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authorRosen Penev <rosenp@gmail.com>2026-09-27 13:35:01 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2026-10-01 11:04:53 +0200
commit8167c1f071426706c233e93ecfd13aba7d5c06c8 (patch)
tree2c0cd5f5e1cc35eadee98d49fe034f96a88856ce /include/asm-generic/bitops/lock.h
downloadlinux-stable-8167c1f071426706c233e93ecfd13aba7d5c06c8.tar.gz
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tty: serial: mpc52xx_uart: move static declarations up.grafted
Avoid a compilation error so that they're not used before being declared. Fixes: 4d105880666a ("tty: serial: mpc52xx_uart: add bounds check for psc_num array index") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202609260356.tJWbd1WU-lkp@intel.com/ Signed-off-by: Rosen Penev <rosenp@gmail.com> Link: https://patch.msgid.link/20260927203501.14105-1-rosenp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/asm-generic/bitops/lock.h')
-rw-r--r--include/asm-generic/bitops/lock.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/lock.h b/include/asm-generic/bitops/lock.h
new file mode 100644
index 000000000..ffb73b612
--- /dev/null
+++ b/include/asm-generic/bitops/lock.h
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_BITOPS_LOCK_H_
+#define _ASM_GENERIC_BITOPS_LOCK_H_
+
+#include <linux/atomic.h>
+#include <linux/compiler.h>
+#include <asm/barrier.h>
+
+/**
+ * arch_test_and_set_bit_lock - Set a bit and return its old value, for lock
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is atomic and provides acquire barrier semantics if
+ * the returned value is 0.
+ * It can be used to implement bit locks.
+ */
+static __always_inline int
+arch_test_and_set_bit_lock(unsigned int nr, volatile unsigned long *addr)
+{
+ long old;
+ unsigned long mask = BIT_MASK(nr);
+
+ addr += BIT_WORD(nr);
+ if (READ_ONCE(*addr) & mask)
+ return 1;
+
+ old = raw_atomic_long_fetch_or_acquire(mask, (atomic_long_t *)addr);
+ return !!(old & mask);
+}
+
+
+/**
+ * arch_clear_bit_unlock - Clear a bit in memory, for unlock
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * This operation is atomic and provides release barrier semantics.
+ */
+static __always_inline void
+arch_clear_bit_unlock(unsigned int nr, volatile unsigned long *addr)
+{
+ addr += BIT_WORD(nr);
+ raw_atomic_long_fetch_andnot_release(BIT_MASK(nr), (atomic_long_t *)addr);
+}
+
+/**
+ * arch___clear_bit_unlock - Clear a bit in memory, for unlock
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * A weaker form of clear_bit_unlock() as used by __bit_lock_unlock(). If all
+ * the bits in the word are protected by this lock some archs can use weaker
+ * ops to safely unlock.
+ *
+ * See for example x86's implementation.
+ */
+static inline void
+arch___clear_bit_unlock(unsigned int nr, volatile unsigned long *addr)
+{
+ unsigned long old;
+
+ addr += BIT_WORD(nr);
+ old = READ_ONCE(*addr);
+ old &= ~BIT_MASK(nr);
+ raw_atomic_long_set_release((atomic_long_t *)addr, old);
+}
+
+#ifndef arch_xor_unlock_is_negative_byte
+static inline bool arch_xor_unlock_is_negative_byte(unsigned long mask,
+ volatile unsigned long *p)
+{
+ long old;
+
+ old = raw_atomic_long_fetch_xor_release(mask, (atomic_long_t *)p);
+ return !!(old & BIT(7));
+}
+#endif
+
+#include <asm-generic/bitops/instrumented-lock.h>
+
+#endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */