This reverts commit 6d9d4b14 as it
breaks working machines.

Cc: Rob Herring <robh@kernel.org>
Cc: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On some simulators like GEM5, caches may not be simulated. In those
cases, the cache levels and leaves will be zero and will result in
following exception:

Unable to handle kernel NULL pointer dereference at virtual address 0040
pgd = ffffffc0008fa000
[00000040] *pgd=00000009f6807003, *pud=00000009f6807003,
	   *pmd=00000009f6808003, *pte=006000002c010707
Internal error: Oops: 96000005 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.1.0-rc5 #198
task: ffffffc9768a0000 ti: ffffffc9768a8000 task.ti: ffffffc9768a8000
PC is at detect_cache_attributes+0x98/0x2c8
LR is at detect_cache_attributes+0x88/0x2c8

kcalloc(0) returns a special value ZERO_SIZE_PTR which is non-NULL value
but results in fault only on any attempt to dereferencing it. So
checking for the non-NULL pointer will not suffice.

This patch checks for non-zero cache leaf nodes and returns error if
there are no cache leaves in detect_cache_attributes.

Cc: <stable@vger.kernel.org> # 3.19.x
Cc: Will Deacon <will.deacon@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: NWilliam Wang <william.wang@arm.com>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The recent fix to use kstrdup_const() failed to add a
kfree upon failure of name allocation...

Cc: Ming Lei <ming.lei@canonical.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Kyle McMartin <kyle@kernel.org>
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NShailendra Verma <shailendra.capricorn@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Failure path of platform_device_add was almost the same as
platform_device_del. Refactor same code in a function.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

insert_resource() can fail when the resource added  overlaps
(partially or fully) with another.

Device tree and AMBA devices may contain resources that overlap, so they
could not call platform_device_add (see 02bbde78 ('Revert "of:
use platform_device_add"'))"

On the other hand, device trees are released using
platform_device_unregister(). This function calls platform_device_del(),
which calls release_resource(), that crashes when the resource has not
been added with with insert_resource. This was not an issue when the
device tree could not be modified online, but this is not the case
anymore.

This patch let the flow continue when there is an insert error, after
notifying the user with a dev_err(). r->parent is set to NULL, so
platform_device_del() knows that the resource was not added, and
therefore it should not be released.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

platform_device_del only checks the type of the resource in order to
call release_resource.

On the other hand, platform_device_add calls insert_resource for any
resource that has a parent.

Make both code branches balanced.
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 5590f319 ("drivers/core/of: Add symlink to device-tree from
devices with an OF node") adds the symlink `of_node` for each device
pointing to it's device tree node while creating/initialising it.

However the devicetree sysfs is created and setup in of_init which is
executed at core_initcall level. For all the devices created before
of_init, the following error is thrown:
	"Error -2(-ENOENT) creating of_node link"

Like many other components in driver model, initialize the sysfs support
for OF/devicetree from driver_init so that it's ready before any devices
are created.

Fixes: 5590f319 ("drivers/core/of: Add symlink to device-tree from
	devices with an OF node")
Suggested-by: NRob Herring <robh+dt@kernel.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Tested-by: NRobert Schwebel <r.schwebel@pengutronix.de>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We currently use flexible arrays with a char at the
end for the remaining internal firmware name uses.
There are two limitations with the way we use this.
Since we're using a flexible array for a string on the
struct if we wanted to use two strings it means we'd
have a disjoint means of handling the strings, one
using the flexible array, and another a char * pointer.
We're also currently not using 'const' for the string.

We wish to later extend some firmware data structures
with other string/char pointers, but we also want to be
very pedantic about const usage. Since we're going to
change things to use 'const' we might as well also address
unified way to use multiple strings on the structs.

