arch: Remove Itanium (IA-64) architecture

The Itanium architecture is obsolete, and an informal survey [0] reveals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>

1 files changed, 0 insertions, 233 deletions

diff --git a/arch/ia64/include/asm/elf.h b/arch/ia64/include/asm/elf.h
deleted file mode 100644
index 2ef5f9966ad1..000000000000
--- a/arch/ia64/include/asm/elf.h
+++ /dev/null
@@ -1,233 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_IA64_ELF_H
-#define _ASM_IA64_ELF_H
-
-/*
- * ELF-specific definitions.
- *
- * Copyright (C) 1998-1999, 2002-2004 Hewlett-Packard Co
- *	David Mosberger-Tang <davidm@hpl.hp.com>
- */
-
-
-#include <asm/fpu.h>
-#include <asm/page.h>
-#include <asm/auxvec.h>
-
-/*
- * This is used to ensure we don't load something for the wrong architecture.
- */
-#define elf_check_arch(x) ((x)->e_machine == EM_IA_64)
-
-/*
- * These are used to set parameters in the core dumps.
- */
-#define ELF_CLASS	ELFCLASS64
-#define ELF_DATA	ELFDATA2LSB
-#define ELF_ARCH	EM_IA_64
-
-#define CORE_DUMP_USE_REGSET
-
-/* Least-significant four bits of ELF header's e_flags are OS-specific.  The bits are
-   interpreted as follows by Linux: */
-#define EF_IA_64_LINUX_EXECUTABLE_STACK	0x1	/* is stack (& heap) executable by default? */
-
-#define ELF_EXEC_PAGESIZE	PAGE_SIZE
-
-/*
- * This is the location that an ET_DYN program is loaded if exec'ed.
- * Typical use of this is to invoke "./ld.so someprog" to test out a
- * new version of the loader.  We need to make sure that it is out of
- * the way of the program that it will "exec", and that there is
- * sufficient room for the brk.
- */
-#define ELF_ET_DYN_BASE		(TASK_UNMAPPED_BASE + 0x800000000UL)
-
-#define PT_IA_64_UNWIND		0x70000001
-
-/* IA-64 relocations: */
-#define R_IA64_NONE		0x00	/* none */
-#define R_IA64_IMM14		0x21	/* symbol + addend, add imm14 */
-#define R_IA64_IMM22		0x22	/* symbol + addend, add imm22 */
-#define R_IA64_IMM64		0x23	/* symbol + addend, mov imm64 */
-#define R_IA64_DIR32MSB		0x24	/* symbol + addend, data4 MSB */
-#define R_IA64_DIR32LSB		0x25	/* symbol + addend, data4 LSB */
-#define R_IA64_DIR64MSB		0x26	/* symbol + addend, data8 MSB */
-#define R_IA64_DIR64LSB		0x27	/* symbol + addend, data8 LSB */
-#define R_IA64_GPREL22		0x2a	/* @gprel(sym+add), add imm22 */
-#define R_IA64_GPREL64I		0x2b	/* @gprel(sym+add), mov imm64 */
-#define R_IA64_GPREL32MSB	0x2c	/* @gprel(sym+add), data4 MSB */
