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path: root/drivers/pci/hotplug
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2013-07-23ACPI / hotplug / PCI: Allow slots without new devices to be rescannedKirill A. Shutemov
Currently, enable_device() checks the return value of pci_scan_slot() and returns immediately if that's 0 (meaning that no new functions have been found in the slot). However, if one of the functions in the slot is a bridge, some new devices may appear below it even if the bridge itself is present continuously, so it generally is necessary to do the rescan anyway just in case. [In particular, that's necessary with the Thunderbolt daisy chaining in which case new devices may be connected to the existing ones down the chain.] The correctness of this change relies on the ability of pcibios_resource_survey_bus() to detect if it has already been called for the given bus and to skip it if so. Failure to do that will lead to resource allocation conflicts. [rjw: Changelog] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-23ACPI / hotplug / PCI: Do not check SLOT_ENABLED in enable_device()Kirill A. Shutemov
With Thunderbolt you can daisy chain devices: connect new devices to an already plugged one. In that case the "hotplug slot" is already enabled, but we still want to look for new PCI devices behind it. Reuse enable_device() to scan for new PCI devices on enabled slots and push the SLOT_ENABLED check up into acpiphp_enable_slot(). [rjw: Rebased, modified the changelog] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-23ACPI / hotplug / PCI: Do not exectute _PS0 and _PS3 directlyRafael J. Wysocki
The ACPI-based PCI hotplug (acpiphp) core code need not and really should not execute _PS0 and _PS3 directly for devices it handles. First of all, it is not necessary to put devices into D3 after acpi_bus_trim() has walked through them, because acpi_device_unregister() invoked by it puts each device into D3cold before returning. Thus after disable_device() the slot should be powered down already. Second, calling _PS0 directly on ACPI device objects may not be appropriate, because it may require power resources to be set up in a specific way in advance and that must be taken care of by the ACPI core. Thus modify acpiphp_bus_add() to power up the device using the appropriate interface after it has run acpi_bus_scan() on its handle. After that, the functions executing _PS0 and _PS3, power_on_slot() and power_off_slot(), are not necessary any more, so drop them and update the code calling them accordingly. Also drop the function flags related to device power states, since they aren't useful any more too. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Do not queue up event handling work items in vainRafael J. Wysocki
Modify handle_hotplug_event() to avoid queing up the execution of handle_hotplug_event_work_fn() as a work item on kacpi_hotplug_wq for non-hotplug events, such as ACPI_NOTIFY_DEVICE_WAKE. Move the code printing diagnostic messages for those events into handle_hotplug_event(). In addition to that, remove the bogus comment about how the core should distinguish between hotplug and non-hotplug events and queue them up on different workqueues. The core clearly cannot know in advance what events will be interesting to the given caller of acpi_install_notify_handler(). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Consolidate slot disabling and ejectingMika Westerberg
Both acpiphp_disable_slot() and acpiphp_eject_slot() are always called together so instead of calling each separately we can consolidate them into one function acpiphp_disable_and_eject_slot() that does both (but it will return success on _EJ0 failures that were ignored in the majority of call sites anyway). [rjw: Rebased plus minor tweaks] Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-23ACPI / hotplug / PCI: Drop redundant checks from check_hotplug_bridge()Rafael J. Wysocki
Two checks in check_hotplug_bridge() are redundant (they have been done by the caller already), so drop them. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Rework namespace scanning and trimming routinesRafael J. Wysocki
The acpiphp_bus_trim() and acpiphp_bus_add() functions need not return error codes that are never checked, so redefine them and simplify them a bit. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Store parent in functions and bus in slotsRafael J. Wysocki
To avoid chasing more pointers than necessary in some situations, move the bridge pointer from struct acpiphp_slot to struct acpiphp_func (and call it 'parent') and add a bus pointer to struct acpiphp_slot. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Drop handle field from struct acpiphp_bridgeRafael J. Wysocki
The handle field in struct acpiphp_bridge is only used by acpiphp_enumerate_slots(), but in that function the local handle variable can be used instead, so make that happen and drop handle from struct acpiphp_bridge. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Drop handle field from struct acpiphp_funcRafael J. Wysocki
