kernel.git/arch/arm/mm/flush.c, branch master

mm: introduce memdesc_flags_t

2025-09-13T23:55:07Z

Patch series "Add and use memdesc_flags_t". At some point struct page will be separated from struct slab and struct folio. This is a step towards that by introducing a type for the 'flags' word of all three structures. This gives us a certain amount of type safety by establishing that some of these unsigned longs are different from other unsigned longs in that they contain things like node ID, section number and zone number in the upper bits. That lets us have functions that can be easily called by anyone who has a slab, folio or page (but not easily by anyone else) to get the node or zone. There's going to be some unusual merge problems with this as some odd bits of the kernel decide they want to print out the flags value or something similar by writing page->flags and now they'll need to write page->flags.f instead. That's most of the churn here. Maybe we should be removing these things from the debug output? This patch (of 11): Wrap the unsigned long flags in a typedef. In upcoming patches, this will provide a strong hint that you can't just pass a random unsigned long to functions which take this as an argument. [willy@infradead.org: s/flags/flags.f/ in several architectures] Link: https://lkml.kernel.org/r/aKMgPRLD-WnkPxYm@casper.infradead.org [nicola.vetrini@gmail.com: mips: fix compilation error] Link: https://lore.kernel.org/lkml/CA+G9fYvkpmqGr6wjBNHY=dRp71PLCoi2341JxOudi60yqaeUdg@mail.gmail.com/ Link: https://lkml.kernel.org/r/20250825214245.1838158-1-nicola.vetrini@gmail.com Link: https://lkml.kernel.org/r/20250805172307.1302730-1-willy@infradead.org Link: https://lkml.kernel.org/r/20250805172307.1302730-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Zi Yan Cc: Shakeel Butt Signed-off-by: Andrew Morton

mm: rename page->index to page->__folio_index

2025-06-01T05:46:06Z

All users of page->index have been converted to not refer to it any more. Update a few pieces of documentation that were missed and prevent new users from appearing (or at least make them easy to grep for). Link: https://lkml.kernel.org/r/20250514181508.3019795-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: David Hildenbrand Signed-off-by: Andrew Morton

ARM: 9359/1: flush: check if the folio is reserved for no-mapping addresses

2024-03-11T16:04:19Z

Since commit a4d5613c4dc6 ("arm: extend pfn_valid to take into account freed memory map alignment") changes the semantics of pfn_valid() to check presence of the memory map for a PFN. A valid page for an address which is reserved but not mapped by the kernel[1], the system crashed during some uio test with the following memory layout: node 0: [mem 0x00000000c0a00000-0x00000000cc8fffff] node 0: [mem 0x00000000d0000000-0x00000000da1fffff] the uio layout is：0xc0900000, 0x100000 the crash backtrace like: Unable to handle kernel paging request at virtual address bff00000 [...] CPU: 1 PID: 465 Comm: startapp.bin Tainted: G O 5.10.0 #1 Hardware name: Generic DT based system PC is at b15_flush_kern_dcache_area+0x24/0x3c LR is at __sync_icache_dcache+0x6c/0x98 [...] (b15_flush_kern_dcache_area) from (__sync_icache_dcache+0x6c/0x98) (__sync_icache_dcache) from (set_pte_at+0x28/0x54) (set_pte_at) from (remap_pfn_range+0x1a0/0x274) (remap_pfn_range) from (uio_mmap+0x184/0x1b8 [uio]) (uio_mmap [uio]) from (__mmap_region+0x264/0x5f4) (__mmap_region) from (__do_mmap_mm+0x3ec/0x440) (__do_mmap_mm) from (do_mmap+0x50/0x58) (do_mmap) from (vm_mmap_pgoff+0xfc/0x188) (vm_mmap_pgoff) from (ksys_mmap_pgoff+0xac/0xc4) (ksys_mmap_pgoff) from (ret_fast_syscall+0x0/0x5c) Code: e0801001 e2423001 e1c00003 f57ff04f (ee070f3e) ---[ end trace 09cf0734c3805d52 ]--- Kernel panic - not syncing: Fatal exception So check if PG_reserved was set to solve this issue. [1]: https://lore.kernel.org/lkml/Zbtdue57RO0QScJM@linux.ibm.com/ Fixes: a4d5613c4dc6 ("arm: extend pfn_valid to take into account freed memory map alignment") Suggested-by: Mike Rapoport Signed-off-by: Yongqiang Liu Signed-off-by: Russell King (Oracle)

arm: implement the new page table range API

2023-08-24T23:20:20Z

Add set_ptes(), update_mmu_cache_range(), flush_dcache_folio() and flush_icache_pages(). Change the PG_dcache_clear flag from being per-page to per-folio which makes __dma_page_dev_to_cpu() a bit more exciting. Also add flush_cache_pages(), even though this isn't used by generic code (yet?) [m.szyprowski@samsung.com: fix potential endless loop in __dma_page_dev_to_cpu()] Link: https://lkml.kernel.org/r/20230809172737.3574190-1-m.szyprowski@samsung.com [willy@infradead.org: fix folio conversion in __dma_page_dev_to_cpu()] Link: https://lkml.kernel.org/r/20230823191852.1556561-1-willy@infradead.org Link: https://lkml.kernel.org/r/20230802151406.3735276-10-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Marek Szyprowski Acked-by: Mike Rapoport (IBM) Reviewed-by: Russell King (Oracle) Signed-off-by: Andrew Morton