-#define R_IA64_GPREL32LSB	0x2d	/* @gprel(sym+add), data4 LSB */
-#define R_IA64_GPREL64MSB	0x2e	/* @gprel(sym+add), data8 MSB */
-#define R_IA64_GPREL64LSB	0x2f	/* @gprel(sym+add), data8 LSB */
-#define R_IA64_LTOFF22		0x32	/* @ltoff(sym+add), add imm22 */
-#define R_IA64_LTOFF64I		0x33	/* @ltoff(sym+add), mov imm64 */
-#define R_IA64_PLTOFF22		0x3a	/* @pltoff(sym+add), add imm22 */
-#define R_IA64_PLTOFF64I	0x3b	/* @pltoff(sym+add), mov imm64 */
-#define R_IA64_PLTOFF64MSB	0x3e	/* @pltoff(sym+add), data8 MSB */
-#define R_IA64_PLTOFF64LSB	0x3f	/* @pltoff(sym+add), data8 LSB */
-#define R_IA64_FPTR64I		0x43	/* @fptr(sym+add), mov imm64 */
-#define R_IA64_FPTR32MSB	0x44	/* @fptr(sym+add), data4 MSB */
-#define R_IA64_FPTR32LSB	0x45	/* @fptr(sym+add), data4 LSB */
-#define R_IA64_FPTR64MSB	0x46	/* @fptr(sym+add), data8 MSB */
-#define R_IA64_FPTR64LSB	0x47	/* @fptr(sym+add), data8 LSB */
-#define R_IA64_PCREL60B		0x48	/* @pcrel(sym+add), brl */
-#define R_IA64_PCREL21B		0x49	/* @pcrel(sym+add), ptb, call */
-#define R_IA64_PCREL21M		0x4a	/* @pcrel(sym+add), chk.s */
-#define R_IA64_PCREL21F		0x4b	/* @pcrel(sym+add), fchkf */
-#define R_IA64_PCREL32MSB	0x4c	/* @pcrel(sym+add), data4 MSB */
-#define R_IA64_PCREL32LSB	0x4d	/* @pcrel(sym+add), data4 LSB */
-#define R_IA64_PCREL64MSB	0x4e	/* @pcrel(sym+add), data8 MSB */
-#define R_IA64_PCREL64LSB	0x4f	/* @pcrel(sym+add), data8 LSB */
-#define R_IA64_LTOFF_FPTR22	0x52	/* @ltoff(@fptr(s+a)), imm22 */
-#define R_IA64_LTOFF_FPTR64I	0x53	/* @ltoff(@fptr(s+a)), imm64 */
-#define R_IA64_LTOFF_FPTR32MSB	0x54	/* @ltoff(@fptr(s+a)), 4 MSB */
-#define R_IA64_LTOFF_FPTR32LSB	0x55	/* @ltoff(@fptr(s+a)), 4 LSB */
-#define R_IA64_LTOFF_FPTR64MSB	0x56	/* @ltoff(@fptr(s+a)), 8 MSB */
-#define R_IA64_LTOFF_FPTR64LSB	0x57	/* @ltoff(@fptr(s+a)), 8 LSB */
-#define R_IA64_SEGREL32MSB	0x5c	/* @segrel(sym+add), data4 MSB */
-#define R_IA64_SEGREL32LSB	0x5d	/* @segrel(sym+add), data4 LSB */
-#define R_IA64_SEGREL64MSB	0x5e	/* @segrel(sym+add), data8 MSB */
-#define R_IA64_SEGREL64LSB	0x5f	/* @segrel(sym+add), data8 LSB */
-#define R_IA64_SECREL32MSB	0x64	/* @secrel(sym+add), data4 MSB */
-#define R_IA64_SECREL32LSB	0x65	/* @secrel(sym+add), data4 LSB */
-#define R_IA64_SECREL64MSB	0x66	/* @secrel(sym+add), data8 MSB */
-#define R_IA64_SECREL64LSB	0x67	/* @secrel(sym+add), data8 LSB */
-#define R_IA64_REL32MSB		0x6c	/* data 4 + REL */
