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* device: Change dev_<level> logging functions to return voidJoe Perches2015-01-26
| | | | | | | | | | No caller or macro uses the return value so make all the functions return void. Compiled x86 allyesconfig and defconfig w/o CONFIG_PRINTK Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'driver-core-3.19-rc1' of ↵Linus Torvalds2014-12-14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core update from Greg KH: "Here's the set of driver core patches for 3.19-rc1. They are dominated by the removal of the .owner field in platform drivers. They touch a lot of files, but they are "simple" changes, just removing a line in a structure. Other than that, a few minor driver core and debugfs changes. There are some ath9k patches coming in through this tree that have been acked by the wireless maintainers as they relied on the debugfs changes. Everything has been in linux-next for a while" * tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits) Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries" fs: debugfs: add forward declaration for struct device type firmware class: Deletion of an unnecessary check before the function call "vunmap" firmware loader: fix hung task warning dump devcoredump: provide a one-way disable function device: Add dev_<level>_once variants ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries ath: use seq_file api for ath9k debugfs files debugfs: add helper function to create device related seq_file drivers/base: cacheinfo: remove noisy error boot message Revert "core: platform: add warning if driver has no owner" drivers: base: support cpu cache information interface to userspace via sysfs drivers: base: add cpu_device_create to support per-cpu devices topology: replace custom attribute macros with standard DEVICE_ATTR* cpumask: factor out show_cpumap into separate helper function driver core: Fix unbalanced device reference in drivers_probe driver core: fix race with userland in device_add() sysfs/kernfs: make read requests on pre-alloc files use the buffer. sysfs/kernfs: allow attributes to request write buffer be pre-allocated. fs: sysfs: return EGBIG on write if offset is larger than file size ...
| * driver core: fix race with userland in device_add()Sergey Klyaus2014-11-07
| | | | | | | | | | | | | | | | | | bus_add_device() should be called before devtmpfs_create_node(), so when userland application opens device from devtmpfs, it wouldn't get ENODEV from kernel, because device_add() wasn't completed. Signed-off-by: Sergey Klyaus <Sergey.Klyaus@Tune-IT.Ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs: driver core: Fix glue dir race condition by gdp_mutexYijing Wang2014-11-07
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a race condition when removing glue directory. It can be reproduced in following test: path 1: Add first child device device_add() get_device_parent() /*find parent from glue_dirs.list*/ list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry) if (k->parent == parent_kobj) { kobj = kobject_get(k); break; } .... class_dir_create_and_add() path2: Remove last child device under glue dir device_del() cleanup_device_parent() cleanup_glue_dir() kobject_put(glue_dir); If path2 has been called cleanup_glue_dir(), but not call kobject_put(glue_dir), the glue dir is still in parent's kset list. Meanwhile, path1 find the glue dir from the glue_dirs.list. Path2 may release glue dir before path1 call kobject_get(). So kernel will report the warning and bug_on. This is a "classic" problem we have of a kref in a list that can be found while the last instance could be removed at the same time. This patch reuse gdp_mutex to fix this race condition. The following calltrace is captured in kernel 3.4, but the latest kernel still has this bug. ----------------------------------------------------- <4>[ 3965.441471] WARNING: at ...include/linux/kref.h:41 kobject_get+0x33/0x40() <4>[ 3965.441474] Hardware name: Romley <4>[ 3965.441475] Modules linked in: isd_iop(O) isd_xda(O)... ... <4>[ 3965.441605] Call Trace: <4>[ 3965.441611] [<ffffffff8103717a>] warn_slowpath_common+0x7a/0xb0 <4>[ 3965.441615] [<ffffffff810371c5>] warn_slowpath_null+0x15/0x20 <4>[ 3965.441618] [<ffffffff81215963>] kobject_get+0x33/0x40 <4>[ 3965.441624] [<ffffffff812d1e45>] get_device_parent.isra.11+0x135/0x1f0 <4>[ 3965.441627] [<ffffffff812d22d4>] device_add+0xd4/0x6d0 <4>[ 3965.441631] [<ffffffff812d0dbc>] ? dev_set_name+0x3c/0x40 .... <2>[ 3965.441912] kernel BUG at ..../fs/sysfs/group.c:65! <4>[ 3965.441915] invalid opcode: 0000 [#1] SMP ... <4>[ 3965.686743] [<ffffffff811a677e>] sysfs_create_group+0xe/0x10 <4>[ 3965.686748] [<ffffffff810cfb04>] blk_trace_init_sysfs+0x14/0x20 <4>[ 3965.686753] [<ffffffff811fcabb>] blk_register_queue+0x3b/0x120 <4>[ 3965.686756] [<ffffffff812030bc>] add_disk+0x1cc/0x490 .... ------------------------------------------------------- Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Weng Meiling <wengmeiling.weng@huawei.com> Cc: <stable@vger.kernel.org> #3.4+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'iommu-updates-v3.18' of ↵Linus Torvalds2014-10-15
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull IOMMU updates from Joerg Roedel: "This pull-request includes: - change in the IOMMU-API to convert the former iommu_domain_capable function to just iommu_capable - various fixes in handling RMRR ranges for the VT-d driver (one fix requires a device driver core change which was acked by Greg KH) - the AMD IOMMU driver now assigns and deassigns complete alias groups to fix issues with devices using the wrong PCI request-id - MMU-401 support for the ARM SMMU driver - multi-master IOMMU group support for the ARM SMMU driver - various other small fixes all over the place" * tag 'iommu-updates-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (41 commits) iommu/vt-d: Work around broken RMRR firmware entries iommu/vt-d: Store bus information in RMRR PCI device path iommu/vt-d: Only remove domain when device is removed driver core: Add BUS_NOTIFY_REMOVED_DEVICE event iommu/amd: Fix devid mapping for ivrs_ioapic override iommu/irq_remapping: Fix the regression of hpet irq remapping iommu: Fix bus notifier breakage iommu/amd: Split init_iommu_group() from iommu_init_device() iommu: Rework iommu_group_get_for_pci_dev() iommu: Make of_device_id array const amd_iommu: do not dereference a NULL pointer address. iommu/omap: Remove omap_iommu unused owner field iommu: Remove iommu_domain_has_cap() API function IB/usnic: Convert to use new iommu_capable() API function vfio: Convert to use new iommu_capable() API function kvm: iommu: Convert to use new iommu_capable() API function iommu/tegra: Convert to iommu_capable() API function iommu/msm: Convert to iommu_capable() API function iommu/vt-d: Convert to iommu_capable() API function iommu/fsl: Convert to iommu_capable() API function ...
