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path: root/drivers/pci/slot.c
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2015-07-31PCI: Hold pci_slot_mutex while searching bus->slots listYijing Wang1-0/+11
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>
2015-07-30PCI: Protect pci_bus->slots with pci_slot_mutex, not pci_bus_semYijing Wang1-7/+11
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>
2014-03-24VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms.Rusty Russell1-3/+3
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>
2014-01-13PCI: Remove unused pci_renumber_slot()Stephen Hemminger1-26/+0
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>
2013-11-14PCI: Fix whitespace, capitalization, and spelling errorsBjorn Helgaas1-1/+1
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: Warn about failures instead of "must_check" functionsBjorn Helgaas1-2/+5
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>
2011-11-01pci: add module.h to files implicitly relying on its presence.Paul Gortmaker1-0/+1
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>
2010-09-01PCI: bus speed strings should be constStephen Hemminger1-1/+1
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-06-12Revert "PCI: create function symlinks in /sys/bus/pci/slots/N/"Jesse Barnes1-48/+0
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>
2010-05-11PCI: create function symlinks in /sys/bus/pci/slots/N/Alex Chiang1-0/+48
Create convenience symlinks in sysfs, linking slots to device functions, and vice versa. These links make it easier for users to figure out which devices actually live in what slots. For example: sapphire:/sys/bus/pci/slots # ls 1 10 2 3 4 5 6 7 8 9 sapphire:/sys/bus/pci/slots # ls -l 3 total 0 -r--r--r-- 1 root root 65536 Aug 18 14:10 address lrwxrwxrwx 1 root root 0 Aug 18 14:10 function0 -> ../../../../devices/pci0000:23/0000:23:01.0 lrwxrwxrwx 1 root root 0 Aug 18 14:10 function1 -> ../../../../devices/pci0000:23/0000:23:01.1 sapphire:/sys/bus/pci/slots # ls -l 3/function0/slot lrwxrwxrwx 1 root root 0 Aug 18 14:13 3/function0/slot -> ../../../bus/pci/slots/3 The original form of this patch was written by Matthew Wilcox, and was enhanced to include links from the sysfs slots/ directory pointing back at the device functions. Cc: willy@linux.intel.com Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo1-0/+1
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>
2010-03-08Driver core: Constify struct sysfs_ops in struct kobj_typeEmese Revfy1-1/+1
Constify struct sysfs_ops. This is part of the ops structure constification effort started by Arjan van de Ven et al. Benefits of this constification: * prevents modification of data that is shared (referenced) by many other structure instances at runtime * detects/prevents accidental (but not intentional) modification attempts on archs that enforce read-only kernel data at runtime * potentially better optimized code as the compiler can assume that the const data cannot be changed * the compiler/linker move const data into .rodata and therefore exclude them from false sharing Signed-off-by: Emese Revfy <re.emese@gmail.com> Acked-by: David Teigland <teigland@redhat.com> Acked-by: Matt Domsch <Matt_Domsch@dell.com> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Acked-by: Hans J. Koch <hjk@linutronix.de> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Jens Axboe <jens.axboe@oracle.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-02-23PCI: Add support for reporting PCIe 3.0 speedsMatthew Wilcox1-0/+1
Add the 8.0 GT/s speed. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-02-23PCI: Add support for AGP in cur/max bus speedMatthew Wilcox1-5/+5
Take advantage of some gaps in the table to fit in support for AGP speeds. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-02-23PCI: Make current and maximum bus speeds part of the PCI coreMatthew Wilcox1-0/+54
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>
2009-06-29PCI: fix kernel-doc warningsRandy Dunlap1-2/+2
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>
2009-06-17PCI hotplug: create symlink to hotplug driver moduleKenji Kaneshige1-0/+39
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>
2009-04-23docbooks: add/fix PCI kernel-docRandy Dunlap1-2/+2
Add drivers/pci/*.c source files to DocBook/kernel-api.tmpl and update those pci/*.c source files that need kernel-doc fixes. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-03-20PCI: enhance physical slot debug informationAlex Chiang1-10/+8
Convert usages of pr_debug to dev_dbg and add physical slot name. Note that we use dev_dbg on the struct pci_bus and still manually print out the PCI slot number (instead of calling dev_dbg on a pci_dev) because a struct pci_bus with empty physical slots will not have any pci_devs. Reviewed-by: Andrew Patterson <andrew.patterson@hp.com> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-12-10PCI: stop leaking 'slot_name' in pci_create_slotAlex Chiang1-0/+1
In pci_create_slot(), the local variable 'slot_name' is allocated by make_slot_name(), but never freed. We never use it after passing it to the kobject core, so we should free it upon function exit. Cc: stable@kernel.org Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-10-23PCI, PCI Hotplug: introduce slot_name helpersAlex Chiang1-1/+1
In preparation for cleaning up the various hotplug drivers such that they don't have to manage their own 'name' parameters anymore, we provide the following convenience functions: pci_slot_name() hotplug_slot_name() These helpers will be used by individual hotplug drivers. 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>
2008-10-23PCI: prevent duplicate slot namesAlex Chiang1-28/+113
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>
2008-10-23PCI: update pci_create_slot() to take a 'hotplug' paramAlex Chiang1-1/+3
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>
2008-10-23PCI: rename pci_update_slot_number to pci_renumber_slotAlex Chiang1-10/+5
The GPL exported symbol pci_update_slot_number has been renamed to pci_renumber_slot. Some of the safety checks were unnecessary and were removed. 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>
2008-10-20PCI: connect struct pci_dev to struct pci_slotAlex Chiang1-0/+10
The introduction of struct pci_slot (f46753c5e354b857b20ab8e0fe7b25) added a struct pci_slot pointer to struct pci_dev, but we forgot to associate the two. Connect the two structs together; the interesting portions of the object lifetimes are: - when a new pci_slot is created, connect it to the appropriate pci_dev's. A single pci_slot may be associated with multiple pci_dev's, e.g. any multi-function PCI device. - when a pci_slot is released, look for all the pci_dev's it was associated with, and set their pci_slot pointers to NULL - when a pci_dev is created, look for slots to associate with. Note -- when a pci_dev is released, we don't need to do any bookkeeping, since pci_slot's do not have pointers to pci_dev's. Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-06-11PCI: introduce pci_slotAlex Chiang1-0/+233
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>