-#define R_IA64_REL32LSB		0x6d	/* data 4 + REL */
-#define R_IA64_REL64MSB		0x6e	/* data 8 + REL */
-#define R_IA64_REL64LSB		0x6f	/* data 8 + REL */
-#define R_IA64_LTV32MSB		0x74	/* symbol + addend, data4 MSB */
-#define R_IA64_LTV32LSB		0x75	/* symbol + addend, data4 LSB */
-#define R_IA64_LTV64MSB		0x76	/* symbol + addend, data8 MSB */
-#define R_IA64_LTV64LSB		0x77	/* symbol + addend, data8 LSB */
-#define R_IA64_PCREL21BI	0x79	/* @pcrel(sym+add), ptb, call */
-#define R_IA64_PCREL22		0x7a	/* @pcrel(sym+add), imm22 */
-#define R_IA64_PCREL64I		0x7b	/* @pcrel(sym+add), imm64 */
-#define R_IA64_IPLTMSB		0x80	/* dynamic reloc, imported PLT, MSB */
-#define R_IA64_IPLTLSB		0x81	/* dynamic reloc, imported PLT, LSB */
-#define R_IA64_COPY		0x84	/* dynamic reloc, data copy */
-#define R_IA64_SUB		0x85	/* -symbol + addend, add imm22 */
-#define R_IA64_LTOFF22X		0x86	/* LTOFF22, relaxable.  */
-#define R_IA64_LDXMOV		0x87	/* Use of LTOFF22X.  */
-#define R_IA64_TPREL14		0x91	/* @tprel(sym+add), add imm14 */
-#define R_IA64_TPREL22		0x92	/* @tprel(sym+add), add imm22 */
-#define R_IA64_TPREL64I		0x93	/* @tprel(sym+add), add imm64 */
-#define R_IA64_TPREL64MSB	0x96	/* @tprel(sym+add), data8 MSB */
-#define R_IA64_TPREL64LSB	0x97	/* @tprel(sym+add), data8 LSB */
-#define R_IA64_LTOFF_TPREL22	0x9a	/* @ltoff(@tprel(s+a)), add imm22 */
-#define R_IA64_DTPMOD64MSB	0xa6	/* @dtpmod(sym+add), data8 MSB */
-#define R_IA64_DTPMOD64LSB	0xa7	/* @dtpmod(sym+add), data8 LSB */
-#define R_IA64_LTOFF_DTPMOD22	0xaa	/* @ltoff(@dtpmod(s+a)), imm22 */
-#define R_IA64_DTPREL14		0xb1	/* @dtprel(sym+add), imm14 */
-#define R_IA64_DTPREL22		0xb2	/* @dtprel(sym+add), imm22 */
-#define R_IA64_DTPREL64I	0xb3	/* @dtprel(sym+add), imm64 */
-#define R_IA64_DTPREL32MSB	0xb4	/* @dtprel(sym+add), data4 MSB */
-#define R_IA64_DTPREL32LSB	0xb5	/* @dtprel(sym+add), data4 LSB */
-#define R_IA64_DTPREL64MSB	0xb6	/* @dtprel(sym+add), data8 MSB */
-#define R_IA64_DTPREL64LSB	0xb7	/* @dtprel(sym+add), data8 LSB */
-#define R_IA64_LTOFF_DTPREL22	0xba	/* @ltoff(@dtprel(s+a)), imm22 */
-
-/* IA-64 specific section flags: */
-#define SHF_IA_64_SHORT		0x10000000	/* section near gp */
-
-/*
- * We use (abuse?) this macro to insert the (empty) vm_area that is
- * used to map the register backing store.  I don't see any better
- * place to do this, but we should discuss this with Linus once we can
- * talk to him...
