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path: root/drivers/pci/hotplug/acpiphp_glue.c
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* | ACPI / hotplug / PCI: Always return success after adding a functionRafael J. Wysocki2013-07-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a new ACPIPHP function is added by register_slot() and the notify handler cannot be installed for it, register_slot() returns an error status without cleaning up, which causes the entire namespace walk in acpiphp_enumerate_slots() to be aborted, although it still may be possible to successfully install the function notify handler for other device objects under the given brigde. To address this issue make register_slot() return success after a new function has been added, even if the addition of the notify handler for it has failed. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
* | ACPI / hotplug / PCI: Consolidate acpiphp_enumerate_slots()Rafael J. Wysocki2013-07-22
| | | | | | | | | | | | | | | | | | | | | | | | The acpiphp_enumerate_slots() function is now split into two parts, acpiphp_enumerate_slots() proper and init_bridge_misc() which is only called by the former. If these functions are combined, it is possible to make the code easier to follow and to clean up the error handling (to prevent memory leaks on error from happening in particular), so do that. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
* | ACPI / PCI: Make bus registration and unregistration symmetricRafael J. Wysocki2013-07-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since acpi_pci_slot_enumerate() and acpiphp_enumerate_slots() can get the ACPI device handle they need from bus->bridge, it is not necessary to pass that handle to them as an argument. Drop the second argument of acpi_pci_slot_enumerate() and acpiphp_enumerate_slots(), rework them to obtain the ACPI handle from bus->bridge and make acpi_pci_add_bus() and acpi_pci_remove_bus() entirely symmetrical. Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org>
* | ACPI / dock / PCI: Drop ACPI dock notifier chainRafael J. Wysocki2013-07-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only user of the ACPI dock notifier chain is the ACPI-based PCI hotplug (acpiphp) driver that uses it to carry out post-dock fixups needed by some systems with broken _DCK. However, it is not necessary to use a separate notifier chain for that, as it can be simply replaced with a new callback in struct acpi_dock_ops. For this reason, add a new .fixup() callback to struct acpi_dock_ops and make hotplug_dock_devices() execute it for all dock devices with hotplug operations registered. Accordingly, make acpiphp point that callback to the function carrying out the post-dock fixups and do not register a separate dock notifier for each device registering dock operations. Finally, drop the ACPI dock notifier chain that has no more users. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | ACPI: simplify acpiphp driver with new helper functionsJiang Liu2013-07-14
|/ | | | | | | | | | Use the new helper functions introduced previously to simplify the ACPI-based PCI hotplug (acpiphp) driver. [rjw: Changelog] Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* ACPI / dock / PCI: Synchronous handling of dock events for PCI devicesRafael J. Wysocki2013-06-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The interactions between the ACPI dock driver and the ACPI-based PCI hotplug (acpiphp) are currently problematic because of ordering issues during hot-remove operations. First of all, the current ACPI glue code expects that physical devices will always be deleted before deleting the companion ACPI device objects. Otherwise, acpi_unbind_one() will fail with a warning message printed to the kernel log, for example: [ 185.026073] usb usb5: Oops, 'acpi_handle' corrupt [ 185.035150] pci 0000:1b:00.0: Oops, 'acpi_handle' corrupt [ 185.035515] pci 0000:18:02.0: Oops, 'acpi_handle' corrupt [ 180.013656] port1: Oops, 'acpi_handle' corrupt This means, in particular, that struct pci_dev objects have to be deleted before the struct acpi_device objects they are "glued" with. Now, the following happens the during the undocking of an ACPI-based dock station: 1) hotplug_dock_devices() invokes registered hotplug callbacks to destroy physical devices associated with the ACPI device objects depending on the dock station. It calls dd->ops->handler() for each of those device objects. 2) For PCI devices dd->ops->handler() points to handle_hotplug_event_func() that queues up a separate work item to execute _handle_hotplug_event_func() for the given device and returns immediately. That work item will be executed later. 3) hotplug_dock_devices() calls dock_remove_acpi_device() for each device depending on the dock station. This runs acpi_bus_trim() for each of them, which causes the underlying ACPI device object to be destroyed, but the work items queued up by handle_hotplug_event_func() haven't been started yet. 4) _handle_hotplug_event_func() queued up in step 2) are executed and cause the above failure to happen, because the PCI devices they handle do not have the companion ACPI device objects any more (those objects have been deleted in step 3). The possible breakage doesn't end here, though, because hotplug_dock_devices() may return before at least some of the _handle_hotplug_event_func() work items spawned by it have a chance to complete and then undock() will cause _DCK to be evaluated and that will cause the devices handled by the _handle_hotplug_event_func() to go away possibly while they are being accessed. This means that dd->ops->handler() for PCI devices should not point to handle_hotplug_event_func(). Instead, it should point to a function that will do the work of _handle_hotplug_event_func() synchronously. For this