Pull dma-mapping updates from Marek Szyprowski:
- added support for batched cache sync, what improves performance of
dma_map/unmap_sg() operations on ARM64 architecture (Barry Song)
- introduced DMA_ATTR_CC_SHARED attribute for explicitly shared memory
used in confidential computing (Jiri Pirko)
- refactored spaghetti-like code in drivers/of/of_reserved_mem.c and
its clients (Marek Szyprowski, shared branch with device-tree updates
to avoid merge conflicts)
- prepared Contiguous Memory Allocator related code for making dma-buf
drivers modularized (Maxime Ripard)
- added support for benchmarking dma_map_sg() calls to tools/dma
utility (Qinxin Xia)
* tag 'dma-mapping-7.1-2026-04-16' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux: (24 commits)
dma-buf: heaps: system: document system_cc_shared heap
dma-buf: heaps: system: add system_cc_shared heap for explicitly shared memory
dma-mapping: introduce DMA_ATTR_CC_SHARED for shared memory
mm: cma: Export cma_alloc(), cma_release() and cma_get_name()
dma: contiguous: Export dev_get_cma_area()
dma: contiguous: Make dma_contiguous_default_area static
dma: contiguous: Make dev_get_cma_area() a proper function
dma: contiguous: Turn heap registration logic around
of: reserved_mem: rework fdt_init_reserved_mem_node()
of: reserved_mem: clarify fdt_scan_reserved_mem*() functions
of: reserved_mem: rearrange code a bit
of: reserved_mem: replace CMA quirks by generic methods
of: reserved_mem: switch to ops based OF_DECLARE()
of: reserved_mem: use -ENODEV instead of -ENOENT
of: reserved_mem: remove fdt node from the structure
dma-mapping: fix false kernel-doc comment marker
dma-mapping: Support batch mode for dma_direct_{map,unmap}_sg
dma-mapping: Separate DMA sync issuing and completion waiting
arm64: Provide dcache_inval_poc_nosync helper
arm64: Provide dcache_clean_poc_nosync helper
...
Firmware-supplied flat DT properties are raw byte sequences. Several
early FDT helpers fetch properties such as status, model, compatible,
and device_type and then use them as C strings with strcmp(), strlen(),
or pr_info() without first proving that the property is NUL-terminated
within its declared length.
Use fdt_stringlist_get() for these string properties instead. That
preserves the existing behavior for valid DTBs while rejecting malformed
unterminated properties before they are passed to C string helpers.
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Link: https://patch.msgid.link/20260403164501.1-drivers-of-fdt-v2-pengpeng@iscas.ac.cn
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
early_init_dt_scan_chosen_stdout() fetches stdout-path and
linux,stdout-path directly from the flat DT and immediately passes the
result to strchrnul(). Flat DT properties are raw firmware-supplied
byte sequences, and this path does not prove that either property is
NUL-terminated within its declared bounds.
Use fdt_stringlist_get() so malformed unterminated stdout-path
properties are rejected before the local parser walks them as C
strings.
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Link: https://patch.msgid.link/20260403143001.1-dt-fdt-stdout-pengpeng@iscas.ac.cn
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Commit 8a6e02d0c0 ("of: reserved_mem: Restructure how the reserved
memory regions are processed") changed the processing order of reserved
memory regions, causing elfcorehdr to overlap with dynamically allocated
reserved memory regions during kdump kernel boot.