| * driver core: Add BUS_NOTIFY_REMOVED_DEVICE eventJoerg Roedel2014-10-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This event closes an important gap in the bus notifiers. There is already the BUS_NOTIFY_DEL_DEVICE event, but that is sent when the device is still bound to its device driver. This is too early for the IOMMU code to destroy any mappings for the device, as they might still be in use by the driver. The new BUS_NOTIFY_REMOVED_DEVICE event introduced with this patch closes this gap as it is sent when the device is already unbound from its device driver and almost completly removed from the driver core. With this event the IOMMU code can safely destroy any mappings and other data structures when a device is removed. Signed-off-by: Joerg Roedel <jroedel@suse.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Jerry Hoemann <jerry.hoemann@hp.com>
* | drivers/base: Fix length checks in create_syslog_header()/dev_vprintk_emit()Ben Hutchings2014-09-24
|/ | | | | | | | | | | | | | | | snprintf() returns the number of bytes that could have been written (excluding the null), not the actual number of bytes written. Given a long enough subsystem or device name, these functions will advance beyond the end of the on-stack buffer in dev_vprintk_exit(), resulting in an information leak or stack corruption. I don't know whether such a long name is currently possible. In case snprintf() returns a value >= the buffer size, do not add structured logging information. Also WARN if this happens, so we can fix the driver or increase the buffer size. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()Tejun Heo2014-04-16
| | | | | | | | | All device_schedule_callback_owner() users are converted to use device_remove_file_self(). Remove now unused {sysfs|device}_schedule_callback_owner(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "sysfs, driver-core: remove unused ↵Greg Kroah-Hartman2014-03-25
| | | | | | | | | | | | | | | | | {sysfs|device}_schedule_callback_owner()" This reverts commit d1ba277e79889085a2faec3b68b91ce89c63f888. As reported by Stephen, this patch breaks linux-next as a ppc patch suddenly (after 2 years) started using this old api call. So revert it for now, it will go away in 3.15-rc2 when we can change the PPC call to the new api. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Tejun Heo <tj@kernel.org> Cc: Stewart Smith <stewart@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "driver core: synchronize device shutdown"Roland Dreier2014-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 401097ea4b89846d66ac78f7f108d49c2e922d9c. The original changelog said: A patch series to make .shutdown execute asynchronously. Some drivers's shutdown can take a lot of time. The patches can help save some shutdown time. The patches use Arjan's async API. This patch: synchronize all tasks submitted by .shutdown However, I'm not able to find any evidence that any other patches from this series were applied, nor am I able to find any async tasks that are scheduled in a .shutdown context. On the other hand, we see occasional hangs on shutdown that appear to be caused by the async_synchronize_full() in device_shutdown() waiting forever for the async probing in sd if a SCSI disk shows up at just the wrong time — the system starts the probe, but begins shutting down and tears down too much of the SCSI driver to finish the probe. If we had any async shutdown tasks, I guess the right fix would be to create a "shutdown" async domain and have device_shutdown() only wait for that domain. But since there apparently are no async shutdown tasks, we can just revert the waiting. Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: unexport static function create_syslog_headerJiang Liu2014-02-15
| | | | | | | | Function create_syslog_header() is defined as static, so it should not be exported. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()Tejun Heo2014-02-07
| | | | | | | | | All device_schedule_callback_owner() users are converted to use device_remove_file_self(). Remove now unused {sysfs|device}_schedule_callback_owner(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappersTejun Heo2014-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sometimes it's necessary to implement a node which wants to delete nodes including itself. This isn't straightforward because of kernfs active reference. While a file operation is in progress, an active reference is held and kernfs_remove() waits for all such references to drain before completing. For a self-deleting node, this is a deadlock as kernfs_remove() ends up waiting for an active reference that itself is sitting on top of. This currently is worked around in the sysfs layer using sysfs_schedule_callback() which makes such removals asynchronous. While it works, it's rather cumbersome and inherently breaks synchronicity of the operation - the file operation which triggered the operation may complete before the removal is finished (or even started) and the removal may fail asynchronously. If a removal operation is immmediately followed by another operation which expects the specific name to be available (e.g. removal followed by rename onto the same name), there's no way to make the latter operation reliable. The thing is there's no inherent reason for this to be asynchrnous. All that's necessary to do this synchronous is a dedicated operation which drops its own active ref and deactivates self. This patch implements kernfs_remove_self() and its wrappers in sysfs and driver core. kernfs_remove_self() is to be called from one of the file operations, drops the active ref the task is holding, removes the self node, and restores active ref to the dead node so that the ref is balanced afterwards. __kernfs_remove() is updated so that it takes an early exit if the target node is already fully removed so that the active ref restored by kernfs_remove_self() after removal doesn't confuse the deactivation path. This makes implementing self-deleting nodes very easy. The normal removal path doesn't even need to be changed to use kernfs_remove_self() for the self-deleting node. The method can invoke kernfs_remove_self() on itself before proceeding the normal removal path. kernfs_remove() invoked on the node by the normal deletion path will simply be ignored. This will replace sysfs_schedule_callback(). A subtle feature of sysfs_schedule_callback() is that it collapses multiple invocations - even if multiple removals are triggered, the removal callback is run only once. An equivalent effect can be achieved by testing the return value of kernfs_remove_self() - only the one which gets %true return value should proceed with actual deletion. All other instances of kernfs_remove_self() will wait till the enclosing kernfs operation which invoked the winning instance of kernfs_remove_self() finishes and then return %false. This trivially makes all users of kernfs_remove_self() automatically show correct synchronous behavior even when there are multiple concurrent operations - all "echo 1 > delete" instances will finish only after the whole operation is completed by one of the instances. Note that manipulation of active ref is implemented in separate public functions - kernfs_[un]break_active_protection(). kernfs_remove_self() is the only user at the moment but this will be used to cater to more complex cases. v2: For !CONFIG_SYSFS, dummy version kernfs_remove_self() was missing and sysfs_remove_file_self() had incorrect return type. Fix it. Reported by kbuild test bot. v3: kernfs_[un]break_active_protection() separated out from kernfs_remove_self() and exposed as public API. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "kernfs, sysfs, driver-core: implement kernfs_remove_self() and its ↵Greg Kroah-Hartman2014-01-13
