csky: Add VDSO with GENERIC_GETTIMEOFDAY, GENERIC_TIME_VSYSCALL, HAVE_GENERIC_VDSO

It could help to reduce the latency of the time-related functions
in user space.

We have referenced arm's and riscv's implementation for the patch.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Vincent Chen <vincent.chen@sifive.com>
Cc: Arnd Bergmann <arnd@arndb.de>

6 files changed, 167 insertions, 0 deletions

diff --git a/arch/csky/include/asm/clocksource.h b/arch/csky/include/asm/clocksource.h
new file mode 100644
index 000000000000..54da0e49efa1
--- /dev/null
+++ b/arch/csky/include/asm/clocksource.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_VDSO_CSKY_CLOCKSOURCE_H
+#define __ASM_VDSO_CSKY_CLOCKSOURCE_H
+
+#include <asm/vdso/clocksource.h>
+
+#endif
diff --git a/arch/csky/include/asm/vdso.h b/arch/csky/include/asm/vdso.h
index 12c5d638e784..eb5142f9c564 100644
--- a/arch/csky/include/asm/vdso.h
+++ b/arch/csky/include/asm/vdso.h
@@ -5,8 +5,10 @@
 
 #include <linux/types.h>
 
+#ifndef GENERIC_TIME_VSYSCALL
 struct vdso_data {
 };
+#endif
 
 /*
  * The VDSO symbols are mapped into Linux so we can just use regular symbol
diff --git a/arch/csky/include/asm/vdso/clocksource.h b/arch/csky/include/asm/vdso/clocksource.h
new file mode 100644
index 000000000000..dfca7b4724b7
--- /dev/null
+++ b/arch/csky/include/asm/vdso/clocksource.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_VDSO_CSKY_CLOCKSOURCE_H
+#define __ASM_VDSO_CSKY_CLOCKSOURCE_H
+
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_ARCHTIMER
+
+#endif /* __ASM_VDSO_CSKY_CLOCKSOURCE_H */
diff --git a/arch/csky/include/asm/vdso/gettimeofday.h b/arch/csky/include/asm/vdso/gettimeofday.h
new file mode 100644
index 000000000000..6c4f1446944f
--- /dev/null
+++ b/arch/csky/include/asm/vdso/gettimeofday.h
@@ -0,0 +1,114 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_VDSO_CSKY_GETTIMEOFDAY_H
+#define __ASM_VDSO_CSKY_GETTIMEOFDAY_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/barrier.h>
+#include <asm/unistd.h>
+#include <abi/regdef.h>
+#include <uapi/linux/time.h>
+
+#define VDSO_HAS_CLOCK_GETRES	1
+
+static __always_inline
+int gettimeofday_fallback(struct __kernel_old_timeval *_tv,
+			  struct timezone *_tz)
+{
+	register struct __kernel_old_timeval *tv asm("a0") = _tv;
+	register struct timezone *tz asm("a1") = _tz;
+	register long ret asm("a0");
+	register long nr asm(syscallid) = __NR_gettimeofday;
+
+	asm volatile ("trap 0\n"
+		      : "=r" (ret)
+		      : "r"(tv), "r"(tz), "r"(nr)
+		      : "memory");
+
+	return ret;
+}
+
+static __always_inline
+long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
+{
+	register clockid_t clkid asm("a0") = _clkid;
+	register struct __kernel_timespec *ts asm("a1") = _ts;
+	register long ret asm("a0");
+	register long nr asm(syscallid) = __NR_clock_gettime64;
+
+	asm volatile ("trap 0\n"
+		      : "=r" (ret)
+		      : "r"(clkid), "r"(ts), "r"(nr)
+		      : "memory");
+
+	return ret;
+}
+
+static __always_inline
+long clock_gettime32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
+{
+	register clockid_t clkid asm("a0") = _clkid;
+	register struct old_timespec32 *ts asm("a1") = _ts;
+	register long ret asm("a0");
+	register long nr asm(syscallid) = __NR_clock_gettime;
+
+	asm volatile ("trap 0\n"
+		      : "=r" (ret)
+		      : "r"(clkid), "r"(ts), "r"(nr)
+		      : "memory");
+
+	return ret;
+}
+
+static __always_inline
+int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
+{
+	register clockid_t clkid asm("a0") = _clkid;
+	register struct __kernel_timespec *ts asm("a1") = _ts;
+	register long ret asm("a0");
+	register long nr asm(syscallid) = __NR_clock_getres_time64;
+
+	asm volatile ("trap 0\n"
+		      : "=r" (ret)
+		      : "r"(clkid), "r"(ts), "r"(nr)
+		      : "memory");
+
+	return ret;
+}
+
+static __always_inline
+int clock_getres32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
+{
+	register clockid_t clkid asm("a0") = _clkid;
+	register struct old_timespec32 *ts asm("a1") = _ts;
+	register long ret asm("a0");
+	register long nr asm(syscallid) = __NR_clock_getres;
+
+	asm volatile ("trap 0\n"
+		      : "=r" (ret)
+		      : "r"(clkid), "r"(ts), "r"(nr)
+		      : "memory");
+
+	return ret;
+}
+
+uint64_t csky_pmu_read_cc(void);
+static __always_inline u64 __arch_get_hw_counter(s32 clock_mode,
+						 const struct vdso_data *vd)
+{
+#ifdef CONFIG_CSKY_PMU_V1
+	return csky_pmu_read_cc();
+#else
+	return 0;
+#endif
+}
+
+static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
+{
+	return _vdso_data;
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_CSKY_GETTIMEOFDAY_H */
diff --git a/arch/csky/include/asm/vdso/processor.h b/arch/csky/include/asm/vdso/processor.h
new file mode 100644
index 000000000000..39a6b561d0cc
--- /dev/null
+++ b/arch/csky/include/asm/vdso/processor.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_VDSO_CSKY_PROCESSOR_H
+#define __ASM_VDSO_CSKY_PROCESSOR_H
+
+#ifndef __ASSEMBLY__
+
+#define cpu_relax()	barrier()
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_CSKY_PROCESSOR_H */
diff --git a/arch/csky/include/asm/vdso/vsyscall.h b/arch/csky/include/asm/vdso/vsyscall.h
new file mode 100644
index 000000000000..c276211a7c4d
--- /dev/null
+++ b/arch/csky/include/asm/vdso/vsyscall.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_VDSO_CSKY_VSYSCALL_H
+#define __ASM_VDSO_CSKY_VSYSCALL_H
+
+#ifndef __ASSEMBLY__
+
+#include <vdso/datapage.h>
+
+extern struct vdso_data *vdso_data;
+
+static __always_inline struct vdso_data *__csky_get_k_vdso_data(void)
+{
+	return vdso_data;
+}
+#define __arch_get_k_vdso_data __csky_get_k_vdso_data
+
+#include <asm-generic/vdso/vsyscall.h>
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_CSKY_VSYSCALL_H */