From: Mark Rutland Date: Tue, 4 Sep 2018 10:48:25 +0000 (+0100) Subject: locking/atomics: Add common header generation files X-Git-Tag: v5.1-rc1~164^2~28^2~7 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ace9bad4df2684f31cbfe8c4ce7a0f5d92b27925;p=thirdparty%2Fkernel%2Flinux.git locking/atomics: Add common header generation files To minimize repetition, to allow for future rework, and to ensure regularity of the various atomic APIs, we'd like to automatically generate (the bulk of) a number of headers related to atomics. This patch adds the infrastructure to do so, leaving actual conversion of headers to subsequent patches. This infrastructure consists of: * atomics.tbl - a table describing the functions in the atomics API, with names, prototypes, and metadata describing the variants that exist (e.g fetch/return, acquire/release/relaxed). Note that the return type is dependent on the particular variant. * atomic-tbl.sh - a library of routines useful for dealing with atomics.tbl (e.g. querying which variants exist, or generating argument/parameter lists for a given function variant). * gen-atomic-fallback.sh - a script which generates a header of fallbacks, covering cases where architecture omit certain functions (e.g. omitting relaxed variants). * gen-atomic-long.sh - a script which generates wrappers providing the atomic_long API atomic of the relevant atomic or atomic64 API, ensuring the APIs are consistent. * gen-atomic-instrumented.sh - a script which generates atomic* wrappers atop of arch_atomic* functions, with automatically generated KASAN instrumentation. * fallbacks/* - a set of fallback implementations for atomics, which should be used when no implementation of a given atomic is provided. These are used by gen-atomic-fallback.sh to generate fallbacks, and these are also used by other scripts to determine the set of optional atomics (as required to generate preprocessor guards correctly). Fallbacks may use the following variables: ${atomic} atomic prefix: atomic/atomic64/atomic_long, which can be used to derive the atomic type, and to prefix functions ${int} integer type: int/s64/long ${pfx} variant prefix, e.g. fetch_ ${name} base function name, e.g. add ${sfx} variant suffix, e.g. _return ${order} order suffix, e.g. _relaxed ${atomicname} full name, e.g. atomic64_fetch_add_relaxed ${ret} return type of the function, e.g. void ${retstmt} a return statement (with a trailing space), unless the variant returns void ${params} parameter list for the function declaration, e.g. "int i, atomic_t *v" ${args} argument list for invoking the function, e.g. "i, v" ... for clarity, ${ret}, ${retstmt}, ${params}, and ${args} are open-coded for fallbacks where these do not vary, or are critical to understanding the logic of the fallback. The MAINTAINERS entry for the atomic infrastructure is updated to cover the new scripts. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Signed-off-by: Peter Zijlstra (Intel) Cc: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com Cc: Will Deacon Cc: linuxdrivers@attotech.com Cc: dvyukov@google.com Cc: Boqun Feng Cc: arnd@arndb.de Cc: aryabinin@virtuozzo.com Cc: glider@google.com Link: http://lkml.kernel.org/r/20180904104830.2975-2-mark.rutland@arm.com Signed-off-by: Ingo Molnar --- diff --git a/MAINTAINERS b/MAINTAINERS index d63705445bf84..bedca40b7e552 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2579,6 +2579,7 @@ L: linux-kernel@vger.kernel.org S: Maintained F: arch/*/include/asm/atomic*.h F: include/*/atomic*.h +F: scripts/atomic/ ATTO EXPRESSSAS SAS/SATA RAID SCSI DRIVER M: Bradley Grove diff --git a/scripts/atomic/atomic-tbl.sh b/scripts/atomic/atomic-tbl.sh new file mode 100644 index 0000000000000..9d6be538a987f --- /dev/null +++ b/scripts/atomic/atomic-tbl.sh @@ -0,0 +1,186 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# helpers for dealing with atomics.tbl + +#meta_in(meta, match) +meta_in() +{ + case "$1" in + [$2]) return 0;; + esac + + return 1 +} + +#meta_has_ret(meta) +meta_has_ret() +{ + meta_in "$1" "bBiIfFlR" +} + +#meta_has_acquire(meta) +meta_has_acquire() +{ + meta_in "$1" "BFIlR" +} + +#meta_has_release(meta) +meta_has_release() +{ + meta_in "$1" "BFIRs" +} + +#meta_has_relaxed(meta) +meta_has_relaxed() +{ + meta_in "$1" "BFIR" +} + +#find_fallback_template(pfx, name, sfx, order) +find_fallback_template() +{ + local pfx="$1"; shift + local name="$1"; shift + local sfx="$1"; shift + local order="$1"; shift + + local base="" + local file="" + + # We may have fallbacks for a specific case (e.g. read_acquire()), or + # an entire class, e.g. *inc*(). + # + # Start at the most specific, and fall back to the most general. Once + # we find a specific fallback, don't bother looking for more. + for base in "${pfx}${name}${sfx}${order}" "${name}"; do + file="${ATOMICDIR}/fallbacks/${base}" + + if [ -f "${file}" ]; then + printf "${file}" + break + fi + done +} + +#gen_ret_type(meta, int) +gen_ret_type() { + local meta="$1"; shift + local int="$1"; shift + + case "${meta}" in + [sv]) printf "void";; + [bB]) printf "bool";; + [aiIfFlR]) printf "${int}";; + esac +} + +#gen_ret_stmt(meta) +gen_ret_stmt() +{ + if meta_has_ret "${meta}"; then + printf "return "; + fi +} + +# gen_param_name(arg) +gen_param_name() +{ + # strip off the leading 'c' for 'cv' + local name="${1#c}" + printf "${name#*:}" +} + +# gen_param_type(arg, int, atomic) +gen_param_type() +{ + local type="${1%%:*}"; shift + local int="$1"; shift + local atomic="$1"; shift + + case "${type}" in + i) type="${int} ";; + p) type="${int} *";; + v) type="${atomic}_t *";; + cv) type="const ${atomic}_t *";; + esac + + printf "${type}" +} + +#gen_param(arg, int, atomic) +gen_param() +{ + local arg="$1"; shift + local int="$1"; shift + local atomic="$1"; shift + local name="$(gen_param_name "${arg}")" + local type="$(gen_param_type "${arg}" "${int}" "${atomic}")" + + printf "${type}${name}" +} + +#gen_params(int, atomic, arg...) +gen_params() +{ + local int="$1"; shift + local atomic="$1"; shift + + while [ "$#" -gt 0 ]; do + gen_param "$1" "${int}" "${atomic}" + [ "$#" -gt 1 ] && printf ", " + shift; + done +} + +#gen_args(arg...) +gen_args() +{ + while [ "$#" -gt 0 ]; do + printf "$(gen_param_name "$1")" + [ "$#" -gt 1 ] && printf ", " + shift; + done +} + +#gen_proto_order_variants(meta, pfx, name, sfx, ...) +gen_proto_order_variants() +{ + local meta="$1"; shift + local pfx="$1"; shift + local name="$1"; shift + local sfx="$1"; shift + + gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "" "$@" + + if meta_has_acquire "${meta}"; then + gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "_acquire" "$@" + fi + if meta_has_release "${meta}"; then + gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "_release" "$@" + fi + if meta_has_relaxed "${meta}"; then + gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "_relaxed" "$@" + fi +} + +#gen_proto_variants(meta, name, ...) +gen_proto_variants() +{ + local meta="$1"; shift + local name="$1"; shift + local pfx="" + local sfx="" + + meta_in "${meta}" "fF" && pfx="fetch_" + meta_in "${meta}" "R" && sfx="_return" + + gen_proto_order_variants "${meta}" "${pfx}" "${name}" "${sfx}" "$@" +} + +#gen_proto(meta, ...) +gen_proto() { + local meta="$1"; shift + for m in $(echo "${meta}" | fold -w1); do + gen_proto_variants "${m}" "$@" + done +} diff --git a/scripts/atomic/atomics.tbl b/scripts/atomic/atomics.tbl new file mode 100644 index 0000000000000..fbee2f6190d9e --- /dev/null +++ b/scripts/atomic/atomics.tbl @@ -0,0 +1,41 @@ +# name meta args... +# +# Where meta contains a string of variants to generate. +# Upper-case implies _{acquire,release,relaxed} variants. +# Valid meta values are: +# * B/b - bool: returns bool +# * v - void: returns void +# * I/i - int: returns base type +# * R - return: returns base type (has _return variants) +# * F/f - fetch: returns base type (has fetch_ variants) +# * l - load: returns base type (has _acquire order variant) +# * s - store: returns void (has _release order variant) +# +# Where args contains list of type[:name], where type is: +# * cv - const pointer to atomic base type (atomic_t/atomic64_t/atomic_long_t) +# * v - pointer to atomic base type (atomic_t/atomic64_t/atomic_long_t) +# * i - base type (int/s64/long) +# * p - pointer to base type (int/s64/long) +# +read l cv +set s v i +add vRF i v +sub vRF i v +inc vRF v +dec vRF v +and vF i v +andnot vF i v +or vF i v +xor vF i v +xchg I v i +cmpxchg I v i:old i:new +try_cmpxchg B v p:old i:new +sub_and_test b i v +dec_and_test b v +inc_and_test b v +add_negative b i v +add_unless fb v i:a i:u +inc_not_zero b v +inc_unless_negative b v +dec_unless_positive b v +dec_if_positive i v diff --git a/scripts/atomic/fallbacks/acquire b/scripts/atomic/fallbacks/acquire new file mode 100644 index 0000000000000..e38871e64db65 --- /dev/null +++ b/scripts/atomic/fallbacks/acquire @@ -0,0 +1,9 @@ +cat < 0)) + return false; + } while (!