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authorIvan Kokshaysky <ink@jurassic.park.msu.ru>2009-04-30 15:08:48 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-05-02 15:36:10 -0700
commit77b4cf5cb0c9d6010a18030a0e0a8d2aaf6b43ec (patch)
treeb9b0b9f25e4495499ae5a35f1beaca7a5b240201 /arch/alpha
parent08a42e86bce511b45ca3eee40f51674b02a777d1 (diff)
alpha: futex implementation
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Richard Henderson <rth@twiddle.net Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/alpha')
-rw-r--r--arch/alpha/include/asm/barrier.h2
-rw-r--r--arch/alpha/include/asm/futex.h118
2 files changed, 116 insertions, 4 deletions
diff --git a/arch/alpha/include/asm/barrier.h b/arch/alpha/include/asm/barrier.h
index ac78eba909b..ce8860a0b32 100644
--- a/arch/alpha/include/asm/barrier.h
+++ b/arch/alpha/include/asm/barrier.h
@@ -16,11 +16,13 @@ __asm__ __volatile__("wmb": : :"memory")
__asm__ __volatile__("mb": : :"memory")
#ifdef CONFIG_SMP
+#define __ASM_SMP_MB "\tmb\n"
#define smp_mb() mb()
#define smp_rmb() rmb()
#define smp_wmb() wmb()
#define smp_read_barrier_depends() read_barrier_depends()
#else
+#define __ASM_SMP_MB
#define smp_mb() barrier()
#define smp_rmb() barrier()
#define smp_wmb() barrier()
diff --git a/arch/alpha/include/asm/futex.h b/arch/alpha/include/asm/futex.h
index 6a332a9f099..945de222ab9 100644
--- a/arch/alpha/include/asm/futex.h
+++ b/arch/alpha/include/asm/futex.h
@@ -1,6 +1,116 @@
-#ifndef _ASM_FUTEX_H
-#define _ASM_FUTEX_H
+#ifndef _ASM_ALPHA_FUTEX_H
+#define _ASM_ALPHA_FUTEX_H
-#include <asm-generic/futex.h>
+#ifdef __KERNEL__
-#endif
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <asm/errno.h>
+#include <asm/barrier.h>
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+ __asm__ __volatile__( \
+ __ASM_SMP_MB \
+ "1: ldl_l %0,0(%2)\n" \
+ insn \
+ "2: stl_c %1,0(%2)\n" \
+ " beq %1,4f\n" \
+ " mov $31,%1\n" \
+ "3: .subsection 2\n" \
+ "4: br 1b\n" \
+ " .previous\n" \
+ " .section __ex_table,\"a\"\n" \
+ " .long 1b-.\n" \
+ " lda $31,3b-1b(%1)\n" \
+ " .long 2b-.\n" \
+ " lda $31,3b-2b(%1)\n" \
+ " .previous\n" \
+ : "=&r" (oldval), "=&r"(ret) \
+ : "r" (uaddr), "r"(oparg) \
+ : "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;
+
+ pagefault_disable();
+
+ switch (op) {
+ case FUTEX_OP_SET:
+ __futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ADD:
+ __futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_OR:
+ __futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ANDN:
+ __futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_XOR:
+ __futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ 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;
+ }
+ }
+ return ret;
+}
+
+static inline int
+futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+{
+ int prev, cmp;
+
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+ return -EFAULT;
+
+ __asm__ __volatile__ (
+ __ASM_SMP_MB
+ "1: ldl_l %0,0(%2)\n"
+ " cmpeq %0,%3,%1\n"
+ " beq %1,3f\n"
+ " mov %4,%1\n"
+ "2: stl_c %1,0(%2)\n"
+ " beq %1,4f\n"
+ "3: .subsection 2\n"
+ "4: br 1b\n"
+ " .previous\n"
+ " .section __ex_table,\"a\"\n"
+ " .long 1b-.\n"
+ " lda $31,3b-1b(%0)\n"
+ " .long 2b-.\n"
+ " lda $31,3b-2b(%0)\n"
+ " .previous\n"
+ : "=&r"(prev), "=&r"(cmp)
+ : "r"(uaddr), "r"((long)oldval), "r"(newval)
+ : "memory");
+
+ return prev;
+}
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_ALPHA_FUTEX_H */