linux/scripts/atomic/gen-atomic-long.sh
Marco Elver c020395b66 asm-generic/atomic: Use __always_inline for pure wrappers
Prefer __always_inline for atomic wrappers. When building for size
(CC_OPTIMIZE_FOR_SIZE), some compilers appear to be less inclined to
inline even relatively small static inline functions that are assumed to
be inlinable such as atomic ops. This can cause problems, for example in
UACCESS regions.

By using __always_inline, we let the real implementation and not the
wrapper determine the final inlining preference.

For x86 tinyconfig we observe:
- vmlinux baseline: 1316204
- vmlinux with patch: 1315988 (-216 bytes)

This came up when addressing UACCESS warnings with CC_OPTIMIZE_FOR_SIZE
in the KCSAN runtime:
http://lkml.kernel.org/r/58708908-84a0-0a81-a836-ad97e33dbb62@infradead.org

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-07 07:47:23 -08:00

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#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
ATOMICDIR=$(dirname $0)
. ${ATOMICDIR}/atomic-tbl.sh
#gen_cast(arg, int, atomic)
gen_cast()
{
local arg="$1"; shift
local int="$1"; shift
local atomic="$1"; shift
[ "${arg%%:*}" = "p" ] || return
printf "($(gen_param_type "${arg}" "${int}" "${atomic}"))"
}
#gen_args_cast(int, atomic, arg...)
gen_args_cast()
{
local int="$1"; shift
local atomic="$1"; shift
while [ "$#" -gt 0 ]; do
local cast="$(gen_cast "$1" "${int}" "${atomic}")"
local arg="$(gen_param_name "$1")"
printf "${cast}${arg}"
[ "$#" -gt 1 ] && printf ", "
shift;
done
}
#gen_proto_order_variant(meta, pfx, name, sfx, order, atomic, int, arg...)
gen_proto_order_variant()
{
local meta="$1"; shift
local name="$1$2$3$4"; shift; shift; shift; shift
local atomic="$1"; shift
local int="$1"; shift
local ret="$(gen_ret_type "${meta}" "long")"
local params="$(gen_params "long" "atomic_long" "$@")"
local argscast="$(gen_args_cast "${int}" "${atomic}" "$@")"
local retstmt="$(gen_ret_stmt "${meta}")"
cat <<EOF
static __always_inline ${ret}
atomic_long_${name}(${params})
{
${retstmt}${atomic}_${name}(${argscast});
}
EOF
}
cat << EOF
// SPDX-License-Identifier: GPL-2.0
// Generated by $0
// DO NOT MODIFY THIS FILE DIRECTLY
#ifndef _ASM_GENERIC_ATOMIC_LONG_H
#define _ASM_GENERIC_ATOMIC_LONG_H
#include <linux/compiler.h>
#include <asm/types.h>
#ifdef CONFIG_64BIT
typedef atomic64_t atomic_long_t;
#define ATOMIC_LONG_INIT(i) ATOMIC64_INIT(i)
#define atomic_long_cond_read_acquire atomic64_cond_read_acquire
#define atomic_long_cond_read_relaxed atomic64_cond_read_relaxed
#else
typedef atomic_t atomic_long_t;
#define ATOMIC_LONG_INIT(i) ATOMIC_INIT(i)
#define atomic_long_cond_read_acquire atomic_cond_read_acquire
#define atomic_long_cond_read_relaxed atomic_cond_read_relaxed
#endif
#ifdef CONFIG_64BIT
EOF
grep '^[a-z]' "$1" | while read name meta args; do
gen_proto "${meta}" "${name}" "atomic64" "s64" ${args}
done
cat <<EOF
#else /* CONFIG_64BIT */
EOF
grep '^[a-z]' "$1" | while read name meta args; do
gen_proto "${meta}" "${name}" "atomic" "int" ${args}
done
cat <<EOF
#endif /* CONFIG_64BIT */
#endif /* _ASM_GENERIC_ATOMIC_LONG_H */
EOF