reason, introduce such a function, hotplug_event_func(), and modity acpiphp_dock_ops to point to it as the handler. Unfortunately, however, this is not sufficient, because if the dock code were not changed further, hotplug_event_func() would now deadlock with hotplug_dock_devices() that called it, since it would run unregister_hotplug_dock_device() which in turn would attempt to acquire the dock station's hp_lock mutex already acquired by hotplug_dock_devices(). To resolve that deadlock use the observation that unregister_hotplug_dock_device() won't need to acquire hp_lock if PCI bridges the devices on the dock station depend on are prevented from being removed prematurely while the first loop in hotplug_dock_devices() is in progress. To make that possible, introduce a mechanism by which the callers of register_hotplug_dock_device() can provide "init" and "release" routines that will be executed, respectively, during the addition and removal of the physical device object associated with the given ACPI device handle. Make acpiphp use two new functions, acpiphp_dock_init() and acpiphp_dock_release(), that call get_bridge() and put_bridge(), respectively, on the acpiphp bridge holding the given device, for this purpose. In addition to that, remove the dock station's list of "hotplug devices" and make the dock code always walk the whole list of "dependent devices" instead in such a way that the loops in hotplug_dock_devices() and dock_event() (replacing the loops over "hotplug devices") will take references to the list entries that register_hotplug_dock_device() has been called for. That prevents the "release" routines associated with those entries from being called while the given entry is being processed and for PCI devices this means that their bridges won't be removed (by a concurrent thread) while hotplug_event_func() handling them is being executed. This change is based on two earlier patches from Jiang Liu. References: https://bugzilla.kernel.org/show_bug.cgi?id=59501 Reported-and-tested-by: Alexander E. Patrakov <patrakov@gmail.com> Tracked-down-by: Jiang Liu <jiang.liu@huawei.com> Tested-by: Illya Klymov <xanf@xanf.me> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Cc: 3.9+ <stable@vger.kernel.org>
* PCI / ACPI: Use boot-time resource allocation rules during hotplugJiang Liu2013-06-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On x86 platforms, the kernel respects PCI resource assignments from the BIOS and only reassigns resources for unassigned BARs at boot time. However, with the ACPI-based hotplug (acpiphp), it ignores the BIOS' PCI resource assignments completely and reassigns all resources by itself. This causes differences in PCI resource allocation between boot time and runtime hotplug to occur, which is generally undesirable and sometimes actively breaks things. Namely, if there are enough resources, reassigning all PCI resources during runtime hotplug should work, but it may fail if the resources are constrained. This may happen, for instance, when some PCI devices with huge MMIO BARs are involved in the runtime hotplug operations, because the current PCI MMIO alignment algorithm may waste huge chunks of MMIO address space in those cases. On the Alexander's Sony VAIO VPCZ23A4R the BIOS allocates limited MMIO resources for the dock station which contains a device (graphics adapter) with a 256MB MMIO BAR. An attempt to reassign that during runtime hotplug causes the dock station MMIO window to be exhausted and acpiphp fails to allocate resources for the majority of devices on the dock station as a result. To prevent that from happening, modify acpiphp to follow the boot time resources allocation behavior so that the BIOS' resource assignments are respected during runtime hotplug too. [rjw: Changelog] References: https://bugzilla.kernel.org/show_bug.cgi?id=56531 Reported-and-tested-by: Alexander E. Patrakov <patrakov@gmail.com> Tested-by: Illya Klymov <xanf@xanf.me> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Cc: 3.9+ <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* PCI: acpiphp: Re-enumerate devices when host bridge receives Bus CheckYinghai Lu2013-05-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When a PCI host bridge device receives a Bus Check notification, we must re-enumerate starting with the bridge to discover changes (devices that have been added or removed). Prior to 668192b678 ("PCI: acpiphp: Move host bridge hotplug to pci_root.c"), this happened in _handle_hotplug_event_bridge(). After that commit, _handle_hotplug_event_bridge() is not installed for host bridges, and the host bridge notify handler, _handle_hotplug_event_root() did not re-enumerate. This patch adds re-enumeration to _handle_hotplug_event_root(). This fixes cases where we don't notice the addition or removal of PCI devices, e.g., the PCI-to-USB ExpressCard in the bugzilla below. [bhelgaas: changelog, references] Reference: https://lkml.kernel.org/r/CAAh6nkmbKR3HTqm5ommevsBwhL_u0N8Rk7Wsms_LfP=nBgKNew@mail.gmail.com Reference: https://bugzilla.kernel.org/show_bug.cgi?id=57961 Reported-by: Gavin Guo <tuffkidtt@gmail.com> Tested-by: Gavin Guo <tuffkidtt@gmail.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Jiang Liu <jiang.liu@huawei.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> CC: stable@vger.kernel.org # v3.9+
* PCI: acpiphp: Protect acpiphp data structures from concurrent updatesJiang Liu2013-04-16
