From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read The buffered read collector zero-fills the tail of a short read that stops below the inode's i_size (netfs_clear_unread()), so a read that races an extending write still returns the expected number of bytes. The non-buffered collector path does no such thing: it just records how much was transferred. Add the same zero-fill for the non-buffered case, gated on NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short result from it is known to be safe to treat as a hole, as opposed to NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of the file and should be reported short as-is. Only CLEAR_TAIL should zero-fill here; a real EOF must stay a real short read. No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest, so this is inert on its own -- a following change teaches cifs to set it in the one case that needs it. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Reviewed-by: David Howells Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- drivers/reset/tegra/Kconfig | 4 +++ drivers/reset/tegra/Makefile | 2 ++ drivers/reset/tegra/reset-bpmp.c | 75 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+) create mode 100644 drivers/reset/tegra/Kconfig create mode 100644 drivers/reset/tegra/Makefile create mode 100644 drivers/reset/tegra/reset-bpmp.c (limited to 'drivers/reset/tegra') diff --git a/drivers/reset/tegra/Kconfig b/drivers/reset/tegra/Kconfig new file mode 100644 index 000000000..4a2d26d12 --- /dev/null +++ b/drivers/reset/tegra/Kconfig @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +config RESET_TEGRA_BPMP + bool "Tegra BPMP Reset Driver" if COMPILE_TEST + default TEGRA_BPMP diff --git a/drivers/reset/tegra/Makefile b/drivers/reset/tegra/Makefile new file mode 100644 index 000000000..eccba896a --- /dev/null +++ b/drivers/reset/tegra/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_RESET_TEGRA_BPMP) += reset-bpmp.o diff --git a/drivers/reset/tegra/reset-bpmp.c b/drivers/reset/tegra/reset-bpmp.c new file mode 100644 index 000000000..4c5bba52b --- /dev/null +++ b/drivers/reset/tegra/reset-bpmp.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2016 NVIDIA Corporation + */ + +#include + +#include +#include + +static struct tegra_bpmp *to_tegra_bpmp(struct reset_controller_dev *rstc) +{ + return container_of(rstc, struct tegra_bpmp, rstc); +} + +static int tegra_bpmp_reset_common(struct reset_controller_dev *rstc, + enum mrq_reset_commands command, + unsigned int id) +{ + struct tegra_bpmp *bpmp = to_tegra_bpmp(rstc); + struct mrq_reset_request request; + struct tegra_bpmp_message msg; + int err; + + memset(&request, 0, sizeof(request)); + request.cmd = command; + request.reset_id = id; + + memset(&msg, 0, sizeof(msg)); + msg.mrq = MRQ_RESET; + msg.tx.data = &request; + msg.tx.size = sizeof(request); + + err = tegra_bpmp_transfer(bpmp, &msg); + if (err) + return err; + if (msg.rx.ret) + return -EINVAL; + + return 0; +} + +static int tegra_bpmp_reset_module(struct reset_controller_dev *rstc, + unsigned long id) +{ + return tegra_bpmp_reset_common(rstc, CMD_RESET_MODULE, id); +} + +static int tegra_bpmp_reset_assert(struct reset_controller_dev *rstc, + unsigned long id) +{ + return tegra_bpmp_reset_common(rstc, CMD_RESET_ASSERT, id); +} + +static int tegra_bpmp_reset_deassert(struct reset_controller_dev *rstc, + unsigned long id) +{ + return tegra_bpmp_reset_common(rstc, CMD_RESET_DEASSERT, id); +} + +static const struct reset_control_ops tegra_bpmp_reset_ops = { + .reset = tegra_bpmp_reset_module, + .assert = tegra_bpmp_reset_assert, + .deassert = tegra_bpmp_reset_deassert, +}; + +int tegra_bpmp_init_resets(struct tegra_bpmp *bpmp) +{ + bpmp->rstc.ops = &tegra_bpmp_reset_ops; + bpmp->rstc.owner = THIS_MODULE; + bpmp->rstc.of_node = bpmp->dev->of_node; + bpmp->rstc.nr_resets = bpmp->soc->num_resets; + + return devm_reset_controller_register(bpmp->dev, &bpmp->rstc); +} -- cgit v1.3.1