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 drv_groups to struct bus_type which should be used
instead of drv_attrs.

drv_attrs will be removed from the structure soon.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NGuenter Roeck <linux@roeck-us.net>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NGuenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make it easier to create attributes without having to always audit the
mode settings.
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes the below 3 warnings running "make htmldocs",
by adding descriptions for recently added structure members:

DOCPROC Documentation/DocBook/device-drivers.xml
Warning(/work/git.free-electrons.com/users/michael-opdenacker/linux//include/linux/device.h:116): No description found for parameter 'lock_key'
Warning(/work/git.free-electrons.com/users/michael-opdenacker/linux//include/linux/device.h:723): No description found for parameter 'cma_area'
Warning(/work/git.free-electrons.com/users/michael-opdenacker/linux//include/linux/device.h:723): No description found for parameter 'iommu_group'

Don't hesitate to propose better descriptions!
Signed-off-by: NMichael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NToshi Kani <toshi.kani@hp.com>

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: NEric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NKay Sievers <kay@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

ca22e56d (driver-core: implement 'sysdev' functionality for regular
devices and buses) has introduced bus_register macro with a static
key to distinguish different subsys mutex classes.

This however doesn't work for different subsys which use a common
registering function. One example is subsys_system_register (and
mce_device and cpu_device).

