From: Martin Schwidefsky <[email protected]>
[patch 8/13] s390: futex atomic operations.
Add support for atomic futex operations.
Signed-off-by: Martin Schwidefsky <[email protected]>
---
include/asm-s390/futex.h | 96 +++++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 92 insertions(+), 4 deletions(-)
diff -urpN linux-2.6/include/asm-s390/futex.h linux-2.6-patched/include/asm-s390/futex.h
--- linux-2.6/include/asm-s390/futex.h 2006-03-20 06:53:29.000000000 +0100
+++ linux-2.6-patched/include/asm-s390/futex.h 2006-04-24 16:47:25.000000000 +0200
@@ -1,6 +1,94 @@
-#ifndef _ASM_FUTEX_H
-#define _ASM_FUTEX_H
+#ifndef _ASM_S390_FUTEX_H
+#define _ASM_S390_FUTEX_H
-#include <asm-generic/futex.h>
+#ifdef __KERNEL__
-#endif
+#include <linux/futex.h>
+#include <asm/errno.h>
+#include <asm/uaccess.h>
+
+#ifndef __s390x__
+#define __futex_atomic_fixup \
+ ".section __ex_table,\"a\"\n" \
+ " .align 4\n" \
+ " .long 0b,2b,1b,2b\n" \
+ ".previous"
+#else /* __s390x__ */
+#define __futex_atomic_fixup \
+ ".section __ex_table,\"a\"\n" \
+ " .align 8\n" \
+ " .quad 0b,2b,1b,2b\n" \
+ ".previous"
+#endif /* __s390x__ */
+
+#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \
+ asm volatile(" l %1,0(%6)\n" \
+ "0: " insn \
+ " cs %1,%2,0(%6)\n" \
+ "1: jl 0b\n" \
+ " lhi %0,0\n" \
+ "2:\n" \
+ __futex_atomic_fixup \
+ : "=d" (ret), "=&d" (oldval), "=&d" (newval), \
+ "=m" (*(unsigned long __user *) uaddr) \
+ : "0" (-EFAULT), "d" (oparg), "a" (uaddr), \
+ "m" (*(unsigned long __user *) uaddr) : "cc" );
+
+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, newval, 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("lr %2,%5\n",
+ ret, oldval, newval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ADD:
+ __futex_atomic_op("lr %2,%1\nar %2,%5\n",
+ ret, oldval, newval, uaddr, oparg);
+ break;
+ case FUTEX_OP_OR:
+ __futex_atomic_op("lr %2,%1\nor %2,%5\n",
+ ret, oldval, newval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ANDN:
+ __futex_atomic_op("lr %2,%1\nnr %2,%5\n",
+ ret, oldval, newval, uaddr, oparg);
+ break;
+ case FUTEX_OP_XOR:
+ __futex_atomic_op("lr %2,%1\nxr %2,%5\n",
+ ret, oldval, newval, 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_S390_FUTEX_H */
-
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