ARM: 9306/1: cacheflush: avoid __flush_anon_page() missing-prototype warning

2023-06-19T08:35:53Z

The prototype for __flush_anon_page() is intentionally hidden inside the flush_anon_page() inline function to prevent it from being called from drivers. When building with 'W=1', this causes a warning: arch/arm/mm/flush.c:358:6: error: no previous prototype for '__flush_anon_page' [-Werror=missing-prototypes] Work around this by adding a prototype directly next to the function definition. Reviewed-by: Kees Cook Signed-off-by: Arnd Bergmann Signed-off-by: Russell King (Oracle)

mm: remove flush_kernel_dcache_page

2021-09-03T16:58:13Z

flush_kernel_dcache_page is a rather confusing interface that implements a subset of flush_dcache_page by not being able to properly handle page cache mapped pages. The only callers left are in the exec code as all other previous callers were incorrect as they could have dealt with page cache pages. Replace the calls to flush_kernel_dcache_page with calls to flush_dcache_page, which for all architectures does either exactly the same thing, can contains one or more of the following: 1) an optimization to defer the cache flush for page cache pages not mapped into userspace 2) additional flushing for mapped page cache pages if cache aliases are possible Link: https://lkml.kernel.org/r/20210712060928.4161649-7-hch@lst.de Signed-off-by: Christoph Hellwig Acked-by: Linus Torvalds Reviewed-by: Ira Weiny Cc: Alex Shi Cc: Geoff Levand Cc: Greentime Hu Cc: Guo Ren Cc: Helge Deller Cc: "James E.J. Bottomley" Cc: Nick Hu Cc: Paul Cercueil Cc: Rich Felker Cc: Russell King Cc: Thomas Bogendoerfer Cc: Ulf Hansson Cc: Vincent Chen Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: introduce compound_nr()

2019-09-24T22:54:08Z

Replace 1 << compound_order(page) with compound_nr(page). Minor improvements in readability. Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Andrew Morton Reviewed-by: Ira Weiny Acked-by: Kirill A. Shutemov Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: introduce page_size()

2019-09-24T22:54:08Z

Patch series "Make working with compound pages easier", v2. These three patches add three helpers and convert the appropriate places to use them. This patch (of 3): It's unnecessarily hard to find out the size of a potentially huge page. Replace 'PAGE_SIZE << compound_order(page)' with page_size(page). Link: http://lkml.kernel.org/r/20190721104612.19120-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Michal Hocko Reviewed-by: Andrew Morton Reviewed-by: Ira Weiny Acked-by: Kirill A. Shutemov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55Z

Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman

mm: fix races between swapoff and flush dcache

2018-04-06T04:36:26Z

Thanks to commit 4b3ef9daa4fc ("mm/swap: split swap cache into 64MB trunks"), after swapoff the address_space associated with the swap device will be freed. So page_mapping() users which may touch the address_space need some kind of mechanism to prevent the address_space from being freed during accessing. The dcache flushing functions (flush_dcache_page(), etc) in architecture specific code may access the address_space of swap device for anonymous pages in swap cache via page_mapping() function. But in some cases there are no mechanisms to prevent the swap device from being swapoff, for example, CPU1 CPU2 __get_user_pages() swapoff() flush_dcache_page() mapping = page_mapping() ... exit_swap_address_space() ... kvfree(spaces) mapping_mapped(mapping) The address space may be accessed after being freed. But from cachetlb.txt and Russell King, flush_dcache_page() only care about file cache pages, for anonymous pages, flush_anon_page() should be used. The implementation of flush_dcache_page() in all architectures follows this too. They will check whether page_mapping() is NULL and whether mapping_mapped() is true to determine whether to flush the dcache immediately. And they will use interval tree (mapping->i_mmap) to find all user space mappings. While mapping_mapped() and mapping->i_mmap isn't used by anonymous pages in swap cache at all. So, to fix the race between swapoff and flush dcache, __page_mapping() is add to return the address_space for file cache pages and NULL otherwise. All page_mapping() invoking in flush dcache functions are replaced with page_mapping_file(). [akpm@linux-foundation.org: simplify page_mapping_file(), per Mike] Link: http://lkml.kernel.org/r/20180305083634.15174-1-ying.huang@intel.com Signed-off-by: "Huang, Ying" Reviewed-by: Andrew Morton Cc: Minchan Kim Cc: Michal Hocko Cc: Johannes Weiner Cc: Mel Gorman Cc: Dave Hansen Cc: Chen Liqin Cc: Russell King Cc: Yoshinori Sato Cc: "James E.J. Bottomley" Cc: Guan Xuetao Cc: "David S. Miller" Cc: Chris Zankel Cc: Vineet Gupta Cc: Ley Foon Tan Cc: Ralf Baechle Cc: Andi Kleen Cc: Mike Rapoport Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds