summaryrefslogtreecommitdiff
path: root/arch/arm64/mm/hugetlbpage.c
AgeCommit message (Collapse)Author
2021-09-29arm64/mm: Add pud_sect_supported()Anshuman Khandual
Section mapping at PUD level is supported only on 4K pages and currently it gets verified with explicit #ifdef or IS_ENABLED() constructs. This adds a new helper pud_sect_supported() for this purpose, which particularly cleans up the HugeTLB code path. It updates relevant switch statements with checks for __PAGETABLE_PMD_FOLDED in order to avoid build failures caused with two identical switch case values in those code blocks. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/1632130171-472-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-30mm/hugetlb: change parameters of arch_make_huge_pte()Christophe Leroy
Patch series "Subject: [PATCH v2 0/5] Implement huge VMAP and VMALLOC on powerpc 8xx", v2. This series implements huge VMAP and VMALLOC on powerpc 8xx. Powerpc 8xx has 4 page sizes: - 4k - 16k - 512k - 8M At the time being, vmalloc and vmap only support huge pages which are leaf at PMD level. Here the PMD level is 4M, it doesn't correspond to any supported page size. For now, implement use of 16k and 512k pages which is done at PTE level. Support of 8M pages will be implemented later, it requires use of hugepd tables. To allow this, the architecture provides two functions: - arch_vmap_pte_range_map_size() which tells vmap_pte_range() what page size to use. A stub returning PAGE_SIZE is provided when the architecture doesn't provide this function. - arch_vmap_pte_supported_shift() which tells __vmalloc_node_range() what page shift to use for a given area size. A stub returning PAGE_SHIFT is provided when the architecture doesn't provide this function. This patch (of 5): At the time being, arch_make_huge_pte() has the following prototype: pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma, struct page *page, int writable); vma is used to get the pages shift or size. vma is also used on Sparc to get vm_flags. page is not used. writable is not used. In order to use this function without a vma, replace vma by shift and flags. Also remove the used parameters. Link: https://lkml.kernel.org/r/cover.1620795204.git.christophe.leroy@csgroup.eu Link: https://lkml.kernel.org/r/f4633ac6a7da2f22f31a04a89e0a7026bb78b15b.1620795204.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05hugetlb/userfaultfd: forbid huge pmd sharing when uffd enabledPeter Xu
Huge pmd sharing could bring problem to userfaultfd. The thing is that userfaultfd is running its logic based on the special bits on page table entries, however the huge pmd sharing could potentially share page table entries for different address ranges. That could cause issues on either: - When sharing huge pmd page tables for an uffd write protected range, the newly mapped huge pmd range will also be write protected unexpectedly, or, - When we try to write protect a range of huge pmd shared range, we'll first do huge_pmd_unshare() in hugetlb_change_protection(), however that also means the UFFDIO_WRITEPROTECT could be silently skipped for the shared region, which could lead to data loss. While at it, a few other things are done altogether: - Move want_pmd_share() from mm/hugetlb.c into linux/hugetlb.h, because that's definitely something that arch code would like to use too - ARM64 currently directly check against CONFIG_ARCH_WANT_HUGE_PMD_SHARE when trying to share huge pmd. Switch to the want_pmd_share() helper. - Move vma_shareable() from huge_pmd_share() into want_pmd_share(). [peterx@redhat.com: fix build with !ARCH_WANT_HUGE_PMD_SHARE] Link: https://lkml.kernel.org/r/20210310185359.88297-1-peterx@redhat.com Link: https://lkml.kernel.org/r/20210218231202.15426-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Axel Rasmussen <axelrasmussen@google.com> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Adam Ruprecht <ruprecht@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Cannon Matthews <cannonmatthews@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chinwen Chang <chinwen.chang@mediatek.com> Cc: David Rientjes <rientjes@google.com> Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michal Koutn" <mkoutny@suse.com> Cc: Michel Lespinasse <walken@google.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oliver Upton <oupton@google.com> Cc: Shaohua Li <shli@fb.com> Cc: Shawn Anastasio <shawn@anastas.io> Cc: Steven Price <steven.price@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05hugetlb: pass vma into huge_pte_alloc() and huge_pmd_share()Peter Xu