The issue occurs because:
1. kexec-tools allocates elfcorehdr in the last crashkernel reserved
memory region and passes it to the second kernel
2. The problematic commit moved dynamic reserved memory allocation
(like bman-fbpr) to occur during fdt_scan_reserved_mem(), before
elfcorehdr reservation in fdt_reserve_elfcorehdr()
3. bman-fbpr with 16MB alignment requirement can get allocated at
addresses that overlap with the elfcorehdr location
4. When fdt_reserve_elfcorehdr() tries to reserve elfcorehdr memory,
overlap detection identifies the conflict and skips reservation
5. kdump kernel fails with "Unable to handle kernel paging request"
because elfcorehdr memory is not properly reserved
The boot log:
Before 8a6e02d0c0:
OF: fdt: Reserving 1 KiB of memory at 0xf4fff000 for elfcorehdr
OF: reserved mem: 0xf3000000..0xf3ffffff bman-fbpr
After 8a6e02d0c0:
OF: reserved mem: 0xf4000000..0xf4ffffff bman-fbpr
OF: fdt: elfcorehdr is overlapped
Fix this by ensuring elfcorehdr reservation occurs before dynamic
reserved memory allocation.
Fixes: 8a6e02d0c0 ("of: reserved_mem: Restructure how the reserved memory regions are processed")
Signed-off-by: Jianpeng Chang <jianpeng.chang.cn@windriver.com>
Link: https://patch.msgid.link/20251205015934.700016-1-jianpeng.chang.cn@windriver.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
When reading the fdt_size value, the argument passed to dt_mem_next_cell()
is dt_root_addr_cells, but it should be dt_root_size_cells.
The same issue occurs when reading the scratch_size value.
Use a helper function to simplify the code and fix these issues.
Fixes: 274cdcb1c0 ("arm64: add KHO support")
Signed-off-by: Yuntao Wang <yuntao.wang@linux.dev>
Link: https://patch.msgid.link/20251115134753.179931-5-yuntao.wang@linux.dev
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
The len value is in bytes, while `dt_root_addr_cells + dt_root_size_cells`
is in cells (4 bytes per cell). Modulo calculation between them is
incorrect, the units must be converted first.
Use helper functions to simplify the code and fix this issue.
Fixes: fb319e77a0 ("of: fdt: Add memory for devices by DT property "linux,usable-memory-range"")
Fixes: 2af2b50acf ("of: fdt: Add generic support for handling usable memory range property")
Fixes: 8f579b1c4e ("arm64: limit memory regions based on DT property, usable-memory-range")
Signed-off-by: Yuntao Wang <yuntao.wang@linux.dev>
Link: https://patch.msgid.link/20251115134753.179931-4-yuntao.wang@linux.dev
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
The len value is in bytes, while `dt_root_addr_cells + dt_root_size_cells`
is in cells (4 bytes per cell). Comparing them directly is incorrect.
Use a helper function to simplify the code and address this issue.
Fixes: f7e7ce93aa ("of: fdt: Add generic support for handling elf core headers property")
Fixes: e62aaeac42 ("arm64: kdump: provide /proc/vmcore file")
Signed-off-by: Yuntao Wang <yuntao.wang@linux.dev>
Link: https://patch.msgid.link/20251115134753.179931-3-yuntao.wang@linux.dev
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Pull MM updates from Andrew Morton:
"The various patchsets are summarized below. Plus of course many
indivudual patches which are described in their changelogs.
- "Allocate and free frozen pages" from Matthew Wilcox reorganizes
the page allocator so we end up with the ability to allocate and
free zero-refcount pages. So that callers (ie, slab) can avoid a
refcount inc & dec
- "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
use large folios other than PMD-sized ones
- "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
and fixes for this small built-in kernel selftest
- "mas_anode_descend() related cleanup" from Wei Yang tidies up part
of the mapletree code
- "mm: fix format issues and param types" from Keren Sun implements a
few minor code cleanups
- "simplify split calculation" from Wei Yang provides a few fixes and
a test for the mapletree code
- "mm/vma: make more mmap logic userland testable" from Lorenzo
Stoakes continues the work of moving vma-related code into the
(relatively) new mm/vma.c
- "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
Hildenbrand cleans up and rationalizes handling of gfp flags in the
page allocator
- "readahead: Reintroduce fix for improper RA window sizing" from Jan
Kara is a second attempt at fixing a readahead window sizing issue.
