aboutsummaryrefslogtreecommitdiff
path: root/include/asm-powerpc/futex.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-powerpc/futex.h')
-rw-r--r--include/asm-powerpc/futex.h84
1 files changed, 84 insertions, 0 deletions
diff --git a/include/asm-powerpc/futex.h b/include/asm-powerpc/futex.h
new file mode 100644
index 00000000000..37c94e52ab6
--- /dev/null
+++ b/include/asm-powerpc/futex.h
@@ -0,0 +1,84 @@
+#ifndef _ASM_POWERPC_FUTEX_H
+#define _ASM_POWERPC_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <asm/errno.h>
+#include <asm/synch.h>
+#include <asm/uaccess.h>
+#include <asm/ppc_asm.h>
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+ __asm__ __volatile ( \
+ SYNC_ON_SMP \
+"1: lwarx %0,0,%2\n" \
+ insn \
+"2: stwcx. %1,0,%2\n" \
+ "bne- 1b\n" \
+ "li %1,0\n" \
+"3: .section .fixup,\"ax\"\n" \
+"4: li %1,%3\n" \
+ "b 3b\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ ".align 3\n" \
+ DATAL " 1b,4b,2b,4b\n" \
+ ".previous" \
+ : "=&r" (oldval), "=&r" (ret) \
+ : "b" (uaddr), "i" (-EFAULT), "1" (oparg) \
+ : "cr0", "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;
+ if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
+ oparg = 1 << oparg;
+
+ if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
+ return -EFAULT;
+
+ inc_preempt_count();
+
+ switch (op) {
+ case FUTEX_OP_SET:
+ __futex_atomic_op("", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ADD:
+ __futex_atomic_op("add %1,%0,%1\n", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_OR:
+ __futex_atomic_op("or %1,%0,%1\n", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ANDN:
+ __futex_atomic_op("andc %1,%0,%1\n", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_XOR:
+ __futex_atomic_op("xor %1,%0,%1\n", 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 /* __KERNEL__ */
+#endif /* _ASM_POWERPC_FUTEX_H */