When a hotplug driver calls pci_hp_register(), all steps necessary for
registration are carried out in one go, including creation of a kobject
and addition to sysfs. That's a problem for pciehp once it's converted
to enable/disable the slot exclusively from the IRQ thread: The thread
needs to be spawned after creation of the kobject (because it uses the
kobject's name), but before addition to sysfs (because it will handle
enable/disable requests submitted via sysfs).
pci_hp_deregister() does offer a ->release callback that's invoked
after deletion from sysfs and before destruction of the kobject. But
because pci_hp_register() doesn't offer a counterpart, hotplug drivers'
->probe and ->remove code becomes asymmetric, which is error prone
as recently discovered use-after-free bugs in pciehp's ->remove hook
have shown.
In a sense, this appears to be a case of the midlayer antipattern:
"The core thesis of the "midlayer mistake" is that midlayers are
bad and should not exist. That common functionality which it is
so tempting to put in a midlayer should instead be provided as
library routines which can [be] used, augmented, or ignored by
each bottom level driver independently. Thus every subsystem
that supports multiple implementations (or drivers) should
provide a very thin top layer which calls directly into the
bottom layer drivers, and a rich library of support code that
eases the implementation of those drivers. This library is
available to, but not forced upon, those drivers."
-- Neil Brown (2009), https://lwn.net/Articles/336262/
The presence of midlayer traits in the PCI hotplug core might be ascribed
to its age: When it was introduced in February 2002, the blessings of a
library approach might not have been well known:
https://git.kernel.org/tglx/history/c/a8a2069f432c
For comparison, the driver core does offer split functions for creating
a kobject (device_initialize()) and addition to sysfs (device_add()) as
an alternative to carrying out everything at once (device_register()).
This was introduced in October 2002:
https://git.kernel.org/tglx/history/c/8b290eb19962
The odd ->release callback in the PCI hotplug core was added in 2003:
https://git.kernel.org/tglx/history/c/69f8d663b595
Clearly, a library approach would not force every hotplug driver to
implement a ->release callback, but rather allow the driver to remove
the sysfs files, release its data structures and finally destroy the
kobject. Alternatively, a driver may choose to remove everything with
pci_hp_deregister(), then release its data structures.
To this end, offer drivers pci_hp_initialize() and pci_hp_add() as a
split-up version of pci_hp_register(). Likewise, offer pci_hp_del()
and pci_hp_destroy() as a split-up version of pci_hp_deregister().
Eliminate the ->release callback and move its code into each driver's
teardown routine.
Declare pci_hp_deregister() void, in keeping with the usual kernel
pattern that enablement can fail, but disablement cannot. It only
returned an error if the caller passed in a NULL pointer or a slot which
has never or is no longer registered or is sharing its name with another
slot. Those would be bugs, so WARN about them. Few hotplug drivers
actually checked the return value and those that did only printed a
useless error message to dmesg. Remove that.
For most drivers the conversion was straightforward since it doesn't
matter whether the code in the ->release callback is executed before or
after destruction of the kobject. But in the case of ibmphp, it was
unclear to me whether setting slot_cur->ctrl and slot_cur->bus_on to
NULL needs to happen before the kobject is destroyed, so I erred on
the side of caution and ensured that the order stays the same. Another
nontrivial case is pnv_php, I've found the list and kref logic difficult
to understand, however my impression was that it is safe to delete the
list element and drop the references until after the kobject is
destroyed.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # drivers/platform/x86
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
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: 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>
Cc: Andy Shevchenko <andy@infradead.org>
Add SPDX GPL-2.0+ to all PCI files that specified the GPL and allowed
either GPL version 2 or any later version.
Remove the boilerplate GPL version 2 or later language, relying on the
assertion in b24413180f ("License cleanup: add SPDX GPL-2.0 license
identifier to files with no license") that the SPDX identifier may be used
instead of the full boilerplate text.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that we have a custom printf format specifier, convert users of
full_name() to use %pOF instead. This is preparation for removing storing
of the full path string for each node.
