From a200c8e51cdb4586ad2eb20d2b45ba367f00beaf Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jean-S=C3=A9bastien=20P=C3=A9dron?= Date: Mon, 26 May 2025 20:12:40 +0200 Subject: [PATCH] linuxkpi: Add eventfd_*() Add and expose the `eventfd_*()` API. This is used by DRM drivers for some time, but the code was commented out so far. Note that Linux uses `struct eventfd_ctx`, but FreeBSD defines `struct eventfd`. We define `eventfd_ctx` as a synonym to `eventfd`. Reviewed by: christos, markj Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D50853 --- .../linuxkpi/common/include/linux/eventfd.h | 54 ++++++++++++++++ .../linuxkpi/common/src/linux_eventfd.c | 63 +++++++++++++++++++ .../linuxkpi/dummy/include/linux/eventfd.h | 0 sys/conf/files | 2 + sys/modules/linuxkpi/Makefile | 1 + 5 files changed, 120 insertions(+) create mode 100644 sys/compat/linuxkpi/common/include/linux/eventfd.h create mode 100644 sys/compat/linuxkpi/common/src/linux_eventfd.c delete mode 100644 sys/compat/linuxkpi/dummy/include/linux/eventfd.h diff --git a/sys/compat/linuxkpi/common/include/linux/eventfd.h b/sys/compat/linuxkpi/common/include/linux/eventfd.h new file mode 100644 index 00000000000..d167d4b7d18 --- /dev/null +++ b/sys/compat/linuxkpi/common/include/linux/eventfd.h @@ -0,0 +1,54 @@ +/*- + * Copyright (c) 2025 The FreeBSD Foundation + * Copyright (c) 2025 Jean-Sébastien Pédron + * + * This software was developed by Jean-Sébastien Pédron under sponsorship + * from the FreeBSD Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef _LINUXKPI_LINUX_EVENTFD_H_ +#define _LINUXKPI_LINUX_EVENTFD_H_ + +#include + +#include +#include +#include +#include +#include + +/* + * Linux uses `struct eventfd_ctx`, but FreeBSD defines `struct eventfd`. Here, + * we define a synonym to the FreeBSD structure. This allows to keep Linux code + * unmodified. + */ +#define eventfd_ctx eventfd + +#define eventfd_ctx_fdget lkpi_eventfd_ctx_fdget +struct eventfd_ctx *lkpi_eventfd_ctx_fdget(int fd); + +#define eventfd_ctx_put lkpi_eventfd_ctx_put +void lkpi_eventfd_ctx_put(struct eventfd_ctx *ctx); + +#endif /* _LINUXKPI_LINUX_EVENTFD_H_ */ diff --git a/sys/compat/linuxkpi/common/src/linux_eventfd.c b/sys/compat/linuxkpi/common/src/linux_eventfd.c new file mode 100644 index 00000000000..126c6c54b9a --- /dev/null +++ b/sys/compat/linuxkpi/common/src/linux_eventfd.c @@ -0,0 +1,63 @@ +/*- + * Copyright (c) 2025 The FreeBSD Foundation + * Copyright (c) 2025 Jean-Sébastien Pédron + * + * This software was developed by Jean-Sébastien Pédron under sponsorship + * from the FreeBSD Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include +#include +#include + +#include + +struct eventfd_ctx * +lkpi_eventfd_ctx_fdget(int fd) +{ + struct file *fp; + struct eventfd_ctx *ctx; + + /* Lookup file pointer by file descriptor index. */ + if (fget_unlocked(curthread, fd, &cap_no_rights, &fp) != 0) + return (ERR_PTR(-EBADF)); + + /* + * eventfd_get() bumps the refcount, so we can safely release the + * reference on the file itself afterwards. + */ + ctx = eventfd_get(fp); + fdrop(fp, curthread); + + if (ctx == NULL) + return (ERR_PTR(-EBADF)); + + return (ctx); +} + +void +lkpi_eventfd_ctx_put(struct eventfd_ctx *ctx) +{ + eventfd_put(ctx); +} diff --git a/sys/compat/linuxkpi/dummy/include/linux/eventfd.h b/sys/compat/linuxkpi/dummy/include/linux/eventfd.h deleted file mode 100644 index e69de29bb2d..00000000000 diff --git a/sys/conf/files b/sys/conf/files index 5f8c9379ddf..66b84fea1bc 100644 --- a/sys/conf/files +++ b/sys/conf/files @@ -4662,6 +4662,8 @@ compat/linuxkpi/common/src/linux_dmi.c optional compat_linuxkpi \ compile-with "${LINUXKPI_C}" compat/linuxkpi/common/src/linux_domain.c optional compat_linuxkpi \ compile-with "${LINUXKPI_C}" +compat/linuxkpi/common/src/linux_eventfd.c optional compat_linuxkpi \ + compile-with "${LINUXKPI_C}" compat/linuxkpi/common/src/linux_firmware.c optional compat_linuxkpi \ compile-with "${LINUXKPI_C}" compat/linuxkpi/common/src/linux_folio.c optional compat_linuxkpi \ diff --git a/sys/modules/linuxkpi/Makefile b/sys/modules/linuxkpi/Makefile index 77d73f19075..2090fe76d85 100644 --- a/sys/modules/linuxkpi/Makefile +++ b/sys/modules/linuxkpi/Makefile @@ -6,6 +6,7 @@ SRCS= linux_compat.c \ linux_devres.c \ linux_dmi.c \ linux_domain.c \ + linux_eventfd.c \ linux_firmware.c \ linux_folio.c \ linux_fpu.c \