kernel/linux.git/drivers/pci/hotplug/cpqphp_ctrl.c, branch v6.6.132

PCI: cpqphp: Remove unused assignments

2022-03-22T16:24:40+00:00

Remove variables and assignments that are never used. Found by Krzysztof using cppcheck, e.g.: $ cppcheck --enable=all --force unreadVariable drivers/pci/hotplug/cpqphp_core.c:1257 Variable 'rc' is assigned a value that is never used. Reported-by: Krzysztof Wilczyński Link: https://lore.kernel.org/r/20220313192933.434746-5-helgaas@kernel.org Signed-off-by: Bjorn Helgaas

PCI: cpqphp: Use PCI_POSSIBLE_ERROR() to check config reads

2021-11-18T20:13:18+00:00

When config pci_ops.read() can detect failed PCI transactions, the data returned to the CPU is PCI_ERROR_RESPONSE (~0 or 0xffffffff). Obviously a successful PCI config read may *also* return that data if a config register happens to contain ~0, so it doesn't definitively indicate an error unless we know the register cannot contain ~0. Use PCI_POSSIBLE_ERROR() to check the response we get when we read data from hardware. This unifies PCI error response checking and makes error checks consistent and easier to find. Link: https://lore.kernel.org/r/b12005c0d57bb9d4c8b486724d078b7bd92f8321.1637243717.git.naveennaidu479@gmail.com Signed-off-by: Naveen Naidu Signed-off-by: Bjorn Helgaas

PCI: Correct misspelled and remove duplicated words

2021-10-08T22:14:04+00:00

Correct a number of misspelled words and remove any words that were duplicated in the PCI tree. No change to functionality intended. Link: https://lore.kernel.org/r/20211006233827.147328-1-kw@linux.com Signed-off-by: Krzysztof Wilczyński Signed-off-by: Bjorn Helgaas

PCI: Fix kernel-doc formatting

2021-07-06T15:37:46+00:00

Fix kernel-doc formatting throughout drivers/pci and related include files. No change to functionality intended. Check for warnings: $ find include drivers/pci -type f -path "*pci*.[ch]" | xargs scripts/kernel-doc -none [bhelgaas: squashed to one commit] Link: https://lore.kernel.org/r/20210509030237.368540-1-kw@linux.com Link: https://lore.kernel.org/r/20210703151306.1922450-1-kw@linux.com Link: https://lore.kernel.org/r/20210703151306.1922450-2-kw@linux.com Link: https://lore.kernel.org/r/20210703151306.1922450-3-kw@linux.com Link: https://lore.kernel.org/r/20210703151306.1922450-4-kw@linux.com Link: https://lore.kernel.org/r/20210703151306.1922450-5-kw@linux.com Signed-off-by: Krzysztof Wilczyński Signed-off-by: Bjorn Helgaas

PCI: Remove unnecessary returns

2019-08-30T19:00:34+00:00

Remove unnecessary "return" statements at the end of void functions. No functional change intended. Link: https://lore.kernel.org/r/20190825221039.6977-1-kw@linux.com Link: https://lore.kernel.org/r/20190826095143.21353-1-kw@linux.com Signed-off-by: Krzysztof Wilczynski Signed-off-by: Bjorn Helgaas

PCI: hotplug: Embed hotplug_slot

2018-09-18T22:52:15+00:00

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 Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki Acked-by: Tyrel Datwyler # drivers/pci/hotplug/rpa* Acked-by: Sebastian Ott # drivers/pci/hotplug/s390* Acked-by: Andy Shevchenko # drivers/platform/x86 Cc: Len Brown Cc: Scott Murray Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Oliver OHalloran Cc: Gavin Shan Cc: Gerald Schaefer Cc: Corentin Chary Cc: Darren Hart

PCI: hotplug: Drop hotplug_slot_info

2018-09-18T22:52:15+00:00

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 Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki Acked-by: Tyrel Datwyler # drivers/pci/hotplug/rpa* Acked-by: Sebastian Ott # drivers/pci/hotplug/s390* Acked-by: Andy Shevchenko # drivers/platform/x86 Cc: Len Brown Cc: Scott Murray Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Oliver OHalloran Cc: Gavin Shan Cc: Gerald Schaefer Cc: Corentin Chary Cc: Darren Hart

PCI: cpqphp: Fix possible NULL pointer dereference

2018-02-28T20:35:54+00:00

Check io_node for NULL before dereferencing it. Signed-off-by: Shawn Lin Signed-off-by: Bjorn Helgaas

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

2018-01-28T21:49:06+00:00

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 Reviewed-by: Greg Kroah-Hartman

PCI: cpqphp: Convert timers to use timer_setup()

2017-11-07T00:48:57+00:00

In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. This has the result of fixing pushbutton_helper_thread(), which was truncating the event pointer to 32 bits. Signed-off-by: Kees Cook Signed-off-by: Bjorn Helgaas Cc: Ingo Molnar Cc: Arvind Yadav Cc: Quentin Lambert Cc: Aleksandr Bezzubikov Cc: "Michael S. Tsirkin" Cc: Marcel Apfelbaum