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The Itanium architecture is obsolete, and an informal survey [0] reveals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

9 files changed, 0 insertions, 165 deletions

diff --git a/arch/ia64/scripts/check-gas b/arch/ia64/scripts/check-gas
deleted file mode 100755
index 787cf9b6b04a..000000000000
--- a/arch/ia64/scripts/check-gas
+++ /dev/null
@@ -1,16 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: GPL-2.0
-dir=$(dirname $0)
-CC=$1
-OBJDUMP=$2
-tmp=${TMPDIR:-/tmp}
-out=$tmp/out$$.o
-$CC -c $dir/check-gas-asm.S -o $out
-res=$($OBJDUMP -r --section .data $out | fgrep 00004 | tr -s ' ' |cut -f3 -d' ')
-rm -f $out
-if [ $res != ".text" ]; then
-	echo buggy
-else
-	echo good
-fi
-exit 0
diff --git a/arch/ia64/scripts/check-gas-asm.S b/arch/ia64/scripts/check-gas-asm.S
deleted file mode 100644
index 010e1d227e5d..000000000000
--- a/arch/ia64/scripts/check-gas-asm.S
+++ /dev/null
@@ -1,2 +0,0 @@
-[1:]	nop 0
-	.xdata4 ".data", 0, 1b-.
diff --git a/arch/ia64/scripts/check-model.c b/arch/ia64/scripts/check-model.c
deleted file mode 100644
index e1d4e86e3d63..000000000000
--- a/arch/ia64/scripts/check-model.c
+++ /dev/null
@@ -1 +0,0 @@
-int __attribute__ ((__model__ (__small__))) x;
diff --git a/arch/ia64/scripts/check-segrel.S b/arch/ia64/scripts/check-segrel.S
deleted file mode 100644
index 65d6378adaaa..000000000000
--- a/arch/ia64/scripts/check-segrel.S
+++ /dev/null
@@ -1,5 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-	.rodata
-	data4 @segrel(start)
-	.data
-start:
diff --git a/arch/ia64/scripts/check-segrel.lds b/arch/ia64/scripts/check-segrel.lds
deleted file mode 100644
index c385d246e458..000000000000
--- a/arch/ia64/scripts/check-segrel.lds
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-SECTIONS {
-	. = SIZEOF_HEADERS;
-	.rodata : { *(.rodata) } :ro
-	.note : { *(.note*) }
-	. = 0xa0000;
-	.data : { *(.data) } :dat
-	/DISCARD/ : { *(*) }
-}
-PHDRS {
-  ro PT_LOAD FILEHDR PHDRS;
-  dat PT_LOAD;
-}
diff --git a/arch/ia64/scripts/check-serialize.S b/arch/ia64/scripts/check-serialize.S
deleted file mode 100644
index 0400c106806c..000000000000
--- a/arch/ia64/scripts/check-serialize.S
+++ /dev/null
@@ -1,2 +0,0 @@
-	.serialize.data
-	.serialize.instruction
diff --git a/arch/ia64/scripts/check-text-align.S b/arch/ia64/scripts/check-text-align.S
deleted file mode 100644
index 107fa1c88c2e..000000000000
--- a/arch/ia64/scripts/check-text-align.S
+++ /dev/null
@@ -1,7 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-	.proc foo
-	.prologue
-foo:	.save rp, r2
-	nop 0
-	.align 64
-	.endp foo
diff --git a/arch/ia64/scripts/toolchain-flags b/arch/ia64/scripts/toolchain-flags
deleted file mode 100755
index 12dff5c981cf..000000000000
--- a/arch/ia64/scripts/toolchain-flags
+++ /dev/null
@@ -1,54 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: GPL-2.0
-#
-# Check whether linker can handle cross-segment @segrel():
-#
-CPPFLAGS=""
-CC=$1
-OBJDUMP=$2
-READELF=$3
-dir=$(dirname $0)
-tmp=${TMPDIR:-/tmp}
-out=$tmp/out$$
-
-# Check whether cross-segment segment-relative relocs work fine.  We need
-# that for building the gate DSO:
-
-$CC -nostdlib -static -Wl,-T$dir/check-segrel.lds $dir/check-segrel.S -o $out
-res=$($OBJDUMP --full --section .rodata $out | fgrep 000 | cut -f3 -d' ')
-rm -f $out
-if [ $res != 00000a00 ]; then
-    CPPFLAGS="$CPPFLAGS -DHAVE_BUGGY_SEGREL"
-    cat >&2 <<EOF
-warning: your linker cannot handle cross-segment segment-relative relocations.
