locking/atomics: Flip fallbacks and instrumentation

Currently instrumentation of atomic primitives is done at the architecture
level, while composites or fallbacks are provided at the generic level.

The result is that there are no uninstrumented variants of the
fallbacks. Since there is now need of such variants to isolate text poke
from any form of instrumentation invert this ordering.

Doing this means moving the instrumentation into the generic code as
well as having (for now) two variants of the fallbacks.

Notes:

 - the various *cond_read* primitives are not proper fallbacks
   and got moved into linux/atomic.c. No arch_ variants are
   generated because the base primitives smp_cond_load*()
   are instrumented.

 - once all architectures are moved over to arch_atomic_ one of the
   fallback variants can be removed and some 2300 lines reclaimed.

 - atomic_{read,set}*() are no longer double-instrumented

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20200505134058.769149955@linutronix.de
This commit is contained in:
Peter Zijlstra
2020-01-24 22:13:03 +01:00
committed by Thomas Gleixner
parent 765dcd2099
commit 37f8173dd8
28 changed files with 2403 additions and 82 deletions

View File

@@ -2,10 +2,11 @@
# SPDX-License-Identifier: GPL-2.0
ATOMICDIR=$(dirname $0)
ARCH=$2
. ${ATOMICDIR}/atomic-tbl.sh
#gen_template_fallback(template, meta, pfx, name, sfx, order, atomic, int, args...)
#gen_template_fallback(template, meta, pfx, name, sfx, order, arch, atomic, int, args...)
gen_template_fallback()
{
local template="$1"; shift
@@ -14,10 +15,11 @@ gen_template_fallback()
local name="$1"; shift
local sfx="$1"; shift
local order="$1"; shift
local arch="$1"; shift
local atomic="$1"; shift
local int="$1"; shift
local atomicname="${atomic}_${pfx}${name}${sfx}${order}"
local atomicname="${arch}${atomic}_${pfx}${name}${sfx}${order}"
local ret="$(gen_ret_type "${meta}" "${int}")"
local retstmt="$(gen_ret_stmt "${meta}")"
@@ -32,7 +34,7 @@ gen_template_fallback()
fi
}
#gen_proto_fallback(meta, pfx, name, sfx, order, atomic, int, args...)
#gen_proto_fallback(meta, pfx, name, sfx, order, arch, atomic, int, args...)
gen_proto_fallback()
{
local meta="$1"; shift
@@ -56,16 +58,17 @@ cat << EOF
EOF
}
#gen_proto_order_variants(meta, pfx, name, sfx, atomic, int, args...)
#gen_proto_order_variants(meta, pfx, name, sfx, arch, atomic, int, args...)
gen_proto_order_variants()
{
local meta="$1"; shift
local pfx="$1"; shift
local name="$1"; shift
local sfx="$1"; shift
local atomic="$1"
local arch="$1"
local atomic="$2"
local basename="${atomic}_${pfx}${name}${sfx}"
local basename="${arch}${atomic}_${pfx}${name}${sfx}"
local template="$(find_fallback_template "${pfx}" "${name}" "${sfx}" "${order}")"
@@ -94,7 +97,7 @@ gen_proto_order_variants()
gen_basic_fallbacks "${basename}"
if [ ! -z "${template}" ]; then
printf "#endif /* ${atomic}_${pfx}${name}${sfx} */\n\n"
printf "#endif /* ${arch}${atomic}_${pfx}${name}${sfx} */\n\n"
gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "" "$@"
gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "_acquire" "$@"
gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "_release" "$@"
@@ -153,18 +156,15 @@ cat << EOF
EOF
for xchg in "xchg" "cmpxchg" "cmpxchg64"; do
for xchg in "${ARCH}xchg" "${ARCH}cmpxchg" "${ARCH}cmpxchg64"; do
gen_xchg_fallbacks "${xchg}"
done
grep '^[a-z]' "$1" | while read name meta args; do
gen_proto "${meta}" "${name}" "atomic" "int" ${args}
gen_proto "${meta}" "${name}" "${ARCH}" "atomic" "int" ${args}
done
cat <<EOF
#define atomic_cond_read_acquire(v, c) smp_cond_load_acquire(&(v)->counter, (c))
#define atomic_cond_read_relaxed(v, c) smp_cond_load_relaxed(&(v)->counter, (c))
#ifdef CONFIG_GENERIC_ATOMIC64
#include <asm-generic/atomic64.h>
#endif
@@ -172,12 +172,9 @@ cat <<EOF
EOF
grep '^[a-z]' "$1" | while read name meta args; do
gen_proto "${meta}" "${name}" "atomic64" "s64" ${args}
gen_proto "${meta}" "${name}" "${ARCH}" "atomic64" "s64" ${args}
done
cat <<EOF
#define atomic64_cond_read_acquire(v, c) smp_cond_load_acquire(&(v)->counter, (c))
#define atomic64_cond_read_relaxed(v, c) smp_cond_load_relaxed(&(v)->counter, (c))
#endif /* _LINUX_ATOMIC_FALLBACK_H */
EOF