Replace the flexible array practice for strings with
kstrdup_const() and kfree_const(), this will avoid
allocations when the vmlinux .rodata is used, and just
allocate a new proper string for us when needed. This
also means we can simplify the struct allocations by
removing the string length from the allocation size
computation, which would otherwise get even more
complicated when supporting multiple strings.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Kyle McMartin <kyle@kernel.org>
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Asynchronous firmware loading copies the pointer to the
name passed as an argument only to be scheduled later and
used. This behaviour works well for synchronous calling
but in asynchronous mode there's a chance the caller could
immediately free the passed string after making the
asynchronous call. This could trigger a use after free
having the kernel look on disk for arbitrary file names.

In order to force-test the issue you can use a test-driver
designed to illustrate this issue on github [0], use the
next-20150505-fix-use-after-free branch.

With this patch applied you get:

[  283.512445] firmware name: test_module_stuff.bin
[  287.514020] firmware name: test_module_stuff.bin
[  287.532489] firmware found

Without this patch applied you can end up with something such as:

[  135.624216] firmware name: \xffffff80BJ
[  135.624249] platform fake-dev.0: Direct firmware load for \xffffff80Bi failed with error -2
[  135.624252] No firmware found
[  135.624252] firmware found

Unfortunatley in the worst and most common case however you
can typically crash your system with a page fault by trying to
free something which you cannot, and/or a NULL pointer
dereference [1].

The fix and issue using schedule_work() for asynchronous
runs is generalized in the following SmPL grammar patch,
when applied to next-20150505 only the firmware_class
code is affected. This grammar patch can and should further
be generalized to vet for for other kernel asynchronous
mechanisms.

@ calls_schedule_work @
type T;
T *priv_work;
identifier func, work_func;
identifier work;
identifier priv_name, name;
expression gfp;
@@

 func(..., const char *name, ...)
 {
 	...
 	priv_work = kzalloc(sizeof(T), gfp);
 	...
-	priv_work->priv_name = name;
+	priv_work->priv_name = kstrdup_const(name, gfp);
	...
(... when any
 	if (...)
 	{
 		...
+ 		kfree_const(priv_work->priv_name);
 		kfree(priv_work);
		...
 	}
) ... when any
 	INIT_WORK(&priv_work->work, work_func);
 	...
 	schedule_work(&priv_work->work);
 	...
 }

@ the_work_func depends on calls_schedule_work @
type calls_schedule_work.T;
T *priv_work;
identifier calls_schedule_work.work_func;
identifier calls_schedule_work.priv_name;
identifier calls_schedule_work.work;
identifier some_work;
@@

 work_func(...)
 {
 	...
 	priv_work = container_of(some_work, T, work);
 	...
+	kfree_const(priv_work->priv_name);
 	kfree(priv_work);
 	...
 }

[0] https://github.com/mcgrof/fake-firmware-test.git
[1] The following kernel ring buffer splat:

