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Commit b987ffc1 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

x86/qspinlock: Fix compile error 



With a compiler that has asm-goto but not asm-cc-output and
CONFIG_PROFILE_ALL_BRANCHES=y we get a compiler error:

  arch/x86/include/asm/rmwcc.h:23:17: error: jump into statement expression

Fix this by writing the if() as a boolean multiplication instead.

Reported-by: default avatarkbuild test robot <lkp@intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Fixes: 7aa54be2 ("locking/qspinlock, x86: Provide liveness guarantee")
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 5b744981

arch/x86/include/asm/qspinlock.h

+8 −5
Original line number Diff line number Diff line
@@ -13,12 +13,15 @@ 
#define queued_fetch_set_pending_acquire queued_fetch_set_pending_acquire

static __always_inline u32 queued_fetch_set_pending_acquire(struct qspinlock *lock)

{

	u32 val = 0;



	if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,

			     "I", _Q_PENDING_OFFSET))

		val |= _Q_PENDING_VAL;

	u32 val;



	/*

	 * We can't use GEN_BINARY_RMWcc() inside an if() stmt because asm goto

	 * and CONFIG_PROFILE_ALL_BRANCHES=y results in a label inside a

	 * statement expression, which GCC doesn't like.

	 */

	val = GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,

			       "I", _Q_PENDING_OFFSET) * _Q_PENDING_VAL;

	val |= atomic_read(&lock->val) & ~_Q_PENDING_MASK;



	return val;