It should reduce the amount of unnecessary reading
- "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
addresses an issue where "huge" amounts of pte pagetables are
accumulated:
https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/
Qi's series addresses this windup by synchronously freeing PTE
memory within the context of madvise(MADV_DONTNEED)
- "selftest/mm: Remove warnings found by adding compiler flags" from
Muhammad Usama Anjum fixes some build warnings in the selftests
code when optional compiler warnings are enabled
- "mm: don't use __GFP_HARDWALL when migrating remote pages" from
David Hildenbrand tightens the allocator's observance of
__GFP_HARDWALL
- "pkeys kselftests improvements" from Kevin Brodsky implements
various fixes and cleanups in the MM selftests code, mainly
pertaining to the pkeys tests
- "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
estimate application working set size
- "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
provides some cleanups to memcg's hugetlb charging logic
- "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
removes the global swap cgroup lock. A speedup of 10% for a
tmpfs-based kernel build was demonstrated
- "zram: split page type read/write handling" from Sergey Senozhatsky
has several fixes and cleaups for zram in the area of
zram_write_page(). A watchdog softlockup warning was eliminated
- "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
Brodsky cleans up the pagetable destructor implementations. A rare
use-after-free race is fixed
- "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
simplifies and cleans up the debugging code in the VMA merging
logic
- "Account page tables at all levels" from Kevin Brodsky cleans up
and regularizes the pagetable ctor/dtor handling. This results in
improvements in accounting accuracy
- "mm/damon: replace most damon_callback usages in sysfs with new
core functions" from SeongJae Park cleans up and generalizes
DAMON's sysfs file interface logic
- "mm/damon: enable page level properties based monitoring" from
SeongJae Park increases the amount of information which is
presented in response to DAMOS actions
- "mm/damon: remove DAMON debugfs interface" from SeongJae Park
removes DAMON's long-deprecated debugfs interfaces. Thus the
migration to sysfs is completed
- "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
Peter Xu cleans up and generalizes the hugetlb reservation
accounting
- "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
removes a never-used feature of the alloc_pages_bulk() interface
- "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
extends DAMOS filters to support not only exclusion (rejecting),
but also inclusion (allowing) behavior
- "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
introduces a new memory descriptor for zswap.zpool that currently
overlaps with struct page for now. This is part of the effort to
reduce the size of struct page and to enable dynamic allocation of
memory descriptors
- "mm, swap: rework of swap allocator locks" from Kairui Song redoes
and simplifies the swap allocator locking. A speedup of 400% was
demonstrated for one workload. As was a 35% reduction for kernel
build time with swap-on-zram
- "mm: update mips to use do_mmap(), make mmap_region() internal"
from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
mmap_region() can be made MM-internal
- "mm/mglru: performance optimizations" from Yu Zhao fixes a few
MGLRU regressions and otherwise improves MGLRU performance
- "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
Park updates DAMON documentation
- "Cleanup for memfd_create()" from Isaac Manjarres does that thing
- "mm: hugetlb+THP folio and migration cleanups" from David
Hildenbrand provides various cleanups in the areas of hugetlb
folios, THP folios and migration
- "Uncached buffered IO" from Jens Axboe implements the new
RWF_DONTCACHE flag which provides synchronous dropbehind for
pagecache reading and writing. To permite userspace to address
issues with massive buildup of useless pagecache when
reading/writing fast devices
- "selftests/mm: virtual_address_range: Reduce memory" from Thomas
Weißschuh fixes and optimizes some of the MM selftests"
* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
mm/compaction: fix UBSAN shift-out-of-bounds warning
s390/mm: add missing ctor/dtor on page table upgrade
kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
tools: add VM_WARN_ON_VMG definition
mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
seqlock: add missing parameter documentation for raw_seqcount_try_begin()
mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
mm/page_alloc: remove the incorrect and misleading comment
zram: remove zcomp_stream_put() from write_incompressible_page()
mm: separate move/undo parts from migrate_pages_batch()
mm/kfence: use str_write_read() helper in get_access_type()
selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
selftests/mm: vm_util: split up /proc/self/smaps parsing
selftests/mm: virtual_address_range: unmap chunks after validation
selftests/mm: virtual_address_range: mmap() without PROT_WRITE
selftests/memfd/memfd_test: fix possible NULL pointer dereference
mm: add FGP_DONTCACHE folio creation flag
mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
...
