1 files changed, 181 insertions, 0 deletions
diff --git a/scripts/atomic/gen-atomic-fallback.sh b/scripts/atomic/gen-atomic-fallback.sh
new file mode 100755
index 000000000000..1bd7c1707633
--- /dev/null
+++ b/scripts/atomic/gen-atomic-fallback.sh
@@ -0,0 +1,181 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+ATOMICDIR=$(dirname $0)
+
+. ${ATOMICDIR}/atomic-tbl.sh
+
+#gen_template_fallback(template, meta, pfx, name, sfx, order, atomic, int, args...)
+gen_template_fallback()
+{
+	local template="$1"; shift
+	local meta="$1"; shift
+	local pfx="$1"; shift
+	local name="$1"; shift
+	local sfx="$1"; shift
+	local order="$1"; shift
+	local atomic="$1"; shift
+	local int="$1"; shift
+
+	local atomicname="${atomic}_${pfx}${name}${sfx}${order}"
+
+	local ret="$(gen_ret_type "${meta}" "${int}")"
+	local retstmt="$(gen_ret_stmt "${meta}")"
+	local params="$(gen_params "${int}" "${atomic}" "$@")"
+	local args="$(gen_args "$@")"
+
+	if [ ! -z "${template}" ]; then
+		printf "#ifndef ${atomicname}\n"
+		. ${template}
+		printf "#define ${atomicname} ${atomicname}\n"
+		printf "#endif\n\n"
+	fi
+}
+
+#gen_proto_fallback(meta, pfx, name, sfx, order, atomic, int, args...)
+gen_proto_fallback()
+{
+	local meta="$1"; shift
+	local pfx="$1"; shift
+	local name="$1"; shift
+	local sfx="$1"; shift
+	local order="$1"; shift
+
+	local tmpl="$(find_fallback_template "${pfx}" "${name}" "${sfx}" "${order}")"
+	gen_template_fallback "${tmpl}" "${meta}" "${pfx}" "${name}" "${sfx}" "${order}" "$@"
+}
+
+#gen_basic_fallbacks(basename)
+gen_basic_fallbacks()
+{
+	local basename="$1"; shift
+cat << EOF
+#define ${basename}_acquire ${basename}
+#define ${basename}_release ${basename}
+#define ${basename}_relaxed ${basename}
+EOF
+}
+
+#gen_proto_order_variants(meta, pfx, name, sfx, 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="$1"
+
+	local basename="${atomic}_${pfx}${name}${sfx}"
+
+	local template="$(find_fallback_template "${pfx}" "${name}" "${sfx}" "${order}")"
+
+	# If we don't have relaxed atomics, then we don't bother with ordering fallbacks
+	# read_acquire and set_release need to be templated, though
+	if ! meta_has_relaxed "${meta}"; then
+		gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "" "$@"
+
+		if meta_has_acquire "${meta}"; then
+			gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "_acquire" "$@"
+		fi
+
+		if meta_has_release "${meta}"; then
+			gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "_release" "$@"
+		fi
+
+		return
+	fi
+
+	printf "#ifndef ${basename}_relaxed\n"
+
+	if [ ! -z "${template}" ]; then
+		printf "#ifdef ${basename}\n"
+	fi
+
+	gen_basic_fallbacks "${basename}"
+
+	if [ ! -z "${template}" ]; then
+		printf "#endif /* ${atomic}_${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" "$@"
+		gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "_relaxed" "$@"
+	fi
+
+	printf "#else /* ${basename}_relaxed */\n\n"
+
+	gen_template_fallback "${ATOMICDIR}/fallbacks/acquire"  "${meta}" "${pfx}" "${name}" "${sfx}" "_acquire" "$@"
+	gen_template_fallback "${ATOMICDIR}/fallbacks/release"  "${meta}" "${pfx}" "${name}" "${sfx}" "_release" "$@"
+	gen_template_fallback "${ATOMICDIR}/fallbacks/fence"  "${meta}" "${pfx}" "${name}" "${sfx}" "" "$@"
+
+	printf "#endif /* ${basename}_relaxed */\n\n"
+}
+
+gen_xchg_fallbacks()
+{
+	local xchg="$1"; shift
+cat <<EOF
+#ifndef ${xchg}_relaxed
+#define ${xchg}_relaxed		${xchg}
+#define ${xchg}_acquire		${xchg}
+#define ${xchg}_release		${xchg}
+#else /* ${xchg}_relaxed */
+
+#ifndef ${xchg}_acquire
+#define ${xchg}_acquire(...) \\
+	__atomic_op_acquire(${xchg}, __VA_ARGS__)
+#endif
+
+#ifndef ${xchg}_release
+#define ${xchg}_release(...) \\
+	__atomic_op_release(${xchg}, __VA_ARGS__)
+#endif
+
+#ifndef ${xchg}
+#define ${xchg}(...) \\
+	__atomic_op_fence(${xchg}, __VA_ARGS__)
+#endif
+
+#endif /* ${xchg}_relaxed */
+
+EOF
+}
+
+cat << EOF
+// SPDX-License-Identifier: GPL-2.0
+
+// Generated by $0
+// DO NOT MODIFY THIS FILE DIRECTLY
+
+#ifndef _LINUX_ATOMIC_FALLBACK_H
+#define _LINUX_ATOMIC_FALLBACK_H
+
+EOF
+
+for xchg in "xchg" "cmpxchg" "cmpxchg64"; do
+	gen_xchg_fallbacks "${xchg}"
+done
+
+grep '^[a-z]' "$1" | while read name meta args; do
+	gen_proto "${meta}" "${name}" "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
+
+EOF
+
+grep '^[a-z]' "$1" | while read name meta args; do
+	gen_proto "${meta}" "${name}" "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