The ACPI handle stored in struct acpiphp_func is also stored in the struct acpiphp_context object containing it and it is trivial to get from a struct acpiphp_func pointer to the handle field of the outer struct acpiphp_context. Hence, the handle field of struct acpiphp_func is redundant, so drop it and provide a helper function, func_to_handle(), allowing it users to get the ACPI handle for the given struct acpiphp_func pointer. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Embed function struct into struct acpiphp_contextRafael J. Wysocki
Since there has to be a struct acpiphp_func object for every struct acpiphp_context created by register_slot(), the struct acpiphp_func one can be embedded into the struct acpiphp_context one, which allows some code simplifications to be made. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Drop flags field from struct acpiphp_bridgeRafael J. Wysocki
The only bridge flag used by the ACPI-based PCI hotplug (ACPIPHP) code is BRIDGE_HAS_EJ0, but it is only used by the event handling function hotplug_event() and if that flag is set, the corresponding function flag FUNC_HAS_EJ0 is set as well, so that bridge flag is redundant. For this reason, drop BRIDGE_HAS_EJ0 and all code referring to it and since it is the only bridge flag defined, drop the flags field from struct acpiphp_bridge entirely. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Drop sun field from struct acpiphp_slotRafael J. Wysocki
If the slot unique number is passed as an additional argument to acpiphp_register_hotplug_slot(), the 'sun' field in struct acpiphp_slot is only used by ibm_[s|g]et_attention_status(), but then it's more efficient to store it in struct slot. Thus move the 'sun' field from struct acpiphp_slot to struct slot changing its data type to unsigned int in the process, and redefine acpiphp_register_hotplug_slot() to take the slot number as separate argument. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Register all devices under the given bridgeRafael J. Wysocki
Rework register_slot() to create a struct acpiphp_func object for every function it is called for and to create acpiphp slots for all of them. Although acpiphp_register_hotplug_slot() is only called for the slots whose functions are identified as "ejectable", so that user space can manipulate them, the ACPIPHP notify handler, handle_hotplug_event(), is now installed for all of the registered functions (that aren't dock stations) and hotplug events may be handled for all of them. As a result, essentially, all PCI bridges represented by objects in the ACPI namespace are now going to be "hotplug" bridges and that may affect resources allocation in general, although it shouldn't lead to problems. This allows the code to be simplified substantially and addresses the problem where bus check or device check notifications for some PCI bridges or devices are not handled, because those devices are not recognized as "ejectable" or there appear to be no "ejectable" devices under those bridges. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Refactor slot allocation code in register_slot()Rafael J. Wysocki
To make the code in register_slot() a bit easier to follow, change the way the slot allocation part is organized. Drop one local variable that's not used any more after that modification. This code change should not lead to any changes in behavior. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Drop func field from struct acpiphp_bridgeRafael J. Wysocki
Since the func pointer in struct acpiphp_context can always be used instead of the func pointer in struct acpiphp_bridge, drop the latter. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Merge hotplug event handling functionsRafael J. Wysocki
There are separate handling event functions for hotplug bridges and for hotplug functions, but they may be combined into one common hotplug event handling function which simplifies the code slightly. That also allows a theoretical bug to be dealt with which in principle may occur if a hotplug bridge is on a dock station, because in that case the bridge-specific notification should be used instead of the function-specific one, but the dock station always uses the latter. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Pass hotplug context objects to event handlersRafael J. Wysocki
Modify handle_hotplug_event() to pass the entire context object (instead of its fields individually) to work functions started by it. This change makes the subsequent consolidation of the event handling work functions a bit more straightforward. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Rework acpiphp_handle_to_bridge()Rafael J. Wysocki
Using the hotplug context objects introduced previously rework the ACPI-based PCI hotplug (ACPIPHP) core code to get to acpiphp_bridge objects associated with hotplug bridges from those context objects rather than from the global list of hotplug bridges. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Unified notify handler for hotplug eventsRafael J. Wysocki
Using the hotplug context objects introduced previously rework the ACPI-based PCI hotplug (ACPIPHP) core code so that all notifications for ACPI device objects corresponding to the hotplug PCI devices are handled by one function, handle_hotplug_event(), which recognizes whether it has to handle a bridge or a function. In addition to code size reduction it allows some ugly pieces of code where notify handlers have to be uninstalled and installed again to go away. Moreover, it fixes a theoretically possible race between handle_hotplug_event() and free_bridge() tearing down data structures for the same handle. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Hotplug context objects for bridges and functionsRafael J. Wysocki