| | | | | | | | | | | | | | | | | | | wrappers" This reverts commit 1ae06819c77cff1ea2833c94f8c093fe8a5c79db. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "sysfs, driver-core: remove unused ↵Greg Kroah-Hartman2014-01-13
| | | | | | | | | | | | | | | | | {sysfs|device}_schedule_callback_owner()" This reverts commit d1ba277e79889085a2faec3b68b91ce89c63f888. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()Tejun Heo2014-01-10
| | | | | | | | | All device_schedule_callback_owner() users are converted to use device_remove_file_self(). Remove now unused {sysfs|device}_schedule_callback_owner(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappersTejun Heo2014-01-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sometimes it's necessary to implement a node which wants to delete nodes including itself. This isn't straightforward because of kernfs active reference. While a file operation is in progress, an active reference is held and kernfs_remove() waits for all such references to drain before completing. For a self-deleting node, this is a deadlock as kernfs_remove() ends up waiting for an active reference that itself is sitting on top of. This currently is worked around in the sysfs layer using sysfs_schedule_callback() which makes such removals asynchronous. While it works, it's rather cumbersome and inherently breaks synchronicity of the operation - the file operation which triggered the operation may complete before the removal is finished (or even started) and the removal may fail asynchronously. If a removal operation is immmediately followed by another operation which expects the specific name to be available (e.g. removal followed by rename onto the same name), there's no way to make the latter operation reliable. The thing is there's no inherent reason for this to be asynchrnous. All that's necessary to do this synchronous is a dedicated operation which drops its own active ref and deactivates self. This patch implements kernfs_remove_self() and its wrappers in sysfs and driver core. kernfs_remove_self() is to be called from one of the file operations, drops the active ref and deactivates using __kernfs_deactivate_self(), removes the self node, and restores active ref to the dead node using __kernfs_reactivate_self() so that the ref is balanced afterwards. __kernfs_remove() is updated so that it takes an early exit if the target node is already fully removed so that the active ref restored by kernfs_remove_self() after removal doesn't confuse the deactivation path. This makes implementing self-deleting nodes very easy. The normal removal path doesn't even need to be changed to use kernfs_remove_self() for the self-deleting node. The method can invoke kernfs_remove_self() on itself before proceeding the normal removal path. kernfs_remove() invoked on the node by the normal deletion path will simply be ignored. This will replace sysfs_schedule_callback(). A subtle feature of sysfs_schedule_callback() is that it collapses multiple invocations - even if multiple removals are triggered, the removal callback is run only once. An equivalent effect can be achieved by testing the return value of kernfs_remove_self() - only the one which gets %true return value should proceed with actual deletion. All other instances of kernfs_remove_self() will wait till the enclosing kernfs operation which invoked the winning instance of kernfs_remove_self() finishes and then return %false. This trivially makes all users of kernfs_remove_self() automatically show correct synchronous behavior even when there are multiple concurrent operations - all "echo 1 > delete" instances will finish only after the whole operation is completed by one of the instances. v2: For !CONFIG_SYSFS, dummy version kernfs_remove_self() was missing and sysfs_remove_file_self() had incorrect return type. Fix it. Reported by kbuild test bot. v3: Updated to use __kernfs_{de|re}activate_self(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Driver core: Fix device_add_attrs() error code pathRafael J. Wysocki2013-12-18
| | | | | | | | | | If the addition of dev_attr_online fails, device_add_attrs() should remove device attribute groups as well as type and class attribute groups before returning an error code. Make that happen. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: fix device_create() error pathDavid Herrmann2013-12-08
| | | | | | | | | | | | We call put_device() in the error path, which is fine for dev==NULL. However, in case kobject_set_name_vargs() fails, we have dev!=NULL but device_initialized() wasn't called, yet. Fix this by splitting device_register() into explicit calls to device_add() and an early call to device_initialize(). Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers/base/core.c: output device renaming messages with dev_dbg().ethan.zhao2013-10-16
| | | | | | | Replace pr_debug() with dev_dbg(). Signed-off-by: ethan.zhao <ethan.kernel@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: remove dev_bin_attrs from struct classGreg Kroah-Hartman2013-10-06
| | | | | | | | | No in-kernel code is now using this, they have all be converted over to using the bin_attrs support in attribute groups, so this field, and the code in the driver core that was creating/remove the binary files can be removed. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: remove dev_attrs from struct classGreg Kroah-Hartman2013-10-06
| | | | | | | Now that all in-kernel users of the dev_attrs field are converted to use dev_groups, we can safely remove dev_attrs from struct class. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge 3.12-rc3 into driver-core-nextGreg Kroah-Hartman2013-09-29
