kernel/linux.git/arch/arc/include/asm/page.h, branch v6.1

ARC: mm: support 4 levels of page tables

2021-08-26T20:43:19+00:00

Acked-by: Mike Rapoport Signed-off-by: Vineet Gupta

ARC: mm: support 3 levels of page tables

2021-08-26T20:43:19+00:00

ARCv2 MMU is software walked and Linux implements 2 levels of paging: pgd/pte. Forthcoming hw will have multiple levels, so this change preps mm code for same. It is also fun to try multi levels even on soft-walked code to ensure generic mm code is robust to handle. overview ________ 2 levels {pgd, pte} : pmd is folded but pmd_* macros are valid and operate on pgd 3 levels {pgd, pmd, pte}: - pud is folded and pud_* macros point to pgd - pmd_* macros operate on actual pmd code changes ____________ 1. #include 2. Define CONFIG_PGTABLE_LEVELS 3 3a. Define PMD_SHIFT, PMD_SIZE, PMD_MASK, pmd_t 3b. Define pmd_val() which actually deals with pmd (pmd_offset(), pmd_index() are provided by generic code) 3c. pmd_alloc_one()/pmd_free() also provided by generic code (pmd_populate/pmd_free already exist) 4. Define pud_none(), pud_bad() macros based on generic pud_val() which internally pertains to pgd now. 4b. define pud_populate() to just setup pgd Acked-by: Mike Rapoport Signed-off-by: Vineet Gupta

ARC: mm: switch pgtable_t back to struct page *

2021-08-26T20:42:42+00:00

So far ARC pgtable_t has not been struct page based to avoid extra page_address() calls involved. However the differences are down to noise and get in the way of using generic code, hence this patch. This also allows us to reuse generic THP depost/withdraw code. There's some additional consideration for PGDIR_SHIFT in 4K page config. Now due to page tables being PAGE_SIZE deep only, the address split can't be really arbitrary. Tested-by: kernel test robot Suggested-by: Mike Rapoport Acked-by: Mike Rapoport Signed-off-by: Vineet Gupta

ARC: mm: non-functional code movement/cleanup

2021-08-24T21:25:48+00:00

Signed-off-by: Vineet Gupta

ARC: mm: Enable STRICT_MM_TYPECHECKS

2021-08-24T21:25:48+00:00

In the past I've refrained from doing this (at least 2 times) due to the slight code bloat due to ABI implications of pte_t etc becoming struct Per ARC ABI, functions return struct via memory and not through register r0, even if the struct would fit in register(s) - caller allocates space on stack and passes the address as first arg (r0), shifting rest of args by one - callee creates return struct in memory (referenced via r0) This time around the code actually shrunk slightly (due to subtle inlining heuristic effects), but still slightly inefficient due to return values passed through memory. That however seems like a small cost compared to maintenance burden given the impending new mmu support for page walk etc Signed-off-by: Vineet Gupta

ARC: mm: PAE: use 40-bit physical page mask

2021-05-10T19:38:59+00:00

32-bit PAGE_MASK can not be used as a mask for physical addresses when PAE is enabled. PAGE_MASK_PHYS must be used for physical addresses instead of PAGE_MASK. Without this, init gets SIGSEGV if pte_modify was called: | potentially unexpected fatal signal 11. | Path: /bin/busybox | CPU: 0 PID: 1 Comm: init Not tainted 5.12.0-rc5-00003-g1e43c377a79f-dirty | Insn could not be fetched | @No matching VMA found | ECR: 0x00040000 EFA: 0x00000000 ERET: 0x00000000 | STAT: 0x80080082 [IE U ] BTA: 0x00000000 | SP: 0x5f9ffe44 FP: 0x00000000 BLK: 0xaf3d4 | LPS: 0x000d093e LPE: 0x000d0950 LPC: 0x00000000 | r00: 0x00000002 r01: 0x5f9fff14 r02: 0x5f9fff20 | ... | Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Signed-off-by: Vladimir Isaev Reported-by: kernel test robot Cc: Vineet Gupta Cc: stable@vger.kernel.org Signed-off-by: Vineet Gupta