| | | | | | | | | | | | | | | | | | | | Now acpiphp_enumerate_slots() and acpiphp_remove_slots() may be invoked concurrently by the PCI core, so add a bridge_mutex and reference count mechanism to protect acpiphp bridge/slot/function data structures. To avoid deadlock, handle_hotplug_event_bridge() will requeue the hotplug event onto the kacpi_hotplug_wq by calling alloc_acpi_hp_work(). But the workaround has introduced a minor race window because the 'bridge' passed to _handle_hotplug_event_bridge() may have already been destroyed when _handle_hotplug_event_bridge() is actually executed by the kacpi_hotplug_wq. So hold a reference count on the passed 'bridge'. Fix the same issue for handle_hotplug_event_func() too. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Yinghai Lu <yinghai@kernel.org> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Toshi Kani <toshi.kani@hp.com>
* PCI: acpiphp: Use normal list to simplify implementationYijing Wang2013-04-16
| | | | | | | | | | Use normal list for struct acpiphp_slot to simplify implementation. Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Yinghai Lu <yinghai@kernel.org> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Toshi Kani <toshi.kani@hp.com>
* PCI: acpiphp: Do not use ACPI PCI subdriver mechanismJiang Liu2013-04-12
| | | | | | | | | | | | | | | | | | | | | | | Previously the acpiphp driver registered itself as an ACPI PCI subdriver, so its callbacks were invoked when creating/destroying PCI root buses to manage ACPI-based PCI hotplug slots. But it doesn't handle P2P bridge hotplug events, so it will cause strange behaviour if there are hotplug slots associated with a hot-removed P2P bridge. This patch fixes this issue by: 1) Directly hooking into PCI core to update hotplug slot devices when creating/destroying PCI buses through: pci_{add|remove}_bus() -> acpi_pci_{add|remove}_bus() 2) Getting rid of unused ACPI PCI subdriver-related code It also cleans up unused code in the acpiphp driver. [bhelgaas: keep acpi_pci_add_bus() stub for CONFIG_ACPI=n] Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Yinghai Lu <yinghai@kernel.org> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Toshi Kani <toshi.kani@hp.com>
* PCI: acpiphp: Replace local macros with standard ACPI macrosJiang Liu2013-04-12
| | | | | | | | | | | Replace local defined macros (ACPI_STA_xxx) with standard ACPI macros (ACPI_STA_DEVICE_xxx). Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Yinghai Lu <yinghai@kernel.org> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Toshi Kani <toshi.kani@hp.com>
* PCI: acpiphp: Remove all functions even if function 0 doesn't existJiang Liu2013-04-12
| | | | | | | | | | | | | | | | | | Currently function disable_device() detects slot state by checking existence of PCI function 0. It's unreliable because the PCI device for function 0 may be removed through the sysfs interface. If that happens, it will cause powering off a hotplug slot without destroying all PCI devices. On the other hand, it won't hurt us except wasting some computation power if the check is removed, because all code of disable_device() is self-protected. So remove the check. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Yinghai Lu <yinghai@kernel.org> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Toshi Kani <toshi.kani@hp.com>
* PCI: acpiphp: Use list_for_each_entry_safe() in acpiphp_sanitize_bus()Yijing Wang2013-04-12
| | | | | | | | | | | | Function acpiphp_sanitize_bus() may call pci_stop_and_remove_bus_device(), which in turn may remove device from bus->devices list. So walk the bus->devices list with list_for_each_entry_safe(). Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Yinghai Lu <yinghai@kernel.org> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Toshi Kani <toshi.kani@hp.com>
* Merge tag 'pci-v3.9-changes' of ↵Linus Torvalds2013-02-26
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI changes from Bjorn Helgaas: "Host bridge hotplug - Major overhaul of ACPI host bridge add/start (Rafael Wysocki, Yinghai Lu) - Major overhaul of PCI/ACPI binding (Rafael Wysocki, Yinghai Lu) - Split out ACPI host bridge and ACPI PCI device hotplug (Yinghai Lu) - Stop caching _PRT and make independent of bus numbers (Yinghai Lu) PCI device hotplug - Clean up cpqphp dead code (Sasha Levin) - Disable ARI unless device and upstream bridge support it (Yijing Wang) - Initialize all hot-added devices (not functions 0-7) (Yijing Wang) Power management - Don't touch ASPM if disabled (Joe Lawrence) - Fix ASPM link state management (Myron Stowe) Miscellaneous - Fix PCI_EXP_FLAGS accessor (Alex Williamson) - Disable Bus Master in pci_device_shutdown (Konstantin Khlebnikov) - Document hotplug resource and MPS parameters (Yijing Wang) - Add accessor for PCIe capabilities (Myron Stowe) - Drop pciehp suspend/resume messages (Paul Bolle) - Make pci_slot built-in only (not a module) (Jiang Liu) - Remove unused PCI/ACPI bind ops (Jiang Liu) - Removed used pci_root_bus (Bjorn Helgaas)" * tag 'pci-v3.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (51 commits) PCI/ACPI: Don't cache _PRT, and don't associate them with bus numbers PCI: Fix PCI Express Capability accessors for PCI_EXP_FLAGS ACPI / PCI: Make pci_slot built-in only, not a module PCI/PM: Clear state_saved during suspend PCI: Use atomic_inc_return() rather than atomic_add_return() PCI: Catch attempts to disable already-disabled devices PCI: Disable Bus Master unconditionally in pci_device_shutdown() PCI: acpiphp: Remove dead code for PCI host bridge hotplug PCI: acpiphp: Create companion ACPI devices before creating PCI devices PCI: Remove unused "rc" in virtfn_add_bus() PCI: pciehp: Drop suspend/resume ENTRY messages PCI/ASPM: Don't touch ASPM if forcibly disabled PCI/ASPM: Deallocate upstream link state even if device is not PCIe PCI: Document MPS parameters pci=pcie_bus_safe, pci=pcie_bus_perf, etc PCI: Document hpiosize= and hpmemsize= resource reservation parameters PCI: Use PCI Express Capability accessor PCI: Introduce accessor to retrieve PCIe Capabilities Register PCI: Put pci_dev in device tree as early as possible PCI: Skip attaching driver in device_add() PCI: acpiphp: Keep driver loaded even if no slots found ...