|\ | | | | | | | | | | | | We want the driver core and sysfs fixes in here to make merges and development easier. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * driver core : Fix use after free of dev->parent in device_shutdownBenson Leung2013-09-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The put_device(dev) at the bottom of the loop of device_shutdown may result in the dev being cleaned up. In device_create_release, the dev is kfreed. However, device_shutdown attempts to use the dev pointer again after put_device by referring to dev->parent. Copy the parent pointer instead to avoid this condition. This bug was found on Chromium OS's chromeos-3.8, which is based on v3.8.11. See bug report : https://code.google.com/p/chromium/issues/detail?id=297842 This can easily be reproduced when shutting down with hidraw devices that report battery condition. Two examples are the HP Bluetooth Mouse X4000b and the Apple Magic Mouse. For example, with the magic mouse : The dev in question is "hidraw0" dev->parent is "magicmouse" In the course of the shutdown for this device, the input event cleanup calls a put on hidraw0, decrementing its reference count. When we finally get to put_device(dev) in device_shutdown, kobject_cleanup is called and device_create_release does kfree(dev). dev->parent is no longer valid, and we may crash in put_device(dev->parent). This change should be applied on any kernel with this change : d1c6c030fcec6f860d9bb6c632a3ebe62e28440b Cc: stable@vger.kernel.org Signed-off-by: Benson Leung <bleung@chromium.org> Reviewed-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs: remove ktype->namespace() invocations in symlink codeTejun Heo2013-09-26
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | There's no reason for sysfs to be calling ktype->namespace(). It is backwards, obfuscates what's going on and unnecessarily tangles two separate layers. There are two places where symlink code calls ktype->namespace(). * sysfs_do_create_link_sd() calls it to find out the namespace tag of the target directory. Unless symlinking races with cross-namespace renaming, this equals @target_sd->s_ns. * sysfs_rename_link() uses it to find out the new namespace to rename to and the new namespace can be different from the existing one. The function is renamed to sysfs_rename_link_ns() with an explicit @ns argument and the ktype->namespace() invocation is shifted to the device layer. While this patch replaces ktype->namespace() invocation with the recorded result in @target_sd, this shouldn't result in any behvior difference. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'pm+acpi-3.12-rc1' of ↵Linus Torvalds2013-09-03
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management updates from Rafael Wysocki: 1) ACPI-based PCI hotplug (ACPIPHP) subsystem rework and introduction of Intel Thunderbolt support on systems that use ACPI for signalling Thunderbolt hotplug events. This also should make ACPIPHP work in some cases in which it was known to have problems. From Rafael J Wysocki, Mika Westerberg and Kirill A Shutemov. 2) ACPI core code cleanups and dock station support cleanups from Jiang Liu and Rafael J Wysocki. 3) Fixes for locking problems related to ACPI device hotplug from Rafael J Wysocki. 4) ACPICA update to version 20130725 includig fixes, cleanups, support for more than 256 GPEs per GPE block and a change to make the ACPI PM Timer optional (we've seen systems without the PM Timer in the field already). One of the fixes, related to the DeRefOf operator, is necessary to prevent some Windows 8 oriented AML from causing problems to happen. From Bob Moore, Lv Zheng, and Jung-uk Kim. 5) Removal of the old and long deprecated /proc/acpi/event interface and related driver changes from Thomas Renninger. 6) ACPI and Xen changes to make the reduced hardware sleep work with the latter from Ben Guthro. 7) ACPI video driver cleanups and a blacklist of systems that should not tell the BIOS that they are compatible with Windows 8 (or ACPI backlight and possibly other things will not work on them). From Felipe Contreras. 8) Assorted ACPI fixes and cleanups from Aaron Lu, Hanjun Guo, Kuppuswamy Sathyanarayanan, Lan Tianyu, Sachin Kamat, Tang Chen, Toshi Kani, and Wei Yongjun. 9) cpufreq ondemand governor target frequency selection change to reduce oscillations between min and max frequencies (essentially, it causes the governor to choose target frequencies proportional to load) from Stratos Karafotis. 10) cpufreq fixes allowing sysfs attributes file permissions to be preserved over suspend/resume cycles Srivatsa S Bhat. 11) Removal of Device Tree parsing for CPU device nodes from multiple cpufreq drivers that required some changes related to of_get_cpu_node() to be made in a few architectures and in the driver core. From Sudeep KarkadaNagesha. 12) cpufreq core fixes and cleanups related to mutual exclusion and driver module references from Viresh Kumar, Lukasz Majewski and Rafael J Wysocki. 13) Assorted cpufreq fixes and cleanups from Amit Daniel Kachhap, Bartlomiej Zolnierkiewicz, Hanjun Guo, Jingoo Han, Joseph Lo, Julia Lawall, Li Zhong, Mark Brown, Sascha Hauer, Stephen Boyd, Stratos Karafotis, and Viresh Kumar. 14) Fixes to prevent race conditions in coupled cpuidle from happening from Colin Cross. 15) cpuidle core fixes and cleanups from Daniel Lezcano and Tuukka Tikkanen. 16) Assorted cpuidle fixes and cleanups from Daniel Lezcano, Geert Uytterhoeven, Jingoo Han, Julia Lawall, Linus Walleij, and Sahara. 17) System sleep tracing changes from Todd E Brandt and Shuah Khan. 18) PNP subsystem conversion to using struct dev_pm_ops for power management from Shuah Khan. * tag 'pm+acpi-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (217 commits) cpufreq: Don't use smp_processor_id() in preemptible context cpuidle: coupled: fix race condition between pokes and safe state cpuidle: coupled: abort idle if pokes are pending cpuidle: coupled: disable interrupts after entering safe state ACPI / hotplug: Remove containers synchronously driver core / ACPI: Avoid device hot remove locking issues cpufreq: governor: Fix typos in comments cpufreq: governors: Remove duplicate check of target freq in supported range cpufreq: Fix timer/workqueue corruption due to double queueing ACPI / EC: Add ASUSTEK L4R to quirk list in order to validate ECDT ACPI / thermal: Add check of "_TZD" availability and evaluating result cpufreq: imx6q: Fix clock enable balance ACPI: blacklist win8 OSI for buggy laptops cpufreq: tegra: fix the wrong clock name cpuidle: Change struct menu_device field types cpuidle: Add a comment warning about possible overflow cpuidle: Fix variable domains in get_typical_interval() cpuidle: Fix menu_device->intervals type cpuidle: CodingStyle: Break up multiple assignments on single line cpuidle: Check called function parameter in get_typical_interval() ...
