PCI/sysfs: Constify struct kobj_type pci_slot_ktype

Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.") the
driver core allows the usage of const struct kobj_type.

Take advantage of

PCI/sysfs: Constify struct kobj_type pci_slot_ktype

Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.") the
driver core allows the usage of const struct kobj_type.

Take advantage of this to constify the structure definition to prevent
modification at runtime.

Link: https://lore.kernel.org/r/20230216-kobj_type-pci-v1-1-46a63c8612b5@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/sysfs: Use default_groups in kobj_type for slot attrs

There are currently two ways to create a set of sysfs files for a
kobj_type: through the default_attrs field, and the default_groups field.

PCI/sysfs: Use default_groups in kobj_type for slot attrs

There are currently two ways to create a set of sysfs files for a
kobj_type: through the default_attrs field, and the default_groups field.
Move the PCI slot code to use the default_groups field which has been the
preferred way since aa30f47cf666 ("kobject: Add support for default
attribute groups to kobj_type") so that we can soon get rid of the obsolete
default_attrs field.

Link: https://lore.kernel.org/r/20211228135722.381023-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/sysfs: Use sysfs_emit() and sysfs_emit_at() in "show" functions

The sysfs_emit() and sysfs_emit_at() functions were introduced to make
it less ambiguous which function is preferred when writing

PCI/sysfs: Use sysfs_emit() and sysfs_emit_at() in "show" functions

The sysfs_emit() and sysfs_emit_at() functions were introduced to make
it less ambiguous which function is preferred when writing to the output
buffer in a device attribute's "show" callback [1].

Convert the PCI sysfs object "show" functions from sprintf(), snprintf()
and scnprintf() to sysfs_emit() and sysfs_emit_at() accordingly, as the
latter is aware of the PAGE_SIZE buffer and correctly returns the number
of bytes written into the buffer.

No functional change intended.

[1] Documentation/filesystems/sysfs.rst

Related commit: ad025f8e46f3 ("PCI/sysfs: Use sysfs_emit() and
sysfs_emit_at() in "show" functions").

Link: https://lore.kernel.org/r/20210603000112.703037-2-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

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PCI: Fix pci_slot_release() NULL pointer dereference

If kobject_init_and_add() fails, pci_slot_release() is called to delete
slot->list from parent->slots. But slot->list hasn't been initialized
ye

PCI: Fix pci_slot_release() NULL pointer dereference

If kobject_init_and_add() fails, pci_slot_release() is called to delete
slot->list from parent->slots. But slot->list hasn't been initialized
yet, so we dereference a NULL pointer:

Unable to handle kernel NULL pointer dereference at virtual address
00000000
...
CPU: 10 PID: 1 Comm: swapper/0 Not tainted 4.4.240 #197
task: ffffeb398a45ef10 task.stack: ffffeb398a470000
PC is at __list_del_entry_valid+0x5c/0xb0
LR is at pci_slot_release+0x84/0xe4
...
__list_del_entry_valid+0x5c/0xb0
pci_slot_release+0x84/0xe4
kobject_put+0x184/0x1c4
pci_create_slot+0x17c/0x1b4
__pci_hp_initialize+0x68/0xa4
pciehp_probe+0x1a4/0x2fc
pcie_port_probe_service+0x58/0x84
driver_probe_device+0x320/0x470

Initialize slot->list before calling kobject_init_and_add() to avoid this.

Fixes: 8a94644b440e ("PCI: Fix pci_create_slot() reference count leak")
Link: https://lore.kernel.org/r/1606876422-117457-1-git-send-email-zhongjubin@huawei.com
Signed-off-by: Jubin Zhong <zhongjubin@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v5.9+

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PCI: Fix kernel-doc markup

Update kernel-doc so the names in the doc match the prototypes.

Link: https://lore.kernel.org/r/f19caf7a68f8365c8b573a42b4ac89ec21925c73.1603469755.git.mchehab+huawei@ker

PCI: Fix kernel-doc markup

Update kernel-doc so the names in the doc match the prototypes.

Link: https://lore.kernel.org/r/f19caf7a68f8365c8b573a42b4ac89ec21925c73.1603469755.git.mchehab+huawei@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI: Fix pci_slot_release() NULL pointer dereference

commit 4684709bf81a2d98152ed6b610e3d5c403f9bced upstream.

If kobject_init_and_add() fails, pci_slot_release() is called to delete
slot->list fro

PCI: Fix pci_slot_release() NULL pointer dereference

commit 4684709bf81a2d98152ed6b610e3d5c403f9bced upstream.

