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Subject[PATCH v2 10/35] nds32: Atomic operations
Date
From: Greentime Hu <greentime@andestech.com>

This patch includes the atomic and futex operations. Many atomic operations use
the load-lock word(llw) and store-condition word(scw) operations.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
---
arch/nds32/include/asm/futex.h | 116 +++++++++++++++++++++++
arch/nds32/include/asm/spinlock.h | 184 +++++++++++++++++++++++++++++++++++++
2 files changed, 300 insertions(+)
create mode 100644 arch/nds32/include/asm/futex.h
create mode 100644 arch/nds32/include/asm/spinlock.h

diff --git a/arch/nds32/include/asm/futex.h b/arch/nds32/include/asm/futex.h
new file mode 100644
index 0000000..5aa107c
--- /dev/null
+++ b/arch/nds32/include/asm/futex.h
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2005-2017 Andes Technology Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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/>.
+ */
+
+#ifndef __NDS32_FUTEX_H__
+#define __NDS32_FUTEX_H__
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <asm/errno.h>
+
+#define __futex_atomic_ex_table(err_reg) \
+ " .pushsection __ex_table,\"a\"\n" \
+ " .align 3\n" \
+ " .long 1b, 4f\n" \
+ " .long 2b, 4f\n" \
+ " .popsection\n" \
+ " .pushsection .fixup,\"ax\"\n" \
+ "4: move %0, " err_reg "\n" \
+ " j 3b\n" \
+ " .popsection"
+
+#define __futex_atomic_op(insn, ret, oldval, tmp, uaddr, oparg) \
+ smp_mb(); \
+ asm volatile( \
+ " movi $ta, #0\n" \
+ "1: llw %1, [%2+$ta]\n" \
+ " " insn "\n" \
+ "2: scw %0, [%2+$ta]\n" \
+ " beqz %0, 1b\n" \
+ " movi %0, #0\n" \
+ "3:\n" \
+ __futex_atomic_ex_table("%4") \
+ : "=&r" (ret), "=&r" (oldval) \
+ : "r" (uaddr), "r" (oparg), "i" (-EFAULT) \
+ : "cc", "memory")
+static inline int
+futex_atomic_cmpxchg_inatomic(u32 * uval, u32 __user * uaddr,
+ u32 oldval, u32 newval)
+{
+ int ret = 0;
+ u32 val, tmp, flags;
+
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ smp_mb();
+ asm volatile (" movi $ta, #0\n"
+ "1: llw %1, [%6 + $ta]\n"
+ " sub %3, %1, %4\n"
+ " cmovz %2, %5, %3\n"
+ " cmovn %2, %1, %3\n"
+ "2: scw %2, [%6 + $ta]\n"
+ " beqz %2, 1b\n"
+ "3:\n " __futex_atomic_ex_table("%7")
+ :"+&r"(ret), "=&r"(val), "=&r"(tmp), "=&r"(flags)
+ :"r"(oldval), "r"(newval), "r"(uaddr), "i"(-EFAULT)
+ :"$ta", "memory");
+ smp_mb();
+
+ *uval = val;
+ return ret;
+}
+
+static inline int
+arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
+{
+ int oldval = 0, ret;
+
+
+ pagefault_disable();
+ switch (op) {
+ case FUTEX_OP_SET:
+ __futex_atomic_op("move %0, %3", ret, oldval, tmp, uaddr,
+ oparg);
+ break;
+ case FUTEX_OP_ADD:
+ __futex_atomic_op("add %0, %1, %3", ret, oldval, tmp, uaddr,
+ oparg);
+ break;
+ case FUTEX_OP_OR:
+ __futex_atomic_op("or %0, %1, %3", ret, oldval, tmp, uaddr,
+ oparg);
+ break;
+ case FUTEX_OP_ANDN:
+ __futex_atomic_op("and %0, %1, %3", ret, oldval, tmp, uaddr,
+ ~oparg);
+ break;
+ case FUTEX_OP_XOR:
+ __futex_atomic_op("xor %0, %1, %3", ret, oldval, tmp, uaddr,
+ oparg);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ pagefault_enable();
+
+ if (!ret)
+ *oval = oldval;
+
+ return ret;
+}
+#endif /* __NDS32_FUTEX_H__ */
diff --git a/arch/nds32/include/asm/spinlock.h b/arch/nds32/include/asm/spinlock.h
new file mode 100644
index 0000000..ca70437
--- /dev/null
+++ b/arch/nds32/include/asm/spinlock.h
@@ -0,0 +1,184 @@
+/*
+ * Copyright (C) 2005-2017 Andes Technology Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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/>.
