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-rw-r--r--arch/csky/include/asm/futex.h121
1 files changed, 121 insertions, 0 deletions
diff --git a/arch/csky/include/asm/futex.h b/arch/csky/include/asm/futex.h
new file mode 100644
index 000000000..6cfd31272
--- /dev/null
+++ b/arch/csky/include/asm/futex.h
@@ -0,0 +1,121 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_FUTEX_H
+#define __ASM_CSKY_FUTEX_H
+
+#ifndef CONFIG_SMP
+#include <asm-generic/futex.h>
+#else
+#include <linux/atomic.h>
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <linux/errno.h>
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+{ \
+ u32 tmp; \
+ \
+ __atomic_pre_full_fence(); \
+ \
+ __asm__ __volatile__ ( \
+ "1: ldex.w %[ov], %[u] \n" \
+ " "insn" \n" \
+ "2: stex.w %[t], %[u] \n" \
+ " bez %[t], 1b \n" \
+ " br 4f \n" \
+ "3: mov %[r], %[e] \n" \
+ "4: \n" \
+ " .section __ex_table,\"a\" \n" \
+ " .balign 4 \n" \
+ " .long 1b, 3b \n" \
+ " .long 2b, 3b \n" \
+ " .previous \n" \
+ : [r] "+r" (ret), [ov] "=&r" (oldval), \
+ [u] "+m" (*uaddr), [t] "=&r" (tmp) \
+ : [op] "Jr" (oparg), [e] "jr" (-EFAULT) \
+ : "memory"); \
+ \
+ __atomic_post_full_fence(); \
+}
+
+static inline int
+arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
+{
+ int oldval = 0, ret = 0;
+
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ switch (op) {
+ case FUTEX_OP_SET:
+ __futex_atomic_op("mov %[t], %[ov]",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ADD:
+ __futex_atomic_op("add %[t], %[ov], %[op]",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_OR:
+ __futex_atomic_op("or %[t], %[ov], %[op]",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ANDN:
+ __futex_atomic_op("and %[t], %[ov], %[op]",
+ ret, oldval, uaddr, ~oparg);
+ break;
+ case FUTEX_OP_XOR:
+ __futex_atomic_op("xor %[t], %[ov], %[op]",
+ ret, oldval, uaddr, oparg);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ if (!ret)
+ *oval = oldval;
+
+ return ret;
+}
+
+
+
+static inline int
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+ u32 oldval, u32 newval)
+{
+ int ret = 0;
+ u32 val, tmp;
+
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ __atomic_pre_full_fence();
+
+ __asm__ __volatile__ (
+ "1: ldex.w %[v], %[u] \n"
+ " cmpne %[v], %[ov] \n"
+ " bt 4f \n"
+ " mov %[t], %[nv] \n"
+ "2: stex.w %[t], %[u] \n"
+ " bez %[t], 1b \n"
+ " br 4f \n"
+ "3: mov %[r], %[e] \n"
+ "4: \n"
+ " .section __ex_table,\"a\" \n"
+ " .balign 4 \n"
+ " .long 1b, 3b \n"
+ " .long 2b, 3b \n"
+ " .previous \n"
+ : [r] "+r" (ret), [v] "=&r" (val), [u] "+m" (*uaddr),
+ [t] "=&r" (tmp)
+ : [ov] "Jr" (oldval), [nv] "Jr" (newval), [e] "Jr" (-EFAULT)
+ : "memory");
+
+ __atomic_post_full_fence();
+
+ *uval = val;
+ return ret;
+}
+
+#endif /* CONFIG_SMP */
+#endif /* __ASM_CSKY_FUTEX_H */