[SPARC64]: Implement futex_atomic_op_inuser().

Signed-off-by: David S. Miller <davem@davemloft.net>

include/asm-sparc64/futex.h

-#ifndef _ASM_FUTEX_H
-#define _ASM_FUTEX_H
+#ifndef _SPARC64_FUTEX_H
+#define _SPARC64_FUTEX_H
 
-#include <asm-generic/futex.h>
+#include <linux/futex.h>
+#include <asm/errno.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
 
-#endif
+#define __futex_cas_op(insn, ret, oldval, uaddr, oparg)	\
+	__asm__ __volatile__(				\
+	"\n1:	lduwa	[%3] %%asi, %2\n"		\
+	"	" insn "\n"				\
+	"2:	casa	[%3] %%asi, %2, %1\n"		\
+	"	cmp	%2, %1\n"			\
+	"	bne,pn	%%icc, 1b\n"			\
+	"	 mov	0, %0\n"			\
+	"3:\n"						\
+	"	.section .fixup,#alloc,#execinstr\n"	\
+	"	.align	4\n"				\
+	"4:	ba	3b\n"				\
+	"	 mov	%5, %0\n"			\
+	"	.previous\n"				\
+	"	.section __ex_table,#alloc\n"		\
+	"	.align	4\n"				\
+	"	.word	1b, 4b\n"			\
+	"	.word	2b, 4b\n"			\
+	"	.previous\n"				\
+	: "=&r" (ret), "=&r" (oldval), "=&r" (tem)	\
+	: "r" (uaddr), "r" (oparg), "i" (-EFAULT)	\
+	: "memory")
+
+static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
+{
+	int op = (encoded_op >> 28) & 7;
+	int cmp = (encoded_op >> 24) & 15;
+	int oparg = (encoded_op << 8) >> 20;
+	int cmparg = (encoded_op << 20) >> 20;
+	int oldval = 0, ret, tem;
+
+	if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(int))))
+		return -EFAULT;
+	if (unlikely((((unsigned long) uaddr) & 0x3UL)))
+		return -EINVAL;
+
+	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
+		oparg = 1 << oparg;
+
+	inc_preempt_count();
+
+	switch (op) {
+	case FUTEX_OP_SET:
+		__futex_cas_op("mov\t%4, %1", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ADD:
+		__futex_cas_op("add\t%2, %4, %1", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_OR:
+		__futex_cas_op("or\t%2, %4, %1", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ANDN:
+		__futex_cas_op("and\t%2, %4, %1", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_XOR:
+		__futex_cas_op("xor\t%2, %4, %1", ret, oldval, uaddr, oparg);
+		break;
+	default:
+		ret = -ENOSYS;
+	}
+
+	dec_preempt_count();
+
+	if (!ret) {
+		switch (cmp) {
+		case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
+		case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
+		case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
+		case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
+		case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
+		case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
+		default: ret = -ENOSYS;
+		}
+	}
+	return ret;
+}
+
+#endif /* !(_SPARC64_FUTEX_H) */