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path: root/drivers/pci/hotplug/pci_hotplug_core.c
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2018-09-18PCI: hotplug: Drop hotplug_slot_infoLukas Wunner
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>
2018-09-18PCI: hotplug: Constify hotplug_slot_opsLukas Wunner
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>
2018-07-23PCI: hotplug: Demidlayer registration with the coreLukas Wunner
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>
2018-07-23PCI: hotplug: Don't leak pci_slot on registration failureLukas Wunner
If addition of sysfs files fails on registration of a hotplug slot, the struct pci_slot as well as the entry in the slot_list is leaked. The issue has been present since the hotplug core was introduced in 2002: https://git.kernel.org/tglx/history/c/a8a2069f432c Perhaps the idea was that even though sysfs addition fails, the slot should still be usable. But that's not how drivers use the interface, they abort probe if a non-zero value is returned. Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: stable@vger.kernel.org # v2.4.15+ Cc: Greg Kroah-Hartman <greg@kroah.com>
2018-01-28PCI: Add SPDX GPL-2.0+ to replace GPL v2 or later boilerplateBjorn Helgaas
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>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12PCI: hotplug: Remove hotplug core messageBjorn Helgaas
Remove the "PCI Hot Plug PCI Core" version message. I don't think it contains any useful information. Remove unused #defines and move the author information to a comment. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-08-24PCI: hotplug: Make core explicitly non-modularPaul Gortmaker
This code is not being built as a module by anyone: obj-$(CONFIG_HOTPLUG_PCI) += pci_hotplug.o [...] pci_hotplug-objs := pci_hotplug_core.o drivers/pci/hotplug/Kconfig:menuconfig HOTPLUG_PCI drivers/pci/hotplug/Kconfig: bool "Support for PCI Hotplug" Remove uses of MODULE_DESCRIPTION(), MODULE_AUTHOR(), MODULE_LICENSE(), etc., so that when reading the driver there is no doubt it is builtin-only. The information is preserved in comments at the top of the file. Remove orphaned exit function in cpci_hotplug_core.c. Note that for non-modular code, module_init() translates to device_initcall(). One could argue that we should use subsys_initcall() here, but for now we stick with runtime equivalence. We would delete module.h and just keep the moduleparam.h include (since the file does use module_param), but there is a try_module_get and module_put pairing that prevents us from doing that. [bhelgaas: changelog] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Scott Murray <scott@spiteful.org> CC: Kristen Carlson Accardi <kristen@linux.intel.com>
2016-01-20Merge branch 'pci/trivial' into nextBjorn Helgaas
* pci/trivial: PCI: shpchp: Constify hpc_ops structure PCI: Use kobj_to_dev() instead of open-coding it PCI: Use to_pci_dev() instead of open-coding it PCI: Fix all whitespace issues PCI/MSI: Fix typos in <linux/msi.h>
2016-01-10PCI: hotplug: Use list_for_each_entry() to simplify codeGeliang Tang
Use list_for_each_entry() instead of list_for_each() to simplify the code. Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-01-08PCI: Fix all whitespace issuesBogicevic Sasa
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>
2015-07-15PCI: Use "slot" and "pci_slot" for struct hotplug_slot and struct pci_slotYijing Wang
Now in pci_hotplug_core.c, we randomly name a struct hotplug_slot and a struct pci_slot. It's easy to confuse them, so let us use "slot" for a struct hotplug_slot and "pci_slot" for a struct pci_slot. No functional change. Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-06-10PCI: Merge multi-line quoted stringsRyan Desfosses
Merge quoted strings that are broken across lines into a single entity. The compiler merges them anyway, but checkpatch complains about it, and merging them makes it easier to grep for strings. No functional change. [bhelgaas: changelog, do the same for everything under drivers/pci] Signed-off-by: Ryan Desfosses <ryan@desfo.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-06-10PCI: Whitespace cleanupRyan Desfosses
Fix various whitespace errors. No functional change. [bhelgaas: fix other similar problems] Signed-off-by: Ryan Desfosses <ryan@desfo.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-06-10PCI: Move EXPORT_SYMBOL so it immediately follows function/variableRyan Desfosses
Move EXPORT_SYMBOL so it immediately follows the function or variable. No functional change. [bhelgaas: squash similar changes, fix hotplug, probe, rom, search, too] Signed-off-by: Ryan Desfosses <ryan@desfo.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-11-14PCI: Fix whitespace, capitalization, and spelling errorsBjorn Helgaas
