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authorLinus Torvalds <torvalds@linux-foundation.org>2023-06-28 00:14:30 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-06-28 00:14:30 +0300
commitbc6cb4d5bc3a44197de30784eae71d8ba28483eb (patch)
treefdd00391c6068c217eeb8a4a06afc40cc1fc6853 /arch/arm
parented3b7923a816ded62dccef377c9ee346c7d3b1b4 (diff)
parentb33eb50a92b0a298fa8a6ac350e741c3ec100f6d (diff)
downloadlinux-bc6cb4d5bc3a44197de30784eae71d8ba28483eb.tar.xz
Merge tag 'locking-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar: - Introduce cmpxchg128() -- aka. the demise of cmpxchg_double() The cmpxchg128() family of functions is basically & functionally the same as cmpxchg_double(), but with a saner interface. Instead of a 6-parameter horror that forced u128 - u64/u64-halves layout details on the interface and exposed users to complexity, fragility & bugs, use a natural 3-parameter interface with u128 types. - Restructure the generated atomic headers, and add kerneldoc comments for all of the generic atomic{,64,_long}_t operations. The generated definitions are much cleaner now, and come with documentation. - Implement lock_set_cmp_fn() on lockdep, for defining an ordering when taking multiple locks of the same type. This gets rid of one use of lockdep_set_novalidate_class() in the bcache code. - Fix raw_cpu_generic_try_cmpxchg() bug due to an unintended variable shadowing generating garbage code on Clang on certain ARM builds. * tag 'locking-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits) locking/atomic: scripts: fix ${atomic}_dec_if_positive() kerneldoc percpu: Fix self-assignment of __old in raw_cpu_generic_try_cmpxchg() locking/atomic: treewide: delete arch_atomic_*() kerneldoc locking/atomic: docs: Add atomic operations to the driver basic API documentation locking/atomic: scripts: generate kerneldoc comments docs: scripts: kernel-doc: accept bitwise negation like ~@var locking/atomic: scripts: simplify raw_atomic*() definitions locking/atomic: scripts: simplify raw_atomic_long*() definitions locking/atomic: scripts: split pfx/name/sfx/order locking/atomic: scripts: restructure fallback ifdeffery locking/atomic: scripts: build raw_atomic_long*() directly locking/atomic: treewide: use raw_atomic*_<op>() locking/atomic: scripts: add trivial raw_atomic*_<op>() locking/atomic: scripts: factor out order template generation locking/atomic: scripts: remove leftover "${mult}" locking/atomic: scripts: remove bogus order parameter locking/atomic: xtensa: add preprocessor symbols locking/atomic: x86: add preprocessor symbols locking/atomic: sparc: add preprocessor symbols locking/atomic: sh: add preprocessor symbols ...
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/assembler.h17
-rw-r--r--arch/arm/include/asm/atomic.h15
-rw-r--r--arch/arm/include/asm/sync_bitops.h29
-rw-r--r--arch/arm/lib/bitops.h14
-rw-r--r--arch/arm/lib/testchangebit.S4
-rw-r--r--arch/arm/lib/testclearbit.S4
-rw-r--r--arch/arm/lib/testsetbit.S4
7 files changed, 76 insertions, 11 deletions
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 505a306e0271..aebe2c8f6a68 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -394,6 +394,23 @@ ALT_UP_B(.L0_\@)
#endif
.endm
+/*
+ * Raw SMP data memory barrier
+ */
+ .macro __smp_dmb mode
+#if __LINUX_ARM_ARCH__ >= 7
+ .ifeqs "\mode","arm"
+ dmb ish
+ .else
+ W(dmb) ish
+ .endif
+#elif __LINUX_ARM_ARCH__ == 6
+ mcr p15, 0, r0, c7, c10, 5 @ dmb
+#else
+ .error "Incompatible SMP platform"
+#endif
+ .endm
+
#if defined(CONFIG_CPU_V7M)
/*
* setmode is used to assert to be in svc mode during boot. For v7-M
diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
index db8512d9a918..f0e3b01afa74 100644
--- a/arch/arm/include/asm/atomic.h
+++ b/arch/arm/include/asm/atomic.h
@@ -197,6 +197,16 @@ static inline int arch_atomic_fetch_##op(int i, atomic_t *v) \
return val; \
}
+#define arch_atomic_add_return arch_atomic_add_return
+#define arch_atomic_sub_return arch_atomic_sub_return
+#define arch_atomic_fetch_add arch_atomic_fetch_add
+#define arch_atomic_fetch_sub arch_atomic_fetch_sub
+
+#define arch_atomic_fetch_and arch_atomic_fetch_and
+#define arch_atomic_fetch_andnot arch_atomic_fetch_andnot
+#define arch_atomic_fetch_or arch_atomic_fetch_or
+#define arch_atomic_fetch_xor arch_atomic_fetch_xor
+
static inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
{
int ret;
@@ -210,8 +220,7 @@ static inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
return ret;
}
-
-#define arch_atomic_fetch_andnot arch_atomic_fetch_andnot
+#define arch_atomic_cmpxchg arch_atomic_cmpxchg
#endif /* __LINUX_ARM_ARCH__ */
@@ -240,8 +249,6 @@ ATOMIC_OPS(xor, ^=, eor)
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
-#define arch_atomic_xchg(v, new) (arch_xchg(&((v)->counter), new))
-
#ifndef CONFIG_GENERIC_ATOMIC64
typedef struct {
s64 counter;
diff --git a/arch/arm/include/asm/sync_bitops.h b/arch/arm/include/asm/sync_bitops.h
index 6f5d627c44a3..f46b3c570f92 100644
--- a/arch/arm/include/asm/sync_bitops.h
+++ b/arch/arm/include/asm/sync_bitops.h
@@ -14,14 +14,35 @@
* ops which are SMP safe even on a UP kernel.