| * driver core / ACPI: Avoid device hot remove locking issuesRafael J. Wysocki2013-08-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | device_hotplug_lock is held around the acpi_bus_trim() call in acpi_scan_hot_remove() which generally removes devices (it removes ACPI device objects at least, but it may also remove "physical" device objects through .detach() callbacks of ACPI scan handlers). Thus, potentially, device sysfs attributes are removed under that lock and to remove those attributes it is necessary to hold the s_active references of their directory entries for writing. On the other hand, the execution of a .show() or .store() callback from a sysfs attribute is carried out with that attribute's s_active reference held for reading. Consequently, if any device sysfs attribute that may be removed from within acpi_scan_hot_remove() through acpi_bus_trim() has a .store() or .show() callback which acquires device_hotplug_lock, the execution of that callback may deadlock with the removal of the attribute. [Unfortunately, the "online" device attribute of CPUs and memory blocks is one of them.] To avoid such deadlocks, make all of the sysfs attribute callbacks that need to lock device hotplug, for example store_online(), use a special function, lock_device_hotplug_sysfs(), to lock device hotplug and return the result of that function immediately if it is not zero. This will cause the s_active reference of the directory entry in question to be released and the syscall to be restarted if device_hotplug_lock cannot be acquired. [show_online() actually doesn't need to lock device hotplug, but it is useful to serialize it with respect to device_offline() and device_online() for the same device (in case user space attempts to run them concurrently) which can be done with the help of device_lock().] Reported-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reported-and-tested-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Toshi Kani <toshi.kani@hp.com>
* | driver core: add #include <linux/sysfs.h> to core files.Greg Kroah-Hartman2013-08-27
| | | | | | | | | | | | | | This is needed to fix the build on sh systems. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | driver core: core: use DEVICE_ATTR_ROGreg Kroah-Hartman2013-08-23
| | | | | | | | | | | | | | Use DEVICE_ATTR_RO() instead of a "raw" __ATTR macro, making it easier to audit exactly what is going on with the sysfs files. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs.h: remove attr_name() macroGreg Kroah-Hartman2013-08-22
| | | | | | | | | | | | | | | | | | | | | | Gotta love a macro that doesn't reduce the typing you have to do. Also, only the driver core, and one network driver uses this. The driver core functions will be going away soon, and I'll convert the network driver soon to not need this as well, so delete it for now before anyone else gets some bright ideas and wants to use it. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs: add sysfs_create/remove_groups()Greg Kroah-Hartman2013-08-21
| | | | | | | | | | | | | | | | | | These functions are being open-coded in 3 different places in the driver core, and other driver subsystems will want to start doing this as well, so move it to the sysfs core to keep it all in one place, where we know it is written properly. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | drivers / base: Fix sysfs_deprecated_setup() __init attribute locationHanjun Guo2013-08-19
| | | | | | | | | | | | | | __init belongs after the return type on functions, not before it. Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | driver core: bus_type: add dev_groupsGreg Kroah-Hartman2013-08-12
| | | | | | | | | | | | | | | | | | | | | | attribute groups are much more flexible than just a list of attributes, due to their support for visibility of the attributes, and binary attributes. Add dev_groups to struct bus_type which should be used instead of dev_attrs. dev_attrs will be removed from the structure soon. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | driver core: replace strict_strto*() with kstrto*()Jingoo Han2013-07-26
| | | | | | | | | | | | | | | | | | The usage of strict_strto*() is not preferred, because strict_strto*() is obsolete. Thus, kstrto*() should be used. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | drivers:base:core: Moved sym export macros to respective functionsDavid Graham White2013-07-26
|/ | | | | | | | Moved 11 calls to the EXPORT_SYMBOL_GPL beneath their respective functions per checkpatch.pl warnings. Signed-off-by: David Graham White <dgwhite11@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: add default groups to struct classGreg Kroah-Hartman2013-07-16
| | | | | | | | | | | | | We should be using groups, not attribute lists, for classes to allow subdirectories, and soon, binary files. Groups are just more flexible overall, so add them. The dev_attrs list will go away after all in-kernel users are converted to use dev_groups. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: Introduce device_create_groupsGuenter Roeck2013-07-16
| | | | | | | | | | | | | device_create_groups lets callers create devices as well as associated sysfs attributes with a single call. This avoids race conditions seen if sysfs attributes on new devices are created later. [fixed up comment block placement and add checks for printk buffer formats - gregkh] Signed-off-by: Guenter Roeck <linux@roeck-us.net> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'pm+acpi-3.11-rc1' of ↵Linus Torvalds2013-07-03
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI updates from Rafael Wysocki: "This time the total number of ACPI commits is slightly greater than the number of cpufreq commits, but Viresh Kumar (who works on cpufreq) remains the most active patch submitter. To me, the most significant change is the addition of offline/online device operations to the driver core (with the Greg's blessing) and the related modifications of the ACPI core hotplug code. Next are the freezer updates from Colin Cross that should make the freezing of tasks a bit less heavy weight. We also have a couple of regression fixes, a number of fixes for issues that have not been identified as regressions, two new drivers and a bunch of cleanups all over. Highlights: - Hotplug changes to support graceful hot-removal failures. It sometimes is necessary to fail device hot-removal operations gracefully if they cannot be carried out completely. For example, if memory from a memory module being hot-removed has been allocated for the kernel's own use and cannot be moved elsewhere, it's desirable to fail the hot-removal operation in a graceful way rather than to crash the kernel, but currenty a success or a kernel crash are the only possible outcomes of an attempted memory hot-removal. Needless to say, that is not a very attractive alternative and it had to be addressed. However, in order to make it work for memory, I first