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
The underlying slot hotplug registration code assumed multiple slots, but
the actual implementation is broken for multiple slots.
This went unnoticed for years do to the fact that PowerVM seems to only
ever provide a single hotplug slot per PHB.
Under qemu/kvm the hotplug slot model aligns more with x86 where
multiple slots are presented under a single PHB. As seen in the
following each additional slot after the first fails to register due to
each slot always being compared against the first child node of the PHB
in the device tree.
rpaphp: RPA HOT Plug PCI Controller Driver version: 0.1
rpaphp: Slot [Slot 0] registered
rpaphp: pci_hp_register failed with error -16
rpaphp: pci_hp_register failed with error -16
rpaphp: pci_hp_register failed with error -16
rpaphp: pci_hp_register failed with error -16
The registration logic is fixed so that each slot is compared
against the existing child devices of the PHB in the device tree to
determine present slots vs empty slots.
rpaphp: RPA HOT Plug PCI Controller Driver version: 0.1
rpaphp: Slot [C0] registered
rpaphp: Slot [C1] registered
rpaphp: Slot [C2] registered
rpaphp: Slot [C3] registered
rpaphp: Slot [C4] registered
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
[mpe: Massage changelog]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fix all whitespace issues (missing or needed whitespace) in all files in
drivers/pci. Code is compiled with allyesconfig before and after code
changes and objects are recorded and checked with objdiff and they are not
changed after this commit.
Signed-off-by: Bogicevic Sasa <brutallesale@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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>
Remove kobject.h from files which don't need it, notably,
sched.h and fs.h.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rpaphp tends to use slot->name directly everywhere, and doesn't
ever need slot->hotplug_slot->name.
struct hotplug_slot->name is going away, so convert rpaphp directly
manipulate its own slot->name everywhere, and don't bother touching
slot->hotplug_slot->name.
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Update pci_hp_register() to take a const char *name parameter.
The motivation for this is to clean up the individual hotplug
drivers so that each one does not have to manage its own name.
The PCI core should be the place where we manage the name.
We update the interface and all callsites first, in a
"no functional change" manner, and clean up the drivers later.
Cc: kristen.c.accardi@intel.com
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Commit f46753c5e3 ("PCI: introduce pci_slot") removed the need for this error path. Eliminate this warning:
drivers/pci/hotplug/rpaphp_slot.c: In function 'rpaphp_register_slot':
drivers/pci/hotplug/rpaphp_slot.c:151: warning: label 'sysfs_fail' defined but not used
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently, /sys/bus/pci/slots/ only exposes hotplug attributes when a
hotplug driver is loaded, but PCI slots have attributes such as address,
speed, width, etc. that are not related to hotplug at all.
Introduce pci_slot as the primary data structure and kobject model.
Hotplug attributes described in hotplug_slot become a secondary
structure associated with the pci_slot.
This patch only creates the infrastructure that allows the separation of
PCI slot attributes and hotplug attributes. In this patch, the PCI
hotplug core remains the only user of this infrastructure, and thus,
/sys/bus/pci/slots/ will still only become populated when a hotplug
driver is loaded.
A later patch in this series will add a second user of this new
infrastructure and demonstrate splitting the task of exposing pci_slot
attributes from hotplug_slot attributes.
- Make pci_slot the primary sysfs entity. hotplug_slot becomes a
subsidiary structure.
o pci_create_slot() creates and registers a slot with the PCI core
o pci_slot_add_hotplug() gives it hotplug capability
- Change the prototype of pci_hp_register() to take the bus and
slot number (on parent bus) as parameters.
- Remove all the ->get_address methods since this functionality is
now handled by pci_slot directly.
[achiang@hp.com: rpaphp-correctly-pci_hp_register-for-empty-pci-slots]
Tested-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: make headers_check happy]
[akpm@linux-foundation.org: nuther build fix]
[akpm@linux-foundation.org: fix typo in #include]
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Cc: Greg KH <greg@kroah.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Len Brown <lenb@kernel.org>
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix presentation of the slot number in the /sys/bus/pci/slots
directory to match that used in the majority of other drivers.