-         please upgrade to a newer version (it is safe to use this linker, but
-         the kernel will be bigger than strictly necessary).
-EOF
-fi
-
-# Check whether .align inside a function works as expected.
-
-$CC -c $dir/check-text-align.S -o $out
-$READELF -u $out | fgrep -q 'prologue(rlen=12)'
-res=$?
-rm -f $out
-if [ $res -eq 0 ]; then
-    CPPFLAGS="$CPPFLAGS -DHAVE_WORKING_TEXT_ALIGN"
-fi
-
-if ! $CC -c $dir/check-model.c -o $out 2>&1 | grep  __model__ | grep -q attrib
-then
-    CPPFLAGS="$CPPFLAGS -DHAVE_MODEL_SMALL_ATTRIBUTE"
-fi
-rm -f $out
-
-# Check whether assembler supports .serialize.{data,instruction} directive.
-
-$CC -c $dir/check-serialize.S -o $out 2>/dev/null
-res=$?
-rm -f $out
-if [ $res -eq 0 ]; then
-    CPPFLAGS="$CPPFLAGS -DHAVE_SERIALIZE_DIRECTIVE"
-fi
-
-echo $CPPFLAGS
diff --git a/arch/ia64/scripts/unwcheck.py b/arch/ia64/scripts/unwcheck.py
deleted file mode 100644
index 9581742f0db2..000000000000
--- a/arch/ia64/scripts/unwcheck.py
+++ /dev/null
@@ -1,65 +0,0 @@
-#!/usr/bin/env python3
-# SPDX-License-Identifier: GPL-2.0
-#
-# Usage: unwcheck.py FILE
-#
-# This script checks the unwind info of each function in file FILE
-# and verifies that the sum of the region-lengths matches the total
-# length of the function.
-#
-# Based on a shell/awk script originally written by Harish Patil,
-# which was converted to Perl by Matthew Chapman, which was converted
-# to Python by David Mosberger.
-#
-import os
-import re
-import sys
-
-if len(sys.argv) != 2:
-    print("Usage: %s FILE" % sys.argv[0])
-    sys.exit(2)
-
-readelf = os.getenv("READELF", "readelf")
-
-start_pattern = re.compile("<([^>]*)>: \[0x([0-9a-f]+)-0x([0-9a-f]+)\]")
-rlen_pattern  = re.compile(".*rlen=([0-9]+)")
-
-def check_func (func, slots, rlen_sum):
-    if slots != rlen_sum:
-        global num_errors
-        num_errors += 1
-        if not func: func = "[%#x-%#x]" % (start, end)
-        print("ERROR: %s: %lu slots, total region length = %lu" % (func, slots, rlen_sum))
-    return
-
-num_funcs = 0
-num_errors = 0
-func = False
-slots = 0
-rlen_sum = 0
-for line in os.popen("%s -u %s" % (readelf, sys.argv[1])):
-    m = start_pattern.match(line)
-    if m:
-        check_func(func, slots, rlen_sum)
-
-        func  = m.group(1)
-        start = int(m.group(2), 16)
-        end   = int(m.group(3), 16)
-        slots = 3 * (end - start) / 16
-        rlen_sum = 0
-        num_funcs += 1
-    else:
-        m = rlen_pattern.match(line)
-        if m:
-            rlen_sum += int(m.group(1))
-check_func(func, slots, rlen_sum)
-
-if num_errors == 0:
-    print("No errors detected in %u functions." % num_funcs)
-else:
-    if num_errors > 1:
-        err="errors"
-    else:
-        err="error"
-    print("%u %s detected in %u functions." % (num_errors, err, num_funcs))
-    sys.exit(1)