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>
2013-04-17PCI: Remove __must_check from definitionsBjorn Helgaas
The __must_check (gcc "warn_unused_result") attribute only makes sense when compiling the *caller* of the function, so the attribute should appear on the declaration in the header file, not on the definition. The declarations of these functions are already annotated with __must_check. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-04-15PCI: Remove unused variablesBjorn Helgaas
This fixes "set but not used" warnings found via "make W=1". Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-04-15PCI: Move cpci_hotplug_init() proto to header fileBjorn Helgaas
cpci_hotplug_init() and cpci_hotplug_exit() are defined in cpci_hotplug_core.c but had extern declarations in pci_hotplug_core.c. This puts the declarations in a header file included both places so the compiler can help keep everything consistent. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-01-13module_param: make bool parameters really bool (drivers & misc)Rusty Russell
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>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-02-22PCI: Make current and maximum bus speeds part of the PCI coreMatthew Wilcox
Move the max_bus_speed and cur_bus_speed into the pci_bus. Expose the values through the PCI slot driver instead of the hotplug slot driver. Update all the hotplug drivers to use the pci_bus instead of their own data structures. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-11-04PCI hotplug: change PCI nomenclatureStefan Assmann
Change PCI nomenclature according to http://www.pcisig.com/developers/procedures/logos/Trademark_and_Logo_Usage_Guidelines_updated_112206.pdf. Signed-off-by: Stefan Assmann <sassmann@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-09-09PCI hotplug: add support for 5.0G link speedKenji Kaneshige
Add support for PCI-E 5.0 GT/s in max_bus_speed and cur_bus_speed. Reviewed-by: Matthew Wilcox <matthew@wil.cx> Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-09-09PCI hotplug: fix typo in pcie link speed infoKenji Kaneshige
Fix typo in PCI-E link speed. Reviewed-by: Matthew Wilcox <matthew@wil.cx> Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-29PCI: fix kernel-doc warningsRandy Dunlap
Add documentation for missing parameters in PCI hotplug code. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-16PCI hotplug: create symlink to hotplug driver moduleKenji Kaneshige
Create symbolic link to hotplug driver module in the PCI slot directory (/sys/bus/pci/slots/<SLOT#>). In the past, we need to load hotplug drivers one by one to identify the hotplug driver that handles the slot, and it was very inconvenient especially for trouble shooting. With this change, we can easily identify the hotplug driver. Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com> Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Reviewed-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-16PCI hotplug: fix return value of has_foo() functionsKenji Kaneshige
Current has_foo() functions in pci_hotplug_core.c returns 0 if the "foo" property is true. It would cause misunderstanding. In addition, the error code of those functions is never checked, so this patch changes those functions' error code to 'bool' and return true if the property "foo" is true. Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Reviewed-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-10-22PCI: Hotplug core: remove 'name'Alex Chiang
Now that the PCI core manages the 'name' for each individual hotplug driver, and all drivers (except rpaphp) have been converted to use hotplug_slot_name(), there is no need for the PCI hotplug core to drag around its own copy of name either. Cc: kristen.c.accardi@intel.com Cc: matthew@wil.cx 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>
2008-10-22PCI: prevent duplicate slot namesAlex Chiang
Prevent callers of pci_create_slot() from registering slots with duplicate names. This condition occurs most often when PCI hotplug drivers are loaded on platforms with broken firmware that assigns identical names to multiple slots. We now rename these duplicate slots on behalf of the user. If firmware assigns the name N to multiple slots, then: The first registered slot is assigned N The second registered slot is assigned N-1 The third registered slot is assigned N-2 etc. This is the permanent fix mentioned in earlier commits d6a9e9b4 and 167e782e (shpchp/pciehp: Rename duplicate slot name...). We take advantage of the new 'hotplug' parameter in pci_create_slot() to prevent a slot create/rename race between hotplug drivers and detection drivers. Scenario A: hotplug