| * PCI: acpiphp: Remove dead code for PCI host bridge hotplugJiang Liu2013-02-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 668192b678201d2fff27c "PCI: acpiphp: Move host bridge hotplug to pci_root.c" has moved PCI host bridge hotplug logic from acpiphp to pci_root, but there is still PCI host bridge hotplug related dead code left in acpiphp. So remove those dead code. Now companion ACPI devices are always created before corresponding PCI devices. And the ACPI event handle_hotplug_event_bridge() will be installed only if it has associated PCI device. So remove dead code to handle bridge hot-adding in function handle_hotplug_event_bridge(). Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
| * PCI: acpiphp: Create companion ACPI devices before creating PCI devicesJiang Liu2013-02-01
| | | | | | | | | | | | | | | | | | | | | | | | With commit 4f535093cf8f6da8c "PCI: Put pci_dev in device tree as early as possible", companion ACPI devices should be created before creating corresponding PCI devices, otherwise it will break the ACPI PCI binding logic. Without this patch, the /sys/bus/pci/devices/.../firmware_node symlink is missing after hot-removing and hot-adding a device with acpiphp. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
| * PCI: acpiphp: Keep driver loaded even if no slots foundYinghai Lu2013-01-25
| | | | | | | | | | | | | | | | | | | | | | | | Could have root bus hot-added later and there may be slots that need acpiphp. The result returned by acpiphp_get_num_slots() is meaningless, because the bridge the slots are under may be added after this function has been called, so drop acpiphp_get_num_slots() and the code using it. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * PCI: acpiphp: Move host bridge hotplug to pci_root.cYinghai Lu2013-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The acpiphp driver is confusing because it contains partial support for PCI host bridge hotplug as well as support for hotplug of PCI devices. This patch moves the host bridge hot-add support to pci_root.c and adds hot-remove support in pci_root.c. How to test it: if sci_emu patch is applied, find out root bus number to ACPI root name mapping from dmesg or /sys. To remove root bus: echo "\_SB.PCIB 3" > /sys/kernel/debug/acpi/sci_notify To add back root bus: echo "\_SB.PCIB 1" > /sys/kernel/debug/acpi/sci_notify Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * PCI/ACPI: acpiphp: Rename alloc_acpiphp_hp_work() to alloc_acpi_hp_work()Yinghai Lu2013-01-25
| | | | | | | | | | | | | | | | | | | | | | Will need to use it for PCI root bridge hotplug support, so rename *acpiphp* to *acpi* and move to osc.c. Also make kacpi_hotplug_wq static after that. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> CC: Len Brown <lenb@kernel.org> CC: linux-acpi@vger.kernel.org
| * PCI: acpiphp: Add is_hotplug_bridge detectionYinghai Lu2013-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When system support hotplug bridge with children hotplug slots, we need to make sure that parent bridge get preallocated resource so later when device is plugged into children slot, those children devices will get resource allocated. We do not meet this problem, because for PCIe hotplug card, when acpiphp is used, pci_scan_bridge will set that for us when detect hotplug bit in slot cap. Reported-and-tested-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Jason Baron <jbaron@redhat.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | ACPI / hotplug: Fix concurrency issues and memory leaksRafael J. Wysocki2013-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This changeset is aimed at fixing a few different but related problems in the ACPI hotplug infrastructure. First of all, since notify handlers may be run in parallel with acpi_bus_scan(), acpi_bus_trim() and acpi_bus_hot_remove_device() and some of them are installed for ACPI handles that have no struct acpi_device objects attached (i.e. before those objects are created), those notify handlers have to take acpi_scan_lock to prevent races from taking place (e.g. a struct acpi_device is found to be present for the given ACPI handle, but right after that it is removed by acpi_bus_trim() running in parallel to the given notify handler). Moreover, since some of them call acpi_bus_scan() and acpi_bus_trim(), this leads to the conclusion that acpi_scan_lock should be acquired by the callers of these two funtions rather by these functions themselves. For these reasons, make all notify handlers that can handle device addition and eject events take acpi_scan_lock and remove the acpi_scan_lock locking from acpi_bus_scan() and acpi_bus_trim(). Accordingly, update all of their users to make sure that they are always called under acpi_scan_lock. Furthermore, since eject operations are carried out asynchronously with respect to the notify events that trigger them, with the help of acpi_bus_hot_remove_device(), even if notify handlers take the ACPI scan lock, it still is possible that, for example, acpi_bus_trim() will run between acpi_bus_hot_remove_device() and