${atomic}_try_cmpxchg(v, &c, c - 1)); + + return true; +} +EOF diff --git a/scripts/atomic/fallbacks/fence b/scripts/atomic/fallbacks/fence new file mode 100644 index 0000000000000..82f68fa6931a0 --- /dev/null +++ b/scripts/atomic/fallbacks/fence @@ -0,0 +1,11 @@ +cat <counter); +} +EOF diff --git a/scripts/atomic/fallbacks/release b/scripts/atomic/fallbacks/release new file mode 100644 index 0000000000000..3f628a3802d98 --- /dev/null +++ b/scripts/atomic/fallbacks/release @@ -0,0 +1,8 @@ +cat <counter, i); +} +EOF diff --git a/scripts/atomic/fallbacks/sub_and_test b/scripts/atomic/fallbacks/sub_and_test new file mode 100644 index 0000000000000..289ef17a2d7a2 --- /dev/null +++ b/scripts/atomic/fallbacks/sub_and_test @@ -0,0 +1,16 @@ +cat <counter, (c)) +#define atomic_cond_read_relaxed(v, c) smp_cond_load_relaxed(&(v)->counter, (c)) + +#ifdef CONFIG_GENERIC_ATOMIC64 +#include +#endif + +EOF + +grep '^[a-z]' "$1" | while read name meta args; do + gen_proto "${meta}" "${name}" "atomic64" "s64" ${args} +done + +cat <counter, (c)) +#define atomic64_cond_read_relaxed(v, c) smp_cond_load_relaxed(&(v)->counter, (c)) + +#endif /* _LINUX_ATOMIC_FALLBACK_H */ +EOF diff --git a/scripts/atomic/gen-atomic-instrumented.sh b/scripts/atomic/gen-atomic-instrumented.sh new file mode 100644 index 0000000000000..e09812372b17e --- /dev/null +++ b/scripts/atomic/gen-atomic-instrumented.sh @@ -0,0 +1,182 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +ATOMICDIR=$(dirname $0) + +. ${ATOMICDIR}/atomic-tbl.sh + +#gen_param_check(arg) +gen_param_check() +{ + local arg="$1"; shift + local type="${arg%%:*}" + local name="$(gen_param_name "${arg}")" + local rw="write" + + case "${type#c}" in + i) return;; + esac + + # We don't write to constant parameters + [ ${type#c} != ${type} ] && rw="read" + + printf "\tkasan_check_${rw}(${name}, sizeof(*${name}));\n" +} + +#gen_param_check(arg...) +gen_params_checks() +{ + while [ "$#" -gt 0 ]; do + gen_param_check "$1" + shift; + done +} + +# gen_guard(meta, atomic, pfx, name, sfx, order) +gen_guard() +{ + local meta="$1"; shift + local atomic="$1"; shift + local pfx="$1"; shift + local name="$1"; shift + local sfx="$1"; shift + local order="$1"; shift + + local atomicname="arch_${atomic}_${pfx}${name}${sfx}${order}" + + local template="$(find_fallback_template "${pfx}" "${name}" "${sfx}" "${order}")" + + # We definitely need a preprocessor symbol for this atomic if it is an + # ordering variant, or if there's a generic fallback. + if [ ! -z "${order}" ] || [ ! -z "${template}" ]; then + printf "defined(${atomicname})" + return + fi + + # If this is a base variant, but a relaxed variant *may* exist, then we + # only have a preprocessor symbol if the relaxed variant isn't defined + if meta_has_relaxed "${meta}"; then + printf "!defined(${atomicname}_relaxed) || defined(${atomicname})" + fi +} + +#gen_proto_order_variant(meta, pfx, name, sfx, order, atomic, int, arg...) +gen_proto_order_variant() +{ + 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 guard="$(gen_guard "${meta}" "${atomic}" "${pfx}" "${name}" "${sfx}" "${order}")" + + local ret="$(gen_ret_type "${meta}" "${int}")" + local params="$(gen_params "${int}" "${atomic}" "$@")" + local checks="$(gen_params_checks "$@")" + local args="$(gen_args "$@")" + local retstmt="$(gen_ret_stmt "${meta}")" + + [ ! -z "${guard}" ] && printf "#if ${guard}\n" + +cat < +#include + +EOF + +grep '^[a-z]' "$1" | while read name meta args; do + gen_proto "${meta}" "${name}" "atomic" "int" ${args} +done + +grep '^[a-z]' "$1" | while read name meta args; do + gen_proto "${meta}" "${name}" "atomic64" "s64" ${args} +done + +for xchg in "xchg" "cmpxchg" "cmpxchg64"; do + for order in "" "_acquire" "_release" "_relaxed"; do + gen_optional_xchg "${xchg}" "${order}" + done +done + +for xchg in "cmpxchg_local" "cmpxchg64_local" "sync_cmpxchg"; do + gen_xchg "${xchg}" "" + printf "\n" +done + +gen_xchg "cmpxchg_double" "2 * " + +printf "\n\n" + +gen_xchg "cmpxchg_double_local" "2 * " + +cat < + +#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 <