kernel/linux.git/include/linux/io-mapping.h, branch v7.0-rc7

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

mm: remove mm/io-mapping.c

2025-08-02T19:06:10+00:00

This is dead code, which was used from commit b739f125e4eb ("i915: use io_mapping_map_user") but reverted a month later by commit 0e4fe0c9f2f9 ("Revert "i915: use io_mapping_map_user"") back in 2021. Since then nobody has used it, so remove it. [akpm@linux-foundation.org: update Documentation/core-api/mm-api.rst, per Vlastimil] Link: https://lkml.kernel.org/r/20250725142901.81502-1-lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Acked-by: David Hildenbrand Acked-by: Vlastimil Babka Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton

io-mapping: don't disable preempt on RT in io_mapping_map_atomic_wc().

2023-03-28T23:20:16+00:00

io_mapping_map_atomic_wc() disables preemption and pagefaults for historical reasons. The conversion to io_mapping_map_local_wc(), which only disables migration, cannot be done wholesale because quite some call sites need to be updated to accommodate with the changed semantics. On PREEMPT_RT enabled kernels the io_mapping_map_atomic_wc() semantics are problematic due to the implicit disabling of preemption which makes it impossible to acquire 'sleeping' spinlocks within the mapped atomic sections. PREEMPT_RT replaces the preempt_disable() with a migrate_disable() for more than a decade. It could be argued that this is a justification to do this unconditionally, but PREEMPT_RT covers only a limited number of architectures and it disables some functionality which limits the coverage further. Limit the replacement to PREEMPT_RT for now. This is also done kmap_atomic(). Link: https://lkml.kernel.org/r/20230310162905.O57Pj7hh@linutronix.de Signed-off-by: Sebastian Andrzej Siewior Reported-by: Richard Weinberger Link: https://lore.kernel.org/CAFLxGvw0WMxaMqYqJ5WgvVSbKHq2D2xcXTOgMCpgq9nDC-MWTQ@mail.gmail.com Cc: Thomas Gleixner Signed-off-by: Andrew Morton

io-mapping: move some code within the include guarded section

2022-12-12T03:30:19+00:00

It is spurious to have some code out-side the include guard in a .h file. Fix it. Link: https://lkml.kernel.org/r/4dbaf427d4300edba6c6bbfaf4d57493b9bec6ee.1669565241.git.christophe.jaillet@wanadoo.fr Fixes: 1fbaf8fc12a0 ("mm: add a io_mapping_map_user helper") Signed-off-by: Christophe JAILLET Signed-off-by: Andrew Morton

include/linux/io-mapping.h: remove fallback for writecombine

2021-11-06T20:30:36+00:00

The fallback was introduced in commit 80c33624e472 ("io-mapping: Fixup for different names of writecombine") to fix the build on microblaze. 5 years later, it seems all archs now provide a pgprot_writecombine(), so just remove the other possible fallbacks. For microblaze, pgprot_writecombine() is available since commit 97ccedd793ac ("microblaze: Provide pgprot_device/writecombine macros for nommu"). This is build-tested on microblaze with a hack to always build mm/io-mapping.o and without DIYing on an x86-only macro (_PAGE_CACHE_MASK) Link: https://lkml.kernel.org/r/20211020204838.1142908-1-lucas.demarchi@intel.com Signed-off-by: Lucas De Marchi Cc: Chris Wilson Cc: Daniel Vetter Cc: Joonas Lahtinen Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: add a io_mapping_map_user helper

2021-04-30T18:20:39+00:00

Add a helper that calls remap_pfn_range for an struct io_mapping, relying on the pgprot pre-validation done when creating the mapping instead of doing it at runtime. Link: https://lkml.kernel.org/r/20210326055505.1424432-3-hch@lst.de Signed-off-by: Christoph Hellwig Cc: Chris Wilson Cc: Daniel Vetter Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Peter Zijlstra Cc: Rodrigo Vivi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

io-mapping: Provide iomap_local variant

2020-11-24T13:42:09+00:00

Similar to kmap local provide a iomap local variant which only disables migration, but neither disables pagefaults nor preemption. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20201118204007.561220818@linutronix.de

io-mapping: Cleanup atomic iomap

2020-11-06T22:14:58+00:00

Switch the atomic iomap implementation over to kmap_local and stick the preempt/pagefault mechanics into the generic code similar to the kmap_atomic variants. Rename the x86 map function in preparation for a non-atomic variant. Signed-off-by: Thomas Gleixner Cc: Linus Torvalds Cc: Christoph Hellwig Cc: Andrew Morton Link: https://lore.kernel.org/r/20201103095858.625310005@linutronix.de

x86/mm/highmem: Use generic kmap atomic implementation

2020-11-06T22:14:55+00:00

Convert X86 to the generic kmap atomic implementation and make the iomap_atomic() naming convention consistent while at it. Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201103095857.375127260@linutronix.de