There are cases when the bootloader provides information to the kernel
in both ACPI and DTB, not interchangeably. One such use case is virtual
machines in Android. When running on x86, the Android Virtualization
Framework (AVF) boots VMs with ACPI like it is usually done on x86 (i.e.
the virtual LAPIC, IOAPIC, HPET, PCI MMCONFIG etc are described in ACPI)
but also passes various AVF-specific boot parameters in DTB. This allows
reusing the same implementations of various AVF components on both
arm64 and x86.
Commit 7b937cc243 ("of: Create of_root if no dtb provided by firmware")
removed the possibility to do that, since among other things
it introduced forcing emptying the bootloader-provided DTB if ACPI is
enabled (probably assuming that if ACPI is available, a DTB can only be
useful for applying overlays to it afterwards, for testing purposes).
So restore this possibility. Instead of completely preventing using ACPI
and DT together, rely on arch-specific setup code to prevent using both
to set up the same things (see various acpi_disabled checks under arch/).
Fixes: 7b937cc243 ("of: Create of_root if no dtb provided by firmware")
Signed-off-by: Dmytro Maluka <dmaluka@chromium.org>
Link: https://lore.kernel.org/r/20250105172741.3476758-3-dmaluka@chromium.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
While OpenFirmware originally allowed walking parent nodes and default
root values for #address-cells and #size-cells, FDT has long required
explicit values. It's been a warning in dtc for the root node since the
beginning (2005) and for any parent node since 2007. Of course, not all
FDT uses dtc, but that should be the majority by far. The various
extracted OF devicetrees I have dating back to the 1990s (various
PowerMac, OLPC, PASemi Nemo) all have explicit root node properties. The
warning is disabled for Sparc as there are known systems relying on
default root node values.
Link: https://lore.kernel.org/r/20241106171028.3830266-1-robh@kernel.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
__pa() is only intended to be used for linear map addresses and using
it for initial_boot_params which is in fixmap for arm64 will give an
incorrect value. Hence save the physical address when it is known at
boot time when calling early_init_dt_scan for arm64 and use it at kexec
time instead of converting the virtual address using __pa().
Note that arm64 doesn't need the FDT region reserved in the DT as the
kernel explicitly reserves the passed in FDT. Therefore, only a debug
warning is fixed with this change.
Reported-by: Breno Leitao <leitao@debian.org>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Fixes: ac10be5cdb ("arm64: Use common of_kexec_alloc_and_setup_fdt()")
Link: https://lore.kernel.org/r/20241023171426.452688-1-usamaarif642@gmail.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Reserved memory regions defined in the devicetree can be broken up into
two groups:
i) Statically-placed reserved memory regions
i.e. regions defined with a static start address and size using the
"reg" property.
ii) Dynamically-placed reserved memory regions.
i.e. regions defined by specifying an address range where they can be
placed in memory using the "alloc_ranges" and "size" properties.
These regions are processed and set aside at boot time.
This is done in two stages as seen below:
Stage 1:
At this stage, fdt_scan_reserved_mem() scans through the child nodes of
the reserved_memory node using the flattened devicetree and does the
following:
1) If the node represents a statically-placed reserved memory region,
i.e. if it is defined using the "reg" property:
- Call memblock_reserve() or memblock_mark_nomap() as needed.
