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2023-09-11arch: Remove Itanium (IA-64) architectureArd Biesheuvel
The Itanium architecture is obsolete, and an informal survey [0] reveals that any residual use of Itanium hardware in production is mostly HP-UX or OpenVMS based. The use of Linux on Itanium appears to be limited to enthusiasts that occasionally boot a fresh Linux kernel to see whether things are still working as intended, and perhaps to churn out some distro packages that are rarely used in practice. None of the original companies behind Itanium still produce or support any hardware or software for the architecture, and it is listed as 'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers that contributed on behalf of those companies (nor anyone else, for that matter) have been willing to support or maintain the architecture upstream or even be responsible for applying the odd fix. The Intel firmware team removed all IA-64 support from the Tianocore/EDK2 reference implementation of EFI in 2018. (Itanium is the original architecture for which EFI was developed, and the way Linux supports it deviates significantly from other architectures.) Some distros, such as Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have dropped support years ago. While the argument is being made [1] that there is a 'for the common good' angle to being able to build and run existing projects such as the Grid Community Toolkit [2] on Itanium for interoperability testing, the fact remains that none of those projects are known to be deployed on Linux/ia64, and very few people actually have access to such a system in the first place. Even if there were ways imaginable in which Linux/ia64 could be put to good use today, what matters is whether anyone is actually doing that, and this does not appear to be the case. There are no emulators widely available, and so boot testing Itanium is generally infeasible for ordinary contributors. GCC still supports IA-64 but its compile farm [3] no longer has any IA-64 machines. GLIBC would like to get rid of IA-64 [4] too because it would permit some overdue code cleanups. In summary, the benefits to the ecosystem of having IA-64 be part of it are mostly theoretical, whereas the maintenance overhead of keeping it supported is real. So let's rip off the band aid, and remove the IA-64 arch code entirely. This follows the timeline proposed by the Debian/ia64 maintainer [5], which removes support in a controlled manner, leaving IA-64 in a known good state in the most recent LTS release. Other projects will follow once the kernel support is removed. [0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/ [1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/ [2] https://gridcf.org/gct-docs/latest/index.html [3] https://cfarm.tetaneutral.net/machines/list/ [4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/ [5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/ Acked-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-08-18arch/ia64/include: remove CONFIG_IA64_DEBUG_CMPXCHG from uapi headerThomas Huth
CONFIG_* switches should not be exposed in uapi headers. The macros that are defined here are also only useful for the kernel code, so let's move them to asm/cmpxchg.h instead. The only two files that are using these macros are the headers arch/ia64/include/asm/bitops.h and arch/ia64/include/asm/atomic.h and these include asm/cmpxchg.h via asm/intrinsics.h, so this movement should not cause any trouble. Link: https://lkml.kernel.org/r/20230426065032.517693-1-thuth@redhat.com Signed-off-by: Thomas Huth <thuth@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-29locking/arch: Rename all internal __xchg() names to __arch_xchg()Andrzej Hajda
Decrease the probability of this internal facility to be used by driver code. Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Acked-by: Palmer Dabbelt <palmer@rivosinc.com> [riscv] Link: https://lore.kernel.org/r/20230118154450.73842-1-andrzej.hajda@intel.com Cc: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-26locking/atomic: ia64: move to ARCH_ATOMICMark Rutland
We'd like all architectures to convert to ARCH_ATOMIC, as once all architectures are converted it will be possible to make significant cleanups to the atomics headers, and this will make it much easier to generically enable atomic functionality (e.g. debug logic in the instrumented wrappers). As a step towards that, this patch migrates ia64 to ARCH_ATOMIC. The arch code provides arch_{atomic,atomic64,xchg,cmpxchg}*(), and common code wraps these with optional instrumentation to provide the regular functions. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210525140232.53872-20-mark.rutland@arm.com
2012-10-09UAPI: (Scripted) Disintegrate arch/ia64/include/asmDavid Howells
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
2012-04-13ia64: populate the cmpxchg header with appropriate codePaul Gortmaker
commit 93f378883cecb9dcb2cf5b51d9d24175906659da "Fix ia64 build errors (fallout from system.h disintegration)" introduced arch/ia64/include/asm/cmpxchg.h as a temporary build fix and stated: "... leave the migration of xchg() and cmpxchg() to this new header file for a future patch." Migrate the appropriate chunks from asm/intrinsics.h and fix the whitespace issues in the migrated chunk. Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: David Howells <dhowells@redhat.com> Acked-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-03-30ia64: Fixup asm/cmpxchg.hDavid Howells
The empty asm/cmpxchg.h file that was provided as a temporary build fix for the asm/system.h disintgration build problem should really include <asm/intrinsics.h> to make definitions of xchg() and cmpxchg() available. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-29Fix ia64 build errors (fallout from system.h disintegration)Luck, Tony
Fix this build error on ia64: In file included from include/linux/sched.h:92, from arch/ia64/kernel/asm-offsets.c:9: include/linux/llist.h:59:25: error: asm/cmpxchg.h: No such file or directory make[1]: *** [arch/ia64/kernel/asm-offsets.s] Error 1 Right now we don't seem to need any actual contents for the asm/cmpxchg.h to make the build work ... so leave the migration of xchg() and cmpxchg() to this new header file for a future patch. Also process.c needs <asm/switch_to.h> (for definition of pfm_syst_info). Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>