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Catalin Marinas 3be9b84689 arm64: support DMA zone above 4GB
Commit 791ab8b2e3 ("arm64: Ignore any DMA offsets in the
max_zone_phys() calculation") made arm64 DMA/DMA32 zones span the entire
RAM when RAM starts above 32-bits. This breaks hardware with DMA area
that start above 32-bits. But the commit log says that "we haven't
noticed any such hardware". It turns out that such hardware does exist.

One such platform has RAM starting at 32GB with an internal bus that has
the following DMA limits:

  #address-cells = <2>;
  #size-cells = <2>;
  dma-ranges = <0x00 0xc0000000 0x08 0x00000000 0x00 0x40000000>;

That is, devices under this bus see 1GB of DMA range between 3GB-4GB in
their address space. This range is mapped to CPU memory at 32GB-33GB.
With current code DMA allocations for devices under this bus are not
limited to DMA area, leading to run-time allocation failure.

This commit reinstates DMA zone at the bottom of RAM. The result is DMA
zone that properly reflects the hardware constraints as follows:

[    0.000000] Zone ranges:
[    0.000000]   DMA      [mem 0x0000000800000000-0x000000083fffffff]
[    0.000000]   DMA32    empty
[    0.000000]   Normal   [mem 0x0000000840000000-0x0000000bffffffff]

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[baruch: split off the original patch]
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Petr Tesarik <ptesarik@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-08-22 06:18:11 +02:00
arch arm64: support DMA zone above 4GB 2024-08-22 06:18:11 +02:00
block block: Fix lockdep warning in blk_mq_mark_tag_wait 2024-08-15 19:25:03 -06:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto crypto: testmgr - generate power-of-2 lengths more often 2024-07-13 11:50:28 +12:00
Documentation powerpc fixes for 6.11 #2 2024-08-17 19:23:02 -07:00
drivers Char/Misc fixes for 6.11-rc4 2024-08-18 10:16:34 -07:00
fs for-6.11-rc3-tag 2024-08-18 08:50:36 -07:00
include dma-mapping: replace zone_dma_bits by zone_dma_limit 2024-08-22 06:18:00 +02:00
init Rust fixes for v6.11 2024-08-16 11:24:06 -07:00
io_uring io_uring/sqpoll: annotate debug task == current with data_race() 2024-08-13 06:10:59 -06:00
ipc sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
kernel dma-mapping: replace zone_dma_bits by zone_dma_limit 2024-08-22 06:18:00 +02:00
lib bcachefs fixes for 6.11-rc4 2024-08-17 09:46:10 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm 16 hotfixes. All except one are for MM. 10 of these are cc:stable and 2024-08-17 19:50:16 -07:00
net Including fixes from wireless and netfilter 2024-08-15 10:35:20 -07:00
rust Rust fixes for v6.11 2024-08-16 11:24:06 -07:00
samples Driver core changes for 6.11-rc1 2024-07-25 10:42:22 -07:00
scripts Rust fixes for v6.11 2024-08-16 11:24:06 -07:00
security KEYS: trusted: dcp: fix leak of blob encryption key 2024-08-15 22:01:14 +03:00
sound ALSA: hda/tas2781: Use correct endian conversion 2024-08-14 16:58:26 +02:00
tools 16 hotfixes. All except one are for MM. 10 of these are cc:stable and 2024-08-17 19:50:16 -07:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt KVM: x86: Disallow read-only memslots for SEV-ES and SEV-SNP (and TDX) 2024-08-14 12:28:24 -04:00
.clang-format Docs: Move clang-format from process/ to dev-tools/ 2024-06-26 16:36:00 -06:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: add script and target to generate pacman package 2024-07-22 01:24:22 +09:00
.mailmap mailmap: update entry for David Heidelberg 2024-08-07 18:33:56 -07:00
.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 tracing: Update of MAINTAINERS and CREDITS file 2024-07-18 14:08:42 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS sound fixes for 6.11-rc3 2024-08-09 09:25:30 -07:00
Makefile Linux 6.11-rc4 2024-08-18 13:17:27 -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.