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Timur Tabi ebe7556050 drm/nouveau: set DMA mask before creating the flush page
Set the DMA mask before calling nvkm_device_ctor(), so that when the
flush page is created in nvkm_fb_ctor(), the allocation will not fail
if the page is outside of DMA address space, which can easily happen if
IOMMU is disable.  In such situations, you will get an error like this:

nouveau 0000:65:00.0: DMA addr 0x0000000107c56000+4096 overflow (mask ffffffff, bus limit 0).

Commit 38f5359354 ("rm/nouveau/pci: set streaming DMA mask early")
set the mask after calling nvkm_device_ctor(), but back then there was
no flush page being created, which might explain why the mask wasn't
set earlier.

Flush page allocation was added in commit 5728d06419 ("drm/nouveau/fb:
handle sysmem flush page from common code").  nvkm_fb_ctor() calls
alloc_page(), which can allocate a page anywhere in system memory, but
then calls dma_map_page() on that page.  But since the DMA mask is still
set to 32, the map can fail if the page is allocated above 4GB.  This is
easy to reproduce on systems with a lot of memory and IOMMU disabled.

An alternative approach would be to force the allocation of the flush
page to low memory, by specifying __GFP_DMA32.  However, this would
always allocate the page in low memory, even though the hardware can
access high memory.

Signed-off-by: Timur Tabi <ttabi@nvidia.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patch.msgid.link/20251014174512.3172102-1-ttabi@nvidia.com
2025-11-06 10:26:51 +10:00
arch - Remove dead code leftovers after a recent mitigations cleanup which fail 2025-10-26 09:57:18 -07:00
block block-6.18-20251023 2025-10-24 12:48:19 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto This push contains the following changes: 2025-10-10 08:56:16 -07:00
Documentation tty/serial driver bugfixes for 6.18-rc3 2025-10-26 10:24:39 -07:00
drivers drm/nouveau: set DMA mask before creating the flush page 2025-11-06 10:26:51 +10:00
fs - Remove dead code leftovers after a recent mitigations cleanup which fail 2025-10-26 09:57:18 -07:00
include drm-fixes for 6.18-rc3 2025-10-24 16:49:16 -07:00
init printk changes for 6.18 2025-10-04 11:13:11 -07:00
io_uring io_uring: fix buffer auto-commit for multishot uring_cmd 2025-10-23 19:41:31 -06:00
ipc namespace-6.18-rc1 2025-09-29 11:20:29 -07:00
kernel - Restore the original buslock locking in a couple of places in the irq core 2025-10-26 09:54:36 -07:00
lib lib/crypto: poly1305: Restore dependency of arch code on !KMSAN 2025-10-22 10:52:10 -07:00
LICENSES LICENSES: Replace the obsolete address of the FSF in the GFDL-1.2 2025-07-24 11:15:39 +02:00
mm slab fixes for 6.18-rc3 2025-10-24 12:40:51 -07:00
net Including fixes from can. Slim pickings, I'm guessing people haven't 2025-10-23 07:03:18 -10:00
rust Driver core fixes for 6.18-rc3 2025-10-25 11:03:46 -07:00
samples Char/Misc/IIO/Binder changes for 6.18-rc1 2025-10-04 16:26:32 -07:00
scripts Kbuild fixes for 6.18 #1 2025-10-11 15:47:12 -07:00
security integrity-v6.18 2025-10-05 10:48:33 -07:00
sound ALSA: hda/realtek: Fix mute led for HP Omen 17-cb0xxx 2025-10-17 16:37:21 +02:00
tools - Fix x32 build due to wrong format specifier on that sub-arch 2025-10-26 09:44:36 -07:00
usr gen_init_cpio: Ignore fsync() returning EINVAL on pipes 2025-10-07 09:53:05 -07:00
virt KVM x86 fixes for 6.18: 2025-10-18 10:25:43 +02:00
.clang-format memblock: drop for_each_free_mem_pfn_range_in_zone_from() 2025-09-14 08:49:03 +03:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: remove Alyssa Rosenzweig 2025-09-18 21:17:31 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore .gitignore: ignore compile_commands.json globally 2025-08-12 15:53:55 -07:00
.mailmap MAINTAINERS: Update Alex Williamson's email address 2025-10-20 15:45:03 -06:00
.pylintrc tools: docs: parse-headers.py: move it from sphinx dir 2025-08-29 15:54:42 -06:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB/Thunderbolt changes for 6.18-rc1 2025-10-04 16:07:08 -07:00
Kbuild sched: Make migrate_{en,dis}able() inline 2025-09-25 09:57:16 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS io_uring-6.18-20251023 2025-10-24 12:44:31 -07:00
Makefile Linux 6.18-rc3 2025-10-26 15:59:49 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.