kernel/arch/xtensa/include/asm/highmem.h, branch linux-rolling-stable

mm: constify highmem related functions for improved const-correctness

2025-09-21T21:22:15Z

Lots of functions in mm/highmem.c do not write to the given pointers and do not call functions that take non-const pointers and can therefore be constified. This includes functions like kunmap() which might be implemented in a way that writes to the pointer (e.g. to update reference counters or mapping fields), but currently are not. kmap() on the other hand cannot be made const because it calls set_page_address() which is non-const in some architectures/configurations. [akpm@linux-foundation.org: "fix" folio_page() build failure] Link: https://lkml.kernel.org/r/20250901205021.3573313-13-max.kellermann@ionos.com Signed-off-by: Max Kellermann Reviewed-by: Lorenzo Stoakes Acked-by: David Hildenbrand Acked-by: Vlastimil Babka Acked-by: Mike Rapoport (Microsoft) Acked-by: Shakeel Butt Cc: Alexander Gordeev Cc: Al Viro Cc: Andreas Larsson Cc: Andy Lutomirski Cc: Axel Rasmussen Cc: Baolin Wang Cc: Borislav Betkov Cc: Christian Borntraeger Cc: Christian Brauner Cc: Christian Zankel Cc: David Rientjes Cc: David S. Miller Cc: Gerald Schaefer Cc: Heiko Carstens Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Hugh Dickins Cc: Ingo Molnar Cc: James Bottomley Cc: Jan Kara Cc: Jocelyn Falempe Cc: Liam Howlett Cc: Mark Brown Cc: Matthew Wilcox (Oracle) Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Hocko Cc: "Nysal Jan K.A" Cc: Oscar Salvador Cc: Peter Zijlstra Cc: Russel King Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Thomas Gleinxer Cc: Thomas Huth Cc: Vasily Gorbik Cc: Vishal Moola (Oracle) Cc: Wei Xu Cc: Yuanchu Xie Signed-off-by: Andrew Morton

xtensa/mm/highmem: Make generic kmap_atomic() work correctly

2020-11-16T20:19:24Z

The conversion to the generic kmap_atomic() implementation missed the fact that xtensa's fixmap works bottom up while all other implementations work top down. There is no real reason why xtensa needs to work that way. Cure it by: - Using the generic fix_to_virt()/virt_to_fix() functions which work top down - Adjusting the mapping defines - Using the generic index calculation for the non cache aliasing case - Making the cache colour offset reverse so the effective index is correct While at it, remove the outdated and misleading comment above the fixmap enum which originates from the initial copy&pasta of this code from i386. [ Max: Fixed the off by one in the index calculation ] Fixes: 629ed3f7dad2 ("xtensa/mm/highmem: Switch to generic kmap atomic") Reported-by: Max Filippov Signed-off-by: Thomas Gleixner Signed-off-by: Max Filippov Signed-off-by: Thomas Gleixner Tested-by: Max Filippov Link: https://lore.kernel.org/r/20201116193253.23875-1-jcmvbkbc@gmail.com

xtensa/mm/highmem: Switch to generic kmap atomic

2020-11-06T22:14:57Z

No reason having the same code in every architecture Signed-off-by: Thomas Gleixner Cc: Chris Zankel Cc: Max Filippov Cc: Arnd Bergmann Link: https://lore.kernel.org/r/20201103095858.311016780@linutronix.de

mm: reorder includes after introduction of linux/pgtable.h

2020-06-09T16:39:13Z

The replacement of with made the include of the latter in the middle of asm includes. Fix this up with the aid of the below script and manual adjustments here and there. import sys import re if len(sys.argv) is not 3: print "USAGE: %s

" % (sys.argv[0]) sys.exit(1) hdr_to_move="#include " % sys.argv[2] moved = False in_hdrs = False with open(sys.argv[1], "r") as f: lines = f.readlines() for _line in lines: line = _line.rstrip(' ') if line == hdr_to_move: continue if line.startswith("#include Signed-off-by: Andrew Morton Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brian Cain Cc: Catalin Marinas Cc: Chris Zankel Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Ungerer Cc: Guan Xuetao Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: Ingo Molnar Cc: Ley Foon Tan Cc: Mark Salter Cc: Matthew Wilcox Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Nick Hu Cc: Paul Walmsley Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Tony Luck Cc: Vincent Chen Cc: Vineet Gupta Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org Signed-off-by: Linus Torvalds