When either a new hotplug bridge or a new hotplug function is added by the ACPI-based PCI hotplug (ACPIPHP) code, attach a context object to its ACPI handle to store hotplug-related information in it. To start with, put the handle's bridge and function pointers into that object. Count references to the context objects and drop them when they are not needed any more. First of all, this makes it possible to find out if the given bridge has been registered as a function already in a much more straightforward way and acpiphp_bridge_handle_to_function() can be dropped (Yay!). This also will allow some more simplifications to be made going forward. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-07-23ACPI / hotplug / PCI: Always return success after adding a functionRafael J. Wysocki
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>
2013-07-23ACPI / hotplug / PCI: Consolidate acpiphp_enumerate_slots()Rafael J. Wysocki
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>
2013-07-23ACPI / PCI: Make bus registration and unregistration symmetricRafael J. Wysocki
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>
2013-07-15ACPI: Remove the old /proc/acpi/event interfaceThomas Renninger
It is quite some time that this one has been deprecated. Get rid of it. Should some really important user be overseen, it may be reverted and the userspace program worked on first, but it is time to do something to get rid of this old stuff... Signed-off-by: Thomas Renninger <trenn@suse.de> Acked-by: Matthew Garrett <matthew.garrett@nebula.com> Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-14ACPI / dock / PCI: Drop ACPI dock notifier chainRafael J. Wysocki
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>
2013-07-14ACPI: simplify acpiphp driver with new helper functionsJiang Liu
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>
2013-07-04Merge branch 'akpm' (updates from Andrew Morton)Linus Torvalds
Merge first patch-bomb from Andrew Morton: - various misc bits - I'm been patchmonkeying ocfs2 for a while, as Joel and Mark have been distracted. There has been quite a bit of activity. - About half the MM queue - Some backlight bits - Various lib/ updates - checkpatch updates - zillions more little rtc patches - ptrace - signals - exec - procfs - rapidio - nbd - aoe - pps - memstick - tools/testing/selftests updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (445 commits) tools/testing/selftests: don't assume the x bit is set on scripts selftests: add .gitignore for kcmp selftests: fix clean target in kcmp Makefile selftests: add .gitignore for vm selftests: add hugetlbfstest self-test: fix make clean selftests: exit 1 on failure kernel/resource.c: remove the unneeded assignment in function __find_resource aio: fix wrong comment in aio_complete() drivers/w1/slaves/w1_ds2408.c: add magic sequence to disable P0 test mode drivers/memstick/host/r592.c: convert to module_pci_driver drivers/memstick/host/jmb38x_ms: convert to module_pci_driver pps-gpio: add device-tree binding and support drivers/pps/clients/pps-gpio.c: convert to module_platform_driver drivers/pps/clients/pps-gpio.c: convert to devm_* helpers drivers/parport/share.c: use kzalloc Documentation/accounting/getdelays.c: avoid strncpy in accounting tool aoe: update internal version number to v83 aoe: update copyright date aoe: perform I/O completions in parallel ...
2013-07-03drivers: avoid format strings in names passed to alloc_workqueue()Kees Cook
For the workqueue creation interfaces that do not expect format strings, make sure they cannot accidently be parsed that way. Additionally, clean up calls made with a single parameter that would be handled as a format string. Many callers are passing potentially dynamic string content, so use "%s" in those cases to avoid any potential accidents. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "This is the bulk of the s390 patches for the 3.11 merge window. Notable enhancements are: the block timeout patches for dasd from Hannes, and more work on the PCI support front. In addition some cleanup and the usual bug fixing." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (42 commits) s390/dasd: Fail all requests when DASD_FLAG_ABORTIO is set s390/dasd: Add 'timeout' attribute block: check for timeout function in blk_rq_timed_out() block/dasd: detailed I/O errors s390/dasd: Reduce amount of messages for specific errors s390/dasd: Implement block timeout handling s390/dasd: process all requests in the device tasklet s390/dasd: make number of retries configurable s390/dasd: Clarify comment s390/hwsampler: Updated misleading member names in hws_data_entry s390/appldata_net_sum: do not use static data s390/appldata_mem: do not use static data s390/vmwatchdog: do not use static data s390/airq: simplify adapter interrupt code s390/pci: remove per device debug attribute s390/dma: remove gratuitous brackets s390/facility: decompose test_facility() s390/sclp: remove duplicated include from sclp_ctl.c s390/irq: store interrupt information in pt_regs s390/drivers: Cocci spatch "ptr_ret.spatch" ...