driver detection driver -------------- ---------------- pci_create_slot(hotplug=set) pci_create_slot(hotplug=NULL) The hotplug driver creates the slot with its desired name, and then releases the semaphore. Now, the detection driver tries to create the same slot, but it already exists. We don't care about renaming, so return the existing slot. Scenario B: hotplug driver detection driver -------------- ---------------- pci_create_slot(hotplug=NULL) pci_create_slot(hotplug=set) The detection driver creates the slot with name "X". Then the hotplug driver tries to create the same slot, but wants the name "Y" instead. We detect that we're trying to create the same slot and that we also want a rename, so rename the slot to "Y" and return. Scenario C: hotplug driver hotplug driver -------------- ---------------- pci_create_slot(hotplug=set) pci_create_slot(hotplug=set) Two separate hotplug drivers are attempting to claim the slot and are passing valid hotplug_slot args to pci_create_slot(). We detect that the slot already has a ->hotplug callback, prevent a rename, and return -EBUSY. Cc: kristen.c.accardi@intel.com Cc: matthew@wil.cx 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>
2008-10-22PCI Hotplug: serialize pci_hp_register and pci_hp_deregisterKenji Kaneshige
Convert the pci_hotplug_slot_list_lock, which only protected the list of hotplug slots, to a pci_hp_mutex which now protects both interfaces. Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-10-22PCI: update pci_create_slot() to take a 'hotplug' paramAlex Chiang
Slot detection drivers can co-exist with hotplug drivers. The names of the detected/claimed slots may be different depending on module load order. For legacy reasons, we need to allow hotplug drivers to override the slot name if a detection driver is loaded first (and they find the same slots). Creating and overriding slot names should be an atomic operation, otherwise you get a locking nightmare as various drivers race to call pci_create_slot(). pci_create_slot() is already serialized by grabbing the pci_bus_sem. We update the API and add a 'hotplug' param, which is: set if the caller is a hotplug driver NULL if the caller is a detection driver pci_create_slot() does not actually use the 'hotplug' parameter in this patch. A later patch will add the logic that uses it. Cc: kristen.c.accardi@intel.com Cc: matthew@wil.cx 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>
2008-10-22PCI Hotplug core: add 'name' param pci_hp_register interfaceAlex Chiang
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>
2008-10-20PCI hotplug: fix get_##name return value problemKenji Kaneshige
The commit 356a9d6f3dd283f83861adf1ac909879f0e66411 (PCI: fix hotplug get_##name return value problem) doesn't seem to be merged properly. Because of this, PCI hotplug no longer works (Read/Write PCI hotplug files always returns -ENODEV). This patch fixes wrong check of try_module_get() return value check in get_##name(). Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-10-20PCI: fix hotplug get_##name return value problemZhao, Yu
Currently, get_##name in pci_hotplug_core.c will return 0 if module unload wins the race between unload & reading the hotplug file. Fix that case to return -ENODEV like it should. Reviewed-by: Alex Chiang <achiang@hp.com> Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Yu Zhao <yu.zhao@intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-06-25Remove unnecessary 'tmp' variable from pci_hp_register().Kenji Kaneshige
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-06-25PCI: fixup kdoc blocks for hotplug functionsJesse Barnes
A few warnings snuck in as parameters were added or renamed. Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-06-10PCI: ACPI PCI slot detection driverAlex Chiang
Detect all physical PCI slots as described by ACPI, and create entries in /sys/bus/pci/slots/. Not all physical slots are hotpluggable, and the acpiphp module does not detect them. Now we know the physical PCI geography of our system, without caring about hotplug. [kaneshige.kenji@jp.fujitsu.com: export-kobject_rename-for-pci_hotplug_core] Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Acked-by: Greg KH <greg@kroah.com> [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix build with CONFIG_DMI=n] Signed-off-by: Alex Chiang <achiang@hp.com> Cc: Greg KH <greg@kroah.com> Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Cc: Len Brown <lenb@kernel.org> Acked-by: Len Brown <len.brown@intel.com> Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-06-10PCI: introduce pci_slotAlex Chiang
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>
2008-05-27pci hotplug core: add check of duplicate slot nameKenji Kaneshige
