kernel/linux.git/arch/arm/include/asm/pgtable.h, branch v5.10.257

ARM: 9266/1: mm: fix no-MMU ZERO_PAGE() implementation

2022-12-14T10:31:53+00:00

[ Upstream commit 340a982825f76f1cff0daa605970fe47321b5ee7 ] Actually in no-MMU SoCs(i.e. i.MXRT) ZERO_PAGE(vaddr) expands to ``` virt_to_page(0) ``` that in order expands to: ``` pfn_to_page(virt_to_pfn(0)) ``` and then virt_to_pfn(0) to: ``` ((((unsigned long)(0) - PAGE_OFFSET) >> PAGE_SHIFT) + PHYS_PFN_OFFSET) ``` where PAGE_OFFSET and PHYS_PFN_OFFSET are the DRAM offset(0x80000000) and PAGE_SHIFT is 12. This way we obtain 16MB(0x01000000) summed to the base of DRAM(0x80000000). When ZERO_PAGE(0) is then used, for example in bio_add_page(), the page gets an address that is out of DRAM bounds. So instead of using fake virtual page 0 let's allocate a dedicated zero_page during paging_init() and assign it to a global 'struct page * empty_zero_page' the same way mmu.c does and it's the same approach used in m68k with commit dc068f462179 as discussed here[0]. Then let's move ZERO_PAGE() definition to the top of pgtable.h to be in common between mmu.c and nommu.c. [0]: https://lore.kernel.org/linux-m68k/2a462b23-5b8e-bbf4-ec7d-778434a3b9d7@google.com/T/#m1266ceb63 ad140743174d6b3070364d3c9a5179b Signed-off-by: Giulio Benetti Reviewed-by: Arnd Bergmann Signed-off-by: Russell King (Oracle) Signed-off-by: Sasha Levin

mm: consolidate pte_index() and pte_offset_*() definitions

2020-06-09T16:39:14+00:00

All architectures define pte_index() as (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1) and all architectures define pte_offset_kernel() as an entry in the array of PTEs indexed by the pte_index(). For the most architectures the pte_offset_kernel() implementation relies on the availability of pmd_page_vaddr() that converts a PMD entry value to the virtual address of the page containing PTEs array. Let's move x86 definitions of the PTE accessors to the generic place in and then simply drop the respective definitions from the other architectures. The architectures that didn't provide pmd_page_vaddr() are updated to have that defined. The generic implementation of pte_offset_kernel() can be overridden by an architecture and alpha makes use of this because it has special ordering requirements for its version of pte_offset_kernel(). [rppt@linux.ibm.com: v2] Link: http://lkml.kernel.org/r/20200514170327.31389-11-rppt@kernel.org [rppt@linux.ibm.com: update] Link: http://lkml.kernel.org/r/20200514170327.31389-12-rppt@kernel.org [rppt@linux.ibm.com: update] Link: http://lkml.kernel.org/r/20200514170327.31389-13-rppt@kernel.org [akpm@linux-foundation.org: fix x86 warning] [sfr@canb.auug.org.au: fix powerpc build] Link: http://lkml.kernel.org/r/20200607153443.GB738695@linux.ibm.com Signed-off-by: Mike Rapoport Signed-off-by: Stephen Rothwell 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/20200514170327.31389-10-rppt@kernel.org Signed-off-by: Linus Torvalds

mm: introduce include/linux/pgtable.h

2020-06-09T16:39:13+00:00

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

arm: add support for folded p4d page tables

2020-06-05T02:06:21+00:00

Implement primitives necessary for the 4th level folding, add walks of p4d level where appropriate, and remove __ARCH_USE_5LEVEL_HACK. [rppt@linux.ibm.com: fix kexec] Link: http://lkml.kernel.org/r/20200508174232.GA759899@linux.ibm.com Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Tested-by: Marek Szyprowski Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Brian Cain Cc: Catalin Marinas Cc: Christophe Leroy Cc: Fenghua Yu Cc: Geert Uytterhoeven Cc: Guan Xuetao Cc: James Morse Cc: Jonas Bonn Cc: Julien Thierry Cc: Ley Foon Tan Cc: Marc Zyngier Cc: Michael Ellerman Cc: Paul Mackerras Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Stefan Kristiansson Cc: Suzuki K Poulose Cc: Tony Luck Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200414153455.21744-3-rppt@kernel.org Signed-off-by: Linus Torvalds

mm/special: create generic fallbacks for pte_special() and pte_mkspecial()

