--- /dev/null
+/* futex.c: futex operations
+ *
+ * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <asm/futex.h>
+#include <asm/errno.h>
+
+/*
+ * the various futex operations; MMU fault checking is ignored under no-MMU
+ * conditions
+ */
+static inline int atomic_futex_op_xchg_set(int oparg, u32 __user *uaddr, int *_oldval)
+{
+ int oldval, ret;
+
+ asm("0: \n"
+ " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
+ " ckeq icc3,cc7 \n"
+ "1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
+ " orcr cc7,cc7,cc3 \n" /* set CC3 to true */
+ "2: cst.p %3,%M0 ,cc3,#1 \n"
+ " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
+ " beq icc3,#0,0b \n"
+ " setlos 0,%2 \n"
+ "3: \n"
+ ".subsection 2 \n"
+ "4: setlos %5,%2 \n"
+ " bra 3b \n"
+ ".previous \n"
+ ".section __ex_table,\"a\" \n"
+ " .balign 8 \n"
+ " .long 1b,4b \n"
+ " .long 2b,4b \n"
+ ".previous"
+ : "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg)
+ : "3"(oparg), "i"(-EFAULT)
+ : "memory", "cc7", "cc3", "icc3"
+ );
+
+ *_oldval = oldval;
+ return ret;
+}
+
+static inline int atomic_futex_op_xchg_add(int oparg, u32 __user *uaddr, int *_oldval)
+{
+ int oldval, ret;
+
+ asm("0: \n"
+ " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
+ " ckeq icc3,cc7 \n"
+ "1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
+ " orcr cc7,cc7,cc3 \n" /* set CC3 to true */
+ " add %1,%3,%3 \n"
+ "2: cst.p %3,%M0 ,cc3,#1 \n"
+ " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
+ " beq icc3,#0,0b \n"
+ " setlos 0,%2 \n"
+ "3: \n"
+ ".subsection 2 \n"
+ "4: setlos %5,%2 \n"
+ " bra 3b \n"
+ ".previous \n"
+ ".section __ex_table,\"a\" \n"
+ " .balign 8 \n"
+ " .long 1b,4b \n"
+ " .long 2b,4b \n"
+ ".previous"
+ : "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg)
+ : "3"(oparg), "i"(-EFAULT)
+ : "memory", "cc7", "cc3", "icc3"
+ );
+
+ *_oldval = oldval;
+ return ret;
+}
+
+static inline int atomic_futex_op_xchg_or(int oparg, u32 __user *uaddr, int *_oldval)
+{
+ int oldval, ret;
+
+ asm("0: \n"
+ " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
+ " ckeq icc3,cc7 \n"
+ "1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
+ " orcr cc7,cc7,cc3 \n" /* set CC3 to true */
+ " or %1,%3,%3 \n"
+ "2: cst.p %3,%M0 ,cc3,#1 \n"
+ " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
+ " beq icc3,#0,0b \n"
+ " setlos 0,%2 \n"
+ "3: \n"
+ ".subsection 2 \n"
+ "4: setlos %5,%2 \n"
+ " bra 3b \n"
+ ".previous \n"
+ ".section __ex_table,\"a\" \n"
+ " .balign 8 \n"
+ " .long 1b,4b \n"
+ " .long 2b,4b \n"
+ ".previous"
+ : "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg)
+ : "3"(oparg), "i"(-EFAULT)
+ : "memory", "cc7", "cc3", "icc3"
+ );
+
+ *_oldval = oldval;
+ return ret;
+}
+
+static inline int atomic_futex_op_xchg_and(int oparg, u32 __user *uaddr, int *_oldval)
+{
+ int oldval, ret;
+
+ asm("0: \n"
+ " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
+ " ckeq icc3,cc7 \n"
+ "1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
+ " orcr cc7,cc7,cc3 \n" /* set CC3 to true */
+ " and %1,%3,%3 \n"
+ "2: cst.p %3,%M0 ,cc3,#1 \n"
+ " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
+ " beq icc3,#0,0b \n"
+ " setlos 0,%2 \n"
+ "3: \n"
+ ".subsection 2 \n"
+ "4: setlos %5,%2 \n"
+ " bra 3b \n"
+ ".previous \n"
+ ".section __ex_table,\"a\" \n"
+ " .balign 8 \n"
+ " .long 1b,4b \n"
+ " .long 2b,4b \n"
+ ".previous"
+ : "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg)
+ : "3"(oparg), "i"(-EFAULT)
+ : "memory", "cc7", "cc3", "icc3"
+ );
+
+ *_oldval = oldval;
+ return ret;
+}
+
+static inline int atomic_futex_op_xchg_xor(int oparg, u32 __user *uaddr, int *_oldval)
+{
+ int oldval, ret;
+
+ asm("0: \n"
+ " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
+ " ckeq icc3,cc7 \n"
+ "1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
+ " orcr cc7,cc7,cc3 \n" /* set CC3 to true */
+ " xor %1,%3,%3 \n"
+ "2: cst.p %3,%M0 ,cc3,#1 \n"
+ " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
+ " beq icc3,#0,0b \n"
+ " setlos 0,%2 \n"
+ "3: \n"
+ ".subsection 2 \n"
+ "4: setlos %5,%2 \n"
+ " bra 3b \n"
+ ".previous \n"
+ ".section __ex_table,\"a\" \n"
+ " .balign 8 \n"
+ " .long 1b,4b \n"
+ " .long 2b,4b \n"
+ ".previous"
+ : "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg)
+ : "3"(oparg), "i"(-EFAULT)
+ : "memory", "cc7", "cc3", "icc3"
+ );
+
+ *_oldval = oldval;
+ return ret;
+}
+
+/*****************************************************************************/
+/*
+ * do the futex operations
+ */
+int futex_atomic_op_inuser(int encoded_op, u32 __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;
+
+ if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
+ oparg = 1 << oparg;
+
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ pagefault_disable();
+
+ switch (op) {
+ case FUTEX_OP_SET:
+ ret = atomic_futex_op_xchg_set(oparg, uaddr, &oldval);
+ break;
+ case FUTEX_OP_ADD:
+ ret = atomic_futex_op_xchg_add(oparg, uaddr, &oldval);
+ break;
+ case FUTEX_OP_OR:
+ ret = atomic_futex_op_xchg_or(oparg, uaddr, &oldval);
+ break;
+ case FUTEX_OP_ANDN:
+ ret = atomic_futex_op_xchg_and(~oparg, uaddr, &oldval);
+ break;
+ case FUTEX_OP_XOR:
+ ret = atomic_futex_op_xchg_xor(oparg, uaddr, &oldval);
+ break;
+ default:
+ ret = -ENOSYS;
+ break;
+ }
+
+ pagefault_enable();
+
+ 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; break;
+ }
+ }
+
+ return ret;
+
+} /* end futex_atomic_op_inuser() */
Code Review / kvmfornfv.git / blobdiff