had to make it work for CPUs and for this purpose I needed to modify the ACPI processor driver. It's been split into two parts, a resident one handling the low-level initialization/cleanup and a modular one playing the actual driver's role (but it binds to the CPU system device objects rather than to the ACPI device objects representing processors). That's been sort of like a live brain surgery on a patient who's riding a bike. So this is a little scary, but since we found and fixed a couple of regressions it caused to happen during the early linux-next testing (a month ago), nobody has complained. As a bonus we remove some duplicated ACPI hotplug code, because the ACPI-based CPU hotplug is now going to use the common ACPI hotplug code. - Lighter weight freezing of tasks. These changes from Colin Cross and Mandeep Singh Baines are targeted at making the freezing of tasks a bit less heavy weight operation. They reduce the number of tasks woken up every time during the freezing, by using the observation that the freezer simply doesn't need to wake up some of them and wait for them all to call refrigerator(). The time needed for the freezer to decide to report a failure is reduced too. Also reintroduced is the check causing a lockdep warining to trigger when try_to_freeze() is called with locks held (which is generally unsafe and shouldn't happen). - cpufreq updates First off, a commit from Srivatsa S Bhat fixes a resume regression introduced during the 3.10 cycle causing some cpufreq sysfs attributes to return wrong values to user space after resume. The fix is kind of fresh, but also it's pretty obvious once Srivatsa has identified the root cause. Second, we have a new freqdomain_cpus sysfs attribute for the acpi-cpufreq driver to provide information previously available via related_cpus. From Lan Tianyu. Finally, we fix a number of issues, mostly related to the CPUFREQ_POSTCHANGE notifier and cpufreq Kconfig options and clean up some code. The majority of changes from Viresh Kumar with bits from Jacob Shin, Heiko Stübner, Xiaoguang Chen, Ezequiel Garcia, Arnd Bergmann, and Tang Yuantian. - ACPICA update A usual bunch of updates from the ACPICA upstream. During the 3.4 cycle we introduced support for ACPI 5 extended sleep registers, but they are only supposed to be used if the HW-reduced mode bit is set in the FADT flags and the code attempted to use them without checking that bit. That caused suspend/resume regressions to happen on some systems. Fix from Lv Zheng causes those registers to be used only if the HW-reduced mode bit is set. Apart from this some other ACPICA bugs are fixed and code cleanups are made by Bob Moore, Tomasz Nowicki, Lv Zheng, Chao Guan, and Zhang Rui. - cpuidle updates New driver for Xilinx Zynq processors is added by Michal Simek. Multidriver support simplification, addition of some missing kerneldoc comments and Kconfig-related fixes come from Daniel Lezcano. - ACPI power management updates Changes to make suspend/resume work correctly in Xen guests from Konrad Rzeszutek Wilk, sparse warning fix from Fengguang Wu and cleanups and fixes of the ACPI device power state selection routine. - ACPI documentation updates Some previously missing pieces of ACPI documentation are added by Lv Zheng and Aaron Lu (hopefully, that will help people to uderstand how the ACPI subsystem works) and one outdated doc is updated by Hanjun Guo. - Assorted ACPI updates We finally nailed down the IA-64 issue that was the reason for reverting commit 9f29ab11ddbf ("ACPI / scan: do not match drivers against objects having scan handlers"), so we can fix it and move the ACPI scan handler check added to the ACPI video driver back to the core. A mechanism for adding CMOS RTC address space handlers is introduced by Lan Tianyu to allow some EC-related breakage to be fixed on some systems. A spec-compliant implementation of acpi_os_get_timer() is added by Mika Westerberg. The evaluation of _STA is added to do_acpi_find_child() to avoid situations in which a pointer to a disabled device object is returned instead of an enabled one with the same _ADR value. From Jeff Wu. Intel BayTrail PCH (Platform Controller Hub) support is added to the ACPI driver for Intel Low-Power Subsystems (LPSS) and that driver is modified to work around a couple of known BIOS issues. Changes from Mika Westerberg and Heikki Krogerus. The EC driver is fixed by Vasiliy Kulikov to use get_user() and put_user() instead of dereferencing user space pointers blindly. Code cleanups are made by Bjorn Helgaas, Nicholas Mazzuca and Toshi Kani. - Assorted power management updates The "runtime idle" helper routine is changed to take the return values of the callbacks executed by it into account and to call rpm_suspend() if they return 0, which allows us to reduce the overall code bloat a bit (by dropping some code that's not necessary any more after that modification). The runtime PM documentation is updated by Alan Stern (to reflect the "runtime idle" behavior change). New trace points for PM QoS are added by Sahara (<keun-o.park@windriver.com>). PM QoS documentation is updated by Lan Tianyu. Code cleanups are made and minor issues are addressed by Bernie Thompson, Bjorn Helgaas, Julius Werner, and Shuah Khan. - devfreq updates New driver for the Exynos5-bus device from Abhilash Kesavan. Minor cleanups, fixes and MAINTAINERS update from MyungJoo Ham, Abhilash Kesavan, Paul Bolle, Rajagopal Venkat, and Wei Yongjun. - OMAP power management updates Adaptive Voltage Scaling (AVS) SmartReflex voltage control driver updates from Andrii Tseglytskyi and Nishanth Menon." * tag 'pm+acpi-3.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (162 commits) cpufreq: Fix cpufreq regression after suspend/resume ACPI / PM: Fix possible NULL pointer deref in acpi_pm_device_sleep_state() PM / Sleep: Warn about system time after resume with pm_trace cpufreq: don't leave stale policy pointer in cdbs->cur_policy acpi-cpufreq: Add new sysfs attribute freqdomain_cpus cpufreq: make sure frequency transitions are serialized ACPI: implement acpi_os_get_timer() according the spec ACPI / EC: Add HP Folio 13 to ec_dmi_table in order to skip DSDT scan ACPI: Add CMOS RTC Operation Region handler support ACPI / processor: Drop unused variable from processor_perflib.c cpufreq: tegra: call CPUFREQ_POSTCHANGE notfier in error cases cpufreq: s3c64xx: call CPUFREQ_POSTCHANGE notfier in error cases cpufreq: omap: call CPUFREQ_POSTCHANGE notfier in error cases cpufreq: imx6q: call CPUFREQ_POSTCHANGE notfier in error cases cpufreq: exynos: call CPUFREQ_POSTCHANGE notfier in error cases cpufreq: dbx500: call CPUFREQ_POSTCHANGE notfier in error cases cpufreq: davinci: call CPUFREQ_POSTCHANGE notfier in error cases cpufreq: arm-big-little: call CPUFREQ_POSTCHANGE notfier in error cases cpufreq: powernow-k8: call CPUFREQ_POSTCHANGE notfier in error cases cpufreq: pcc: call CPUFREQ_POSTCHANGE notfier in error cases ...