2013-07-03Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull second set of VFS changes from Al Viro: "Assorted f_pos race fixes, making do_splice_direct() safe to call with i_mutex on parent, O_TMPFILE support, Jeff's locks.c series, ->d_hash/->d_compare calling conventions changes from Linus, misc stuff all over the place." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) Document ->tmpfile() ext4: ->tmpfile() support vfs: export lseek_execute() to modules lseek_execute() doesn't need an inode passed to it block_dev: switch to fixed_size_llseek() cpqphp_sysfs: switch to fixed_size_llseek() tile-srom: switch to fixed_size_llseek() proc_powerpc: switch to fixed_size_llseek() ubi/cdev: switch to fixed_size_llseek() pci/proc: switch to fixed_size_llseek() isapnp: switch to fixed_size_llseek() lpfc: switch to fixed_size_llseek() locks: give the blocked_hash its own spinlock locks: add a new "lm_owner_key" lock operation locks: turn the blocked_list into a hashtable locks: convert fl_link to a hlist_node locks: avoid taking global lock if possible when waking up blocked waiters locks: protect most of the file_lock handling with i_lock locks: encapsulate the fl_link list handling locks: make "added" in __posix_lock_file a bool ...
2013-07-02Merge tag 'driver-core-3.11-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here's the big driver core merge for 3.11-rc1 Lots of little things, and larger firmware subsystem updates, all described in the shortlog. Nice thing here is that we finally get rid of CONFIG_HOTPLUG, after 10+ years, thanks to Stephen Rohtwell (it had been always on for a number of kernel releases, now it's just removed)" * tag 'driver-core-3.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (27 commits) driver core: device.h: fix doc compilation warnings firmware loader: fix another compile warning with PM_SLEEP unset build some drivers only when compile-testing firmware loader: fix compile warning with PM_SLEEP set kobject: sanitize argument for format string sysfs_notify is only possible on file attributes firmware loader: simplify holding module for request_firmware firmware loader: don't export cache_firmware and uncache_firmware drivers/base: Use attribute groups to create sysfs memory files firmware loader: fix compile warning firmware loader: fix build failure with !CONFIG_FW_LOADER_USER_HELPER Documentation: Updated broken link in HOWTO Finally eradicate CONFIG_HOTPLUG driver core: firmware loader: kill FW_ACTION_NOHOTPLUG requests before suspend driver core: firmware loader: don't cache FW_ACTION_NOHOTPLUG firmware Documentation: Tidy up some drivers/base/core.c kerneldoc content. platform_device: use a macro instead of platform_driver_register firmware: move EXPORT_SYMBOL annotations firmware: Avoid deadlock of usermodehelper lock at shutdown dell_rbu: Select CONFIG_FW_LOADER_USER_HELPER explicitly ...
2013-06-29cpqphp_sysfs: switch to fixed_size_llseek()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-26s390/pci: remove pdev during unplugSebastian Ott
The disable slot implementation on s390 currently just detaches the pci function from the partition - without informing the pci layer. Fix this by calling pci_stop_and_remove_bus_device prior to the operation. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-06-26s390/pci: cleanup hotplug codeSebastian Ott
Provide wrappers for the [de]configure operations, add some error handling, and use pci_scan_slot instead of pci_scan_single_device. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-06-24ACPI / dock / PCI: Synchronous handling of dock events for PCI devicesRafael J. Wysocki
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>
2013-06-22PCI / ACPI: Use boot-time resource allocation rules during hotplugJiang Liu
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>
2013-06-03Finally eradicate CONFIG_HOTPLUGStephen Rothwell
Ever since commit 45f035ab9b8f ("CONFIG_HOTPLUG should be always on"), it has been basically impossible to build a kernel with CONFIG_HOTPLUG turned off. Remove all the remaining references to it. Cc: Russell King <linux@arm.linux.org.uk> Cc: Doug Thompson <dougthompson@xmission.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-17PCI: acpiphp: Re-enumerate devices when host bridge receives Bus CheckYinghai Lu
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+
