Linux SNPS ARC Archive on lore.kernel.org
 help / color / Atom feed
From: Alistair Francis <alistair23@gmail.com>
To: Vineet Gupta <vineetg76@gmail.com>
Cc: Florian Weimer <fweimer@redhat.com>,
	GNU C Library <libc-alpha@sourceware.org>,
	Arnd Bergmann <arnd@arndb.de>,
	Palmer Dabbelt <palmerdabbelt@google.com>,
	Zong Li <zongbox@gmail.com>,
	Alistair Francis <alistair.francis@wdc.com>,
	Adhemerval Zanella <adhemerval.zanella@linaro.org>,
	"Maciej W. Rozycki" <macro@wdc.com>,
	arcml <linux-snps-arc@lists.infradead.org>,
	Joseph Myers <joseph@codesourcery.com>
Subject: Re: [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64
Date: Tue, 11 Feb 2020 16:14:49 -0800
Message-ID: <CAKmqyKMyf2psPp+-EHoidvbPbSXv0=dP26GjVQnT5BUriLc1gA@mail.gmail.com> (raw)
In-Reply-To: <00574bfb-981a-3a1c-cbdf-b2fee4eddc32@gmail.com>

On Tue, Feb 11, 2020 at 4:14 PM Vineet Gupta <vineetg76@gmail.com> wrote:
>
> Hi Alistair,

Hi Vineet,

>
> On 1/12/20 2:33 AM, Alistair Francis wrote:
> > 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 kerne 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.
> > ---
> >  .../unix/sysv/linux/riscv/bits/environments.h | 85 ++++++++++++++++++
> >  sysdeps/unix/sysv/linux/riscv/bits/time64.h   | 36 ++++++++
> >  sysdeps/unix/sysv/linux/riscv/bits/timesize.h | 22 +++++
> >  .../unix/sysv/linux/riscv/bits/typesizes.h    | 90 +++++++++++++++++++
> >  sysdeps/unix/sysv/linux/riscv/kernel_stat.h   | 23 +++++
> >  5 files changed, 256 insertions(+)
> >  create mode 100644 sysdeps/unix/sysv/linux/riscv/bits/environments.h
> >  create mode 100644 sysdeps/unix/sysv/linux/riscv/bits/time64.h
> >  create mode 100644 sysdeps/unix/sysv/linux/riscv/bits/timesize.h
> >  create mode 100644 sysdeps/unix/sysv/linux/riscv/bits/typesizes.h
> >  create mode 100644 sysdeps/unix/sysv/linux/riscv/kernel_stat.h
> >
> > 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..8d401d1976
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/riscv/bits/environments.h
> > @@ -0,0 +1,85 @@
> > +/* Copyright (C) 1999-2020 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
> > +   <http://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
> > +  # undef _POSIX_V7_ILP32_OFF32
> > +  # undef _POSIX_V6_ILP32_OFF32
> > +  # undef _XBS5_ILP32_OFF32
> > + */
> > +
> > +# 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
> > +
> > +/* CFLAGS.  */
> > +#define __ILP32_OFFBIG_CFLAGS   "-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"
> > +
> > +#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..cc21b45ef1
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/riscv/bits/time64.h
> > @@ -0,0 +1,36 @@
> > +/* bits/time64.h -- underlying types for __time64_t.  Generic version.
> > +   Copyright (C) 2018-2020 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
> > +   <http://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..afb5d86b2b
> > --- /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, general case.
> > +   Copyright (C) 2018-2020 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
> > +   <http://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/bits/typesizes.h b/sysdeps/unix/sysv/linux/riscv/bits/typesizes.h
> > new file mode 100644
> > index 0000000000..0da3bdeb5d
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/riscv/bits/typesizes.h
>
> I was hoping newer arches could simply use the asm-generic one ?

We need to specify that RV32 uses a 64-bit time_t. The generic ones
don't do that for 32-bit arches.

>
> > +/* Tell the libc code that off_t and off64_t are actually the same type
> > +   for all ABI purposes, even if possibly expressed as different base types
> > +   for C type-checking purposes.  */
> > +# define __OFF_T_MATCHES_OFF64_T 1
>
> This is orthogonal to time_t but since we are on topic of newer ports, how are you
> doing this. The asm-generic uapi defines
>
>         typedef __kernel_long_t __kernel_off_t;
>
> and types.h defines
>
>         typedef __kernel_off_t off_t;
>
> And I presume long on RV32 is 32-bits

Can you point me to the code? Last time I looked the kernel used the
64-bit versions for the syscalls on RV32.

>
> > +
> > +/* Same for ino_t and ino64_t.  */
> > +# define __INO_T_MATCHES_INO64_T 1
>
>
>
> > +
> > +/* And for rlim_t and rlim64_t.  */
> > +# define __RLIM_T_MATCHES_RLIM64_T  1
> > +
> > +/* And for fsblkcnt_t and fsfilcnt_t */
> > +# define __STATFS_MATCHES_STATFS64 1
> > +
> > +/* And for fsblkcnt_t, fsblkcnt64_t, fsfilcnt_t and fsfilcnt64_t.  */
> > +# define __STATFS_MATCHES_STATFS64  1
> > +
> > +/* Define these as RV32 requires 64-bit syscall. */
> > +#if __riscv_xlen == 32
> > +#define __ASSUME_TIME64_SYSCALLS 1
>
> From the POV of newer arches needing 64-bit time_t support, this need not be
> forced as it is set automatically for kernel >= 5.1

Ah, I think you are right about this and we don't need to define it.

