 0 Jul 28 16:00 subsystem -> ../../../../class/acpihp -r--r--r-- 1 root root 65536 Jul 28 16:01 type -rw-r--r-- 1 root root 65536 Jul 28 16:01 uevent linux-drf:/sys/bus/acpi/acpihp # ls NODE00 NODE00.IOX01 NODE01 NODE02 linux-drf:/sys/bus/acpi/acpihp # ll lrwxrwxrwx 1 root root 0 Jul 28 16:03 NODE00 -> ../../../devices/LNXSYSTM:00/acpihp/NODE00 lrwxrwxrwx 1 root root 0 Jul 28 16:03 NODE00.IOX01 -> ../../../devices/LNXSYSTM:00/acpihp/NODE00/IOX01 lrwxrwxrwx 1 root root 0 Jul 28 16:03 NODE01 -> ../../../devices/LNXSYSTM:00/acpihp/NODE01 lrwxrwxrwx 1 root root 0 Jul 28 16:03 NODE02 -> ../../../devices/LNXSYSTM:00/acpihp/NODE02 Jiang Liu (3): ACPIHP: introduce a framework for ACPI based system device hotplug ACPIHP: ACPI system device hotplug slot enumerator ACPIHP: detect ACPI hotplug slots by checking ACPI _EJ0 method drivers/acpi/Kconfig | 33 ++ drivers/acpi/Makefile | 2 + drivers/acpi/hotplug/Makefile | 10 + drivers/acpi/hotplug/core.c | 590 ++++++++++++++++++++++++++++++++++ drivers/acpi/hotplug/slot_enum.c | 469 +++++++++++++++++++++++++++ drivers/acpi/hotplug/slot_enum_ej0.c | 113 +++++++ include/acpi/acpi_hotplug.h | 191 +++++++++++ 7 files changed, 1408 insertions(+) create mode 100644 drivers/acpi/hotplug/Makefile create mode 100644 drivers/acpi/hotplug/core.c create mode 100644 drivers/acpi/hotplug/slot_enum.c create mode 100644 drivers/acpi/hotplug/slot_enum_ej0.c create mode 100644 include/acpi/acpi_hotplug.h -- 220.127.116.11 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to email@example.com More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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