*/
+/*
+ * Unordered
+ */
+
#define sync_set_bit(nr, p) _set_bit(nr, p)
#define sync_clear_bit(nr, p) _clear_bit(nr, p)
#define sync_change_bit(nr, p) _change_bit(nr, p)
-#define sync_test_and_set_bit(nr, p) _test_and_set_bit(nr, p)
-#define sync_test_and_clear_bit(nr, p) _test_and_clear_bit(nr, p)
-#define sync_test_and_change_bit(nr, p) _test_and_change_bit(nr, p)
#define sync_test_bit(nr, addr) test_bit(nr, addr)
-#define arch_sync_cmpxchg arch_cmpxchg
+/*
+ * Fully ordered
+ */
+
+int _sync_test_and_set_bit(int nr, volatile unsigned long * p);
+#define sync_test_and_set_bit(nr, p) _sync_test_and_set_bit(nr, p)
+
+int _sync_test_and_clear_bit(int nr, volatile unsigned long * p);
+#define sync_test_and_clear_bit(nr, p) _sync_test_and_clear_bit(nr, p)
+
+int _sync_test_and_change_bit(int nr, volatile unsigned long * p);
+#define sync_test_and_change_bit(nr, p) _sync_test_and_change_bit(nr, p)
+
+#define arch_sync_cmpxchg(ptr, old, new) \
+({ \
+ __typeof__(*(ptr)) __ret; \
+ __smp_mb__before_atomic(); \
+ __ret = arch_cmpxchg_relaxed((ptr), (old), (new)); \
+ __smp_mb__after_atomic(); \
+ __ret; \
+})
#endif
diff --git a/arch/arm/lib/bitops.h b/arch/arm/lib/bitops.h
index 95bd35991288..f069d1b2318e 100644
--- a/arch/arm/lib/bitops.h
+++ b/arch/arm/lib/bitops.h
@@ -28,7 +28,7 @@ UNWIND( .fnend )
ENDPROC(\name )
.endm
- .macro testop, name, instr, store
+ .macro __testop, name, instr, store, barrier
ENTRY( \name )
UNWIND( .fnstart )
ands ip, r1, #3
@@ -38,7 +38,7 @@ UNWIND( .fnstart )
mov r0, r0, lsr #5
add r1, r1, r0, lsl #2 @ Get word offset
mov r3, r2, lsl r3 @ create mask
- smp_dmb
+ \barrier
#if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
.arch_extension mp
ALT_SMP(W(pldw) [r1])
@@ -50,13 +50,21 @@ UNWIND( .fnstart )
strex ip, r2, [r1]
cmp ip, #0
bne 1b
- smp_dmb
+ \barrier
cmp r0, #0
movne r0, #1
2: bx lr
UNWIND( .fnend )
ENDPROC(\name )
.endm
+
+ .macro testop, name, instr, store
+ __testop \name, \instr, \store, smp_dmb
+ .endm
+
+ .macro sync_testop, name, instr, store
+ __testop \name, \instr, \store, __smp_dmb
+ .endm
#else
.macro bitop, name, instr
ENTRY( \name )
diff --git a/arch/arm/lib/testchangebit.S b/arch/arm/lib/testchangebit.S
index 4ebecc67e6e0..f13fe9bc2399 100644
--- a/arch/arm/lib/testchangebit.S
+++ b/arch/arm/lib/testchangebit.S
@@ -10,3 +10,7 @@
.text
testop _test_and_change_bit, eor, str
+
+#if __LINUX_ARM_ARCH__ >= 6
+sync_testop _sync_test_and_change_bit, eor, str
+#endif
diff --git a/arch/arm/lib/testclearbit.S b/arch/arm/lib/testclearbit.S
index 009afa0f5b4a..4d2c5ca620eb 100644
--- a/arch/arm/lib/testclearbit.S
+++ b/arch/arm/lib/testclearbit.S
@@ -10,3 +10,7 @@
.text
testop _test_and_clear_bit, bicne, strne
+
+#if __LINUX_ARM_ARCH__ >= 6
+sync_testop _sync_test_and_clear_bit, bicne, strne
+#endif
diff --git a/arch/arm/lib/testsetbit.S b/arch/arm/lib/testsetbit.S
index f3192e55acc8..649dbab65d8d 100644
--- a/arch/arm/lib/testsetbit.S
+++ b/arch/arm/lib/testsetbit.S
@@ -10,3 +10,7 @@
.text
testop _test_and_set_bit, orreq, streq
+
+#if __LINUX_ARM_ARCH__ >= 6
+sync_testop _sync_test_and_set_bit, orreq, streq
+#endif