- */
-extern void ia64_init_addr_space (void);
-#define ELF_PLAT_INIT(_r, load_addr)	ia64_init_addr_space()
-
-/* ELF register definitions.  This is needed for core dump support.  */
-
-/*
- * elf_gregset_t contains the application-level state in the following order:
- *	r0-r31
- *	NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
- *	predicate registers (p0-p63)
- *	b0-b7
- *	ip cfm psr
- *	ar.rsc ar.bsp ar.bspstore ar.rnat
- *	ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec ar.csd ar.ssd
- */
-#define ELF_NGREG	128	/* we really need just 72 but let's leave some headroom... */
-#define ELF_NFPREG	128	/* f0 and f1 could be omitted, but so what... */
-
-/* elf_gregset_t register offsets */
-#define ELF_GR_0_OFFSET     0
-#define ELF_NAT_OFFSET     (32 * sizeof(elf_greg_t))
-#define ELF_PR_OFFSET      (33 * sizeof(elf_greg_t))
-#define ELF_BR_0_OFFSET    (34 * sizeof(elf_greg_t))
-#define ELF_CR_IIP_OFFSET  (42 * sizeof(elf_greg_t))
-#define ELF_CFM_OFFSET     (43 * sizeof(elf_greg_t))
-#define ELF_CR_IPSR_OFFSET (44 * sizeof(elf_greg_t))
-#define ELF_GR_OFFSET(i)   (ELF_GR_0_OFFSET + i * sizeof(elf_greg_t))
-#define ELF_BR_OFFSET(i)   (ELF_BR_0_OFFSET + i * sizeof(elf_greg_t))
-#define ELF_AR_RSC_OFFSET  (45 * sizeof(elf_greg_t))
-#define ELF_AR_BSP_OFFSET  (46 * sizeof(elf_greg_t))
-#define ELF_AR_BSPSTORE_OFFSET (47 * sizeof(elf_greg_t))
-#define ELF_AR_RNAT_OFFSET (48 * sizeof(elf_greg_t))
-#define ELF_AR_CCV_OFFSET  (49 * sizeof(elf_greg_t))
-#define ELF_AR_UNAT_OFFSET (50 * sizeof(elf_greg_t))
-#define ELF_AR_FPSR_OFFSET (51 * sizeof(elf_greg_t))
-#define ELF_AR_PFS_OFFSET  (52 * sizeof(elf_greg_t))
-#define ELF_AR_LC_OFFSET   (53 * sizeof(elf_greg_t))
-#define ELF_AR_EC_OFFSET   (54 * sizeof(elf_greg_t))
-#define ELF_AR_CSD_OFFSET  (55 * sizeof(elf_greg_t))
-#define ELF_AR_SSD_OFFSET  (56 * sizeof(elf_greg_t))
-#define ELF_AR_END_OFFSET  (57 * sizeof(elf_greg_t))
-
-typedef unsigned long elf_greg_t;
-typedef elf_greg_t elf_gregset_t[ELF_NGREG];
-
-typedef struct ia64_fpreg elf_fpreg_t;
-typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
-
-
-
-struct pt_regs;	/* forward declaration... */
-extern void ia64_elf_core_copy_regs (struct pt_regs *src, elf_gregset_t dst);
-#define ELF_CORE_COPY_REGS(_dest,_regs)	ia64_elf_core_copy_regs(_regs, _dest);
-
-/* This macro yields a bitmask that programs can use to figure out
-   what instruction set this CPU supports.  */
-#define ELF_HWCAP 	0
-
-/* This macro yields a string that ld.so will use to load
-   implementation specific libraries for optimization.  Not terribly
-   relevant until we have real hardware to play with... */
-#define ELF_PLATFORM	NULL
-
-#define elf_read_implies_exec(ex, executable_stack)					\
-	((executable_stack!=EXSTACK_DISABLE_X) && ((ex).e_flags & EF_IA_64_LINUX_EXECUTABLE_STACK) != 0)
-
-struct task_struct;
-
-#define GATE_EHDR	((const struct elfhdr *) GATE_ADDR)
-
-/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
-#define ARCH_DLINFO								\
-do {										\
-	extern char __kernel_syscall_via_epc[];					\
-	NEW_AUX_ENT(AT_SYSINFO, (unsigned long) __kernel_syscall_via_epc);	\
-	NEW_AUX_ENT(AT_SYSINFO_EHDR, (unsigned long) GATE_EHDR);		\
-} while (0)
-
-/*
- * format for entries in the Global Offset Table
- */
-struct got_entry {
-	uint64_t val;
-};
-
-/*
- * Layout of the Function Descriptor
- */
-struct fdesc {
-	uint64_t addr;
-	uint64_t gp;
-};
-
-#endif /* _ASM_IA64_ELF_H */