firmware name: test_module_stuff.bin
firmware name:
firmware found
general protection fault: 0000 [#1] SMP
Modules linked in: test(O) <...etc-it-does-not-matter>
 drm sr_mod cdrom xhci_pci xhci_hcd rtsx_pci mfd_core video button sg
CPU: 3 PID: 87 Comm: kworker/3:2 Tainted: G           O    4.0.0-00010-g22b5bb0-dirty #176
Hardware name: LENOVO 20AW000LUS/20AW000LUS, BIOS GLET43WW (1.18 ) 12/04/2013
Workqueue: events request_firmware_work_func
task: ffff8800c7f8e290 ti: ffff8800c7f94000 task.ti: ffff8800c7f94000
RIP: 0010:[<ffffffff814a586c>]  [<ffffffff814a586c>] fw_free_buf+0xc/0x40
RSP: 0000:ffff8800c7f97d78  EFLAGS: 00010286
RAX: ffffffff81ae3700 RBX: ffffffff816d1181 RCX: 0000000000000006
RDX: 0001ee850ff68500 RSI: 0000000000000246 RDI: c35d5f415e415d41
RBP: ffff8800c7f97d88 R08: 000000000000000a R09: 0000000000000000
R10: 0000000000000358 R11: ffff8800c7f97a7e R12: ffff8800c7ec1e80
R13: ffff88021e2d4cc0 R14: ffff88021e2dff00 R15: 00000000000000c0
FS:  0000000000000000(0000) GS:ffff88021e2c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000034b8cd8 CR3: 000000021073c000 CR4: 00000000001407e0
Stack:
 ffffffff816d1181 ffff8800c7ec1e80 ffff8800c7f97da8 ffffffff814a58f8
 000000000000000a ffffffff816d1181 ffff8800c7f97dc8 ffffffffa047002c
 ffff88021e2dff00 ffff8802116ac1c0 ffff8800c7f97df8 ffffffff814a65fe
Call Trace:
 [<ffffffff816d1181>] ? __schedule+0x361/0x940
 [<ffffffff814a58f8>] release_firmware+0x58/0x80
 [<ffffffff816d1181>] ? __schedule+0x361/0x940
 [<ffffffffa047002c>] test_mod_cb+0x2c/0x43 [test]
 [<ffffffff814a65fe>] request_firmware_work_func+0x5e/0x80
 [<ffffffff816d1181>] ? __schedule+0x361/0x940
 [<ffffffff8108d23a>] process_one_work+0x14a/0x3f0
 [<ffffffff8108d911>] worker_thread+0x121/0x460
 [<ffffffff8108d7f0>] ? rescuer_thread+0x310/0x310
 [<ffffffff810928f9>] kthread+0xc9/0xe0
 [<ffffffff81092830>] ? kthread_create_on_node+0x180/0x180
 [<ffffffff816d52d8>] ret_from_fork+0x58/0x90
 [<ffffffff81092830>] ? kthread_create_on_node+0x180/0x180
Code: c7 c6 dd ad a3 81 48 c7 c7 20 97 ce 81 31 c0 e8 0b b2 ed ff e9 78 ff ff ff 66 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 41 54 53 <4c> 8b 67 38 48 89 fb 4c 89 e7 e8 85 f7 22 00 f0 83 2b 01 74 0f
RIP  [<ffffffff814a586c>] fw_free_buf+0xc/0x40
 RSP <ffff8800c7f97d78>
---[ end trace 4e62c56a58d0eac1 ]---
BUG: unable to handle kernel paging request at ffffffffffffffd8
IP: [<ffffffff81093ee0>] kthread_data+0x10/0x20
PGD 1c13067 PUD 1c15067 PMD 0
Oops: 0000 [#2] SMP
Modules linked in: test(O) <...etc-it-does-not-matter>
 drm sr_mod cdrom xhci_pci xhci_hcd rtsx_pci mfd_core video button sg
CPU: 3 PID: 87 Comm: kworker/3:2 Tainted: G      D    O    4.0.0-00010-g22b5bb0-dirty #176
Hardware name: LENOVO 20AW000LUS/20AW000LUS, BIOS GLET43WW (1.18 ) 12/04/2013
task: ffff8800c7f8e290 ti: ffff8800c7f94000 task.ti: ffff8800c7f94000
RIP: 0010:[<ffffffff81092ee0>]  [<ffffffff81092ee0>] kthread_data+0x10/0x20
RSP: 0018:ffff8800c7f97b18  EFLAGS: 00010096
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000000000d
RDX: 0000000000000003 RSI: 0000000000000003 RDI: ffff8800c7f8e290
RBP: ffff8800c7f97b18 R08: 000000000000bc00 R09: 0000000000007e76
R10: 0000000000000001 R11: 000000000000002f R12: ffff8800c7f8e290
R13: 00000000000154c0 R14: 0000000000000003 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88021e2c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 0000000210675000 CR4: 00000000001407e0
Stack:
 ffff8800c7f97b38 ffffffff8108dcd5 ffff8800c7f97b38 ffff88021e2d54c0
 ffff8800c7f97b88 ffffffff816d1500 ffff880213d42368 ffff8800c7f8e290
 ffff8800c7f97b88 ffff8800c7f97fd8 ffff8800c7f8e710 0000000000000246
Call Trace:
 [<ffffffff8108dcd5>] wq_worker_sleeping+0x15/0xa0
 [<ffffffff816d1500>] __schedule+0x6e0/0x940
 [<ffffffff816d1797>] schedule+0x37/0x90
 [<ffffffff810779bc>] do_exit+0x6bc/0xb40
 [<ffffffff8101898f>] oops_end+0x9f/0xe0
 [<ffffffff81018efb>] die+0x4b/0x70
 [<ffffffff81015622>] do_general_protection+0xe2/0x170
 [<ffffffff816d74e8>] general_protection+0x28/0x30
 [<ffffffff816d1181>] ? __schedule+0x361/0x940
 [<ffffffff814a586c>] ? fw_free_buf+0xc/0x40
 [<ffffffff816d1181>] ? __schedule+0x361/0x940
 [<ffffffff814a58f8>] release_firmware+0x58/0x80
 [<ffffffff816d1181>] ? __schedule+0x361/0x940
 [<ffffffffa047002c>] test_mod_cb+0x2c/0x43 [test]
 [<ffffffff814a65fe>] request_firmware_work_func+0x5e/0x80
 [<ffffffff816d1181>] ? __schedule+0x361/0x940
 [<ffffffff8108d23a>] process_one_work+0x14a/0x3f0
 [<ffffffff8108d911>] worker_thread+0x121/0x460
 [<ffffffff8108d7f0>] ? rescuer_thread+0x310/0x310
 [<ffffffff810928f9>] kthread+0xc9/0xe0
 [<ffffffff81092830>] ? kthread_create_on_node+0x180/0x180
 [<ffffffff816d52d8>] ret_from_fork+0x58/0x90
 [<ffffffff81092830>] ? kthread_create_on_node+0x180/0x180
Code: 00 48 89 e5 5d 48 8b 40 c8 48 c1 e8 02 83 e0 01 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 8b 87 30 05 00 00 55 48 89 e5 <48> 8b 40 d8 5d c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00
RIP  [<ffffffff81092ee0>] kthread_data+0x10/0x20
 RSP <ffff8800c7f97b18>
CR2: ffffffffffffffd8
---[ end trace 4e62c56a58d0eac2 ]---
Fixing recursive fault but reboot is needed!