If kobject_init_and_add() fails, pci_slot_release() is called to delete
slot->list from parent->slots. But slot->list hasn't been initialized
yet, so we dereference a NULL pointer:

Unable to handle kernel NULL pointer dereference at virtual address
00000000
...
CPU: 10 PID: 1 Comm: swapper/0 Not tainted 4.4.240 #197
task: ffffeb398a45ef10 task.stack: ffffeb398a470000
PC is at __list_del_entry_valid+0x5c/0xb0
LR is at pci_slot_release+0x84/0xe4
...
__list_del_entry_valid+0x5c/0xb0
pci_slot_release+0x84/0xe4
kobject_put+0x184/0x1c4
pci_create_slot+0x17c/0x1b4
__pci_hp_initialize+0x68/0xa4
pciehp_probe+0x1a4/0x2fc
pcie_port_probe_service+0x58/0x84
driver_probe_device+0x320/0x470

Initialize slot->list before calling kobject_init_and_add() to avoid this.

Fixes: 8a94644b440e ("PCI: Fix pci_create_slot() reference count leak")
Link: https://lore.kernel.org/r/1606876422-117457-1-git-send-email-zhongjubin@huawei.com
Signed-off-by: Jubin Zhong <zhongjubin@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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PCI: Fix pci_create_slot() reference count leak

kobject_init_and_add() takes a reference even when it fails. If it returns
an error, kobject_put() must be called to clean up the memory associated
w

PCI: Fix pci_create_slot() reference count leak

kobject_init_and_add() takes a reference even when it fails. If it returns
an error, kobject_put() must be called to clean up the memory associated
with the object.

When kobject_init_and_add() fails, call kobject_put() instead of kfree().

b8eb718348b8 ("net-sysfs: Fix reference count leak in
rx|netdev_queue_add_kobject") fixed a similar problem.

Link: https://lore.kernel.org/r/20200528021322.1984-1-wu000273@umn.edu
Signed-off-by: Qiushi Wu <wu000273@umn.edu>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI: Add pci_speed_string()

Add pci_speed_string() to return a text description of the supplied bus or
link speed. The slot code previously used the private
pci_bus_speed_strings[] array for this p

PCI: Add pci_speed_string()

Add pci_speed_string() to return a text description of the supplied bus or
link speed. The slot code previously used the private
pci_bus_speed_strings[] array for this purpose, but adding this interface
will enable us to consolidate similar code elsewhere.

Export pcie_link_speed[] and pci_speed_string() so they can be used by
modules.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI: Decode PCIe 32 GT/s link speed

PCIe r5.0, sec 7.5.3.18, defines a new 32.0 GT/s bit in the Supported Link
Speeds Vector of Link Capabilities 2. Decode this new speed. This does
not affect the

PCI: Decode PCIe 32 GT/s link speed

PCIe r5.0, sec 7.5.3.18, defines a new 32.0 GT/s bit in the Supported Link
Speeds Vector of Link Capabilities 2. Decode this new speed. This does
not affect the speed of the link, which should be negotiated automatically
by the hardware; it only adds decoding when showing the speed to the user.

Previously, reading the speed of a link operating at this speed showed
"Unknown speed" instead of "32.0 GT/s".

Link: https://lore.kernel.org/lkml/92365e3caf0fc559f9ab14bcd053bfc92d4f661c.1559664969.git.gustavo.pimentel@synopsys.com
Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI: Replace printk(KERN_INFO) with pr_info(), etc

Replace printk() with pr_*() to be more consistent with other logging and
avoid checkpatch warnings.

Link: https://lore.kernel.org/lkml/1555733026

PCI: Replace printk(KERN_INFO) with pr_info(), etc

Replace printk() with pr_*() to be more consistent with other logging and
avoid checkpatch warnings.

Link: https://lore.kernel.org/lkml/1555733026-19609-1-git-send-email-mohankumar718@gmail.com
Link: https://lore.kernel.org/lkml/1555733130-19804-1-git-send-email-mohankumar718@gmail.com
Signed-off-by: Mohan Kumar <mohankumar718@gmail.com>
[bhelgaas: squash in similar changes from second patch in series]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ERR: Use slot reset if available

The secondary bus reset may have link side effects that a hotplug capable
port may incorrectly react to. Use the slot specific reset for hotplug
ports, fixing t

PCI/ERR: Use slot reset if available

The secondary bus reset may have link side effects that a hotplug capable
port may incorrectly react to. Use the slot specific reset for hotplug
ports, fixing the undesirable link down-up handling during error
recovering.