- Add the information for that region into the reserved_mem array
using fdt_reserved_mem_save_node().
i.e. fdt_reserved_mem_save_node(node, name, base, size).
2) If the node represents a dynamically-placed reserved memory region,
i.e. if it is defined using "alloc-ranges" and "size" properties:
- Add the information for that region to the reserved_mem array with
the starting address and size set to 0.
i.e. fdt_reserved_mem_save_node(node, name, 0, 0).
Note: This region is saved to the array with a starting address of 0
because a starting address is not yet allocated for it.
Stage 2:
After iterating through all the reserved memory nodes and storing their
relevant information in the reserved_mem array,fdt_init_reserved_mem() is
called and does the following:
1) For statically-placed reserved memory regions:
- Call the region specific init function using
__reserved_mem_init_node().
2) For dynamically-placed reserved memory regions:
- Call __reserved_mem_alloc_size() which is used to allocate memory
for each of these regions, and mark them as nomap if they have the
nomap property specified in the DT.
- Call the region specific init function.
The current size of the resvered_mem array is 64 as is defined by
MAX_RESERVED_REGIONS. This means that there is a limitation of 64 for
how many reserved memory regions can be specified on a system.
As systems continue to grow more and more complex, the number of
reserved memory regions needed are also growing and are starting to hit
this 64 count limit, hence the need to make the reserved_mem array
dynamically sized (i.e. dynamically allocating memory for the
reserved_mem array using membock_alloc_*).
On architectures such as arm64, memory allocated using memblock is
writable only after the page tables have been setup. This means that if
the reserved_mem array is going to be dynamically allocated, it needs to
happen after the page tables have been setup, not before.
Since the reserved memory regions are currently being processed and
added to the array before the page tables are setup, there is a need to
change the order in which some of the processing is done to allow for
the reserved_mem array to be dynamically sized.
It is possible to process the statically-placed reserved memory regions
without needing to store them in the reserved_mem array until after the
page tables have been setup because all the information stored in the
array is readily available in the devicetree and can be referenced at
any time.
Dynamically-placed reserved memory regions on the other hand get
assigned a start address only at runtime, and hence need a place to be
stored once they are allocated since there is no other referrence to the
start address for these regions.
Hence this patch changes the processing order of the reserved memory
regions in the following ways:
Step 1:
fdt_scan_reserved_mem() scans through the child nodes of
the reserved_memory node using the flattened devicetree and does the
following:
1) If the node represents a statically-placed reserved memory region,
i.e. if it is defined using the "reg" property:
- Call memblock_reserve() or memblock_mark_nomap() as needed.
2) If the node represents a dynamically-placed reserved memory region,
i.e. if it is defined using "alloc-ranges" and "size" properties:
- Call __reserved_mem_alloc_size() which will:
i) Allocate memory for the reserved region and call
memblock_mark_nomap() as needed.
ii) Call the region specific initialization function using
fdt_init_reserved_mem_node().
iii) Save the region information in the reserved_mem array using
fdt_reserved_mem_save_node().
Step 2:
1) This stage of the reserved memory processing is now only used to add
the statically-placed reserved memory regions into the reserved_mem
array using fdt_scan_reserved_mem_reg_nodes(), as well as call their
region specific initialization functions.
2) This step has also been moved to be after the page tables are
setup. Moving this will allow us to replace the reserved_mem
array with a dynamically sized array before storing the rest of
these regions.
Signed-off-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com>
Link: https://lore.kernel.org/r/20241008220624.551309-2-quic_obabatun@quicinc.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
scripts/Makefile.lib is included not only from scripts/Makefile.build
but also from scripts/Makefile.{modfinal,package,vmlinux,vmlinux_o},
where DT build rules are not required.
Split the DT build rules out to scripts/Makefile.dtbs, and include it
only when necessary.
While I was here, I added $(DT_TMP_SCHEMA) as a prerequisite of
$(multi-dtb-y).
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
