csky: System Call

This patch adds files related to syscall.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

arch/csky/include/asm/syscall.h

+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_SYSCALL_H
+#define __ASM_SYSCALL_H
+
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <abi/regdef.h>
+
+static inline int
+syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
+{
+	return regs_syscallid(regs);
+}
+
+static inline void
+syscall_rollback(struct task_struct *task, struct pt_regs *regs)
+{
+	regs->a0 = regs->orig_a0;
+}
+
+static inline long
+syscall_get_error(struct task_struct *task, struct pt_regs *regs)
+{
+	unsigned long error = regs->a0;
+
+	return IS_ERR_VALUE(error) ? error : 0;
+}
+
+static inline long
+syscall_get_return_value(struct task_struct *task, struct pt_regs *regs)
+{
+	return regs->a0;
+}
+
+static inline void
+syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
+		int error, long val)
+{
+	regs->a0 = (long) error ?: val;
+}
+
+static inline void
+syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
+		      unsigned int i, unsigned int n, unsigned long *args)
+{
+	BUG_ON(i + n > 6);
+	if (i == 0) {
+		args[0] = regs->orig_a0;
+		args++;
+		i++;
+		n--;
+	}
+	memcpy(args, &regs->a1 + i * sizeof(regs->a1), n * sizeof(args[0]));
+}
+
+static inline void
+syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
+		      unsigned int i, unsigned int n, const unsigned long *args)
+{
+	BUG_ON(i + n > 6);
+	if (i == 0) {
+		regs->orig_a0 = args[0];
+		args++;
+		i++;
+		n--;
+	}
+	memcpy(&regs->a1 + i * sizeof(regs->a1), args, n * sizeof(regs->a0));
+}
+
+#endif	/* __ASM_SYSCALL_H */

arch/csky/include/asm/syscalls.h

+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_SYSCALLS_H
+#define __ASM_CSKY_SYSCALLS_H
+
+#include <asm-generic/syscalls.h>
+
+long sys_cacheflush(void __user *, unsigned long, int);
+
+long sys_set_thread_area(unsigned long addr);
+
+long sys_csky_fadvise64_64(int fd, int advice, loff_t offset, loff_t len);
+
+#endif /* __ASM_CSKY_SYSCALLS_H */

arch/csky/include/uapi/asm/unistd.h

+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#define __ARCH_WANT_SYS_CLONE
+#include <asm-generic/unistd.h>
+
+#define __NR_set_thread_area	(__NR_arch_specific_syscall + 0)
+__SYSCALL(__NR_set_thread_area, sys_set_thread_area)
+#define __NR_cacheflush		(__NR_arch_specific_syscall + 1)
+__SYSCALL(__NR_cacheflush, sys_cacheflush)

arch/csky/kernel/syscall.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/syscalls.h>
+
+SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
+{
+	struct thread_info *ti = task_thread_info(current);
+	struct pt_regs *reg = current_pt_regs();
+
+	reg->tls = addr;
+	ti->tp_value = addr;
+
+	return 0;
+}
+
+SYSCALL_DEFINE6(mmap2,
+	unsigned long, addr,
+	unsigned long, len,
+	unsigned long, prot,
+	unsigned long, flags,
+	unsigned long, fd,
+	off_t, offset)
+{
+	if (unlikely(offset & (~PAGE_MASK >> 12)))
+		return -EINVAL;
+
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
+			       offset >> (PAGE_SHIFT - 12));
+}
+
+/*
+ * for abiv1 the 64bits args should be even th, So we need mov the advice
+ * forward.
+ */
+SYSCALL_DEFINE4(csky_fadvise64_64,
+	int, fd,
+	int, advice,
+	loff_t, offset,
+	loff_t, len)
+{
+	return ksys_fadvise64_64(fd, offset, len, advice);
+}

arch/csky/kernel/syscall_table.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/syscalls.h>
+#include <asm/syscalls.h>
+
+#undef __SYSCALL
+#define __SYSCALL(nr, call)[nr] = (call),
+
+#define sys_fadvise64_64 sys_csky_fadvise64_64
+void * const sys_call_table[__NR_syscalls] __page_aligned_data = {
+	[0 ... __NR_syscalls - 1] = sys_ni_syscall,
+#include <asm/unistd.h>
+};