2020-04-10T22:36:21+00:00

Currently there are many platforms that dont enable ARCH_HAS_PTE_SPECIAL but required to define quite similar fallback stubs for special page table entry helpers such as pte_special() and pte_mkspecial(), as they get build in generic MM without a config check. This creates two generic fallback stub definitions for these helpers, eliminating much code duplication. mips platform has a special case where pte_special() and pte_mkspecial() visibility is wider than what ARCH_HAS_PTE_SPECIAL enablement requires. This restricts those symbol visibility in order to avoid redefinitions which is now exposed through this new generic stubs and subsequent build failure. arm platform set_pte_at() definition needs to be moved into a C file just to prevent a build failure. [anshuman.khandual@arm.com: use defined(CONFIG_ARCH_HAS_PTE_SPECIAL) in mips per Thomas] Link: http://lkml.kernel.org/r/1583851924-21603-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Signed-off-by: Andrew Morton Acked-by: Guo Ren [csky] Acked-by: Geert Uytterhoeven [m68k] Acked-by: Stafford Horne [openrisc] Acked-by: Helge Deller [parisc] Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Russell King Cc: Brian Cain Cc: Tony Luck Cc: Fenghua Yu Cc: Sam Creasey Cc: Michal Simek Cc: Ralf Baechle Cc: Paul Burton Cc: Nick Hu Cc: Greentime Hu Cc: Vincent Chen Cc: Ley Foon Tan Cc: Jonas Bonn Cc: Stefan Kristiansson Cc: "James E.J. Bottomley" Cc: "David S. Miller" Cc: Jeff Dike Cc: Richard Weinberger Cc: Anton Ivanov Cc: Guan Xuetao Cc: Chris Zankel Cc: Max Filippov Cc: Thomas Bogendoerfer Link: http://lkml.kernel.org/r/1583802551-15406-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds

arm: Remove HYP/Stage-2 page-table support

2020-03-24T10:56:05+00:00

Remove all traces of Stage-2 and HYP page table support. Signed-off-by: Marc Zyngier Acked-by: Olof Johansson Acked-by: Arnd Bergmann Acked-by: Will Deacon Acked-by: Vladimir Murzin Acked-by: Catalin Marinas Acked-by: Linus Walleij Acked-by: Christoffer Dall

arm: nommu: use pgtable-nopud instead of 4level-fixup

2019-12-05T03:44:14+00:00

The generic nommu implementation of page table manipulation takes care of folding of the upper levels and does not require fixups. Simply replace of include/asm-generic/4level-fixup.h with include/asm-generic/pgtable-nopud.h. Link: http://lkml.kernel.org/r/1572938135-31886-3-git-send-email-rppt@kernel.org Signed-off-by: Mike Rapoport Acked-by: Russell King Cc: Anatoly Pugachev Cc: Anton Ivanov Cc: Arnd Bergmann Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Ungerer Cc: Helge Deller Cc: "James E.J. Bottomley" Cc: Jeff Dike Cc: "Kirill A. Shutemov" Cc: Mark Salter Cc: Matt Turner Cc: Michal Simek Cc: Peter Rosin Cc: Richard Weinberger Cc: Rolf Eike Beer Cc: Russell King Cc: Sam Creasey Cc: Vincent Chen Cc: Vineet Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: consolidate pgtable_cache_init() and pgd_cache_init()

2019-09-24T22:54:09+00:00

Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem cache for page table allocations on several architectures that do not use PAGE_SIZE tables for one or more levels of the page table hierarchy. Most architectures do not implement these functions and use __weak default NOP implementation of pgd_cache_init(). Since there is no such default for pgtable_cache_init(), its empty stub is duplicated among most architectures. Rename the definitions of pgd_cache_init() to pgtable_cache_init() and drop empty stubs of pgtable_cache_init(). Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport Acked-by: Will Deacon [arm64] Acked-by: Thomas Gleixner [x86] Cc: Catalin Marinas Cc: Ingo Molnar Cc: Borislav Petkov Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

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

2019-06-19T15:09:55+00:00

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

ARM: 8823/1: Implement pgprot_device()

2019-02-01T21:44:11+00:00

This is used when mmapping the PCI resource* files in sys. Because ARM currently lacks an implementation of pgprot_device(), it falls back to pgprot_uncached() (Strongly Ordered), but we should be able to use Device memory instead. Doing this speeds up large writes to the resource files by about 40% on one of my systems. It also ensures that mmaps on these resources use the same memory type as ioremap(). Signed-off-by: Vincent Whitchurch Signed-off-by: Russell King