[newlib-cygwin] RISC-V: Using SYS_clock_gettime64 for rv32 libgloss.

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=20d00819984058e439cfe40818f81d7315c89201

commit 20d00819984058e439cfe40818f81d7315c89201
Author: Kito Cheng <kito.cheng@sifive.com>
Date:   Tue Apr 13 17:33:03 2021 +0800

    RISC-V: Using SYS_clock_gettime64 for rv32 libgloss.
    
     - RISC-V 32 bits linux/glibc didn't provide gettimeofday anymore
       after upstream, because RV32 didn't have backward compatible issue,
       so RV32 only support 64 bits time related system call.
    
     - So using clock_gettime64 call instead for rv32 libgloss.

Diff:
---
 libgloss/riscv/machine/syscall.h  |  1 +
 libgloss/riscv/sys_gettimeofday.c | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/libgloss/riscv/machine/syscall.h b/libgloss/riscv/machine/syscall.h
index 88b9fdfda..1ac8b1a4b 100644
--- a/libgloss/riscv/machine/syscall.h
+++ b/libgloss/riscv/machine/syscall.h
@@ -44,6 +44,7 @@
 #define SYS_munmap 215
 #define SYS_mremap 216
 #define SYS_mmap 222
+#define SYS_clock_gettime64 403
 #define SYS_open 1024
 #define SYS_link 1025
 #define SYS_unlink 1026
diff --git a/libgloss/riscv/sys_gettimeofday.c b/libgloss/riscv/sys_gettimeofday.c
index daa14e475..81bea8e55 100644
--- a/libgloss/riscv/sys_gettimeofday.c
+++ b/libgloss/riscv/sys_gettimeofday.c
@@ -1,10 +1,31 @@
 #include <machine/syscall.h>
 #include <sys/time.h>
+#include <stdint.h>
 #include "internal_syscall.h"
 
 /* Get the current time.  Only relatively correct.  */
 int
 _gettimeofday(struct timeval *tp, void *tzp)
 {
+#if __riscv_xlen == 32
+  struct __timespec64
+  {
+    int64_t tv_sec;         /* Seconds */
+# if BYTE_ORDER == BIG_ENDIAN
+    int32_t __padding;      /* Padding */
+    int32_t tv_nsec;        /* Nanoseconds */
+# else
+    int32_t tv_nsec;        /* Nanoseconds */
+    int32_t __padding;      /* Padding */
+# endif
+  };
+  struct __timespec64 ts64;
+  int rv;
+  rv = syscall_errno (SYS_clock_gettime64, 2, 0, (long)&ts64, 0, 0, 0, 0);
+  tp->tv_sec = ts64.tv_sec;
+  tp->tv_usec = ts64.tv_nsec * 1000;
+  return rv;
+#else
   return syscall_errno (SYS_gettimeofday, 1, tp, 0, 0, 0, 0, 0);
+#endif
 }