Fix the following errors reported by Jan C. Nordholz in http://bugzilla.kernel.org/show_bug.cgi?id=10751. kobject_add_internal failed for 2 with -EEXIST, don't try to register things with the same name in the same directory. Pid: 1, comm: swapper Tainted: G W 2.6.26-rc3 #1 [<c0266980>] kobject_add_internal+0x140/0x190 [<c0266afd>] kobject_init_and_add+0x2d/0x40 [<c027bc91>] pci_hp_register+0x81/0x2f0 [<c027fd07>] pciehp_probe+0x1a7/0x470 [<c01b3b84>] sysfs_add_one+0x44/0xa0 [<c01b3c1f>] sysfs_addrm_start+0x3f/0xb0 [<c01b497a>] sysfs_create_link+0x8a/0xf0 [<c0279570>] pcie_port_probe_service+0x50/0x80 [<c02e0545>] driver_sysfs_add+0x55/0x70 [<c02e0662>] driver_probe_device+0x82/0x180 [<c02e07cc>] __driver_attach+0x6c/0x70 [<c02dfe0a>] bus_for_each_dev+0x3a/0x60 [<c05db2d0>] pcied_init+0x0/0x80 [<c02e04e6>] driver_attach+0x16/0x20 [<c02e0760>] __driver_attach+0x0/0x70 [<c02e0341>] bus_add_driver+0x1a1/0x220 [<c05db2d0>] pcied_init+0x0/0x80 [<c02e09cd>] driver_register+0x4d/0x120 [<c05db050>] ibm_acpiphp_init+0x0/0x190 [<c0125aab>] printk+0x1b/0x20 [<c05db2d0>] pcied_init+0x0/0x80 [<c05db2de>] pcied_init+0xe/0x80 [<c05c751a>] kernel_init+0x10a/0x300 [<c0120138>] schedule_tail+0x18/0x50 [<c0103b9a>] ret_from_fork+0x6/0x1c [<c05c7410>] kernel_init+0x0/0x300 [<c05c7410>] kernel_init+0x0/0x300 [<c010485b>] kernel_thread_helper+0x7/0x1c ======================= pci_hotplug: Unable to register kobject '2'<3>pciehp: pci_hp_register failed with error -22 Slot with the same name can be registered multiple times if shpchp or pciehp driver is loaded after acpiphp is loaded because ACPI based hotplug driver and Native OS hotplug driver trying to handle the same physical slot. In this case, current pci_hotplug core will call kobject_init_and_add() muliple time with the same name. This is the cause of this problem. To fix this problem, this patch adds the check into pci_hp_register() to see if the slot with the same name. Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-04-20PCI: replace remaining __FUNCTION__ occurrencesHarvey Harrison
__FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-01PCI: Add missing "space" in printk messagesJoe Perches
Signed-off-by: Joe Perches <joe@perches.com> Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-01PCI: hotplug: pci_hotplug_core whitespace fixAlex Chiang
Remove superfluous space. Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Matthew Wilcox <matthew@wil.cx> Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24Kobject: convert drivers/* from kobject_unregister() to kobject_put()Greg Kroah-Hartman
There is no need for kobject_unregister() anymore, thanks to Kay's kobject cleanup changes, so replace all instances of it with kobject_put(). Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24driver core: add way to get to bus ksetGreg Kroah-Hartman
This allows an easier way to get to the kset associated with a struct bus_type (you have three to choose from...) This will make it easier to move these fields to be dynamic in a future patch. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24Kobject: change drivers/pci/hotplug/pci_hotplug_core.c to use ↵Greg Kroah-Hartman
kobject_init_and_add Stop using kobject_register, as this way we can control the sending of the uevent properly, after everything is properly initialized. Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24kset: convert pci hotplug to use kset_create_and_addGreg Kroah-Hartman
This also renames pci_hotplug_slots_subsys to pcis_hotplug_slots_kset catch all current users with a build error instead of a build warning which can easily be missed. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24kobject: remove struct kobj_type from struct ksetGreg Kroah-Hartman
We don't need a "default" ktype for a kset. We should set this explicitly every time for each kset. This change is needed so that we can make ksets dynamic, and cleans up one of the odd, undocumented assumption that the kset/kobject/ktype model has. This patch is based on a lot of help from Kay Sievers. Nasty bug in the block code was found by Dave Young <hidave.darkstar@gmail.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-15Get rid of unused variable warning in drivers/pci/hotplug/pci_hotplug_core.cLinus Torvalds
Commit 5a7ad7f044941316dc98eda2a087a12a7a50649d removed all uses of 'retval', but didn't remove the variable itself. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-12sysfs: kill sysfs_update_file()Tejun Heo
sysfs_update_file() depends on inode->i_mtime but sysfs iondes are now reclaimable making the reported modification time unreliable. There's only one user (pci hotplug) of this notification mechanism and it reportedly isn't utilized from userland. Kill sysfs_update_file(). Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>