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Kyle McMartin <kyle@kernel.org>
Generated-by: Coccinelle SmPL
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When direct firmware loading is used we iterate over a list
of possible firmware paths and concatenate the desired firmware
name with each path and look for the file there. Should the
passed firmware name be too long we end up truncating the
file we want to look for, the search however is still done.
Add a check for truncation instead of looking for a
truncated firmware filename.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@kernel.org>
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The request_firmware*() APIs uses __getname() to iterate
over the list of paths possible for firmware to be found,
the code however never checked for failure on __getname().
Although *very unlikely*, this can still happen. Add the
missing check.

There is still no checks on the concatenation of the path
and filename passed, that requires a bit more work and
subsequent patches address this. The commit that introduced
this is abb139e7 ("firmware: teach the kernel to load
firmware files directly from the filesystem").

mcgrof@ergon ~/linux (git::firmware-fixes) $ git describe --contains abb139e7
v3.7-rc1~120

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@kernel.org>
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 5590f319 ("drivers/core/of: Add symlink to device-tree from
devices with an OF node") adds the symlink `of_node` for each device
pointing to it's device tree node while creating/initialising it.

However the devicetree sysfs is created and setup in of_init which is
executed at core_initcall level. For all the devices created before
of_init, the following error is thrown:
	"Error -2(-ENOENT) creating of_node link"

Like many other components in driver model, initialize the sysfs support
for OF/devicetree from driver_init so that it's ready before any devices
are created.