the notify handler that scheduled its execution and that acpi_bus_trim() will remove the device node passed to acpi_bus_hot_remove_device() for ejection. In that case, the struct acpi_device object obtained by acpi_bus_hot_remove_device() will be invalid and not-so-funny things will ensue. To protect agaist that, make the users of acpi_bus_hot_remove_device() run get_device() on ACPI device node objects that are about to be passed to it and make acpi_bus_hot_remove_device() run put_device() on them and check if their ACPI handles are not NULL (make acpi_device_unregister() clear the device nodes' ACPI handles for that check to work). Finally, observe that acpi_os_hotplug_execute() actually can fail, in which case its caller ought to free memory allocated for the context object to prevent leaks from happening. It also needs to run put_device() on the device node that it ran get_device() on previously in that case. Modify the code accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org>
* | ACPI / scan: Make it clear that acpi_bus_trim() cannot failRafael J. Wysocki2013-01-25
|/ | | | | | | | | | | Since acpi_bus_trim() cannot fail, change its definition to a void function, so that its callers don't check the return value in vain and update the callers. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Acked-by: Toshi Kani <toshi.kani@hp.com>
* ACPI / scan: Drop acpi_bus_add() and use acpi_bus_scan() insteadRafael J. Wysocki2013-01-18
| | | | | | | | | | | | | | | | The only difference between acpi_bus_scan() and acpi_bus_add() is the invocation of acpi_update_all_gpes() in the latter which in fact is unnecessary, because acpi_update_all_gpes() has already been called by acpi_scan_init() and the way it is implemented guarantees the next invocations of it to do nothing. For this reason, drop acpi_bus_add() and make all its callers use acpi_bus_scan() directly instead of it. Additionally, rearrange the code in acpi_scan_init() slightly to improve the visibility of the acpi_update_all_gpes() call in there. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org>
* ACPI / scan: Drop the second argument of acpi_bus_trim()Rafael J. Wysocki2013-01-15
| | | | | | | | | | | All callers of acpi_bus_trim() pass 1 (true) as the second argument of it, so remove that argument entirely and change acpi_bus_trim() to always behave as though it were 1. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
* ACPI: Make acpi_bus_scan() and acpi_bus_add() take only one argumentRafael J. Wysocki2013-01-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The callers of acpi_bus_add() usually assume that if it has succeeded, then a struct acpi_device object has been attached to the handle passed as the first argument. Unfortunately, however, this assumption is wrong, because acpi_bus_scan(), and acpi_bus_add() too as a result, may return a pointer to a different struct acpi_device object on success (it may be an object corresponding to one of the descendant ACPI nodes in the namespace scope below that handle). For this reason, the callers of acpi_bus_add() who care about whether or not a struct acpi_device object has been created for its first argument need to check that using acpi_bus_get_device() anyway, so the second argument of acpi_bus_add() is not really useful for them. The same observation applies to acpi_bus_scan() executed directly from acpi_scan_init(). Therefore modify the relevant callers of acpi_bus_add() to check the existence of the struct acpi_device in question with the help of acpi_bus_get_device() and drop the no longer necessary second argument of acpi_bus_add(). Accordingly, modify acpi_scan_init() to use acpi_bus_get_device() to get acpi_root and drop the no longer needed second argument of acpi_bus_scan(). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Toshi Kani <toshi.kani@hp.com>
* ACPI: Remove the arguments of acpi_bus_add() that are not usedRafael J. Wysocki2013-01-03
| | | | | | | | | | | | | | | Notice that acpi_bus_add() uses only 2 of its 4 arguments and redefine its header to match the body. Update all of its callers as necessary and observe that this leads to quite a number of removed lines of code (Linus will like that). Add a kerneldoc comment documenting acpi_bus_add() and wonder how its callers make wrong assumptions about the second argument (make note to self to take care of that later). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Toshi Kani <toshi.kani@hp.com>
* ACPI: Remove acpi_start_single_object() and acpi_bus_start()Rafael J. Wysocki2013-01-03
| | | | | | | | | | | | | | | | | | | | | | | | The ACPI PCI root bridge driver was the only ACPI driver implementing the .start() callback, which isn't used by any ACPI drivers any more now. For this reason, acpi_start_single_object() has no purpose any more, so remove it and all references to it. Also remove acpi_bus_start_device(), whose only purpose was to call acpi_start_single_object(). Moreover, since after the removal of acpi_bus_start_device() the only purpose of acpi_bus_start() remains to call acpi_update_all_gpes(), move that into acpi_bus_add() and drop acpi_bus_start() too, remove its header from acpi_bus.h and update all of its former users accordingly. This change was previously proposed in a different from by Yinghai Lu. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Toshi Kani <toshi.kani@hp.com>
