kernel/Documentation/driver-api/device-io.rst, branch linux-rolling-stable

docs: driver-api: fix spelling of "buses".

2025-09-18T16:40:46Z

Replace incorrect plural form "busses" with "buses" in multiple documentation files under "Documentation/driver-api". Signed-off-by: Marneni PoornaChandu Signed-off-by: Jonathan Corbet Message-ID: <20250917220430.5815-1-Poornachandumarneni@gmail.com>

PCI: Move pci_iomap.c to drivers/pci/

2024-02-12T16:35:40Z

The entirety of pci_iomap.c is guarded by an #ifdef CONFIG_PCI. It, consequently, does not belong to lib/ because it is not generic infrastructure. Move pci_iomap.c to drivers/pci/ and implement the necessary changes to Makefiles and Kconfigs. Update MAINTAINERS file. Update Documentation. Link: https://lore.kernel.org/r/20240131090023.12331-3-pstanner@redhat.com [bhelgaas: squash in https://lore.kernel.org/r/20240212150934.24559-1-pstanner@redhat.com] Suggested-by: Danilo Krummrich Signed-off-by: Philipp Stanner Signed-off-by: Bjorn Helgaas Reviewed-by: Arnd Bergmann

arch/*/io.h: remove ioremap_uc in some architectures

2023-11-23T09:32:52Z

ioremap_uc() is only meaningful on old x86-32 systems with the PAT extension, and on ia64 with its slightly unconventional ioremap() behavior. So remove the ioremap_uc() definition in architecutures other than x86 and ia64. These architectures all have asm-generic/io.h included and will have the default ioremap_uc() definition which returns NULL. This changes the existing behaviour, while no need to worry about any breakage because in the only callsite of ioremap_uc(), code has been adjusted to eliminate the impact. Please see atyfb_setup_generic() of drivers/video/fbdev/aty/atyfb_base.c. If any new invocation of ioremap_uc() need be added, please consider using ioremap() intead or adding a ARCH specific version if necessary. Signed-off-by: Baoquan He Acked-by: Geert Uytterhoeven Acked-by: Michael Ellerman (powerpc) Acked-by: Helge Deller # parisc Acked-by: Arnd Bergmann Acked-by: Thomas Bogendoerfer Acked-by: John Paul Adrian Glaubitz (SuperH) Cc: linux-alpha@vger.kernel.org Cc: linux-hexagon@vger.kernel.org Cc: linux-m68k@lists.linux-m68k.org Cc: linux-mips@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-sh@vger.kernel.org Cc: sparclinux@vger.kernel.org Signed-off-by: Arnd Bergmann

docs: move x86 documentation into Documentation/arch/

2023-03-30T18:58:51Z

Move the x86 documentation under Documentation/arch/ as a way of cleaning up the top-level directory and making the structure of our docs more closely match the structure of the source directories it describes. All in-kernel references to the old paths have been updated. Acked-by: Dave Hansen Cc: linux-arch@vger.kernel.org Cc: x86@kernel.org Cc: Borislav Petkov Cc: Thomas Gleixner Link: https://lore.kernel.org/lkml/20230315211523.108836-1-corbet@lwn.net/ Signed-off-by: Jonathan Corbet

dma-buf-map: Rename to iosys-map

2022-02-08T00:35:35Z

Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include + #include Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi Acked-by: Christian König Acked-by: Sumit Semwal Acked-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com

docs: driver-api: device-io: Document ioremap() variants & access funcs

2021-04-08T11:18:38Z

This documents the newly introduced ioremap_np() along with all the other common ioremap() variants, and some higher-level abstractions available. Reviewed-by: Linus Walleij Signed-off-by: Hector Martin

docs: driver-api: device-io: Document I/O access functions

2021-04-08T11:18:38Z

This adds more detailed descriptions of the various read/write primitives available for use with I/O memory/ports. Reviewed-by: Linus Walleij Signed-off-by: Arnd Bergmann Signed-off-by: Hector Martin

Driver-API: Documentation: Replace deprecated :c:func: Usage

2020-07-13T15:56:03Z

Replace :c:func: with func() as the previous usage is deprecated. Signed-off-by: Puranjay Mohan Link: https://lore.kernel.org/r/20200707053252.32703-1-puranjay12@gmail.com Signed-off-by: Jonathan Corbet

Documentation: Kill all references to mmiowb()

2019-04-08T11:00:45Z

The guarantees provided by mmiowb() are now provided implicitly by spin_unlock(), so remove all references to this most confusing of barriers from our Documentation. Good riddance. Acked-by: Linus Torvalds Signed-off-by: Will Deacon

docs: Convert the deviceio template to RST

2017-02-01T00:31:21Z

Convert deviceiobook.tmpl to RST and incorporate it into the driver API manual. Like the rest of our documentation, this one could use some work. There's no mention of ioremap() and friends, no mention of io_read*() and friends. But we have nice documentation for all those folks writing new drivers that do port I/O :). The :c:func: notation has been left off of all the read*/write* functions. There's no kerneldoc comments for them anyway, so those links will never be live, and writing a bunch of repetitive "read a byte from I/O memory" comments lacks appeal. Cc: Matthew Wilcox Cc: Alan Cox Signed-off-by: Jonathan Corbet