In the end this leads to the following lockdep splat:
[  207.271924] ======================================================
[  207.271932] [ INFO: possible circular locking dependency detected ]
[  207.271942] 3.9.0-rc1-0.7-default+ #34 Not tainted
[  207.271948] -------------------------------------------------------
[  207.271957] bash/10493 is trying to acquire lock:
[  207.271963]  (subsys mutex){+.+.+.}, at: [<ffffffff8134af27>] bus_remove_device+0x37/0x1c0
[  207.271987]
[  207.271987] but task is already holding lock:
[  207.271995]  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff81046ccf>] cpu_hotplug_begin+0x2f/0x60
[  207.272012]
[  207.272012] which lock already depends on the new lock.
[  207.272012]
[  207.272023]
[  207.272023] the existing dependency chain (in reverse order) is:
[  207.272033]
[  207.272033] -> #4 (cpu_hotplug.lock){+.+.+.}:
[  207.272044]        [<ffffffff810ae329>] lock_acquire+0xe9/0x120
[  207.272056]        [<ffffffff814ad807>] mutex_lock_nested+0x37/0x360
[  207.272069]        [<ffffffff81046ba9>] get_online_cpus+0x29/0x40
[  207.272082]        [<ffffffff81185210>] drain_all_stock+0x30/0x150
[  207.272094]        [<ffffffff811853da>] mem_cgroup_reclaim+0xaa/0xe0
[  207.272104]        [<ffffffff8118775e>] __mem_cgroup_try_charge+0x51e/0xcf0
[  207.272114]        [<ffffffff81188486>] mem_cgroup_charge_common+0x36/0x60
[  207.272125]        [<ffffffff811884da>] mem_cgroup_newpage_charge+0x2a/0x30
[  207.272135]        [<ffffffff81150531>] do_wp_page+0x231/0x830
[  207.272147]        [<ffffffff8115151e>] handle_pte_fault+0x19e/0x8d0
[  207.272157]        [<ffffffff81151da8>] handle_mm_fault+0x158/0x1e0
[  207.272166]        [<ffffffff814b6153>] do_page_fault+0x2a3/0x4e0
[  207.272178]        [<ffffffff814b2578>] page_fault+0x28/0x30
[  207.272189]
[  207.272189] -> #3 (&mm->mmap_sem){++++++}:
[  207.272199]        [<ffffffff810ae329>] lock_acquire+0xe9/0x120
[  207.272208]        [<ffffffff8114c5ad>] might_fault+0x6d/0x90
[  207.272218]        [<ffffffff811a11e3>] filldir64+0xb3/0x120
[  207.272229]        [<ffffffffa013fc19>] call_filldir+0x89/0x130 [ext3]
[  207.272248]        [<ffffffffa0140377>] ext3_readdir+0x6b7/0x7e0 [ext3]
[  207.272263]        [<ffffffff811a1519>] vfs_readdir+0xa9/0xc0
[  207.272273]        [<ffffffff811a15cb>] sys_getdents64+0x9b/0x110
[  207.272284]        [<ffffffff814bb599>] system_call_fastpath+0x16/0x1b
[  207.272296]
[  207.272296] -> #2 (&type->i_mutex_dir_key#3){+.+.+.}:
[  207.272309]        [<ffffffff810ae329>] lock_acquire+0xe9/0x120
[  207.272319]        [<ffffffff814ad807>] mutex_lock_nested+0x37/0x360
[  207.272329]        [<ffffffff8119c254>] link_path_walk+0x6f4/0x9a0
[  207.272339]        [<ffffffff8119e7fa>] path_openat+0xba/0x470
[  207.272349]        [<ffffffff8119ecf8>] do_filp_open+0x48/0xa0
[  207.272358]        [<ffffffff8118d81c>] file_open_name+0xdc/0x110
[  207.272369]        [<ffffffff8118d885>] filp_open+0x35/0x40
[  207.272378]        [<ffffffff8135c76e>] _request_firmware+0x52e/0xb20
[  207.272389]        [<ffffffff8135cdd6>] request_firmware+0x16/0x20
[  207.272399]        [<ffffffffa03bdb91>] request_microcode_fw+0x61/0xd0 [microcode]
[  207.272416]        [<ffffffffa03bd554>] microcode_init_cpu+0x104/0x150 [microcode]
[  207.272431]        [<ffffffffa03bd61c>] mc_device_add+0x7c/0xb0 [microcode]
[  207.272444]        [<ffffffff8134a419>] subsys_interface_register+0xc9/0x100
[  207.272457]        [<ffffffffa04fc0f4>] 0xffffffffa04fc0f4
[  207.272472]        [<ffffffff81000202>] do_one_initcall+0x42/0x180
[  207.272485]        [<ffffffff810bbeff>] load_module+0x19df/0x1b70
[  207.272499]        [<ffffffff810bc376>] sys_init_module+0xe6/0x130
[  207.272511]        [<ffffffff814bb599>] system_call_fastpath+0x16/0x1b
[  207.272523]
[  207.272523] -> #1 (umhelper_sem){++++.+}:
[  207.272537]        [<ffffffff810ae329>] lock_acquire+0xe9/0x120
[  207.272548]        [<ffffffff814ae9c4>] down_read+0x34/0x50
[  207.272559]        [<ffffffff81062bff>] usermodehelper_read_trylock+0x4f/0x100
[  207.272575]        [<ffffffff8135c7dd>] _request_firmware+0x59d/0xb20
[  207.272587]        [<ffffffff8135cdd6>] request_firmware+0x16/0x20
[  207.272599]        [<ffffffffa03bdb91>] request_microcode_fw+0x61/0xd0 [microcode]
[  207.272613]        [<ffffffffa03bd554>] microcode_init_cpu+0x104/0x150 [microcode]
[  207.272627]        [<ffffffffa03bd61c>] mc_device_add+0x7c/0xb0 [microcode]
[  207.272641]        [<ffffffff8134a419>] subsys_interface_register+0xc9/0x100