* Merge branch 'pci/jiang-acpiphp' into nextBjorn Helgaas2012-09-24
|\
| * PCI: acpiphp: Handle PCIe ports without native hotplug capabilityJiang Liu2012-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 0d52f54e2ef64c189dedc332e680b2eb4a34590a (PCI / ACPI: Make acpiphp ignore root bridges using PCIe native hotplug) added code that made the acpiphp driver completely ignore PCIe root complexes for which the kernel had been granted control of the native PCIe hotplug feature by the BIOS through _OSC. Later commit 619a5182d1f38a3d629ee48e04fa182ef9170052 "PCI hotplug: Always allow acpiphp to handle non-PCIe bridges" relaxed the constraints to allow acpiphp driver handle non-PCIe bridges under such a complex. The constraint needs to be relaxed further to allow acpiphp driver to handle PCIe ports without native PCIe hotplug capability. Some MR-IOV switch chipsets, such PLX8696, support multiple virtual PCIe switches and may migrate downstream ports among virtual switches. To migrate a downstream port from the source virtual switch to the target, the port needs to be hot-removed from the source and hot-added into the target. The pciehp driver can't be used here because there are no slots within the virtual PCIe switch. So acpiphp driver is used to support downstream port migration. A typical configuration is as below: [Root without native PCIe HP] [Upstream port of vswitch without native PCIe HP] [Downstream port of vswitch with native PCIe HP] [PCIe endpoint] Here acpiphp driver will be used to handle root ports and upstream port in the virtual switch, and pciehp driver will be used to handle downstream ports in the virtual switch. Signed-off-by: Jiang Liu <liuj97@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
* | PCI/ACPI: Pass acpi_pci_root to acpi_pci_drivers' add/remove interfaceTaku Izumi2012-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch changes .add/.remove interfaces of acpi_pci_driver. In the current implementation acpi_handle is passed as a parameter of .add/.remove interface. However, the acpi_pci_root structure contains more useful information than just the acpi_handle. This enables us to avoid some useless lookups in each acpi_pci_driver. Note: This changes interfaces used by acpi_pci_register_driver(), an exported symbol. This patch updates all the in-kernel users, but any out-of-kernel acpi_pci_register_driver() users will need updates. [bhelgaas: changelog] Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* | PCI: Remove unused, commented-out, codeBjorn Helgaas2012-08-22
| | | | | | | | | | | | | | This removes unused code that was already commented out. Tested-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Yinghai Lu <yinghai@kernel.org>
* | PCI: acpiphp: Use common pci_stop_and_remove_bus_device()Bjorn Helgaas2012-08-22
| | | | | | | | | | | | | | | | Use pci_stop_and_remove_bus_device() like most other hotplug drivers rather than stopping and removing separately. Tested-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Yinghai Lu <yinghai@kernel.org>
* | PCI: acpiphp: Stop disabling bridges on removeBjorn Helgaas2012-08-17
|/ | | | | | | | | acpiphp_disable_slot() turns off power to the slot immediately after calling disable_device(), so there's no point in disabling any bridges below the slot: we're about to turn them off anyway. Tested-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Yinghai Lu <yinghai@kernel.org>
* Merge branch 'pci/yinghai-hotplug-cleanup' into nextBjorn Helgaas2012-07-11
|\ | | | | | | | | | | * pci/yinghai-hotplug-cleanup: PCI: acpiphp: merge acpiphp_debug and debug PCI: acpiphp: remove unused res_lock
| * PCI: acpiphp: remove unused res_lockYinghai Lu2012-07-10
| | | | | | | | | | | | res_lock is never used, so remove it. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* | Merge branch 'topic/bjorn-trivial' into nextBjorn Helgaas2012-06-22
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * topic/bjorn-trivial: PCI: remove useless pcix_set_mmrbc() dev->bus check PCI: acpiphp: check whether _ADR evaluation succeeded PCI: shpchp: remove dead code PCI: fix P2P bridge I/O port window sign extension PCI: fix upstream P2P bridge checks when enabling OBFF and LTR PCI: use __weak consistently PCI: cleanup assign_requested_resources_sorted() kernel-doc warning sparc/PCI: remove unused pcibios_assign_resource() definition
| * | PCI: acpiphp: check whether _ADR evaluation succeededBjorn Helgaas2012-06-20
