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

21 files changed, 63 insertions, 65 deletions

diff --git a/scripts/atomic/fallbacks/acquire b/scripts/atomic/fallbacks/acquire
index ea489acc285e5..59c00529dc7cf 100755
--- a/scripts/atomic/fallbacks/acquire
+++ b/scripts/atomic/fallbacks/acquire
@@ -1,8 +1,8 @@
 cat <<EOF
 static __always_inline ${ret}
-${atomic}_${pfx}${name}${sfx}_acquire(${params})
+${arch}${atomic}_${pfx}${name}${sfx}_acquire(${params})
 {
-	${ret} ret = ${atomic}_${pfx}${name}${sfx}_relaxed(${args});
+	${ret} ret = ${arch}${atomic}_${pfx}${name}${sfx}_relaxed(${args});
 	__atomic_acquire_fence();
 	return ret;
 }
diff --git a/scripts/atomic/fallbacks/add_negative b/scripts/atomic/fallbacks/add_negative
index 03cc2e07fac54..a66635bceefbf 100755
--- a/scripts/atomic/fallbacks/add_negative
+++ b/scripts/atomic/fallbacks/add_negative
@@ -1,6 +1,6 @@
 cat <<EOF
 /**
- * ${atomic}_add_negative - add and test if negative
+ * ${arch}${atomic}_add_negative - add and test if negative
  * @i: integer value to add
  * @v: pointer of type ${atomic}_t
  *
@@ -9,8 +9,8 @@ cat <<EOF
  * result is greater than or equal to zero.
  */
 static __always_inline bool
-${atomic}_add_negative(${int} i, ${atomic}_t *v)
+${arch}${atomic}_add_negative(${int} i, ${atomic}_t *v)
 {
-	return ${atomic}_add_return(i, v) < 0;
+	return ${arch}${atomic}_add_return(i, v) < 0;
 }
 EOF
diff --git a/scripts/atomic/fallbacks/add_unless b/scripts/atomic/fallbacks/add_unless
index daf87a04c8505..2ff598a3f9ece 100755
--- a/scripts/atomic/fallbacks/add_unless
+++ b/scripts/atomic/fallbacks/add_unless
@@ -1,6 +1,6 @@
 cat << EOF
 /**
- * ${atomic}_add_unless - add unless the number is already a given value
+ * ${arch}${atomic}_add_unless - add unless the number is already a given value
  * @v: pointer of type ${atomic}_t
  * @a: the amount to add to v...
  * @u: ...unless v is equal to u.
@@ -9,8 +9,8 @@ cat << EOF
  * Returns true if the addition was done.
  */
 static __always_inline bool
-${atomic}_add_unless(${atomic}_t *v, ${int} a, ${int} u)
+${arch}${atomic}_add_unless(${atomic}_t *v, ${int} a, ${int} u)
 {
-	return ${atomic}_fetch_add_unless(v, a, u) != u;
+	return ${arch}${atomic}_fetch_add_unless(v, a, u) != u;
 }
 EOF
diff --git a/scripts/atomic/fallbacks/andnot b/scripts/atomic/fallbacks/andnot
index 14efce01225a3..3f18663dcefb4 100755
--- a/scripts/atomic/fallbacks/andnot
+++ b/scripts/atomic/fallbacks/andnot
@@ -1,7 +1,7 @@
 cat <<EOF
 static __always_inline ${ret}
-${atomic}_${pfx}andnot${sfx}${order}(${int} i, ${atomic}_t *v)
+${arch}${atomic}_${pfx}andnot${sfx}${order}(${int} i, ${atomic}_t *v)
 {
-	${retstmt}${atomic}_${pfx}and${sfx}${order}(~i, v);
+	${retstmt}${arch}${atomic}_${pfx}and${sfx}${order}(~i, v);
 }
 EOF
diff --git a/scripts/atomic/fallbacks/dec b/scripts/atomic/fallbacks/dec
index 118282f3a5a34..e2e01f0574bbc 100755
--- a/scripts/atomic/fallbacks/dec
+++ b/scripts/atomic/fallbacks/dec
@@ -1,7 +1,7 @@
 cat <<EOF
 static __always_inline ${ret}
-${atomic}_${pfx}dec${sfx}${order}(${atomic}_t *v)
+${arch}${atomic}_${pfx}dec${sfx}${order}(${atomic}_t *v)
 {
-	${retstmt}${atomic}_${pfx}sub${sfx}${order}(1, v);
+	${retstmt}${arch}${atomic}_${pfx}sub${sfx}${order}(1, v);
 }
 EOF
diff --git a/scripts/atomic/fallbacks/dec_and_test b/scripts/atomic/fallbacks/dec_and_test
index f8967a8911173..e8a5e492eb5fb 100755
--- a/scripts/atomic/fallbacks/dec_and_test
+++ b/scripts/atomic/fallbacks/dec_and_test
@@ -1,6 +1,6 @@
 cat <<EOF
 /**
- * ${atomic}_dec_and_test - decrement and test
+ * ${arch}${atomic}_dec_and_test - decrement and test
  * @v: pointer of type ${atomic}_t
  *
  * Atomically decrements @v by 1 and
@@ -8,8 +8,8 @@ cat <<EOF
  * cases.
  */
 static __always_inline bool
-${atomic}_dec_and_test(${atomic}_t *v)
+${arch}${atomic}_dec_and_test(${atomic}_t *v)
 {
-	return ${atomic}_dec_return(v) == 0;
+	return ${arch}${atomic}_dec_return(v) == 0;
 }
 EOF
diff --git a/scripts/atomic/fallbacks/dec_if_positive b/scripts/atomic/fallbacks/dec_if_positive
index cfb380bd2da68..527adec89c378 100755
--- a/scripts/atomic/fallbacks/dec_if_positive
+++ b/scripts/atomic/fallbacks/dec_if_positive
@@ -1,14 +1,14 @@
 cat <<EOF
 static __always_inline ${ret}
-${atomic}_dec_if_positive(${atomic}_t *v)
+${arch}${atomic}_dec_if_positive(${atomic}_t *v)
 {
-	${int} dec, c = ${atomic}_read(v);
+	${int} dec, c = ${arch}${atomic}_read(v);
 
