PCI: hotplug: Embed hotplug_slot

When the PCI hotplug core and its first user, cpqphp, were introduced in
February 2002 with historic commit a8a2069f432c, cpqphp allocated a slot
struct for its internal use plus a hotplug_slot struct to be registered
with the hotplug core and linked the two with pointers:
https://git.kernel.org/tglx/history/c/a8a2069f432c

Nowadays, the predominant pattern in the tree is to embed ("subclass")
such structures in one another and cast to the containing struct with
container_of(). But it wasn't until July 2002 that container_of() was
introduced with historic commit ec4f214232cf:
https://git.kernel.org/tglx/history/c/ec4f214232cf

pnv_php, introduced in 2016, did the right thing and embedded struct
hotplug_slot in its internal struct pnv_php_slot, but all other drivers
cargo-culted cpqphp's design and linked separate structs with pointers.

Embedding structs is preferrable to linking them with pointers because
it requires fewer allocations, thereby reducing overhead and simplifying
error paths. Casting an embedded struct to the containing struct
becomes a cheap subtraction rather than a dereference. And having fewer
pointers reduces the risk of them pointing nowhere either accidentally
or due to an attack.

Convert all drivers to embed struct hotplug_slot in their internal slot
struct. The "private" pointer in struct hotplug_slot thereby becomes
unused, so drop it.

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: Sebastian Ott <sebott@linux.ibm.com> # drivers/pci/hotplug/s390*
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: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Corentin Chary <corentin.chary@gmail.com>
Cc: Darren Hart <dvhart@infradead.org>

PCI: hotplug: Drop hotplug_slot_info

Ever since the PCI hotplug core was introduced in 2002, drivers had to
allocate and register a struct hotplug_slot_info for every slot:
https://git.kernel.org/tglx/history/c/a8a2069f432c

Apparently the idea was that drivers furnish the hotplug core with an
up-to-date card presence status, power status, latch status and
attention indicator status as well as notify the hotplug core of changes
thereof. However only 4 out of 12 hotplug drivers bother to notify the
hotplug core with pci_hp_change_slot_info() and the hotplug core never
made any use of the information: There is just a single macro in
pci_hotplug_core.c, GET_STATUS(), which uses the hotplug_slot_info if
the driver lacks the corresponding callback in hotplug_slot_ops. The
macro is called when the user reads the attribute via sysfs.

Now, if the callback isn't defined, the attribute isn't exposed in sysfs
in the first place (see e.g. has_power_file()). There are only two
situations when the hotplug_slot_info would actually be accessed:

* If the driver defines ->enable_slot or ->disable_slot but not
->get_power_status.

* If the driver defines ->set_attention_status but not
->get_attention_status.

There is no driver doing the former and just a single driver doing the
latter, namely pnv_php.c. Amend it with a ->get_attention_status
callback. With that, the hotplug_slot_info becomes completely unused by
the PCI hotplug core. But a few drivers use it internally as a cache:

cpcihp uses it to cache the latch_status and adapter_status.
cpqhp uses it to cache the adapter_status.
pnv_php and rpaphp use it to cache the attention_status.
shpchp uses it to cache all four values.

Amend these drivers to cache the information in their private slot
struct. shpchp's slot struct already contains members to cache the
power_status and adapter_status, so additional members are only needed
for the other two values. In the case of cpqphp, the cached value is
only accessed in a single place, so instead of caching it, read the
current value from the hardware.

Caution: acpiphp, cpci, cpqhp, shpchp, asus-wmi and eeepc-laptop
populate the hotplug_slot_info with initial values on probe. That code
is herewith removed. There is a theoretical chance that the code has
side effects without which the driver fails to function, e.g. if the
ACPI method to read the adapter status needs to be executed at least
once on probe. That seems unlikely to me, still maintainers should
review the changes carefully for this possibility.

Rafael adds: "I'm not aware of any case in which it will break anything,
[...] but if that happens, it may be necessary to add the execution of
the control methods in question directly to the initialization part."

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: Sebastian Ott <sebott@linux.ibm.com> # drivers/pci/hotplug/s390*
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: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Corentin Chary <corentin.chary@gmail.com>
Cc: Darren Hart <dvhart@infradead.org>

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>

PCI: Add SPDX GPL-2.0+ to replace GPL v2 or later boilerplate

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 b24413180f56 ("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>

hotplug/drc-info: Add code to search ibm,drc-info property

rpadlpar_core.c: Provide parallel routines to search the older device-
tree properties ("ibm,drc-indexes", "ibm,drc-names", "ibm,drc-types"
and "ibm,drc-power-domains"), or the new property "ibm,drc-info".

The interface to examine the DRC information is changed from a "get"
function that returns values for local verification elsewhere, to a
"check" function that validates the 'name' and/or 'type' of a device
node. This update hides the format of the underlying device-tree
properties, and concentrates the value checks into a single function
without requiring the user to verify whether a search was successful.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

PCI: Fix all whitespace issues

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>

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>

PCI: Remove "extern" from function declarations

We had an inconsistent mix of using and omitting the "extern" keyword
on function declarations in header files. This removes them all.

