ARC: Add llock/scond to futex backend (9138d413) · Commits · e / devices / android_kernel_sony_msm8998

arch/arc/include/asm/futex.h

+42 −6

Original line number	Original line	Diff line number	Diff line
	@@ -16,6 +16,34 @@
	#include <linux/uaccess.h>		#include <linux/uaccess.h>
	#include <asm/errno.h>		#include <asm/errno.h>

			#ifdef CONFIG_ARC_HAS_LLSC

			#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)\
			\
			__asm__ __volatile__( \
			"1: llock %1, [%2] \n" \
			insn "\n" \
			"2: scond %0, [%2] \n" \
			" bnz 1b \n" \
			" mov %0, 0 \n" \
			"3: \n" \
			" .section .fixup,\"ax\" \n" \
			" .align 4 \n" \
			"4: mov %0, %4 \n" \
			" b 3b \n" \
			" .previous \n" \
			" .section __ex_table,\"a\" \n" \
			" .align 4 \n" \
			" .word 1b, 4b \n" \
			" .word 2b, 4b \n" \
			" .previous \n" \
			\
			: "=&r" (ret), "=&r" (oldval) \
			: "r" (uaddr), "r" (oparg), "ir" (-EFAULT) \
			: "cc", "memory")

			#else /* !CONFIG_ARC_HAS_LLSC */

	#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)\		#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)\
	\		\
	__asm__ __volatile__( \		__asm__ __volatile__( \
	@@ -39,6 +67,8 @@
	: "r" (uaddr), "r" (oparg), "ir" (-EFAULT) \		: "r" (uaddr), "r" (oparg), "ir" (-EFAULT) \
	: "cc", "memory")		: "cc", "memory")

			#endif

	static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)		static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
	{		{
	int op = (encoded_op >> 28) & 7;		int op = (encoded_op >> 28) & 7;
	@@ -123,11 +153,17 @@ futex_atomic_cmpxchg_inatomic(u32 uval, u32 __user uaddr, u32 oldval,

	pagefault_disable();		pagefault_disable();

	/* TBD : can use llock/scond */
	__asm__ __volatile__(		__asm__ __volatile__(
			#ifdef CONFIG_ARC_HAS_LLSC
			"1: llock %0, [%3] \n"
			" brne %0, %1, 3f \n"
			"2: scond %2, [%3] \n"
			" bnz 1b \n"
			#else
	"1: ld %0, [%3] \n"		"1: ld %0, [%3] \n"
	" brne %0, %1, 3f \n"		" brne %0, %1, 3f \n"
	"2: st %2, [%3] \n"		"2: st %2, [%3] \n"
			#endif
	"3: \n"		"3: \n"
	" .section .fixup,\"ax\" \n"		" .section .fixup,\"ax\" \n"
	"4: mov %0, %4 \n"		"4: mov %0, %4 \n"