> Greg said:
> How is anyone supposed to write sane managability tools in the
> presence
> of such anarchy?
>
> > ~ # cat /sys/bus/pci/slots/0000:00:02.2/phy_location
> > U787A.001.DNZ00Z5-P1-C2
>
> Right. This should look like:
>
> # cat /sys/bus/pci/slots/U787A.001.DNZ00Z5-P1-C2/address
> 0000:00:02
This patch implements exactly what you describe. Boot tested.
I assume you really mean it -- if so, then please review and
ack the patch !?
I have absolutely no clue if this breaks any existing IBM tools.
I'm pretty sure it doesn't ... but attention Mike Strosaker! does it?
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: <strosake@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The rpaphp_set_attention_status() routine seems to be a wrapper
around a single rtas call. Abolish it.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Cc: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Remove another stovepipe: a call which wraps another call, and
just adds printks.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Cc: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix a memleak; the slot->location string was never freed.
Fix some whitespace and overlong-line probelms while we're here.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Cc: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The routine that called an alloc should be the same routine that
calles the mathcing free, if anything in the middle failed.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Cc: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Cleanup cruft: remove the global "num_slots" variable;
although scattered across multiple files, it is used only
once, in a debug statement.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Cc: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This janitorial patch removes the following annoying
compile-time message:
drivers/pci/hotplug/rpaphp_slot.c:57: warning: ignoring return
value of sfs_create_file declared with attribute warn_unused_result
It also fixes a typo, removes some misc crud.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Cc: John Rose <johnrose@us.ibm.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
this patch converts drivers/pci to kzalloc usage.
Compile tested with allyes config.
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Build break: Building PCI hotplug on PowerPC results in
a build break, due to failure to export symbols.
Reported today by Dave Jones <davej@redhat.com>:
drivers/pci/hotplug/rpaphp.ko needs unknown symbol pcibios_add_pci_devices
This patch fixes same problem in drivers/pci tree
Previous patch fixes the break in the arch/powerpc tree.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Minor cleanup. Add the prefix rpaphp_* to several generic-sounding routines.
Remove rpaphp_remove_slot(), which is a one-liner.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Acked-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
I recently picked up my older work to remove unnecessary #includes of
sched.h, starting from a patch by Dave Jones to not include sched.h
from module.h. This reduces the number of indirect includes of sched.h
by ~300. Another ~400 pointless direct includes can be removed after
this disentangling (patch to follow later).
However, quite a few indirect includes need to be fixed up for this.
In order to feed the patches through -mm with as little disturbance as
possible, I've split out the fixes I accumulated up to now (complete for
i386 and x86_64, more archs to follow later) and post them before the real
patch. This way this large part of the patch is kept simple with only
adding #includes, and all hunks are independent of each other. So if any
hunk rejects or gets in the way of other patches, just drop it. My scripts
will pick it up again in the next round.
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently rpaphp registers the following bus types as hotplug slots:
1) Actual PCI Hotplug slots
2) Embedded/Internal PCI slots
3) PCI Host Bridges
The second and third bus types are not actually direct parents of
removable adapters. As such, the rpaphp has special case code to fake
results for attributes like power, adapter status, etc. This patch
removes types 2 and 3 from the rpaphp module.
This patch also changes the DLPAR module so that slots can be
DLPAR-added/removed without having been designated as hotplug-capable.
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Currently, rpaphp registers Virtual I/O slots as hotplug slots. The
only purpose of this registration is to ensure that the VIO subsystem
is notified of new VIO buses during DLPAR adds. Similarly, rpaphp
notifies the VIO subsystem when a VIO bus is DLPAR-removed. The rpaphp
module has special case code to fake results for attributes like power,
adapter status, etc.
The VIO register/unregister functions could just as easily be made from
the DLPAR module. This patch moves the VIO registration calls to the
DLPAR module, and removes the VIO fluff from rpaphp altogether.
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Lukas Wunner