Fixes: 5590f319 ("drivers/core/of: Add symlink to device-tree from
	devices with an OF node")
Suggested-by: NRob Herring <robh+dt@kernel.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Tested-by: NRobert Schwebel <r.schwebel@pengutronix.de>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

s/hierarcy/hierarchy/

Maybe the typo will annoy people enough so that they add the missing
nodes to their device-tree files, but I still think this is better off
fixed.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit f2411da7 ("driver-core: add driver module asynchronous probe
support") broke build in case modules are disabled, because in this case
"struct module" is not defined and we can't dereference it. Let's define
module_requested_async_probing() helper and stub it out if modules are
disabled.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It is only used within dd.c and thus need not be global.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Because platform_driver_probe() checks, after trying to register driver,
if there are any devices that driver successfully bound to, driver's
probe routine must be run synchronously.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There are drivers that can not be probed asynchronously. One such group
is platform drivers registered with platform_driver_probe(), which
expects driver's probe routine be discarded after the driver has been
registered and initial binding attempt executed. Also
platform_driver_probe() an error when no devices were bound to the
driver, allowing failing to load such driver module altogether.

Other drivers do not work well with asynchronous probing because of
driver bug or not optimal driver organization.

To allow using such drivers even when user requests asynchronous probing
as default boot strategy, let's allow them to opt out.
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some init systems may wish to express the desire to have device drivers
run their probe() code asynchronously. This implements support for this
and allows userspace to request async probe as a preference through a
generic shared device driver module parameter, async_probe.

Implementation for async probe is supported through a module parameter
given that since synchronous probe has been prevalent for years some
userspace might exist which relies on the fact that the device driver
will probe synchronously and the assumption that devices it provides
will be immediately available after this.
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some devices take a long time when initializing, and not all drivers are
suited to initialize their devices when they are open. For example,
input drivers need to interrogate their devices in order to publish
device's capabilities before userspace will open them. When such drivers
are compiled into kernel they may stall entire kernel initialization.

This change allows drivers request for their probe functions to be
called asynchronously during driver and device registration (manual
binding is still synchronous). Because async_schedule is used to perform
asynchronous calls module loading will still wait for the probing to
complete.

Note that the end goal is to make the probing asynchronous by default,
so annotating drivers with PROBE_PREFER_ASYNCHRONOUS is a temporary
measure that allows us to speed up boot process while we validating and
fixing the rest of the drivers and preparing userspace.

This change is based on earlier patch by "Luis R. Rodriguez"
<mcgrof@suse.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently there is no way to query which CPUs are in nohz_full
mode from userspace.

Export the CPU list running in nohz_full mode in sysfs,
specifically in the file /sys/devices/system/cpu/nohz_full

This can be used by system management tools like libvirt,
openstack, and others to ensure proper task placement.
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NMike Galbraith <umgwanakikbuti@gmail.com>
Acked-by: NChris Metcalf <cmetcalf@ezchip.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

After system bootup, there is no totally reliable way to see
which CPUs are isolated, because the kernel may modify the
CPUs specified on the isolcpus= kernel command line option.

Export the CPU list that actually got isolated in sysfs,
specifically in the file /sys/devices/system/cpu/isolated

This can be used by system management tools like libvirt,
openstack, and others to ensure proper placement of tasks.
Suggested-by: NLi Zefan <lizefan@huawei.com>
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NMike Galbraith <umgwanakikbuti@gmail.com>
Acked-by: NChris Metcalf <cmetcalf@ezchip.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The seq_printf return value, because it's frequently misused,
will eventually be converted to void.

See: commit 1f33c41c ("seq_file: Rename seq_overflow() to
     seq_has_overflowed() and make public")
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

There's a deadlock when concurrently hot-adding memory through the probe
interface and switching a memory block from offline to online.

When hot-adding memory via the probe interface, add_memory() first takes
mem_hotplug_begin() and then device_lock() is later taken when registering
the newly initialized memory block.  This creates a lock dependency of (1)
mem_hotplug.lock (2) dev->mutex.