| * Merge branch 'acpi-hotplug'Rafael J. Wysocki2013-06-28
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * acpi-hotplug: ACPI: Do not use CONFIG_ACPI_HOTPLUG_MEMORY_MODULE ACPI / cpufreq: Add ACPI processor device IDs to acpi-cpufreq Memory hotplug: Move alternative function definitions to header ACPI / processor: Fix potential NULL pointer dereference in acpi_processor_add() Memory hotplug / ACPI: Simplify memory removal ACPI / scan: Add second pass of companion offlining to hot-remove code Driver core / MM: Drop offline_memory_block() ACPI / processor: Pass processor object handle to acpi_bind_one() ACPI: Drop removal_type field from struct acpi_device Driver core / memory: Simplify __memory_block_change_state() ACPI / processor: Initialize per_cpu(processors, pr->id) properly CPU: Fix sysfs cpu/online of offlined CPUs Driver core: Introduce offline/online callbacks for memory blocks ACPI / memhotplug: Bind removable memory blocks to ACPI device nodes ACPI / processor: Use common hotplug infrastructure ACPI / hotplug: Use device offline/online for graceful hot-removal Driver core: Use generic offline/online for CPU offline/online Driver core: Add offline/online device operations
| | * Driver core: Add offline/online device operationsRafael J. Wysocki2013-05-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In some cases, graceful hot-removal of devices is not possible, although in principle the devices in question support hotplug. For example, that may happen for the last CPU in the system or for memory modules holding kernel memory. In those cases it is nice to be able to check if the given device can be gracefully hot-removed before triggering a removal procedure that cannot be aborted or reversed. Unfortunately, however, the kernel currently doesn't provide any support for that. To address that deficiency, introduce support for offline and online operations that can be performed on devices, respectively, before a hot-removal and in case when it is necessary (or convenient) to put a device back online after a successful offline (that has not been followed by removal). The idea is that the offline will fail whenever the given device cannot be gracefully removed from the system and it will not be allowed to use the device after a successful offline (until a subsequent online) in analogy with the existing CPU offline/online mechanism. For now, the offline and online operations are introduced at the bus type level, as that should be sufficient for the most urgent use cases (CPUs and memory modules). In the future, however, the approach may be extended to cover some more complicated device offline/online scenarios involving device drivers etc. The lock_device_hotplug() and unlock_device_hotplug() functions are introduced because subsequent patches need to put larger pieces of code under device_hotplug_lock to prevent race conditions between device offline and removal from happening. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Toshi Kani <toshi.kani@hp.com>
* | | Documentation: Tidy up some drivers/base/core.c kerneldoc content.Robert P. J. Day2013-06-03
| | | | | | | | | | | | | | | | | | | | | | | | Standardize the indentation, and switch the order of a couple kerneldoc entries to match the parameter order. No functional change. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | Merge 3.10-rc3 into driver-core-nextGreg Kroah-Hartman2013-05-26
|\| | | | | | | | | | | | | | | | | We want the changes here. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | driver core: print sysfs attribute name when warning about bogus permissionsdyoung@redhat.com2013-05-21
| |/ | | | | | | | | | | | | | | Make it obvious to see what attribute is using bogus permissions. Signed-off-by: Dave Young <dyoung@redhat.com> Acked-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* / base/core.c: improve comment of the function device_find_child()Federico Vaga2013-05-21
|/ | | | | Signed-off-by: Federico Vaga <federico.vaga@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branch 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds2013-04-29
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull workqueue updates from Tejun Heo: "A lot of activities on workqueue side this time. The changes achieve the followings. - WQ_UNBOUND workqueues - the workqueues which are per-cpu - are updated to be able to interface with multiple backend worker pools. This involved a lot of churning but the end result seems actually neater as unbound workqueues are now a lot closer to per-cpu ones. - The ability to interface with multiple backend worker pools are used to implement unbound workqueues with custom attributes. Currently the supported attributes are the nice level and CPU affinity. It may be expanded to include cgroup association in future. The attributes can be specified either by calling apply_workqueue_attrs() or through /sys/bus/workqueue/WQ_NAME/* if the workqueue in question is exported through sysfs. The backend worker pools are keyed by the actual attributes and shared by any workqueues which share the same attributes. When attributes of a workqueue are changed, the workqueue binds to the worker pool with the specified attributes while leaving the work items which are already executing in its previous worker pools alone. This allows converting custom worker pool implementations which want worker attribute tuning to use workqueues. The writeback pool is already converted in block tree and there are a couple others are likely to follow including btrfs io workers. - WQ_UNBOUND's ability to bind to multiple worker pools is also used to make it NUMA-aware. Because there's no association between work item issuer and the specific worker assigned to execute it, before this change, using unbound workqueue led to unnecessary cross-node bouncing and it couldn't be helped by autonuma as it requires tasks to have implicit node affinity and workers are assigned randomly. After these changes, an unbound workqueue now binds to multiple NUMA-affine worker pools so that queued work items are executed in the same node. This is turned on by default but can be disabled system-wide or for individual workqueues. Crypto was requesting NUMA affinity as encrypting data across