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

1 files changed, 13 insertions, 16 deletions

diff --git a/scripts/atomic/gen-atomic-fallback.sh b/scripts/atomic/gen-atomic-fallback.sh
index b6c6f5d306a7..0fd1cf0c2b94 100755
--- a/scripts/atomic/gen-atomic-fallback.sh
+++ b/scripts/atomic/gen-atomic-fallback.sh
@@ -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