2013-04-29Merge tag 'pci-v3.10-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "PCI changes for the v3.10 merge window: PCI device hotplug - Remove ACPI PCI subdrivers (Jiang Liu, Myron Stowe) - Make acpiphp builtin only, not modular (Jiang Liu) - Add acpiphp mutual exclusion (Jiang Liu) Power management - Skip "PME enabled/disabled" messages when not supported (Rafael Wysocki) - Fix fallback to PCI_D0 (Rafael Wysocki) Miscellaneous - Factor quirk_io_region (Yinghai Lu) - Cache MSI capability offsets & cleanup (Gavin Shan, Bjorn Helgaas) - Clean up EISA resource initialization and logging (Bjorn Helgaas) - Fix prototype warnings (Andy Shevchenko, Bjorn Helgaas) - MIPS: Initialize of_node before scanning bus (Gabor Juhos) - Fix pcibios_get_phb_of_node() declaration "weak" annotation (Gabor Juhos) - Add MSI INTX_DISABLE quirks for AR8161/AR8162/etc (Xiong Huang) - Fix aer_inject return values (Prarit Bhargava) - Remove PME/ACPI dependency (Andrew Murray) - Use shared PCI_BUS_NUM() and PCI_DEVID() (Shuah Khan)" * tag 'pci-v3.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (63 commits) vfio-pci: Use cached MSI/MSI-X capabilities vfio-pci: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASK PCI: Remove "extern" from function declarations PCI: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASK PCI: Drop msi_mask_reg() and remove drivers/pci/msi.h PCI: Use msix_table_size() directly, drop multi_msix_capable() PCI: Drop msix_table_offset_reg() and msix_pba_offset_reg() macros PCI: Drop is_64bit_address() and is_mask_bit_support() macros PCI: Drop msi_data_reg() macro PCI: Drop msi_lower_address_reg() and msi_upper_address_reg() macros PCI: Drop msi_control_reg() macro and use PCI_MSI_FLAGS directly PCI: Use cached MSI/MSI-X offsets from dev, not from msi_desc PCI: Clean up MSI/MSI-X capability #defines PCI: Use cached MSI-X cap while enabling MSI-X PCI: Use cached MSI cap while enabling MSI interrupts PCI: Remove MSI/MSI-X cap check in pci_msi_check_device() PCI: Cache MSI/MSI-X capability offsets in struct pci_dev PCI: Use u8, not int, for PM capability offset [SCSI] megaraid_sas: Use correct #define for MSI-X capability PCI: Remove "extern" from function declarations ...
2013-04-17Merge branch 'pci/cleanup' into nextBjorn Helgaas
* pci/cleanup: PCI: Remove "extern" from function declarations PCI: Warn about failures instead of "must_check" functions PCI: Remove __must_check from definitions PCI: Remove unused variables PCI: Move cpci_hotplug_init() proto to header file PCI: Make local functions/structs static PCI: Fix missing prototype for pcie_port_acpi_setup() Conflicts: drivers/pci/hotplug/acpiphp.h include/linux/pci.h
2013-04-17PCI: Remove "extern" from function declarationsBjorn Helgaas
We had an inconsistent mix of using and omitting the "extern" keyword on function declarations in header files. This removes them all. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-04-17PCI: Remove __must_check from definitionsBjorn Helgaas
The __must_check (gcc "warn_unused_result") attribute only makes sense when compiling the *caller* of the function, so the attribute should appear on the declaration in the header file, not on the definition. The declarations of these functions are already annotated with __must_check. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-04-17s390/pci: do not modify function handlesSebastian Ott
Don't modify function handles to get a disabled handle - call clp_disable_fh. With this change we also do no longer deconfigure enabled functions. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-04-17s390/pci: debug device statesSebastian Ott
Use the debugfs to keep track of a pci function's status changes. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-04-16Merge branch 'pci/jiang-subdrivers' into nextBjorn Helgaas
* pci/jiang-subdrivers: PCI/ACPI: Remove support of ACPI PCI subdrivers PCI: acpiphp: Protect acpiphp data structures from concurrent updates PCI: acpiphp: Use normal list to simplify implementation PCI: acpiphp: Do not use ACPI PCI subdriver mechanism PCI: acpiphp: Convert acpiphp to be builtin only, not modular PCI/ACPI: Handle PCI slot devices when creating/destroying PCI buses x86/PCI: Implement pcibios_{add|remove}_bus() hooks ia64/PCI: Implement pcibios_{add|remove}_bus() hooks PCI/ACPI: Prepare stub functions to handle ACPI PCI (hotplug) slots PCI: Add pcibios hooks for adding and removing PCI buses PCI: acpiphp: Replace local macros with standard ACPI macros PCI: acpiphp: Remove all functions even if function 0 doesn't exist PCI: acpiphp: Use list_for_each_entry_safe() in acpiphp_sanitize_bus() PCI: Clean up usages of pci_bus->is_added PCI: When removing bus, always remove legacy files & unregister
2013-04-16PCI: acpiphp: Protect acpiphp data structures from concurrent updatesJiang Liu
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>
2013-04-16PCI: acpiphp: Use normal list to simplify implementationYijing Wang
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>
2013-04-15PCI: Use PCI_EXP_SLTCAP_PSN mask when extracting slot numberBjorn Helgaas
Use PCI_EXP_SLTCAP_PSN mask to make it easier to find where the Physical Slot Number is used. The Physical Slot Number is bits 31:19 of the Slot Capabilities Register, and slot_cap is a u32, so the mask is technically unnecessary, but it's helpful for human readers. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-04-15PCI: Remove unused variablesBjorn Helgaas
This fixes "set but not used" warnings found via "make W=1". Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>