| |/ | | | | | | | | | | | | | | | | | | | | | | Check whether we evaluated _ADR successfully. Previously we ignored failure, so we would have used garbage data from the stack as the device and function number. We return AE_OK so that we ignore only this slot and continue looking for other slots. Found by Coverity (CID 113981). Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* | PCI: acpiphp: remove all functions in slot, even without ACPI _EJxAmos Kong2012-06-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we add a device with acpiphp, we enumerate all functions in the slot with pci_scan_slot(), regardless of whether they have associated ACPI methods such as _EJ0. When removing the device, we previously removed only the functions with those ACPI methods. This patch makes the remove symmetric with the add: we remove all functions in the slot, whether they have associated ACPI methods or not. With qemu-kvm and SeaBIOS, we can build a multi-function device where only function 0 has _EJ0 and _ADR (see bugzilla below). Removing and re-adding that slot (including all functions of the device) works correctly with Windows guests. This patch makes it also work in Linux guests. [bhelgaas: restructure loop iteration, pull out of slot->funcs loop] Reference: https://bugzilla.kernel.org/show_bug.cgi?id=43219 Signed-off-by: Amos Kong <kongjianjun@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* | PCI: acpiphp: fix function 0 leak when disabling a slotAmos Kong2012-06-13
| | | | | | | | | | | | | | | | | | Previously, we acquired two references to function 0, but only released one. [bhelgaas: split this out from "remove all functions" fix] Signed-off-by: Amos Kong <kongjianjun@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* | PCI: replace struct pci_bus secondary/subordinate with busn_resYinghai Lu2012-06-13
|/ | | | | | | | | Replace the struct pci_bus secondary/subordinate members with the struct resource busn_res. Later we'll build a resource tree of these bus numbers. [bhelgaas: changelog] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* PCI: make acpihp use __pci_remove_bus_device insteadYinghai Lu2012-02-27
| | | | | | | pci_stop_bus_device gets called before in the same loop. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* PCI: Rename pci_remove_bus_device to pci_stop_and_remove_bus_deviceYinghai Lu2012-02-27
| | | | | | | | | | | | | The old pci_remove_bus_device actually did stop and remove. Make the name reflect that to reduce confusion. This patch is done by sed scripts and changes back some incorrect __pci_remove_bus_device changes. Suggested-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* PCI: Can continually add funcs after adding func0Amos Kong2012-02-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Boot up a KVM guest, and hotplug multifunction devices(func1,func2,func0,func3) to guest. for i in 1 2 0 3;do qemu-img create /tmp/resize$i.qcow2 1G -f qcow2 (qemu) drive_add 0x11.$i id=drv11$i,if=none,file=/tmp/resize$i.qcow2 (qemu) device_add virtio-blk-pci,id=dev11$i,drive=drv11$i,addr=0x11.$i,multifunction=on done In linux kernel, when func0 of the slot is hot-added, the whole slot will be marked as 'enabled', then driver will ignore other new hotadded funcs. But in Win7 & WinXP, we can continaully add other funcs after adding func0, all funcs will be added in guest. drivers/pci/hotplug/acpiphp_glue.c: static int acpiphp_check_bridge(struct acpiphp_bridge *bridge) { .... for (slot = bridge->slots; slot; slot = slot->next) { if (slot->flags & SLOT_ENABLED) { acpiphp_disable_slot() else acpiphp_enable_slot() .... | } v enable_device() | v //only don't enable slot if func0 is not added list_for_each_entry(func, &slot->funcs, sibling) { ... } slot->flags |= SLOT_ENABLED; //mark slot to 'enabled' This patch just make pci driver can continaully add funcs after adding func 0. Only mark slot to 'enabled' when all funcs are added. For pci multifunction hotplug, we can add functions one by one(func 0 is necessary), and all functions will be removed in one time. Signed-off-by: Amos Kong <akong@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* PCI: Set device power state to PCI_D0 for device without native PM supportAjaykumar Hotchandani2011-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During test of one IB card with guest VM, found that, msi is not initialized properly. It turns out __write_msi_msg will do nothing if device current_state is not PCI_D0. And, that pci device does not have pm_cap in guest VM. There is an error in setting of power state to PCI_D0 in pci_enable_device(), but error is not returned for this. Following is code flow: pci_enable_device() --> __pci_enable_device_flags() --> do_pci_enable_device() --> pci_set_power_state() --> __pci_start_power_transition() We have following condition inside __pci_start_power_transition(): if (platform_pci_power_manageable(dev)) { error = platform_pci_set_power_state(dev, state); if (!error) pci_update_current_state(dev, state); } else { error = -ENODEV; /* Fall back to PCI_D0 if native PM is not supported */ if (!dev->pm_cap) dev->current_state = PCI_D0; } Here, from platform_pci_set_power_state(), acpi_pci_set_power_state() is getting called and that is failing with ENODEV because of following condition: if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0",&tmp))) return -ENODEV; Because of that, pci_update_current_state() is not getting called. With this patch, if device power state can not be set via platform_pci_set_power_state and that device does not have native pm support, then PCI device power state will be set to PCI_D0. -v2: This also reverts 47e9037ac16637cd7f12b8790ea7ce6680e42168, as it's not needed after this change. Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Ajaykumar Hotchandani<ajaykumar.hotchandani@oracle.com> Signed-off-by: Yinghai Lu<yinghai.lu@oracle.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* PCI hotplug: Always allow acpiphp to handle non-PCIe bridgesRafael J. Wysocki2011-12-13
