summaryrefslogtreecommitdiff
path: root/include/uapi/linux/aspeed-lpc-ctrl.h
Commit message (Collapse)AuthorAgeFilesLines
* License cleanup: add SPDX license identifier to uapi header files with a licenseGreg Kroah-Hartman2017-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many user space API headers have licensing information, which is either incomplete, badly formatted or just a shorthand for referring to the license under which the file is supposed to be. This makes it hard for compliance tools to determine the correct license. Update these files with an SPDX license identifier. The identifier was chosen based on the license information in the file. GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license identifier with the added 'WITH Linux-syscall-note' exception, which is the officially assigned exception identifier for the kernel syscall exception: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". This exception makes it possible to include GPL headers into non GPL code, without confusing license compliance tools. Headers which have either explicit dual licensing or are just licensed under a non GPL license are updated with the corresponding SPDX identifier and the GPLv2 with syscall exception identifier. The format is: ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE) SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. The update does not remove existing license information as this has to be done on a case by case basis and the copyright holders might have to be consulted. This will happen in a separate step. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* aspeed-lpc-ctrl: include linux/types.h for uapi headerArnd Bergmann2017-04-081-0/+1
| | | | | | | | | | | | | | The newly added header file triggers a sanity check: usr/include/linux/aspeed-lpc-ctrl.h:44: found __[us]{8,16,32,64} type without #include <linux/types.h> We should include linux/types.h explicitly to ensure the header can be included from user space. Fixes: 6c4e97678501 ("drivers/misc: Add Aspeed LPC control driver") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers/misc: Add Aspeed LPC control driverCyril Bur2017-03-171-0/+60
In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>