[  207.272654]        [<ffffffffa04fc0f4>] 0xffffffffa04fc0f4
[  207.272666]        [<ffffffff81000202>] do_one_initcall+0x42/0x180
[  207.272678]        [<ffffffff810bbeff>] load_module+0x19df/0x1b70
[  207.272690]        [<ffffffff810bc376>] sys_init_module+0xe6/0x130
[  207.272702]        [<ffffffff814bb599>] system_call_fastpath+0x16/0x1b
[  207.272715]
[  207.272715] -> #0 (subsys mutex){+.+.+.}:
[  207.272729]        [<ffffffff810ae002>] __lock_acquire+0x13b2/0x15f0
[  207.272740]        [<ffffffff810ae329>] lock_acquire+0xe9/0x120
[  207.272751]        [<ffffffff814ad807>] mutex_lock_nested+0x37/0x360
[  207.272763]        [<ffffffff8134af27>] bus_remove_device+0x37/0x1c0
[  207.272775]        [<ffffffff81349114>] device_del+0x134/0x1f0
[  207.272786]        [<ffffffff813491f2>] device_unregister+0x22/0x60
[  207.272798]        [<ffffffff814a24ea>] mce_cpu_callback+0x15e/0x1ad
[  207.272812]        [<ffffffff814b6402>] notifier_call_chain+0x72/0x130
[  207.272824]        [<ffffffff81073d6e>] __raw_notifier_call_chain+0xe/0x10
[  207.272839]        [<ffffffff81498f76>] _cpu_down+0x1d6/0x350
[  207.272851]        [<ffffffff81499130>] cpu_down+0x40/0x60
[  207.272862]        [<ffffffff8149cc55>] store_online+0x75/0xe0
[  207.272874]        [<ffffffff813474a0>] dev_attr_store+0x20/0x30
[  207.272886]        [<ffffffff812090d9>] sysfs_write_file+0xd9/0x150
[  207.272900]        [<ffffffff8118e10b>] vfs_write+0xcb/0x130
[  207.272911]        [<ffffffff8118e924>] sys_write+0x64/0xa0
[  207.272923]        [<ffffffff814bb599>] system_call_fastpath+0x16/0x1b
[  207.272936]
[  207.272936] other info that might help us debug this:
[  207.272936]
[  207.272952] Chain exists of:
[  207.272952]   subsys mutex --> &mm->mmap_sem --> cpu_hotplug.lock
[  207.272952]
[  207.272973]  Possible unsafe locking scenario:
[  207.272973]
[  207.272984]        CPU0                    CPU1
[  207.272992]        ----                    ----
[  207.273000]   lock(cpu_hotplug.lock);
[  207.273009]                                lock(&mm->mmap_sem);
[  207.273020]                                lock(cpu_hotplug.lock);
[  207.273031]   lock(subsys mutex);
[  207.273040]
[  207.273040]  *** DEADLOCK ***
[  207.273040]
[  207.273055] 5 locks held by bash/10493:
[  207.273062]  #0:  (&buffer->mutex){+.+.+.}, at: [<ffffffff81209049>] sysfs_write_file+0x49/0x150
[  207.273080]  #1:  (s_active#150){.+.+.+}, at: [<ffffffff812090c2>] sysfs_write_file+0xc2/0x150
[  207.273099]  #2:  (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff81027557>] cpu_hotplug_driver_lock+0x17/0x20
[  207.273121]  #3:  (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff8149911c>] cpu_down+0x2c/0x60
[  207.273140]  #4:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff81046ccf>] cpu_hotplug_begin+0x2f/0x60
[  207.273158]
[  207.273158] stack backtrace:
[  207.273170] Pid: 10493, comm: bash Not tainted 3.9.0-rc1-0.7-default+ #34
[  207.273180] Call Trace:
[  207.273192]  [<ffffffff810ab373>] print_circular_bug+0x223/0x310
[  207.273204]  [<ffffffff810ae002>] __lock_acquire+0x13b2/0x15f0
[  207.273216]  [<ffffffff812086b0>] ? sysfs_hash_and_remove+0x60/0xc0
[  207.273227]  [<ffffffff810ae329>] lock_acquire+0xe9/0x120
[  207.273239]  [<ffffffff8134af27>] ? bus_remove_device+0x37/0x1c0
[  207.273251]  [<ffffffff814ad807>] mutex_lock_nested+0x37/0x360
[  207.273263]  [<ffffffff8134af27>] ? bus_remove_device+0x37/0x1c0
[  207.273274]  [<ffffffff812086b0>] ? sysfs_hash_and_remove+0x60/0xc0
[  207.273286]  [<ffffffff8134af27>] bus_remove_device+0x37/0x1c0
[  207.273298]  [<ffffffff81349114>] device_del+0x134/0x1f0
[  207.273309]  [<ffffffff813491f2>] device_unregister+0x22/0x60
[  207.273321]  [<ffffffff814a24ea>] mce_cpu_callback+0x15e/0x1ad
[  207.273332]  [<ffffffff814b6402>] notifier_call_chain+0x72/0x130
[  207.273344]  [<ffffffff81073d6e>] __raw_notifier_call_chain+0xe/0x10
[  207.273356]  [<ffffffff81498f76>] _cpu_down+0x1d6/0x350
[  207.273368]  [<ffffffff81027557>] ? cpu_hotplug_driver_lock+0x17/0x20
[  207.273380]  [<ffffffff81499130>] cpu_down+0x40/0x60
[  207.273391]  [<ffffffff8149cc55>] store_online+0x75/0xe0
[  207.273402]  [<ffffffff813474a0>] dev_attr_store+0x20/0x30
[  207.273413]  [<ffffffff812090d9>] sysfs_write_file+0xd9/0x150
[  207.273425]  [<ffffffff8118e10b>] vfs_write+0xcb/0x130
[  207.273436]  [<ffffffff8118e924>] sys_write+0x64/0xa0
[  207.273447]  [<ffffffff814bb599>] system_call_fastpath+0x16/0x1b

