kernel/drivers/pci/hotplug/rpaphp.h, branch 0x221E-v0.0.1-v6.19

PCI: hotplug: Embed hotplug_slot

2018-09-18T22:52:15Z

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

2018-09-18T22:52:15Z

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: hotplug: Constify hotplug_slot_ops

2018-09-18T22:52:15Z

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 Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki Acked-by: Tyrel Datwyler # drivers/pci/hotplug/rpa* 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: Sebastian Ott Cc: Gerald Schaefer Cc: Corentin Chary Cc: Darren Hart

Merge tag 'pci-v4.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2018-02-06T17:59:40Z

Pull PCI updates from Bjorn Helgaas: - skip AER driver error recovery callbacks for correctable errors reported via ACPI APEI, as we already do for errors reported via the native path (Tyler Baicar) - fix DPC shared interrupt handling (Alex Williamson) - print full DPC interrupt number (Keith Busch) - enable DPC only if AER is available (Keith Busch) - simplify DPC code (Bjorn Helgaas) - calculate ASPM L1 substate parameter instead of hardcoding it (Bjorn Helgaas) - enable Latency Tolerance Reporting for ASPM L1 substates (Bjorn Helgaas) - move ASPM internal interfaces out of public header (Bjorn Helgaas) - allow hot-removal of VGA devices (Mika Westerberg) - speed up unplug and shutdown by assuming Thunderbolt controllers don't support Command Completed events (Lukas Wunner) - add AtomicOps support for GPU and Infiniband drivers (Felix Kuehling, Jay Cornwall) - expose "ari_enabled" in sysfs to help NIC naming (Stuart Hayes) - clean up PCI DMA interface usage (Christoph Hellwig) - remove PCI pool API (replaced with DMA pool) (Romain Perier) - deprecate pci_get_bus_and_slot(), which assumed PCI domain 0 (Sinan Kaya) - move DT PCI code from drivers/of/ to drivers/pci/ (Rob Herring) - add PCI-specific wrappers for dev_info(), etc (Frederick Lawler) - remove warnings on sysfs mmap failure (Bjorn Helgaas) - quiet ROM validation messages (Alex Deucher) - remove redundant memory alloc failure messages (Markus Elfring) - fill in types for compile-time VGA and other I/O port resources (Bjorn Helgaas) - make "pci=pcie_scan_all" work for Root Ports as well as Downstream Ports to help AmigaOne X1000 (Bjorn Helgaas) - add SPDX tags to all PCI files (Bjorn Helgaas) - quirk Marvell 9128 DMA aliases (Alex Williamson) - quirk broken INTx disable on Ceton InfiniTV4 (Bjorn Helgaas) - fix CONFIG_PCI=n build by adding dummy pci_irqd_intx_xlate() (Niklas Cassel) - use DMA API to get MSI address for DesignWare IP (Niklas Cassel) - fix endpoint-mode DMA mask configuration (Kishon Vijay Abraham I) - fix ARTPEC-6 incorrect IS_ERR() usage (Wei Yongjun) - add support for ARTPEC-7 SoC (Niklas Cassel) - add endpoint-mode support for ARTPEC (Niklas Cassel) - add Cadence PCIe host and endpoint controller driver (Cyrille Pitchen) - handle multiple INTx status bits being set in dra7xx (Vignesh R) - translate dra7xx hwirq range to fix INTD handling (Vignesh R) - remove deprecated Exynos PHY initialization code (Jaehoon Chung) - fix MSI erratum workaround for HiSilicon Hip06/Hip07 (Dongdong Liu) - fix NULL pointer dereference in iProc BCMA driver (Ray Jui) - fix Keystone interrupt-controller-node lookup (Johan Hovold) - constify qcom driver structures (Julia Lawall) - rework Tegra config space mapping to increase space available for endpoints (Vidya Sagar) - simplify Tegra driver by using bus->sysdata (Manikanta Maddireddy) - remove PCI_REASSIGN_ALL_BUS usage on Tegra (Manikanta Maddireddy) - add support for Global Fabric Manager Server (GFMS) event to Microsemi Switchtec switch driver (Logan Gunthorpe) - add IDs for Switchtec PSX 24xG3 and PSX 48xG3 (Kelvin Cao) * tag 'pci-v4.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (140 commits) PCI: cadence: Add EndPoint Controller driver for Cadence PCIe controller dt-bindings: PCI: cadence: Add DT bindings for Cadence PCIe endpoint controller PCI: endpoint: Fix EPF device name to support multi-function devices PCI: endpoint: Add the function number as argument to EPC ops PCI: cadence: Add host driver for Cadence PCIe controller dt-bindings: PCI: cadence: Add DT bindings for Cadence PCIe host controller PCI: Add vendor ID for Cadence PCI: Add generic function to probe PCI host controllers PCI: generic: fix missing call of pci_free_resource_list() PCI: OF: Add generic function to parse and allocate PCI resources PCI: Regroup all PCI related entries into drivers/pci/Makefile PCI/DPC: Reformat DPC register definitions PCI/DPC: Add and use DPC Status register field definitions PCI/DPC: Squash dpc_rp_pio_get_info() into dpc_process_rp_pio_error() PCI/DPC: Remove unnecessary RP PIO register structs PCI/DPC: Push dpc->rp_pio_status assignment into dpc_rp_pio_get_info() PCI/DPC: Squash dpc_rp_pio_print_error() into dpc_rp_pio_get_info() PCI/DPC: Make RP PIO log size check more generic PCI/DPC: Rename local "status" to "dpc_status" PCI/DPC: Squash dpc_rp_pio_print_tlp_header() into dpc_rp_pio_print_error() ...

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

2018-01-28T21:49:06Z

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

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

2018-01-21T05:21:48Z

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 Signed-off-by: Michael Ellerman

PCI: Fix all whitespace issues

2016-01-08T16:35:24Z

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 Signed-off-by: Bjorn Helgaas

PCI: Fix whitespace, capitalization, and spelling errors

2013-11-14T18:28:18Z

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 (pci_reset_bridge_secondary_bus()) Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki

PCI: Remove "extern" from function declarations

2013-04-17T16:21:17Z

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

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

2012-01-12T23:02:20Z

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 Signed-off-by: Rusty Russell