| | | | | | | | | | | | | | | | | | | | | | | Commit 0d52f54e2ef64c189dedc332e680b2eb4a34590a (PCI / ACPI: Make acpiphp ignore root bridges using PCIe native hotplug) added code that made the acpiphp driver completely ignore PCIe root complexes for which the kernel had been granted control of the native PCIe hotplug feature by the BIOS through _OSC. Unfortunately, however, this was a mistake, because on some systems there were PCI bridges supporting PCI (non-PCIe) hotplug under such root complexes and those bridges should have been handled by acpiphp. For this reason, revert the changes made by the commit mentioned above and make register_slot() in drivers/pci/hotplug/acpiphp_glue.c avoid registering hotplug slots for PCIe ports that belong to root complexes with native PCIe hotplug enabled (which means that the BIOS has granted the kernel control of this feature for the given root complex). This is reported to address the original issue fixed by commit 0d52f54e2ef64c189dedc332e680b2eb4a34590a and to work on the system where that commit broke things. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* PCI / ACPI: Make acpiphp ignore root bridges using PCIe native hotplugRafael J. Wysocki2011-10-31
| | | | | | | | | | | | | | | | | | | If the kernel has requested control of the PCIe native hotplug feature for a given root complex, the acpiphp driver should not try to handle that root complex and it should leave it to pciehp. Failing to do so causes problems to happen if acpiphp is loaded before pciehp on such systems. To address this issue make find_root_bridges() ignore PCIe root complexes with PCIe native hotplug enabled and make add_bridge() return error code if PCIe native hotplug is enabled for the given root port. This causes acpiphp to refuse to load if PCIe native hotplug is enabled for all complexes and to refuse binding to the root complexes with PCIe native hotplug is enabled. Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* PCI hotplug: acpiphp: Prevent deadlock on PCI-to-PCI bridge removePrarit Bhargava2011-10-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I originally submitted a patch to workaround this by pushing all Ejection Requests and Device Checks onto the kacpi_hotplug queue. http://marc.info/?l=linux-acpi&m=131678270930105&w=2 The patch is still insufficient in that Bus Checks also need to be added. Rather than add all events, including non-PCI-hotplug events, to the hotplug queue, mjg suggested that a better approach would be to modify the acpiphp driver so only acpiphp events would be added to the kacpi_hotplug queue. It's a longer patch, but at least we maintain the benefit of having separate queues in ACPI. This, of course, is still only a workaround the problem. As Bjorn and mjg pointed out, we have to refactor a lot of this code to do the right thing but at this point it is a better to have this code working. The acpi core places all events on the kacpi_notify queue. When the acpiphp driver is loaded and a PCI card with a PCI-to-PCI bridge is removed the following call sequence occurs: cleanup_p2p_bridge() -> cleanup_bridge() -> acpi_remove_notify_handler() -> acpi_os_wait_events_complete() -> flush_workqueue(kacpi_notify_wq) which is the queue we are currently executing on and the process will hang. Move all hotplug acpiphp events onto the kacpi_hotplug workqueue. In handle_hotplug_event_bridge() and handle_hotplug_event_func() we can simply push the rest of the work onto the kacpi_hotplug queue and then avoid the deadlock. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Cc: mjg@redhat.com Cc: bhelgaas@google.com Cc: linux-acpi@vger.kernel.org Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* ACPI: constify ops structsVasiliy Kulikov2011-07-16
| | | | | | | | | | | | Structs battery_file, acpi_dock_ops, file_operations, thermal_cooling_device_ops, thermal_zone_device_ops, kernel_param_ops are not changed in runtime. It is safe to make them const. register_hotplug_dock_device() was altered to take const "ops" argument to respect acpi_dock_ops' const notion. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Acked-by: Jeff Garzik <jgarzik@redhat.com> Signed-off-by: Len Brown <len.brown@intel.com>
* PCI hotplug: acpiphp: assume device is in state D0 after powering on a slot.Ian Campbell2011-05-11
| | | | | | | | Devices which do not support PCI configuration space based power management may not otherwise be enabled. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>