RISC-V: Use 64-bit time_t and off_t for RV32 and RV64

Using the original glibc headers under bits/ let's make small
modifications to use 64-bit time_t and off_t for both RV32 and RV64.

For the typesizes.h, here are justifications for the changes from the
generic version (based on Arnd's very helpful feedback):
- All the !__USE_FILE_OFFSET64 types (__off_t, __ino_t, __rlim_t, ...)
  are changed to match the 64-bit replacements.

- __time_t is defined to 64 bit, but no __time64_t is added. This makes
  sense as we don't have the time64 support for other 32-bit
  architectures yet, and it will be easy to change when that happens.

- __suseconds_t is 64-bit. This matches what we use the kernel ABI for
  the few drivers that are relying on 'struct timeval' input arguments
  in ioctl, as well as the adjtimex system call. It means that timeval
  has to be defined without the padding, unlike timespec, which needs
  padding.

Reviewed-by: Maciej W. Rozycki <macro@wdc.com>

4 files changed, 162 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/riscv/bits/environments.h b/sysdeps/unix/sysv/linux/riscv/bits/environments.h
new file mode 100644
index 0000000000..9ee21a217d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/bits/environments.h
@@ -0,0 +1,81 @@
+/* Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _UNISTD_H
+# error "Never include this file directly.  Use <unistd.h> instead"
+#endif
+
+#include <bits/wordsize.h>
+
+/* This header should define the following symbols under the described
+   situations.  A value `1' means that the model is always supported,
+   `-1' means it is never supported.  Undefined means it cannot be
+   statically decided.
+
+   _POSIX_V7_ILP32_OFF32   32bit int, long, pointers, and off_t type
+   _POSIX_V7_ILP32_OFFBIG  32bit int, long, and pointers and larger off_t type
+
+   _POSIX_V7_LP64_OFF32    64bit long and pointers and 32bit off_t type
+   _POSIX_V7_LPBIG_OFFBIG  64bit long and pointers and large off_t type
+
+   The macros _POSIX_V6_ILP32_OFF32, _POSIX_V6_ILP32_OFFBIG,
+   _POSIX_V6_LP64_OFF32, _POSIX_V6_LPBIG_OFFBIG, _XBS5_ILP32_OFF32,
+   _XBS5_ILP32_OFFBIG, _XBS5_LP64_OFF32, and _XBS5_LPBIG_OFFBIG were
+   used in previous versions of the Unix standard and are available
+   only for compatibility.
+*/
+
+#if __WORDSIZE == 64
+
+/* We can never provide environments with 32-bit wide pointers.  */
+# define _POSIX_V7_ILP32_OFF32	-1
+# define _POSIX_V7_ILP32_OFFBIG	-1
+# define _POSIX_V6_ILP32_OFF32	-1
+# define _POSIX_V6_ILP32_OFFBIG	-1
+# define _XBS5_ILP32_OFF32	-1
+# define _XBS5_ILP32_OFFBIG	-1
+/* We also have no use (for now) for an environment with bigger pointers
+   and offsets.  */
+# define _POSIX_V7_LPBIG_OFFBIG	-1
+# define _POSIX_V6_LPBIG_OFFBIG	-1
+# define _XBS5_LPBIG_OFFBIG	-1
+
+/* By default we have 64-bit wide `long int', pointers and `off_t'.  */
+# define _POSIX_V7_LP64_OFF64	1
+# define _POSIX_V6_LP64_OFF64	1
+# define _XBS5_LP64_OFF64	1
+
+#else /* __WORDSIZE == 32 */
+
+/* RISC-V requires 64-bit off_t */
+# define _POSIX_V7_ILP32_OFF32 -1
+# define _POSIX_V6_ILP32_OFF32 -1
+# define _XBS5_ILP32_OFF32 -1
+
+# define _POSIX_V7_ILP32_OFFBIG	1
+# define _POSIX_V6_ILP32_OFFBIG	1
+# define _XBS5_ILP32_OFFBIG	1
+
+/* We can never provide environments with 64-bit wide pointers.  */
+# define _POSIX_V7_LP64_OFF64	-1
+# define _POSIX_V7_LPBIG_OFFBIG	-1
+# define _POSIX_V6_LP64_OFF64	-1
+# define _POSIX_V6_LPBIG_OFFBIG	-1
+# define _XBS5_LP64_OFF64	-1
+# define _XBS5_LPBIG_OFFBIG	-1
+
+#endif /* __WORDSIZE == 32 */
diff --git a/sysdeps/unix/sysv/linux/riscv/bits/time64.h b/sysdeps/unix/sysv/linux/riscv/bits/time64.h
new file mode 100644
index 0000000000..139a7c7335
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/bits/time64.h
@@ -0,0 +1,36 @@
+/* bits/time64.h -- underlying types for __time64_t.  RISC-V version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _BITS_TYPES_H
+# error "Never include <bits/time64.h> directly; use <sys/types.h> instead."
+#endif
+
+#ifndef	_BITS_TIME64_H
+#define	_BITS_TIME64_H	1
+
+/* Define __TIME64_T_TYPE so that it is always a 64-bit type.  */
+
+#if __WORDSIZE == 64
+/* If we already have 64-bit time type then use it.  */
+# define __TIME64_T_TYPE		__TIME_T_TYPE
+#else
+/* Define a 64-bit time type alongsize the 32-bit one.  */
+# define __TIME64_T_TYPE		__SQUAD_TYPE
+#endif
+
+#endif /* bits/time64.h */
diff --git a/sysdeps/unix/sysv/linux/riscv/bits/timesize.h b/sysdeps/unix/sysv/linux/riscv/bits/timesize.h
new file mode 100644
index 0000000000..728d6c5053
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/bits/timesize.h
@@ -0,0 +1,22 @@
+/* Bit size of the time_t type at glibc build time, RISC-V case.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <bits/wordsize.h>
+
+/* RV32 and RV64 both use 64-bit time_t */
+#define __TIMESIZE	64
diff --git a/sysdeps/unix/sysv/linux/riscv/kernel_stat.h b/sysdeps/unix/sysv/linux/riscv/kernel_stat.h
new file mode 100644
index 0000000000..06eb5bce96
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/kernel_stat.h
@@ -0,0 +1,23 @@
+/* Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <bits/wordsize.h>
+
+#define STAT_IS_KERNEL_STAT 1
+
+#define XSTAT_IS_XSTAT64 1
+#define STATFS_IS_STATFS64 0