Which reports a false possitive deadlock because it sees:
1) load_module -> subsys_interface_register -> mc_deveice_add (*) -> subsys->p->mutex -> link_path_walk -> lookup_slow -> i_mutex
2) sys_write -> _cpu_down -> cpu_hotplug_begin -> cpu_hotplug.lock -> mce_cpu_callback -> mce_device_remove(**) -> device_unregister -> bus_remove_device -> subsys mutex
3) vfs_readdir -> i_mutex -> filldir64 -> might_fault -> might_lock_read(mmap_sem) -> page_fault -> mmap_sem -> drain_all_stock -> cpu_hotplug.lock

but
1) takes cpu_subsys subsys (*) but 2) takes mce_device subsys (**) so
the deadlock is not possible AFAICS.

The fix is quite simple. We can pull the key inside bus_type structure
because they are defined per device so the pointer will be unique as
well. bus_register doesn't need to be a macro anymore so change it
to the inline. We could get rid of __bus_register as there is no other
caller but maybe somebody will want to use a different key so keep it
around for now.
Reported-by: NLi Zefan <lizefan@huawei.com>
Signed-off-by: NMichal Hocko <mhocko@suse.cz>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NTejun Heo <tj@kernel.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>

Sometimes drivers need to execute one-off actions in their error handling
or device teardown paths. An example would be toggling a GPIO line to
reset the controlled device into predefined state.

To allow performing such actions when using managed resources let's allow
adding them to stack/group of devres resources.
Acked-by: NTejun Heo <tj@kernel.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

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: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This makes the device core auto-grab the pinctrl handle and set
the "default" (PINCTRL_STATE_DEFAULT) state for every device
that is present in the device model right before probe. This will
account for the lion's share of embedded silicon devcies.

A modification of the semantics for pinctrl_get() is also done:
previously if the pinctrl handle for a certain device was already
taken, the pinctrl core would return an error. Now, since the
core may have already default-grabbed the handle and set its
state to "default", if the handle was already taken, this will
be disregarded and the located, previously instanitated handle
will be returned to the caller.