 	do {
 		dec = c - 1;
 		if (unlikely(dec < 0))
 			break;
-	} while (!${atomic}_try_cmpxchg(v, &c, dec));
+	} while (!${arch}${atomic}_try_cmpxchg(v, &c, dec));
 
 	return dec;
 }
diff --git a/scripts/atomic/fallbacks/dec_unless_positive b/scripts/atomic/fallbacks/dec_unless_positive
index 69cb7aa01f9cd..dcab6848ca1e5 100755
--- a/scripts/atomic/fallbacks/dec_unless_positive
+++ b/scripts/atomic/fallbacks/dec_unless_positive
@@ -1,13 +1,13 @@
 cat <<EOF
 static __always_inline bool
-${atomic}_dec_unless_positive(${atomic}_t *v)
+${arch}${atomic}_dec_unless_positive(${atomic}_t *v)
 {
-	${int} c = ${atomic}_read(v);
+	${int} c = ${arch}${atomic}_read(v);
 
 	do {
 		if (unlikely(c > 0))
 			return false;
-	} while (!${atomic}_try_cmpxchg(v, &c, c - 1));
+	} while (!${arch}${atomic}_try_cmpxchg(v, &c, c - 1));
 
 	return true;
 }
diff --git a/scripts/atomic/fallbacks/fence b/scripts/atomic/fallbacks/fence
index 92a3a4691baba..3764fc8ce945d 100755
--- a/scripts/atomic/fallbacks/fence
+++ b/scripts/atomic/fallbacks/fence
@@ -1,10 +1,10 @@
 cat <<EOF
 static __always_inline ${ret}
-${atomic}_${pfx}${name}${sfx}(${params})
+${arch}${atomic}_${pfx}${name}${sfx}(${params})
 {
 	${ret} ret;
 	__atomic_pre_full_fence();
-	ret = ${atomic}_${pfx}${name}${sfx}_relaxed(${args});
+	ret = ${arch}${atomic}_${pfx}${name}${sfx}_relaxed(${args});
 	__atomic_post_full_fence();
 	return ret;
 }
diff --git a/scripts/atomic/fallbacks/fetch_add_unless b/scripts/atomic/fallbacks/fetch_add_unless
index fffbc0d16fdf5..0e0b9aef15153 100755
--- a/scripts/atomic/fallbacks/fetch_add_unless
+++ b/scripts/atomic/fallbacks/fetch_add_unless
@@ -1,6 +1,6 @@
 cat << EOF
 /**
- * ${atomic}_fetch_add_unless - add unless the number is already a given value
+ * ${arch}${atomic}_fetch_add_unless - add unless the number is already a given value
  * @v: pointer of type ${atomic}_t
  * @a: the amount to add to v...
  * @u: ...unless v is equal to u.
@@ -9,14 +9,14 @@ cat << EOF
  * Returns original value of @v
  */
 static __always_inline ${int}
-${atomic}_fetch_add_unless(${atomic}_t *v, ${int} a, ${int} u)
+${arch}${atomic}_fetch_add_unless(${atomic}_t *v, ${int} a, ${int} u)
 {
-	${int} c = ${atomic}_read(v);
+	${int} c = ${arch}${atomic}_read(v);
 