+ */
+
+#ifndef __ASM_SPINLOCK_H
+#define __ASM_SPINLOCK_H
+
+#include <asm/processor.h>
+
+#define arch_spin_is_locked(x) ((x)->lock != 0)
+
+#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock)
+
+static inline void arch_spin_lock(arch_spinlock_t * lock)
+{
+ unsigned long tmp;
+
+ asm volatile(
+ "1:\n"
+ "llw %0, [%1]\n"
+ "bnez %0, 1b\n"
+ "movi %0, #0x1\n"
+ "scw %0, [%1]\n"
+ "beqz %0, 1b\n"
+ :"=&r"(tmp)
+ :"r"(&lock->lock)
+ :"memory");
+}
+
+static inline int arch_spin_trylock(arch_spinlock_t * lock)
+{
+ unsigned long ret, tmp;
+
+ asm volatile(
+ "1:\n"
+ "llw %0, [%2]\n"
+ "movi %1, #0x1\n"
+ "scw %1, [%2]\n"
+ "beqz %1, 1b\n"
+ :"=&r"(ret), "=&r"(tmp)
+ :"r"(&lock->lock)
+ :"memory");
+
+ return ret == 0;
+}
+
+static inline void arch_spin_unlock(arch_spinlock_t * lock)
+{
+ asm volatile(
+ "xor $r15, $r15, $r15\n"
+ "swi $r15, [%0]\n"
+ :
+ :"r"(&lock->lock)
+ :"memory");
+}
+
+static inline void arch_write_lock(arch_rwlock_t * rw)
+{
+ unsigned long tmp;
+
+ asm volatile(
+ "1:\n"
+ "llw %0, [%1]\n"
+ "bnez %0, 1b\n"
+ "sethi %0, 0x80000\n"
+ "scw %0, [%1]\n"
+ "beqz %0, 1b\n"
+ :"=&r"(tmp)
+ :"r"(&rw->lock)
+ :"memory");
+}
+
+static inline void arch_write_unlock(arch_rwlock_t * rw)
+{
+ asm volatile(
+ "xor $r15, $r15, $r15\n"
+ "swi $r15, [%0]\n"
+ :
+ :"r"(&rw->lock)
+ :"memory","$r15");
+}
+
+#define arch_write_can_lock(x) ((x)->lock == 0)
+static inline void arch_read_lock(arch_rwlock_t * rw)
+{
+ int tmp;
+
+ asm volatile(
+ "1:\n"
+ "llw %0, [%1]\n"
+ "bltz %0, 1b\n"
+ "addi %0, %0, #1\n"
+ "scw %0, [%1]\n"
+ "beqz %0, 1b\n"
+ :"=&r"(tmp)
+ :"r"(&rw->lock)
+ :"memory");
+}
+
+static inline void arch_read_unlock(arch_rwlock_t * rw)
+{
+ unsigned long tmp;
+
+ asm volatile(
+ "1:\n"
+ "llw %0, [%1]\n"
+ "addi %0, %0, #-1\n"
+ "scw %0, [%1]\n"
+ "beqz %0, 1b\n"
+ :"=&r"(tmp)
+ :"r"(&rw->lock)
+ :"memory");
+}
+
+static inline int arch_read_trylock(arch_rwlock_t * rw)
+{
+ unsigned long ret, tmp;
+
+ asm volatile(
+ "movi %0, #0x0\n"
+ "1:\n"
+ "llw %1, [%2]\n"
+ "bltz %1, 2f\n"
+ "addi %1, %1, #1\n"
+ "scw %1, [%2]\n"
+ "beqz %1, 1b\n"
+ "movi %0, #0x1\n"
+ "j 3f\n"
+ "2:\n"
+ "scw %1, [%2]\n"
+ "3:\n"
+ :"=&r"(ret), "=&r"(tmp)
+ :"r"(&rw->lock)
+ :"memory");
+
+ return ret;
+}
+
+static inline int arch_write_trylock(arch_rwlock_t * rw)
+{
+ unsigned long ret, tmp;
+
+ asm volatile(
+ "movi %0, #0x0\n"
+ "1:\n"
+ "llw %1, [%2]\n"
+ "bnez %1, 2f\n"
+ "sethi %1, 0x80000\n"
+ "scw %1, [%2]\n"
+ "beqz %1, 1b\n"
+ "movi %0, #0x1\n"
+ "j 3f\n"
+ "2:\n"
+ "scw %1, [%2]\n"
+ "3:\n"
+ :"=&r"(ret), "=&r"(tmp)
+ :"r"(&rw->lock)
+ :"memory");
+
+ return ret;
+}
+
+#define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
+#define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
+
+#define arch_read_can_lock(x) ((x)->lock < 0x80000000)
+
+#define arch_spin_relax(lock) cpu_relax()
+#define arch_read_relax(lock) cpu_relax()
+#define arch_write_relax(lock) cpu_relax()
+
+#endif /* __ASM_SPINLOCK_H */
--
1.7.9.5
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