This way all code in drivers explicitly requesting their pinctrl
handlers will still be functional, and drivers that want to
explicitly retrieve and switch their handles can still do that.
But if the desired functionality is just boilerplate of this
type in the probe() function:

struct pinctrl  *p;

p = devm_pinctrl_get_select_default(&dev);
if (IS_ERR(p)) {
   if (PTR_ERR(p) == -EPROBE_DEFER)
        return -EPROBE_DEFER;
        dev_warn(&dev, "no pinctrl handle\n");
}

The discussion began with the addition of such boilerplate
to the omap4 keypad driver:
http://marc.info/?l=linux-input&m=135091157719300&w=2

A previous approach using notifiers was discussed:
http://marc.info/?l=linux-kernel&m=135263661110528&w=2
This failed because it could not handle deferred probes.

This patch alone does not solve the entire dilemma faced:
whether code should be distributed into the drivers or
if it should be centralized to e.g. a PM domain. But it
solves the immediate issue of the addition of boilerplate
to a lot of drivers that just want to grab the default
state. As mentioned, they can later explicitly retrieve
the handle and set different states, and this could as
well be done by e.g. PM domains as it is only related
to a certain struct device * pointer.

ChangeLog v4->v5 (Stephen):
- Simplified the devicecore grab code.
- Deleted a piece of documentation recommending that pins
  be mapped to a device rather than hogged.
ChangeLog v3->v4 (Linus):
- Drop overzealous NULL checks.
- Move kref initialization to pinctrl_create().
- Seeking Tested-by from Stephen Warren so we do not disturb
  the Tegra platform.
- Seeking ACK on this from Greg (and others who like it) so I
  can merge it through the pinctrl subsystem.
ChangeLog v2->v3 (Linus):
- Abstain from using IS_ERR_OR_NULL() in the driver core,
  Russell recently sent a patch to remove it. Handle the
  NULL case explicitly even though it's a bogus case.
- Make sure we handle probe deferral correctly in the device
  core file. devm_kfree() the container on error so we don't
  waste memory for devices without pinctrl handles.
- Introduce reference counting into the pinctrl core using
  <linux/kref.h> so that we don't release pinctrl handles
  that have been obtained for two or more places.
ChangeLog v1->v2 (Linus):
- Only store a pointer in the device struct, and only allocate
  this if it's really used by the device.

Cc: Felipe Balbi <balbi@ti.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Mitch Bradley <wmb@firmworks.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Rickard Andersson <rickard.andersson@stericsson.com>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
[swarren: fixed and simplified error-handling in pinctrl_bind_pins(), to
correctly handle deferred probe. Removed admonition from docs not to use
pinctrl hogs for devices]
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The devm_request_and_ioremap() function is very useful and helps avoid a
whole lot of boilerplate. However, one issue that keeps popping up is
its lack of a specific error code to determine which of the steps that
it performs failed. Furthermore, while the function gives an example and
suggests what error code to return on failure, a wide variety of error
codes are used throughout the tree.

In an attempt to fix these problems, this patch adds a new function that
drivers can transition to. The devm_ioremap_resource() returns a pointer
to the remapped I/O memory on success or an ERR_PTR() encoded error code
on failure. Callers can check for failure using IS_ERR() and determine
its cause by extracting the error code using PTR_ERR().

devm_request_and_ioremap() is implemented as a wrapper around the new
API and return NULL on failure as before. This ensures that backwards
compatibility is maintained until all users have been converted to the
new API, at which point the old devm_request_and_ioremap() function
should be removed.

A semantic patch is included which can be used to convert from the old
devm_request_and_ioremap() API to the new devm_ioremap_resource() API.
Some non-trivial cases may require manual intervention, though.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To avoid adding an ACPI handle pointer to struct device on
architectures that don't use ACPI, or generally when CONFIG_ACPI is
not set, in which cases that pointer is useless, define struct
acpi_dev_node that will contain the handle pointer if CONFIG_ACPI is
set and will be empty otherwise and use it to represent the ACPI
device node field in struct device.

