forked from Minki/linux
fd9879b9bb
Pull powerpc updates from Michael Ellerman: "Here's a first pull request for powerpc updates for 3.18. The bulk of the additions are for the "cxl" driver, for IBM's Coherent Accelerator Processor Interface (CAPI). Most of it's in drivers/misc, which Greg & Arnd maintain, Greg said he was happy for us to take it through our tree. There's the usual minor cleanups and fixes, including a bit of noise in drivers from some of those. A bunch of updates to our EEH code, which has been getting more testing. Several nice speedups from Anton, including 20% in clear_page(). And a bunch of updates for freescale from Scott" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (130 commits) cxl: Fix afu_read() not doing finish_wait() on signal or non-blocking cxl: Add documentation for userspace APIs cxl: Add driver to Kbuild and Makefiles cxl: Add userspace header file cxl: Driver code for powernv PCIe based cards for userspace access cxl: Add base builtin support powerpc/mm: Add hooks for cxl powerpc/opal: Add PHB to cxl mode call powerpc/mm: Add new hash_page_mm() powerpc/powerpc: Add new PCIe functions for allocating cxl interrupts cxl: Add new header for call backs and structs powerpc/powernv: Split out set MSI IRQ chip code powerpc/mm: Export mmu_kernel_ssize and mmu_linear_psize powerpc/msi: Improve IRQ bitmap allocator powerpc/cell: Make spu_flush_all_slbs() generic powerpc/cell: Move data segment faulting code out of cell platform powerpc/cell: Move spu_handle_mm_fault() out of cell platform powerpc/pseries: Use new defines when calling H_SET_MODE powerpc: Update contact info in Documentation files powerpc/perf/hv-24x7: Simplify catalog_read() ... |
||
|---|---|---|
| .. | ||
| obsolete | ||
| removed | ||
| stable | ||
| testing | ||
| README | ||
This directory attempts to document the ABI between the Linux kernel and userspace, and the relative stability of these interfaces. Due to the everchanging nature of Linux, and the differing maturity levels, these interfaces should be used by userspace programs in different ways. We have four different levels of ABI stability, as shown by the four different subdirectories in this location. Interfaces may change levels of stability according to the rules described below. The different levels of stability are: stable/ This directory documents the interfaces that the developer has defined to be stable. Userspace programs are free to use these interfaces with no restrictions, and backward compatibility for them will be guaranteed for at least 2 years. Most interfaces (like syscalls) are expected to never change and always be available. testing/ This directory documents interfaces that are felt to be stable, as the main development of this interface has been completed. The interface can be changed to add new features, but the current interface will not break by doing this, unless grave errors or security problems are found in them. Userspace programs can start to rely on these interfaces, but they must be aware of changes that can occur before these interfaces move to be marked stable. Programs that use these interfaces are strongly encouraged to add their name to the description of these interfaces, so that the kernel developers can easily notify them if any changes occur (see the description of the layout of the files below for details on how to do this.) obsolete/ This directory documents interfaces that are still remaining in the kernel, but are marked to be removed at some later point in time. The description of the interface will document the reason why it is obsolete and when it can be expected to be removed. removed/ This directory contains a list of the old interfaces that have been removed from the kernel. Every file in these directories will contain the following information: What: Short description of the interface Date: Date created KernelVersion: Kernel version this feature first showed up in. Contact: Primary contact for this interface (may be a mailing list) Description: Long description of the interface and how to use it. Users: All users of this interface who wish to be notified when it changes. This is very important for interfaces in the "testing" stage, so that kernel developers can work with userspace developers to ensure that things do not break in ways that are unacceptable. It is also important to get feedback for these interfaces to make sure they are working in a proper way and do not need to be changed further. How things move between levels: Interfaces in stable may move to obsolete, as long as the proper notification is given. Interfaces may be removed from obsolete and the kernel as long as the documented amount of time has gone by. Interfaces in the testing state can move to the stable state when the developers feel they are finished. They cannot be removed from the kernel tree without going through the obsolete state first. It's up to the developer to place their interfaces in the category they wish for it to start out in. Notable bits of non-ABI, which should not under any circumstances be considered stable: - Kconfig. Userspace should not rely on the presence or absence of any particular Kconfig symbol, in /proc/config.gz, in the copy of .config commonly installed to /boot, or in any invocation of the kernel build process. - Kernel-internal symbols. Do not rely on the presence, absence, location, or type of any kernel symbol, either in System.map files or the kernel binary itself. See Documentation/stable_api_nonsense.txt.