different nodes can contribute noticeable overhead and doing it per-cpu was too limiting for certain cases and IO throughput could be bottlenecked by one CPU being fully occupied while others have idle cycles. While the new features required a lot of changes including restructuring locking, it didn't complicate the execution paths much. The unbound workqueue handling is now closer to per-cpu ones and the new features are implemented by simply associating a workqueue with different sets of backend worker pools without changing queue, execution or flush paths. As such, even though the amount of change is very high, I feel relatively safe in that it isn't likely to cause subtle issues with basic correctness of work item execution and handling. If something is wrong, it's likely to show up as being associated with worker pools with the wrong attributes or OOPS while workqueue attributes are being changed or during CPU hotplug. While this creates more backend worker pools, it doesn't add too many more workers unless, of course, there are many workqueues with unique combinations of attributes. Assuming everything else is the same, NUMA awareness costs an extra worker pool per NUMA node with online CPUs. There are also a couple things which are being routed outside the workqueue tree. - block tree pulled in workqueue for-3.10 so that writeback worker pool can be converted to unbound workqueue with sysfs control exposed. This simplifies the code, makes writeback workers NUMA-aware and allows tuning nice level and CPU affinity via sysfs. - The conversion to workqueue means that there's no 1:1 association between a specific worker, which makes writeback folks unhappy as they want to be able to tell which filesystem caused a problem from backtrace on systems with many filesystems mounted. This is resolved by allowing work items to set debug info string which is printed when the task is dumped. As this change involves unifying implementations of dump_stack() and friends in arch codes, it's being routed through Andrew's -mm tree." * 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (84 commits) workqueue: use kmem_cache_free() instead of kfree() workqueue: avoid false negative WARN_ON() in destroy_workqueue() workqueue: update sysfs interface to reflect NUMA awareness and a kernel param to disable NUMA affinity workqueue: implement NUMA affinity for unbound workqueues workqueue: introduce put_pwq_unlocked() workqueue: introduce numa_pwq_tbl_install() workqueue: use NUMA-aware allocation for pool_workqueues workqueue: break init_and_link_pwq() into two functions and introduce alloc_unbound_pwq() workqueue: map an unbound workqueues to multiple per-node pool_workqueues workqueue: move hot fields of workqueue_struct to the end workqueue: make workqueue->name[] fixed len workqueue: add workqueue->unbound_attrs workqueue: determine NUMA node of workers accourding to the allowed cpumask workqueue: drop 'H' from kworker names of unbound worker pools workqueue: add wq_numa_tbl_len and wq_numa_possible_cpumask[] workqueue: move pwq_pool_locking outside of get/put_unbound_pool() workqueue: fix memory leak in apply_workqueue_attrs() workqueue: fix unbound workqueue attrs hashing / comparison workqueue: fix race condition in unbound workqueue free path workqueue: remove pwq_lock which is no longer used ...
| * driver/base: implement subsys_virtual_register()Tejun Heo2013-03-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kay tells me the most appropriate place to expose workqueues to userland would be /sys/devices/virtual/workqueues/WQ_NAME which is symlinked to /sys/bus/workqueue/devices/WQ_NAME and that we're lacking a way to do that outside of driver core as virtual_device_parent() isn't exported and there's no inteface to conveniently create a virtual subsystem. This patch implements subsys_virtual_register() by factoring out subsys_register() from subsys_system_register() and using it with virtual_device_parent() as the origin directory. It's identical to subsys_system_register() other than the origin directory but we aren't gonna restrict the device names which should be used under it. This will be used to expose workqueue attributes to userland. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Kay Sievers <kay.sievers@vrfy.org>
* | driver core: handle user namespaces properly with the uid/gid devtmpfs changeGreg Kroah-Hartman2013-04-11
| | | | | | | | | | | | | | | | | | | | | | | | | | Now that devtmpfs is caring about uid/gid, we need to use the correct internal types so users who have USER_NS enabled will have things work properly for them. Thanks to Eric for pointing this out, and the patch review. Reported-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | driver core: add uid and gid to devtmpfsKay Sievers2013-04-08
| | | | | | | | | | | | | | | | | | | | | | | | Some drivers want to tell userspace what uid and gid should be used for their device nodes, so allow that information to percolate through the driver core to userspace in order to make this happen. This means that some systems (i.e. Android and friends) will not need to even run a udev-like daemon for their device node manager and can just rely in devtmpfs fully, reducing their footprint even more. Signed-off-by: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | base: core: WARN() about bogus permissions on device attributesFelipe Balbi2013-03-15
|/ | | | | | | | | | | Whenever a struct device_attribute is registered with mismatched permissions - read permission without a show routine or write permission without store routine - we will issue a big warning so we catch those early enough. Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver-core: constify data for class_find_device()Michał Mirosław2013-02-06
| | | | | | | | | | | | | | | | | | All in-kernel users of class_find_device() don't really need mutable data for match callback. In two places (kernel/power/suspend_test.c, drivers/scsi/osd/osd_uld.c) this patch changes match callbacks to use const search data. The const is propagated to rtc_class_open() and power_supply_get_by_name() parameters. Note that there's a dev reference leak in suspend_test.c that's not touched in this patch. Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>