In addition to that define macros for reading and setting the ACPI
handle of a device that don't generate code when CONFIG_ACPI is
unset.  Modify the ACPI subsystem to use those macros instead of
referring to the given device's ACPI handle directly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With ACPI 5 we are starting to see devices that don't natively support
discovery but can be enumerated with the help of the ACPI namespace.
Typically, these devices can be represented in the Linux device driver
model as platform devices or some serial bus devices, like SPI or I2C
devices.

Since we want to re-use existing drivers for those devices, we need a
way for drivers to specify the ACPI IDs of supported devices, so that
they can be matched against device nodes in the ACPI namespace.  To
this end, it is sufficient to add a pointer to an array of supported
ACPI device IDs, that can be provided by the driver, to struct device.

Moreover, things like ACPI power management need to have access to
the ACPI handle of each supported device, because that handle is used
to invoke AML methods associated with the corresponding ACPI device
node.  The ACPI handles of devices are now stored in the archdata
member structure of struct device whose definition depends on the
architecture and includes the ACPI handle only on x86 and ia64. Since
the pointer to an array of supported ACPI IDs is added to struct
device_driver in an architecture-independent way, it is logical to
move the ACPI handle from archdata to struct device itself at the same
time.  This also makes code more straightforward in some places and
follows the example of Device Trees that have a poiter to struct
device_node in there too.

This changeset is based on Mika Westerberg's work.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

... which, analogous to DEVICE_INT_ATTR provides functionality to
set/clear bools. Its purpose is to be used where values need to be used
as booleans in configuration context.

Next patch uses this.
Signed-off-by: NBorislav Petkov <bp@alien8.de>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NTony Luck <tony.luck@intel.com>

Also add __printf() verification for format string.
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Convert direct calls of vprintk_emit and printk_emit to the
dev_ equivalents.

Make create_syslog_header static.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Tested-by: NJim Cromie <jim.cromie@gmail.com>
Acked-by: NJason Baron <jbaron@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add utility functions to consolidate the use of
create_syslog_header and vprintk_emit.

This allows conversion of logging functions that
call create_syslog_header and then call vprintk_emit
or printk_emit to the dev_ equivalents.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Tested-by: NJim Cromie <jim.cromie@gmail.com>
Acked-by: NJason Baron <jbaron@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c4e00daa
("driver-core: extend dev_printk() to pass structured data")
changed __dev_printk and broke dynamic-debug's ability to control the
dynamic prefix of dev_dbg(dev,..).

commit af7f2158
("drivers-core: make structured logging play nice with dynamic-debug")
made a minimal correction.

The current dynamic debug code uses up to 3 recursion levels via %pV.
This can consume quite a bit of stack.  Directly call printk_emit to
reduce the recursion depth.

These changes include:

dev_dbg:
o Create and use function create_syslog_header to format the syslog
  header for printk_emit uses.
o Call create_syslog_header and neaten __dev_printk
o Make __dev_printk static not global
o Remove include header declaration of __dev_printk
o Remove now unused EXPORT_SYMBOL() of __dev_printk
o Whitespace neatening

dynamic_dev_dbg:
o Remove KERN_DEBUG from dynamic_emit_prefix
o Call create_syslog_header and printk_emit
o Whitespace neatening
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Tested-by: NJim Cromie <jim.cromie@gmail.com>
Acked-by: NJason Baron <jbaron@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

dev_dbg_reatelimited() without DEBUG printed "217078 callbacks
suppressed". This shouldn't print anything without DEBUG.

With CONFIG_DYNAMIC_DEBUG, the print should be configured as expected.
Signed-off-by: NHiroshi Doyu <hdoyu@nvidia.com>
Reported-by: NHin-Tak Leung <htl10@users.sourceforge.net>
Tested-by: NAntti Palosaari <crope@iki.fi>
Tested-by: NHin-Tak Leung <htl10@users.sourceforge.net>
Acked-by: NHin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The syscore device PM flag used to mark the devices (belonging to
PM domains) that should never be turned off, except for the system
core (syscore) suspend/hibernation and resume stages, need not be
accessed by the runtime PM core functions, because all of the devices
it is set for need to be marked as "irq safe" anyway and are
protected from being turned off by runtime PM by ensuring that their
usage counters are always set.