 	do {
 		if (unlikely(c == u))
 			break;
-	} while (!${atomic}_try_cmpxchg(v, &c, c + a));
+	} while (!${arch}${atomic}_try_cmpxchg(v, &c, c + a));
 
 	return c;
 }
diff --git a/scripts/atomic/fallbacks/inc b/scripts/atomic/fallbacks/inc
index 10751cd62829d..15ec62946e8ce 100755
--- a/scripts/atomic/fallbacks/inc
+++ b/scripts/atomic/fallbacks/inc
@@ -1,7 +1,7 @@
 cat <<EOF
 static __always_inline ${ret}
-${atomic}_${pfx}inc${sfx}${order}(${atomic}_t *v)
+${arch}${atomic}_${pfx}inc${sfx}${order}(${atomic}_t *v)
 {
-	${retstmt}${atomic}_${pfx}add${sfx}${order}(1, v);
+	${retstmt}${arch}${atomic}_${pfx}add${sfx}${order}(1, v);
 }
 EOF
diff --git a/scripts/atomic/fallbacks/inc_and_test b/scripts/atomic/fallbacks/inc_and_test
index 4acea9c936049..cecc8322a21ff 100755
--- a/scripts/atomic/fallbacks/inc_and_test
+++ b/scripts/atomic/fallbacks/inc_and_test
@@ -1,6 +1,6 @@
 cat <<EOF
 /**
- * ${atomic}_inc_and_test - increment and test
+ * ${arch}${atomic}_inc_and_test - increment and test
  * @v: pointer of type ${atomic}_t
  *
  * Atomically increments @v by 1
@@ -8,8 +8,8 @@ cat <<EOF
  * other cases.
  */
 static __always_inline bool
-${atomic}_inc_and_test(${atomic}_t *v)
+${arch}${atomic}_inc_and_test(${atomic}_t *v)
 {
-	return ${atomic}_inc_return(v) == 0;
+	return ${arch}${atomic}_inc_return(v) == 0;
 }
 EOF
diff --git a/scripts/atomic/fallbacks/inc_not_zero b/scripts/atomic/fallbacks/inc_not_zero
index d9f7b97aab42d..50f2d4d48279c 100755
--- a/scripts/atomic/fallbacks/inc_not_zero
+++ b/scripts/atomic/fallbacks/inc_not_zero
@@ -1,14 +1,14 @@
 cat <<EOF
 /**
- * ${atomic}_inc_not_zero - increment unless the number is zero
+ * ${arch}${atomic}_inc_not_zero - increment unless the number is zero
  * @v: pointer of type ${atomic}_t
  *
  * Atomically increments @v by 1, if @v is non-zero.
  * Returns true if the increment was done.
  */
 static __always_inline bool
-${atomic}_inc_not_zero(${atomic}_t *v)
+${arch}${atomic}_inc_not_zero(${atomic}_t *v)
 {
-	return ${atomic}_add_unless(v, 1, 0);
+	return ${arch}${atomic}_add_unless(v, 1, 0);
 }
 EOF
diff --git a/scripts/atomic/fallbacks/inc_unless_negative b/scripts/atomic/fallbacks/inc_unless_negative
index 177a7cb51edad..87629e0d4a80d 100755
--- a/scripts/atomic/fallbacks/inc_unless_negative
+++ b/scripts/atomic/fallbacks/inc_unless_negative
@@ -1,13 +1,13 @@
 cat <<EOF
 static __always_inline bool
-${atomic}_inc_unless_negative(${atomic}_t *v)
+${arch}${atomic}_inc_unless_negative(${atomic}_t *v)
 {
-	${int} c = ${atomic}_read(v);
+	${int} c = ${arch}${atomic}_read(v);
 
 	do {
 		if (unlikely(c < 0))
 			return false;
-	} while (!${atomic}_try_cmpxchg(v, &c, c + 1));
+	} while (!${arch}${atomic}_try_cmpxchg(v, &c, c + 1));
 