arch/arc: add copy_user_page() to to fix build error on ARC

2021-01-05T20:59:40+00:00

fs/dax.c uses copy_user_page() but ARC does not provide that interface, resulting in a build error. Provide copy_user_page() in . ../fs/dax.c: In function 'copy_cow_page_dax': ../fs/dax.c:702:2: error: implicit declaration of function 'copy_user_page'; did you mean 'copy_to_user_page'? [-Werror=implicit-function-declaration] Reported-by: kernel test robot Signed-off-by: Randy Dunlap Cc: Vineet Gupta Cc: linux-snps-arc@lists.infradead.org Cc: Dan Williams #Acked-by: Vineet Gupta # v1 Cc: Andrew Morton Cc: Matthew Wilcox Cc: Jan Kara Cc: linux-fsdevel@vger.kernel.org Cc: linux-nvdimm@lists.01.org #Reviewed-by: Ira Weiny # v2 Signed-off-by: Vineet Gupta

arc: use FLATMEM with freeing of unused memory map instead of DISCONTIGMEM

2020-12-15T20:13:42+00:00

Currently ARC uses DISCONTIGMEM to cope with sparse physical memory address space on systems with 2 memory banks. While DISCONTIGMEM avoids wasting memory on unpopulated memory map, it adds both memory and CPU overhead relatively to FLATMEM. Moreover, DISCONTINGMEM is generally considered deprecated. The obvious replacement for DISCONTIGMEM would be SPARSEMEM, but it is also less efficient than FLATMEM in pfn_to_page() and page_to_pfn() conversions. Besides it requires tuning of SECTION_SIZE which is not trivial for possible ARC memory configuration. Since the memory map for both banks is always allocated from the "lowmem" bank, it is possible to use FLATMEM for two-bank configuration and simply free the unused hole in the memory map. All is required for that is to provide ARC-specific pfn_valid() that will take into account actual physical memory configuration and define HAVE_ARCH_PFN_VALID. The resulting kernel image configured with defconfig + HIGHMEM=y is smaller: $ size a/vmlinux b/vmlinux text data bss dec hex filename 4673503 1245456 279756 6198715 5e95bb a/vmlinux 4658706 1246864 279756 6185326 5e616e b/vmlinux $ ./scripts/bloat-o-meter a/vmlinux b/vmlinux add/remove: 28/30 grow/shrink: 42/399 up/down: 10986/-29025 (-18039) ... Total: Before=4709315, After = 4691276, chg -0.38% Booting nSIM with haps_ns.dts results in the following memory usage reports: a: Memory: 1559104K/1572864K available (3531K kernel code, 595K rwdata, 752K rodata, 136K init, 275K bss, 13760K reserved, 0K cma-reserved, 1048576K highmem) b: Memory: 1559112K/1572864K available (3519K kernel code, 594K rwdata, 752K rodata, 136K init, 280K bss, 13752K reserved, 0K cma-reserved, 1048576K highmem) Link: https://lkml.kernel.org/r/20201101170454.9567-11-rppt@kernel.org Signed-off-by: Mike Rapoport Cc: Alexey Dobriyan Cc: Catalin Marinas Cc: Geert Uytterhoeven Cc: Greg Ungerer Cc: John Paul Adrian Glaubitz Cc: Jonathan Corbet Cc: Matt Turner Cc: Meelis Roos Cc: Michael Schmitz Cc: Russell King Cc: Tony Luck Cc: Vineet Gupta Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS

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

There are many platforms with exact same value for VM_DATA_DEFAULT_FLAGS This creates a default value for VM_DATA_DEFAULT_FLAGS in line with the existing VM_STACK_DEFAULT_FLAGS. While here, also define some more macros with standard VMA access flag combinations that are used frequently across many platforms. Apart from simplification, this reduces code duplication as well. Signed-off-by: Anshuman Khandual Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka Acked-by: Geert Uytterhoeven Cc: Richard Henderson Cc: Vineet Gupta Cc: Russell King Cc: Catalin Marinas Cc: Mark Salter Cc: Guo Ren Cc: Yoshinori Sato Cc: Brian Cain Cc: Tony Luck Cc: Michal Simek Cc: Ralf Baechle Cc: Paul Burton Cc: Nick Hu Cc: Ley Foon Tan Cc: Jonas Bonn Cc: "James E.J. Bottomley" Cc: Michael Ellerman Cc: Paul Walmsley Cc: Heiko Carstens Cc: Rich Felker Cc: "David S. Miller" Cc: Guan Xuetao Cc: Thomas Gleixner Cc: Jeff Dike Cc: Chris Zankel Link: http://lkml.kernel.org/r/1583391014-8170-2-git-send-email-anshuman.khandual@arm.com 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