For this reason, make the syscore flag system-wide PM-specific
and simplify the code used for manipulating it, because it need not
acquire the device's power.lock any more.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

This patch introduces one devres API of devres_for_each_res
so that the device's driver can iterate each resource it has
interest in.

The firmware loader will use the API to get each firmware name
from the device instance.
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit a7a20d10 ("sd: limit the scope of the async probe domain")
make the SCSI device probing run device discovery in it's own async
domain.

However, as a result, the partition detection was no longer synchronized
by async_synchronize_full() (which, despite the name, only synchronizes
the global async space, not all of them).  Which in turn meant that
"wait_for_device_probe()" would not wait for the SCSI partitions to be
parsed.

And "wait_for_device_probe()" was what the boot time init code relied on
for mounting the root filesystem.

Now, most people never noticed this, because not only is it
timing-dependent, but modern distributions all use initrd.  So the root
filesystem isn't actually on a disk at all.  And then before they
actually mount the final disk filesystem, they will have loaded the
scsi-wait-scan module, which not only does the expected
wait_for_device_probe(), but also does scsi_complete_async_scans().

[ Side note: scsi_complete_async_scans() had also been partially broken,
  but that was fixed in commit 43a8d39d ("fix async probe
  regression"), so that same commit a7a20d10 had actually broken
  setups even if you used scsi-wait-scan explicitly ]

Solve this problem by just moving the scsi_complete_async_scans() call
into wait_for_device_probe().  Everybody who wants to wait for device
probing to finish really wants the SCSI probing to complete, so there's
no reason not to do this.

So now "wait_for_device_probe()" really does what the name implies, and
properly waits for device probing to finish.  This also removes the now
unnecessary extra calls to scsi_complete_async_scans().
Reported-and-tested-by: NArtem S. Tashkinov <t.artem@mailcity.com>
Cc: Dan Williams <dan.j.williams@gmail.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: Borislav Petkov <bp@amd64.org>
Cc: linux-scsi <linux-scsi@vger.kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This function is not really specific to the genhd layer and there are various
re-implementations or open-coded variants of it all throughout the kernel. To
avoid further duplications move the function to a more generic place.

While moving also convert it from a macro to a inline function.

Potential users of this function can be detected and converted using the
following coccinelle patch:

// <smpl>
@@
expression k;
@@
-container_of(k, struct device, kobj)
+kobj_to_dev(kobj)
// </smpl>
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

IOMMU groups allow IOMMU drivers to represent DMA visibility
and isolation of devices.  Multiple devices may be grouped
together for the purposes of DMA.  Placing a pointer on
struct device enable easy access for things like streaming
DMA programming and drivers like VFIO.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

The Contiguous Memory Allocator is a set of helper functions for DMA
mapping framework that improves allocations of contiguous memory chunks.

CMA grabs memory on system boot, marks it with MIGRATE_CMA migrate type
and gives back to the system. Kernel is allowed to allocate only movable
pages within CMA's managed memory so that it can be used for example for
page cache when DMA mapping do not use it. On
dma_alloc_from_contiguous() request such pages are migrated out of CMA
area to free required contiguous block and fulfill the request. This
allows to allocate large contiguous chunks of memory at any time
assuming that there is enough free memory available in the system.

This code is heavily based on earlier works by Michal Nazarewicz.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NMichal Nazarewicz <mina86@mina86.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Tested-by: NRob Clark <rob.clark@linaro.org>
Tested-by: NOhad Ben-Cohen <ohad@wizery.com>
Tested-by: NBenjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: NRobert Nelson <robertcnelson@gmail.com>
Tested-by: NBarry Song <Baohua.Song@csr.com>

This patch (as1554) fixes a lockdep false-positive report.  The
problem arises because lockdep is unable to deal with the
tree-structured locks created by the device core and sysfs.

This particular problem involves a sysfs attribute method that
unregisters itself, not from the device it was called for, but from a
descendant device.  Lockdep doesn't understand the distinction and
reports a possible deadlock, even though the operation is safe.

This is the sort of thing that would normally be handled by using a
nested lock annotation; unfortunately it's not feasible to do that
here.  There's no sensible way to tell sysfs when attribute removal
occurs in the context of a parent attribute method.

As a workaround, the patch adds a new flag to struct attribute
telling sysfs not to inform lockdep when it acquires a readlock on a
sysfs_dirent instance for the attribute.  The readlock is still
acquired, but lockdep doesn't know about it and hence does not
complain about impossible deadlock scenarios.

Also added are macros for static initialization of attribute
structures with the ignore_lockdep flag set.  The three offending
attributes in the USB subsystem are converted to use the new macros.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: NTejun Heo <tj@kernel.org>
CC: Eric W. Biederman <ebiederm@xmission.com>
CC: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add dev_*_ratelimited() family, dev_* version of pr_*_ratelimited().

Using Joe Perches's proposal/implementation.
Signed-off-by: NHiroshi DOYU <hdoyu@nvidia.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

APIs using devres frequently want to implement a "remove and free the
resource" operation so it seems sensible that they should be able to
just have devres do the freeing for them since that's a big part of what
devres is all about.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

DEVICE_INT_ATTR() should use device_show_int() and device_store_int()
not device_show_ulong() and device_store_ulong()
Signed-off-by: NMichael Davidson <md@google.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit a15d49fd as that
patch broke the build.

Cc: Hannes Reinecke <hare@suse.de>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

klist_iter_init_node() takes a node as a start argument.
However, this node might not be valid anymore.
This patch updates the klist_iter_init_node() and
dependent functions to return an error if so.
All calling functions have been audited to check
for a return code here.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Cc: Greg Kroah-Hartmann <gregkh@linuxfoundation.org>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Stable Kernel <stable@kernel.org>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Allow module_driver take additional parameters which will be passed to the
register and unregister function calls. This allows it to be used in cases
where additional parameters are required (e.g. usb_serial_register_drivers).
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The PowerPC legacy iSeries plateform is being removed along with the
"one looney iseries driver", so this code can now be removed as well.

cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Nothing outside of the driver core needs to get to the deferred probe
pointer, so move it inside the private area of 'struct device' so no one
tries to mess around with it.

Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Allow drivers to report at probe time that they cannot get all the resources
required by the device, and should be retried at a later time.

This should completely solve the problem of getting devices
initialized in the right order.  Right now this is mostly handled by
mucking about with initcall ordering which is a complete hack, and
doesn't even remotely handle the case where device drivers are in
modules.  This approach completely sidesteps the issues by allowing
driver registration to occur in any order, and any driver can request
to be retried after a few more other drivers get probed.

v4: - Integrate Manjunath's addition of a separate workqueue
    - Change -EAGAIN to -EPROBE_DEFER for drivers to trigger deferral
    - Update comment blocks to reflect how the code really works
v3: - Hold off workqueue scheduling until late_initcall so that the bulk
      of driver probes are complete before we start retrying deferred devices.
    - Tested with simple use cases.  Still needs more testing though.
      Using it to get rid of the gpio early_initcall madness, or to replace
      the ASoC internal probe deferral code would be ideal.
v2: - added locking so it should no longer be utterly broken in that regard
    - remove device from deferred list at device_del time.
    - Still completely untested with any real use case, but has been
      boot tested.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dilan Lee <dilee@nvidia.com>
Cc: Manjunath GKondaiah <manjunath.gkondaiah@linaro.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Reviewed-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NDavid Daney <david.daney@cavium.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that there are no users of get_driver() or put_driver(), this
patch (as1513) removes those routines completely.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>