When switching a memory block from offline to online, dev->mutex is first
grabbed in device_online() when the write(2) transitions an existing
memory block from offline to online, and then online_pages() will take
mem_hotplug_begin().

This creates a lock inversion between mem_hotplug.lock and dev->mutex.
Vitaly reports that this deadlock can happen when kworker handling a probe
event races with systemd-udevd switching a memory block's state.

This patch requires the state transition to take mem_hotplug_begin()
before dev->mutex.  Hot-adding memory via the probe interface creates a
memory block while holding mem_hotplug_begin(), there is no way to take
dev->mutex first in this case.

online_pages() and offline_pages() are only called when transitioning
memory block state.  We now require that mem_hotplug_begin() is taken
before calling them -- this requires exporting the mem_hotplug_begin() and
mem_hotplug_done() to generic code.  In all hot-add and hot-remove cases,
mem_hotplug_begin() is done prior to device_online().  This is all that is
needed to avoid the deadlock.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Reported-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhang Zhen <zhenzhang.zhang@huawei.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Wang Nan <wangnan0@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use macro section_nr_to_pfn() to switch between section and pfn, instead
of open-coding it.  No semantic changes.
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Introduce data structures and code allowing "built-in" properties
to be associated with devices in such a way that they will be used
by the device_property_* API if no proper firmware node (neither DT
nor ACPI) is present for the given device.

Each property is to be represented by a property_entry structure.
An array of property_entry structures (terminated with a null
entry) can be pointed to by the properties field of struct
property_set that can be added as a firmware node to a struct
device using device_add_property_set().  That will cause the
device_property_* API to use that property_set as the source
of properties if the given device does not have a DT node or
an ACPI companion device object associated with it.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add a secondary pointer to struct fwnode_handle so as to make it
possible for a device to have two firmware nodes associated with
it at the same time, for example, an ACPI node and a node with
a set of properties provided by platform initialization code.

In the future that will allow device property lookup to fall back
from the primary firmware node to the secondary one if the given
property is not present there to make it easier to provide defaults
for device properties used by device drivers.

Introduce two helper routines, set_primary_fwnode() and
set_secondary_fwnode() allowing callers to add a primary/secondary
firmware node to the given device in such a way that

 (1) If there's only one firmware node for that device, it will be
     pointed to by the device's firmware node pointer.
 (2) If both the primary and secondary firmware nodes are present,
     the primary one will be pointed to by the device's firmware
     node pointer, while the secondary one will be pointed to by the
     primary node's secondary pointer.
 (3) If one of these nodes is removed (by calling one of the new
     nelpers with NULL as the second argument), the other one will
     be preserved.

Make ACPI use set_primary_fwnode() for attaching its firmware nodes
to devices.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that the ACPI companions of devices are pointed to by the fwnode
field in struct device, the device_property_*() accessor functions
can be modified to use their fwnode_property_*() counterparts
internally with minimum extra overhead in the IS_ENABLED(CONFIG_OF)
case, so make those changes.

This allows us to get rid of the rather ugly DEV_PROP_READ_ARRAY()
macro among other things.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 5c0acf3b (driver core: Add comments about returning array
counts) forgot to update fwnode_property_read_string_array() along
the lines of device_property_read_string_array(), although it did
change the kerneldoc comment of it.  Fix that.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This fixes a regression from the net subsystem:
After commit d52fdbb7
"smc91x: retrieve IRQ and trigger flags in a modern way"
a regression would appear on some legacy platforms such
as the ARM PXA Zylonite that specify IRQ resources like
this:

static struct resource r = {
       .start  = X,
       .end    = X,
       .flags  = IORESOURCE_IRQ | IORESOURCE_IRQ_HIGHEDGE,
};

The previous code would retrieve the resource and parse
the high edge setting in the SMC91x driver, a use pattern
that means every driver specifying an IRQ flag from a
static resource need to parse resource flags and apply
them at runtime.

