Now that the driver core can properly handle constant struct bus_type,
move all of the USB subsystem struct bus_type structures as const,
placing them into read-only memory which can not be modified at runtime.

Cc: Johan Hovold <johan@kernel.org>
Cc: Evan Green <evgreen@chromium.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-usb@vger.kernel.org
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-36-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that all users who accessed the bus_type structure in struct device
are properly using it as a const *, mark it as such so that no one can
modify it going forward anymore.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-35-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

A number of iommu functions take a struct bus_type * and never modify
the data passed in, so make them all const * as that is what the driver
core is expecting to have passed into as well.

This is a step toward making all struct bus_type pointers constant in
the kernel.

Cc: Will Deacon <will@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: iommu@lists.linux.dev
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20230313182918.1312597-34-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Change the function arm_iommu_create_mapping() to take a pointer to a
const bus_type as the function does not modify the variable the pointer
points to at all, and the driver core bus functions it calls all expect
a const * type.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230313182918.1312597-33-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In the functions unbind_store() and bind_store(), a struct bus_type *
should be a const one, as the driver core bus functions used by this
variable are expecting the pointer to be constant, and these functions
do not modify the pointer at all.

Cc: dmaengine@vger.kernel.org
Acked-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-32-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The function, vhost_vdpa_alloc_domain(), has a pointer to a struct
bus_type, but it should be constant as the function it passes it to
expects it to be const, and the vhost code does not modify it in any
way.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: kvm@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20230313182918.1312597-31-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The struct bus_type pointers in the functions
intel_huc_register_gsc_notifier() and
intel_huc_unregister_gsc_notifier() should be a const pointer, as the
structure is not modified anywhere in the functions, and the pointer
they are passed will be a const * in the near future.

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tony Ye <tony.ye@intel.com>
Cc: Vitaly Lubart <vitaly.lubart@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-30-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In the function, qm_get_qos_value(), a struct bus_type * is used, but it
really should be a const pointer as it is not modified anywhere in the
function, and the driver core function it is used in expects a constant
pointer.

Cc: Weili Qian <qianweili@huawei.com>
Cc: Zhou Wang <wangzhou1@hisilicon.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Link: https://lore.kernel.org/r/20230313182918.1312597-29-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The pointer to struct bus_type in struct device_driver should only be
pointing to something that can never change now that the driver core has
fixed up the previously writable fields.  So mark it as a constant
pointer to enforce this and move forward with the goal of moving
bus_type into read-only memory.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-28-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

It's funny to think about getting a reference count of a constant
structure pointer, but this locks into place the private data
"underneath" the struct bus_type() which is important to not go away
while we are working with the bus structure for some callbacks.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-27-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The driver_find() function can now take a const * to bus_type, not just
a * so fix that up.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-26-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The bus_rescan_devices() function was missed in the previous change of
the bus_for_each* constant pointer changes, so fix it up now to take a
const * to struct bus_type.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-25-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

bus_register() is now safe to take a constant * to bus_type, so make
that change and mark the subsys_private bus_type * constant as well.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-24-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

struct bus_type should never be modified in a sysfs callback as there is
nothing in the structure to modify, and frankly, the structure is almost
never used in a sysfs callback, so mark it as constant to allow struct
bus_type to be moved to read-only memory.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Ben Widawsky <bwidawsk@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hu Haowen <src.res@email.cn>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Stuart Yoder <stuyoder@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Acked-by: Ilya Dryomov <idryomov@gmail.com> # rbd
Acked-by: Ira Weiny <ira.weiny@intel.com> # cxl
Reviewed-by: Alex Shi <alexs@kernel.org>
Acked-by: Iwona Winiarska <iwona.winiarska@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>	# pci
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com> # scsi
Link: https://lore.kernel.org/r/20230313182918.1312597-23-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that all accesses of dev_root is through the bus_get_dev_root()
call, move the pointer out of struct bus_type and into the private
dynamic structure, subsys_private.

With this change, there is no modifiable portions of struct bus_type so
it can be marked as a constant structure and moved to read-only memory.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-22-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

This allows us to clean up the cpuidle_add_interface() call a bit as it
was only called in one place, with the same argument so just put that
into the function itself.  Note that cpuidle_remove_interface() should
also probably be removed in the future as there are no callers of it for
some reason.

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-pm@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230322090557.2943479-1-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20230322083646.2937580-1-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: James Morse <james.morse@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rric@kernel.org>
Cc: linux-edac@vger.kernel.org
Link: https://lore.kernel.org/r/20230313182918.1312597-1-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Smatch reports:
	drivers/char/tpm/tpm-interface.c:470 tpm_init() error:
	'tpm_class' dereferencing possible ERR_PTR()

If class_create() returns error pointer, we are dereferencing a possible
error pointer. Fix this by moving the dereference post error handling.

Fixes: a010eb88 ("tpm: fix up the tpm_class shutdown_pre pointer when created")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Link: https://lore.kernel.org/r/20230321061416.626561-1-harshit.m.mogalapalli@oracle.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-21-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

In doing so, remove the unneded kobject structure that was only being
created to cause a subdirectory for the attributes.  The name of the
attribute group is the correct way to do this, saving code and
complexity as well as allowing the attributes to properly show up to
userspace tools (the raw kobject would not allow that.)

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-pm@vger.kernel.org
Acked-by: Huang Rui <ray.huang@.amd.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-20-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-19-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-18-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: linux-sh@vger.kernel.org
Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20230313182918.1312597-17-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: linux-sh@vger.kernel.org
Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20230313182918.1312597-16-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230313182918.1312597-15-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Link: https://lore.kernel.org/r/20230313182918.1312597-14-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Liang He <windhl@126.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230313182918.1312597-13-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Hildenbrand <david@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230313182918.1312597-12-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Kristina Martsenko <kristina.martsenko@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230313182918.1312597-11-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-10-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-9-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-8-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-7-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Mark Gross <markgross@kernel.org>
Cc: platform-driver-x86@vger.kernel.org
Acked-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-5-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Mark Gross <markgross@kernel.org>
Cc: platform-driver-x86@vger.kernel.org
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-4-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-pm@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-3-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The debug files under sched/domains can take a long time to regenerate,
especially when updates are done one at a time. Move these files under
the sched verbose debug flag. Allow changes to verbose to trigger
generation of the files. This lets a user batch the updates but still
have the information available.  The detailed topology printk messages
are also under verbose.

Discussion that lead to this approach can be found in the link below.

Simplified code to maintain use of debugfs bool routines suggested by
Michael Ellerman <mpe@ellerman.id.au>.
Signed-off-by: Phil Auld <pauld@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Vishal Chourasia <vishalc@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vishal Chourasia <vishalc@linux.vnet.ibm.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/all/Y01UWQL2y2r69sBX@li-05afa54c-330e-11b2-a85c-e3f3aa0db1e9.ibm.com/
Link: https://lore.kernel.org/r/20230303183754.3076321-1-pauld@redhat.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The functions device_create() and device_create_with_groups() do not
modify the struct class passed into it, so enforce this by changing the
function parameters to be struct const class.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-12-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The pointer to a struct class in a struct device should never be used to
change anything in that class.  So mark it as constant to enforce this
requirement.

This requires a few minor changes to some internal driver core functions
to enforce the const * being used here now.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-11-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>