mm: introduce include/linux/pgtable.h

2020-06-09T16:39:13Z

The include/linux/pgtable.h is going to be the home of generic page table manipulation functions. Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and make the latter include asm/pgtable.h. Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brian Cain Cc: Catalin Marinas Cc: Chris Zankel Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Ungerer Cc: Guan Xuetao Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: Ingo Molnar Cc: Ley Foon Tan Cc: Mark Salter Cc: Matthew Wilcox Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Nick Hu Cc: Paul Walmsley Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Tony Luck Cc: Vincent Chen Cc: Vineet Gupta Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org Signed-off-by: Linus Torvalds

arch/kunmap_atomic: consolidate duplicate code

2020-06-05T02:06:22Z

Every single architecture (including !CONFIG_HIGHMEM) calls... pagefault_enable(); preempt_enable(); ... before returning from __kunmap_atomic(). Lift this code into the kunmap_atomic() macro. While we are at it rename __kunmap_atomic() to kunmap_atomic_high() to be consistent. [ira.weiny@intel.com: don't enable pagefault/preempt twice] Link: http://lkml.kernel.org/r/20200518184843.3029640-1-ira.weiny@intel.com [akpm@linux-foundation.org: coding style fixes] Signed-off-by: Ira Weiny Signed-off-by: Andrew Morton Reviewed-by: Christoph Hellwig Cc: Al Viro Cc: Andy Lutomirski Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Christian König Cc: Chris Zankel Cc: Daniel Vetter Cc: Dan Williams Cc: Dave Hansen Cc: "David S. Miller" Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Max Filippov Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Guenter Roeck Link: http://lkml.kernel.org/r/20200507150004.1423069-8-ira.weiny@intel.com Signed-off-by: Linus Torvalds

arch/kmap_atomic: consolidate duplicate code

2020-06-05T02:06:22Z

Every arch has the same code to ensure atomic operations and a check for !HIGHMEM page. Remove the duplicate code by defining a core kmap_atomic() which only calls the arch specific kmap_atomic_high() when the page is high memory. [akpm@linux-foundation.org: coding style fixes] Signed-off-by: Ira Weiny Signed-off-by: Andrew Morton Reviewed-by: Christoph Hellwig Cc: Al Viro Cc: Andy Lutomirski Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Christian König Cc: Chris Zankel Cc: Daniel Vetter Cc: Dan Williams Cc: Dave Hansen Cc: "David S. Miller" Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Max Filippov Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20200507150004.1423069-7-ira.weiny@intel.com Signed-off-by: Linus Torvalds

arch/kunmap: remove duplicate kunmap implementations

2020-06-05T02:06:22Z

All architectures do exactly the same thing for kunmap(); remove all the duplicate definitions and lift the call to the core. This also has the benefit of changing kmap_unmap() on a number of architectures to be an inline call rather than an actual function. [akpm@linux-foundation.org: fix CONFIG_HIGHMEM=n build on various architectures] Signed-off-by: Ira Weiny Signed-off-by: Andrew Morton Reviewed-by: Christoph Hellwig Cc: Al Viro Cc: Andy Lutomirski Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Christian König Cc: Chris Zankel Cc: Daniel Vetter Cc: Dan Williams Cc: Dave Hansen Cc: "David S. Miller" Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Max Filippov Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20200507150004.1423069-5-ira.weiny@intel.com Signed-off-by: Linus Torvalds

arch/kmap: remove redundant arch specific kmaps

2020-06-05T02:06:22Z

The kmap code for all the architectures is almost 100% identical. Lift the common code to the core. Use ARCH_HAS_KMAP_FLUSH_TLB to indicate if an arch defines kmap_flush_tlb() and call if if needed. This also has the benefit of changing kmap() on a number of architectures to be an inline call rather than an actual function. Signed-off-by: Ira Weiny Signed-off-by: Andrew Morton Reviewed-by: Christoph Hellwig Cc: Al Viro Cc: Andy Lutomirski Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Christian König Cc: Chris Zankel Cc: Daniel Vetter Cc: Dan Williams Cc: Dave Hansen Cc: "David S. Miller" Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Max Filippov Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20200507150004.1423069-4-ira.weiny@intel.com Signed-off-by: Linus Torvalds

arch/xtensa: move kmap build bug out of the way

2020-06-05T02:06:22Z

Move the kmap() build bug to kmap_init() to facilitate patches to lift kmap() to the core. Signed-off-by: Ira Weiny Signed-off-by: Andrew Morton Reviewed-by: Christoph Hellwig Cc: Al Viro Cc: Andy Lutomirski Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Christian König Cc: Chris Zankel Cc: Daniel Vetter Cc: Dan Williams Cc: Dave Hansen Cc: "David S. Miller" Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Max Filippov Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20200507150004.1423069-3-ira.weiny@intel.com Signed-off-by: Linus Torvalds