As we switched the code to use IRQ descriptors to retrieve
the the trigger type like this:

  irqd_get_trigger_type(irq_get_irq_data(...));

the code would work for new platforms using e.g. device
tree as the backing irq descriptor would have its flags
properly set, whereas this kind of oldstyle static
resources at no point assign the trigger flags to the
corresponding IRQ descriptor.

To make the behaviour identical on modern device tree
and legacy static platform data platforms, modify
platform_get_irq() to assign the trigger flags to the
irq descriptor when a client looks up an IRQ from static
resources.

Fixes: d52fdbb7 ("smc91x: retrieve IRQ and trigger flags in a modern way")
Tested-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently probe deferral prints a message every time a device requests
deferral at info severity (which is displayed by default). This can have
an impact on system boot times with serial consoles and is generally quite
noisy.

Since subsystems and drivers should already be logging the specific reason
for probe deferral in order to aid users in understanding problems the
messages from the driver core should be redundant lower the severity of
the messages printed, cutting down on the volume of output on the console.

This does mean that if the drivers and subsystems aren't doing a good job
we get no output on the console by default. Ideally we'd be able to arrange
to print if nothing else printed, though that's a little fun. Even better
would be to come up with a mechanism that explicitly does dependencies so
we don't have to keep polling and erroring.
Signed-off-by: NMark Brown <broonie@kernel.org>
Reviewed-by: NBjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

So I've been annoyed lately with having a bunch of devices such as i2c
eeproms (for use by VPDs, server world !) and other bits and pieces that
I want to be able to identify from userspace, and possibly provide
additional data about from FW.

Basically, it boils down to correlating the sysfs device with the OF
tree device node, so that user space can use device-tree info such as
additional "location" or "label" (or whatever else we can come up with)
propreties to identify a given device, or get some attributes of use
about it, etc...

Now, so far, we've done that in some subsystem in a fairly ad-hoc basis
using "devspec" properties. For example, PCI creates them if it can
correlate the probed device with a DT node. Some powerpc specific busses
do that too.

However, i2c doesn't and it would be nice to have something more generic
since technically any device can have a corresponding device tree node.

This patch adds an "of_node" symlink to devices that have a non-NULL
dev->of_node pointer, the patch is pretty trivial and seems to work just
fine for me.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When using the user mode helper to load firmwares the function _request_firmware
gets a positive return value from fw_load_from_user_helper and because of this
the firmware buffer is not assigned. This happens only when the return value
is zero. This patch fixes this problem in _request_firmware_load. When the
completion is ready the return value is set to zero.
Signed-off-by: NZahari Doychev <zahari.doychev@linux.com>
Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the static attribute groups assigned to the device instead of
manual device_create_file() & co calls.  It simplifies the code and
can avoid possible races, too.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On architectures that depend on DT for obtaining cache hierarcy, we need
to validate the device node for all the cache indices, failing to do so
might result in wrong information being exposed to the userspace.

This is quite possible on initial/incomplete versions of the device
trees. In such cases, it's better to bail out if all the required device
nodes are not present.

This patch adds checks for the validation of device node for all the
caches and doesn't initialise the cacheinfo if there's any error.
Reported-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Cc: stable <stable@vger.kernel.org> # 4.0
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Linux kernel coding style require that tabs should be used instead of
spaces for code indentation.
Problem found using checkpatch.pl script.
Signed-off-by: NLavinia Tache <lavinia.tachee@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Found using checkpatch.pl
Signed-off-by: NLavinia Tache <lavinia.tachee@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes the following error found by checkpatch.pl:
ERROR: "foo * bar" should be "foo *bar"
Signed-off-by: NAna Nedelcu <anafnedelcu@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch changes spaces to tabs. Found using checkpatch.pl
Signed-off-by: NIoana Ciornei <ciorneiioana@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>