>
> > +#define __ASSUME_RLIM64_SYSCALLS 1
>
> Is this used anywhere ?

Apparently not, I have removed it.

Alistair

>
> Thx,
> -Vineet

_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc

  reply index

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <cover.1578824547.git.alistair.francis@wdc.com>
     [not found] ` <4e95f95966d8d7c6a8339160dc62d81c1f6a1bfb.1578824547.git.alistair.francis@wdc.com>
2020-02-12  0:14   ` Vineet Gupta
2020-02-12  0:14     ` Alistair Francis [this message]
2020-02-12  1:30       ` Joseph Myers
2020-02-14 22:39         ` Alistair Francis
2020-02-18 23:05           ` switching ARC to 64-bit time_t (Re: [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64) Vineet Gupta
2020-02-18 23:13             ` Joseph Myers
2020-02-19 23:09               ` Lukasz Majewski
2020-02-19 23:11             ` Lukasz Majewski
2020-02-20  8:31               ` Arnd Bergmann
2020-02-20  9:37                 ` Lukasz Majewski
2020-02-20 12:37                   ` Arnd Bergmann
2020-02-20 13:14                     ` Lukasz Majewski
2020-02-20 14:44                       ` Arnd Bergmann
2020-02-20 15:42                         ` Lukasz Majewski
2020-02-20 16:08                           ` Arnd Bergmann
2020-02-20 16:31                             ` Lukasz Majewski
2020-02-24  2:48                         ` Viresh Kumar
2020-02-21 19:56                     ` Alistair Francis
2020-02-22  8:42                   ` Arnd Bergmann
2020-02-24  9:00                     ` Lukasz Majewski
2020-02-24  9:46                       ` Andreas Schwab
2020-02-24 10:14                         ` Lukasz Majewski
2020-02-24 10:23                           ` Andreas Schwab
2020-02-24 10:36                             ` Lukasz Majewski
2020-02-24 10:42                               ` Andreas Schwab
2020-02-24 11:13                                 ` Lukasz Majewski
2020-02-24 12:41                                   ` Lukasz Majewski
2020-02-25  0:03                               ` Joseph Myers
2020-02-25 11:39                                 ` Lukasz Majewski
2020-02-25 14:36                                   ` Joseph Myers
2020-02-26 13:18                                     ` Lukasz Majewski
2020-02-26 14:48                                       ` Joseph Myers
2020-02-26 16:28                                         ` Lukasz Majewski
2020-02-25  9:03                       ` Arnd Bergmann
2020-02-20 16:27                 ` Helmut Grohne
2020-03-26  0:25                   ` ARC rebootstrap prereq (was Re: switching ARC to 64-bit time_t ) Vineet Gupta
2020-03-26  5:54                     ` Helmut Grohne
2020-03-26 11:51                       ` Alexey Brodkin
2020-03-26 12:24                         ` Helmut Grohne
2020-03-26 12:53                           ` Alexey Brodkin
2020-03-26 14:28                             ` Helmut Grohne
2020-03-26 19:04                               ` Lennart Sorensen
2020-08-26 14:39                       ` Vineet Gupta
2020-08-26 15:43                         ` Helmut Grohne
2020-08-26 21:16                           ` Aurelien Jarno
2020-02-12  1:42       ` [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64 Vineet Gupta
2020-02-12 12:58         ` Arnd Bergmann
2020-02-19  0:56   ` Vineet Gupta
2020-02-19  1:03     ` Alistair Francis
2020-02-19  1:31       ` Vineet Gupta
2020-02-19  8:30         ` Andreas Schwab
2020-02-19 18:42           ` Vineet Gupta
2020-02-19 23:18             ` Lukasz Majewski
2020-02-20  0:26               ` Vineet Gupta
2020-02-20  0:46                 ` Joseph Myers
2020-02-20  8:24                   ` Arnd Bergmann
2020-02-20 10:28                     ` Lukasz Majewski
2020-02-20 14:14                     ` Joseph Myers

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAKmqyKMyf2psPp+-EHoidvbPbSXv0=dP26GjVQnT5BUriLc1gA@mail.gmail.com' \
    --to=alistair23@gmail.com \
    --cc=adhemerval.zanella@linaro.org \
    --cc=alistair.francis@wdc.com \
    --cc=arnd@arndb.de \
    --cc=fweimer@redhat.com \
    --cc=joseph@codesourcery.com \
    --cc=libc-alpha@sourceware.org \
    --cc=linux-snps-arc@lists.infradead.org \
    --cc=macro@wdc.com \
    --cc=palmerdabbelt@google.com \
    --cc=vineetg76@gmail.com \
    --cc=zongbox@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux SNPS ARC Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-snps-arc/0 linux-snps-arc/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-snps-arc linux-snps-arc/ https://lore.kernel.org/linux-snps-arc \
		linux-snps-arc@lists.infradead.org
	public-inbox-index linux-snps-arc

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-snps-arc


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git