 	return true;
 }
diff --git a/scripts/atomic/fallbacks/read_acquire b/scripts/atomic/fallbacks/read_acquire
index 12fa83cb3a6d1..341a88dccaa7e 100755
--- a/scripts/atomic/fallbacks/read_acquire
+++ b/scripts/atomic/fallbacks/read_acquire
@@ -1,6 +1,6 @@
 cat <<EOF
 static __always_inline ${ret}
-${atomic}_read_acquire(const ${atomic}_t *v)
+${arch}${atomic}_read_acquire(const ${atomic}_t *v)
 {
 	return smp_load_acquire(&(v)->counter);
 }
diff --git a/scripts/atomic/fallbacks/release b/scripts/atomic/fallbacks/release
index 730d2a6d3e072..f8906d537c0f4 100755
--- a/scripts/atomic/fallbacks/release
+++ b/scripts/atomic/fallbacks/release
@@ -1,8 +1,8 @@
 cat <<EOF
 static __always_inline ${ret}
-${atomic}_${pfx}${name}${sfx}_release(${params})
+${arch}${atomic}_${pfx}${name}${sfx}_release(${params})
 {
 	__atomic_release_fence();
-	${retstmt}${atomic}_${pfx}${name}${sfx}_relaxed(${args});
+	${retstmt}${arch}${atomic}_${pfx}${name}${sfx}_relaxed(${args});
 }
 EOF
diff --git a/scripts/atomic/fallbacks/set_release b/scripts/atomic/fallbacks/set_release
index e5d72c7174343..76068272d5f52 100755
--- a/scripts/atomic/fallbacks/set_release
+++ b/scripts/atomic/fallbacks/set_release
@@ -1,6 +1,6 @@
 cat <<EOF
 static __always_inline void
-${atomic}_set_release(${atomic}_t *v, ${int} i)
+${arch}${atomic}_set_release(${atomic}_t *v, ${int} i)
 {
 	smp_store_release(&(v)->counter, i);
 }
diff --git a/scripts/atomic/fallbacks/sub_and_test b/scripts/atomic/fallbacks/sub_and_test
index 6cfe4ed497467..c580f4c2136e5 100755
--- a/scripts/atomic/fallbacks/sub_and_test
+++ b/scripts/atomic/fallbacks/sub_and_test
@@ -1,6 +1,6 @@
 cat <<EOF
 /**
- * ${atomic}_sub_and_test - subtract value from variable and test result
+ * ${arch}${atomic}_sub_and_test - subtract value from variable and test result
  * @i: integer value to subtract
  * @v: pointer of type ${atomic}_t
  *
@@ -9,8 +9,8 @@ cat <<EOF
  * other cases.
  */
 static __always_inline bool
-${atomic}_sub_and_test(${int} i, ${atomic}_t *v)
+${arch}${atomic}_sub_and_test(${int} i, ${atomic}_t *v)
 {
-	return ${atomic}_sub_return(i, v) == 0;
+	return ${arch}${atomic}_sub_return(i, v) == 0;
 }
 EOF
diff --git a/scripts/atomic/fallbacks/try_cmpxchg b/scripts/atomic/fallbacks/try_cmpxchg
index c7a26213b9782..06db0f738e45e 100755
--- a/scripts/atomic/fallbacks/try_cmpxchg
+++ b/scripts/atomic/fallbacks/try_cmpxchg
@@ -1,9 +1,9 @@
 cat <<EOF
 static __always_inline bool
-${atomic}_try_cmpxchg${order}(${atomic}_t *v, ${int} *old, ${int} new)
+${arch}${atomic}_try_cmpxchg${order}(${atomic}_t *v, ${int} *old, ${int} new)
 {
 	${int} r, o = *old;
-	r = ${atomic}_cmpxchg${order}(v, o, new);
+	r = ${arch}${atomic}_cmpxchg${order}(v, o, new);
 	if (unlikely(r != o))
 		*old = r;
 	return likely(r == o);
diff --git a/scripts/atomic/gen-atomic-fallback.sh b/scripts/atomic/gen-atomic-fallback.sh
index b6c6f5d306a7b..0fd1cf0c2b94b 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
diff --git a/scripts/atomic/gen-atomics.sh b/scripts/atomic/gen-atomics.sh
index 000dc6437893b..d29e159ef4891 100644
--- a/scripts/atomic/gen-atomics.sh
+++ b/scripts/atomic/gen-atomics.sh
@@ -10,10 +10,11 @@ LINUXDIR=${ATOMICDIR}/../..
 cat <<EOF |
 gen-atomic-instrumented.sh      asm-generic/atomic-instrumented.h
 gen-atomic-long.sh              asm-generic/atomic-long.h
+gen-atomic-fallback.sh          linux/atomic-arch-fallback.h		arch_
 gen-atomic-fallback.sh          linux/atomic-fallback.h
 EOF
-while read script header; do
-	/bin/sh ${ATOMICDIR}/${script} ${ATOMICTBL} > ${LINUXDIR}/include/${header}
+while read script header args; do
+	/bin/sh ${ATOMICDIR}/${script} ${ATOMICTBL} ${args} > ${LINUXDIR}/include/${header}
 	HASH="$(sha1sum ${LINUXDIR}/include/${header})"
 	HASH="${HASH%% *}"
 	printf "// %s\n" "${HASH}" >> ${LINUXDIR}/include/${header}