[PATCH v2 21/29] nios2: Futex operations

Ley Foon Tan
2014-07-15T08:45:48Z

This patch introduces the futex operation.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
---
arch/nios2/include/asm/futex-irq.h | 130 +++++++++++++++++++++++++++++++++++++
arch/nios2/include/asm/futex.h | 110 +++++++++++++++++++++++++++++++
2 files changed, 240 insertions(+)
create mode 100644 arch/nios2/include/asm/futex-irq.h
create mode 100644 arch/nios2/include/asm/futex.h

diff --git a/arch/nios2/include/asm/futex-irq.h b/arch/nios2/include/asm/futex-irq.h
new file mode 100644
index 0000000..ade9296
--- /dev/null
+++ b/arch/nios2/include/asm/futex-irq.h
@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) 2013 Altera Corporation
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Based on asm/futex.h from sh platform.
+ *
+ */
+
+#ifndef __ASM_NIOS2_FUTEX_IRQ_H
+#define __ASM_NIOS2_FUTEX_IRQ_H
+
+
+static inline int atomic_futex_op_xchg_set(int oparg, u32 __user *uaddr,
+ int *oldval)
+{
+ unsigned long flags;
+ int ret;
+
+ local_irq_save(flags);
+
+ ret = get_user(*oldval, uaddr);
+ if (!ret)
+ ret = put_user(oparg, uaddr);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+static inline int atomic_futex_op_xchg_add(int oparg, u32 __user *uaddr,
+ int *oldval)
+{
+ unsigned long flags;
+ int ret;
+
+ local_irq_save(flags);
+
+ ret = get_user(*oldval, uaddr);
+ if (!ret)
+ ret = put_user(*oldval + oparg, uaddr);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+static inline int atomic_futex_op_xchg_or(int oparg, u32 __user *uaddr,
+ int *oldval)
+{
+ unsigned long flags;
+ int ret;
+
+ local_irq_save(flags);
+
+ ret = get_user(*oldval, uaddr);
+ if (!ret)
+ ret = put_user(*oldval | oparg, uaddr);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+static inline int atomic_futex_op_xchg_and(int oparg, u32 __user *uaddr,
+ int *oldval)
+{
+ unsigned long flags;
+ int ret;
+
+ local_irq_save(flags);
+
+ ret = get_user(*oldval, uaddr);
+ if (!ret)
+ ret = put_user(*oldval & oparg, uaddr);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+static inline int atomic_futex_op_xchg_xor(int oparg, u32 __user *uaddr,
+ int *oldval)
+{
+ unsigned long flags;
+ int ret;
+
+ local_irq_save(flags);
+
+ ret = get_user(*oldval, uaddr);
+ if (!ret)
+ ret = put_user(*oldval ^ oparg, uaddr);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+static inline int atomic_futex_op_cmpxchg_inatomic(u32 *uval,
+ u32 __user *uaddr,
+ u32 oldval, u32 newval)
+{
+ unsigned long flags;
+ int ret;
+ u32 prev = 0;
+
+ local_irq_save(flags);
+
+ ret = get_user(prev, uaddr);
+ if (!ret && oldval == prev)
+ ret = put_user(newval, uaddr);
+
+ local_irq_restore(flags);
+
+ *uval = prev;
+ return ret;
+}
+
+#endif /* __ASM_NIOS2_FUTEX_IRQ_H */
diff --git a/arch/nios2/include/asm/futex.h b/arch/nios2/include/asm/futex.h
new file mode 100644
index 0000000..52b2fa9
--- /dev/null
+++ b/arch/nios2/include/asm/futex.h
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2013 Altera Corporation
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Based on asm/futex.h from sh platform.
+ *
+ */
+
+#ifndef __ASM_NIOS2_FUTEX_H
+#define __ASM_NIOS2_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <linux/errno.h>
+
+#include <asm/futex-irq.h>
+
+static inline 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;
+ }
+ }
+
+ return ret;
+}
+
+static inline int
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+ u32 oldval, u32 newval)
+{
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ return atomic_futex_op_cmpxchg_inatomic(uval, uaddr, oldval, newval);
+}
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_NIOS2_FUTEX_H */
--
1.8.2.1