Signed-off-by: Keith Busch <keith.busch@intel.com>
[bhelgaas: fold in
https://lore.kernel.org/linux-pci/20180926152326.14821-1-keith.busch@intel.com
for issue reported by Stephen Rothwell <sfr@canb.auug.org.au>]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>

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PCI: hotplug: Constify hotplug_slot_ops

Hotplug drivers cannot declare their hotplug_slot_ops const, making them
attractive targets for attackers, because upon registration of a hotplug
slot, __pci_

PCI: hotplug: Constify hotplug_slot_ops

Hotplug drivers cannot declare their hotplug_slot_ops const, making them
attractive targets for attackers, because upon registration of a hotplug
slot, __pci_hp_initialize() writes to the "owner" and "mod_name" members
in that struct.

Fix by moving these members to struct hotplug_slot and constify every
driver's hotplug_slot_ops except for pciehp.

pciehp constructs its hotplug_slot_ops at runtime based on the PCIe
port's capabilities, hence cannot declare them const. It can be
converted to __write_rarely once that's mainlined:
http://www.openwall.com/lists/kernel-hardening/2016/11/16/3

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> # drivers/pci/hotplug/rpa*
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # drivers/platform/x86
Cc: Len Brown <lenb@kernel.org>
Cc: Scott Murray <scott@spiteful.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Oliver OHalloran <oliveroh@au1.ibm.com>
Cc: Gavin Shan <gwshan@linux.vnet.ibm.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Corentin Chary <corentin.chary@gmail.com>
Cc: Darren Hart <dvhart@infradead.org>

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PCI: Add decoding for 16 GT/s link speed

PCIe 4.0 defines the 16.0 GT/s link speed. Links can run at that speed
without any Linux changes, but previously their sysfs "max_link_speed" and
"current_l

PCI: Add decoding for 16 GT/s link speed

PCIe 4.0 defines the 16.0 GT/s link speed. Links can run at that speed
without any Linux changes, but previously their sysfs "max_link_speed" and
"current_link_speed" files contained "Unknown speed", not the expected
"16.0 GT/s".

Add decoding for the new 16 GT/s link speed.

Signed-off-by: Jay Fang <f.fangjian@huawei.com>
[bhelgaas: add PCI_EXP_LNKCAP2_SLS_16_0GB]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Dongdong Liu <liudongdong3@huawei.com>

show more ...

PCI: Tidy comments

Remove pointless comments that tell us the file name, remove blank line
comments, follow multi-line comment conventions. No functional change
intended.

Signed-off-by: Bjorn Helg

PCI: Tidy comments

Remove pointless comments that tell us the file name, remove blank line
comments, follow multi-line comment conventions. No functional change
intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI: Add SPDX GPL-2.0 when no license was specified

b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to
files with no license") added SPDX GPL-2.0 to several PCI files that
previo

PCI: Add SPDX GPL-2.0 when no license was specified

b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to
files with no license") added SPDX GPL-2.0 to several PCI files that
previously contained no license information.

Add SPDX GPL-2.0 to all other PCI files that did not contain any license
information and hence were under the default GPL version 2 license of the
kernel.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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locking/atomic, kref: Add kref_read()

Since we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages

locking/atomic, kref: Add kref_read()

Since we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages.

Kills two anti-patterns:

atomic_read(&kref->refcount)
kref->refcount.counter

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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PCI: Hold pci_slot_mutex while searching bus->slots list

Previously, pci_setup_device() and similar functions searched the
pci_bus->slots list without any locking. It was possible for another
threa

PCI: Hold pci_slot_mutex while searching bus->slots list

Previously, pci_setup_device() and similar functions searched the
pci_bus->slots list without any locking. It was possible for another
thread to update the list while we searched it.

Add pci_dev_assign_slot() to search the list while holding pci_slot_mutex.

[bhelgaas: changelog, fold in CONFIG_SYSFS fix]
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI: Protect pci_bus->slots with pci_slot_mutex, not pci_bus_sem

Rajat Jain reported a deadlock when PCIe hot-add and AER recovery happen at
the same time:

thread 1:

pciehp_enable_slot
pcieh

PCI: Protect pci_bus->slots with pci_slot_mutex, not pci_bus_sem

Rajat Jain reported a deadlock when PCIe hot-add and AER recovery happen at
the same time:

thread 1:

pciehp_enable_slot
pciehp_configure_device
pci_bus_add_devices
pci_bus_add_device
device_attach
device_lock(dev) # acquire device lock
...
pciehp_probe
init_slot
pci_hp_register
pci_create_slot
down_write(pci_bus_sem) # deadlock here

thread 2:

aer_isr_one_error
aer_process_err_device
do_recovery
broadcast_error_message(..., report_error_detected)
pci_walk_bus(..., cb=report_error_detected, ...)
down_read(&pci_bus_sem) # acquire pci_bus_sem
report_error_detected(dev) # cb()
device_lock(dev) # deadlock here

Previously, the bus->devices and bus->slots list were protected by
pci_bus_sem. In pci_create_slot(), we held it for writing so we could
add to the bus->slots list.

Add a new local pci_slot_mutex to protect bus->slots. Hold pci_bus_sem for
reading while searching the bus->devices list.

[bhelgaas: changelog]
Link: http://lkml.kernel.org/r/CAA93t1qpPqbih+UB0McA_d_+2rVaNkXsinAUxYzK9+JXSS+L-g@mail.gmail.com
Reported-by: Rajat Jain <rajatja@google.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms.

Summary of http://lkml.org/lkml/2014/3/14/363 :

Ted: module_param(queue_depth, int, 444)
Joe: 0444!
Rusty: User perms >= group per

VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms.

Summary of http://lkml.org/lkml/2014/3/14/363 :

Ted: module_param(queue_depth, int, 444)
Joe: 0444!
Rusty: User perms >= group perms >= other perms?
Joe: CLASS_ATTR, DEVICE_ATTR, SENSOR_ATTR and SENSOR_ATTR_2?

Side effect of stricter permissions means removing the unnecessary
S_IFREG from several callers.

Note that the BUILD_BUG_ON_ZERO((perm) & 2) test was removed: a fair
number of drivers fail this test, so that will be the debate for a
future patch.

Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> for drivers/pci/slot.c
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

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PCI: Remove unused pci_renumber_slot()

My philosophy is unused code is dead code. And dead code is subject to bit
rot and is a likely source of bugs. Use it or lose it.

This reverts part of f4675

PCI: Remove unused pci_renumber_slot()

My philosophy is unused code is dead code. And dead code is subject to bit
rot and is a likely source of bugs. Use it or lose it.

This reverts part of f46753c5e354 ("PCI: introduce pci_slot") and
d25b7c8d6ba2 ("PCI: rename pci_update_slot_number to pci_renumber_slot"),
removing this interface:

pci_renumber_slot()

[bhelgaas: split to separate patch, add historical link from Alex]
Link: http://lkml.kernel.org/r/20081009043140.8678.44164.stgit@bob.kio
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Chiang <achiang@canonical.com>

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PCI: Fix whitespace, capitalization, and spelling errors

Fix whitespace, capitalization, and spelling errors. No functional change.
I know "busses" is not an error, but "buses" was more common, so

PCI: Fix whitespace, capitalization, and spelling errors

Fix whitespace, capitalization, and spelling errors. No functional change.
I know "busses" is not an error, but "buses" was more common, so I used it
consistently.

Signed-off-by: Marta Rybczynska <rybczynska@gmail.com> (pci_reset_bridge_secondary_bus())
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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PCI: Warn about failures instead of "must_check" functions

These places capture return values to avoid "must_check" warnings,
but we didn't *do* anything with the return values, which causes
"set bu

PCI: Warn about failures instead of "must_check" functions

These places capture return values to avoid "must_check" warnings,
but we didn't *do* anything with the return values, which causes
"set but not used" warnings. We might as well do something instead
of just trying to evade the "must_check" warnings.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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pci: add module.h to files implicitly relying on its presence.

These were getting module.h implicitly from device.h but we want
to clean that up, so we fix it here to avoid things like:

pci/slot.c:

pci: add module.h to files implicitly relying on its presence.

These were getting module.h implicitly from device.h but we want
to clean that up, so we fix it here to avoid things like:

pci/slot.c: In function ‘pci_hp_create_module_link’:
pci/slot.c:383: error: ‘module_kset’ undeclared (first use in this function)

Similarly, rpadlpar_core.c is modular, so add module.h to its includes.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

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PCI: bus speed strings should be const

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Revert "PCI: create function symlinks in /sys/bus/pci/slots/N/"

This reverts commit 75568f8094eb0333e9c2109b23cbc8b82d318a3c.

Since they're just a convenience anyway, remove these symlinks since
th

Revert "PCI: create function symlinks in /sys/bus/pci/slots/N/"

This reverts commit 75568f8094eb0333e9c2109b23cbc8b82d318a3c.

Since they're just a convenience anyway, remove these symlinks since
they're causing duplicate filename errors in the wild.

Acked-by: Alex Chiang <achiang@canonical.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

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