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

module_param: make bool parameters really bool (drivers & misc)

module_param(bool) used to counter-intuitively take an int. In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

It's time to remove the int/unsigned int option. For this version
it'll simply give a warning, but it'll break next kernel version.

Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

PCI hotplug: rpaphp: make debug var unique

Change debug variable name to one more unique to this driver.

Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

pci hotplug: fix rpaphp directory naming

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>

PCI: rpaphp: Rename rpaphp_register_pci_slot() to rpaphp_enable_slot()

Rename rpaphp_register_pci_slot() because its easy to confuse
with rpaphp_register_slot() even though it does something
completely different. Rename it to rpaphp_enable_slot() because
its almost identical to enbale_slot().

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>

PCI: rpaphp: remove rpaphp_set_attention_status()

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>

PCI: rpaphp: Remove another wrappered function

Remove another stove-pipe; this funcion was called from
two different places, with a compile-time const that is
then run-time checked to perform two different things.

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>

PCI: rpaphp: Remve another call that is a wrapper

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>

PCI: rpaphp: Remove global num_slots variable

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>

[PATCH] Fix up rpaphp driver for pci hotplug header move

Use grep instead of make during interface changes.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] powerpc/PCI hotplug: cleanup: add prefix

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>

[PATCH] powerpc/PCI hotplug: merge rpaphp_enable_pci_slot()

Remove general baroqueness. The function rpaphp_enable_pci_slot()
has a fairly simple logic structure, once all of the debug printk's
are removed. Its called from only one place, and that place also
has a very simple structure once he printk's are removed. Merge
the two together.

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>

[PATCH] powerpc/PCI hotplug: de-convolute rpaphp_unconfig_pci_adap

Remove general baroqueness. The function rpaphp_unconfig_pci_adapter()
is really just three lines of code, once all the dbg printks are removed.
And its called in only one place. So replace the call by the thre lines.
Also, provide proper semaphore locking in the affected function
disable_slot()

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>

[PATCH] powerpc/PCI hotplug: merge config_pci_adapter

Remove general baroqueness. The function rpaphp_config_pci_adapter()
is really just one line of code, once all the dbg printks are removed.
And its called in only one place. So replace the call by the one line.

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>

[PATCH] powerpc/PCI hotplug: remove rpaphp_fixup_new_pci_devices()

The function rpaphp_fixup_new_pci_devices() has been migrated to
pcibios_fixup_new_pci_devices() in
arch/powerpc/platforms/pseries/pci_dlpar.c
This patch removes the old version.

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>

[PATCH] powerpc/PCI hotplug: remove rpaphp_find_bus()

The function rpaphp_find_pci_bus() has been migrated to
pcibios_find_pci_bus() in arch/powerpc/platforms/pseries/pci_dlpar.c
This patch removes the old version.

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>

[PATCH] dlpar regression for ppc64 - probe change

This patch contains the driver bits for enabling DLPAR and PCI Hotplug
for the new OF-based PCI probe. This functionality was regressed when
the new PCI approach was introduced. Please apply if appropriate.

Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] ppc64 PCI Hotplug: cleanup unsymmetric API routines

This is a minor patch to the ppc64 PCI hotplug code; it makes the call to
rpaphp_unconfig_pci_adapter() symmetric with respect to the call to
rpaphp_config_pci_adapter(). I discussed this with John Rose, who
had provided the last round of changes for these functions; he
appearently had this patch but somehow failed to mail it out.

Tested. (added/removed device).

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>

drivers/pci/hotplug/rpaphp.h | 3 ++-
drivers/pci/hotplug/rpaphp_core.c | 5 ++++-
drivers/pci/hotplug/rpaphp_pci.c | 11 +++--------
3 files changed, 9 insertions(+), 10 deletions(-)

[PATCH] PCI Hotplug: rpaphp: Purify hotplug

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>

[PATCH] PCI Hotplug: rpaphp: Export slot enable

This patch exports rpaphp_config_pci_adapter() for use by the rpadlpar
module. It also changes this function by removing any dependencies on
struct slot. The patch also changes the RPA DLPAR-add path to enable
newly-added slots in a separate step from that which registers them as
hotplug slots.

Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] PCI Hotplug: rpaphp: Remove rpaphp_find_pci

The rpaphp module currently uses a fragile method to find a pci device
by its device node. This function is unnecessary, so this patch scraps
it.

Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] PCI Hotplug: rpaphp: Change slot pci reference

The slot structure in the rpaphp module currently references the PCI
contents of the slot using the PCI device of the parent bridge. This
is unnecessary, since the module is actually interested in the
subordinate bus of the bridge. The dependency on a PCI bridge device
also prohibits the module from registering hotplug slots that have a
root bridge as a parent, since root bridges on PPC64 don't have PCI
devices.

This patch changes struct slot to reference the PCI subsystem using a
pci_bus rather than a pci_dev.

Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] PCI Hotplug: rpaphp: Move VIO registration

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>

[PATCH] PCI Hotplug: rpaphp: Remove unused stuff

Subject line says it all :)

Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Linux-2.6.12-rc2

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!