Patch series "hugetlb: Disable huge pmd unshare for uffd-wp", v4. This series tries to disable huge pmd unshare of hugetlbfs backed memory for uffd-wp. Although uffd-wp of hugetlbfs is still during rfc stage, the idea of this series may be needed for multiple tasks (Axel's uffd minor fault series, and Mike's soft dirty series), so I picked it out from the larger series. This patch (of 4): It is a preparation work to be able to behave differently in the per architecture huge_pte_alloc() according to different VMA attributes. Pass it deeper into huge_pmd_share() so that we can avoid the find_vma() call. [peterx@redhat.com: build fix] Link: https://lkml.kernel.org/r/20210304164653.GB397383@xz-x1Link: https://lkml.kernel.org/r/20210218230633.15028-1-peterx@redhat.com Link: https://lkml.kernel.org/r/20210218230633.15028-2-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Suggested-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Adam Ruprecht <ruprecht@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Cannon Matthews <cannonmatthews@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chinwen Chang <chinwen.chang@mediatek.com> Cc: David Rientjes <rientjes@google.com> Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michal Koutn" <mkoutny@suse.com> Cc: Michel Lespinasse <walken@google.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oliver Upton <oupton@google.com> Cc: Shaohua Li <shli@fb.com> Cc: Shawn Anastasio <shawn@anastas.io> Cc: Steven Price <steven.price@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm: remove unneeded includes of <asm/pgalloc.h>Mike Rapoport
Patch series "mm: cleanup usage of <asm/pgalloc.h>" Most architectures have very similar versions of pXd_alloc_one() and pXd_free_one() for intermediate levels of page table. These patches add generic versions of these functions in <asm-generic/pgalloc.h> and enable use of the generic functions where appropriate. In addition, functions declared and defined in <asm/pgalloc.h> headers are used mostly by core mm and early mm initialization in arch and there is no actual reason to have the <asm/pgalloc.h> included all over the place. The first patch in this series removes unneeded includes of <asm/pgalloc.h> In the end it didn't work out as neatly as I hoped and moving pXd_alloc_track() definitions to <asm-generic/pgalloc.h> would require unnecessary changes to arches that have custom page table allocations, so I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local to mm/. This patch (of 8): In most cases <asm/pgalloc.h> header is required only for allocations of page table memory. Most of the .c files that include that header do not use symbols declared in <asm/pgalloc.h> and do not require that header. As for the other header files that used to include <asm/pgalloc.h>, it is possible to move that include into the .c file that actually uses symbols from <asm/pgalloc.h> and drop the include from the header file. The process was somewhat automated using sed -i -E '/[<"]asm\/pgalloc\.h/d' \ $(grep -L -w -f /tmp/xx \ $(git grep -E -l '[<"]asm/pgalloc\.h')) where /tmp/xx contains all the symbols defined in arch/*/include/asm/pgalloc.h. [rppt@linux.ibm.com: fix powerpc warning] Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Joerg Roedel <joro@8bytes.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Cc: Stafford Horne <shorne@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Joerg Roedel <jroedel@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-15arm64/hugetlb: Reserve CMA areas for gigantic pages on 16K and 64K configsAnshuman Khandual
Currently 'hugetlb_cma=' command line argument does not create CMA area on ARM64_16K_PAGES and ARM64_64K_PAGES based platforms. Instead, it just ends up with the following warning message. Reason being, hugetlb_cma_reserve() never gets called for these huge page sizes. [ 64.255669] hugetlb_cma: the option isn't supported by current arch This enables CMA areas reservation on ARM64_16K_PAGES and ARM64_64K_PAGES configs by defining an unified arm64_hugetlb_cma_reseve() that is wrapped in CONFIG_CMA. Call site for arm64_hugetlb_cma_reserve() is also protected as <asm/hugetlb.h> is conditionally included and hence cannot contain stub for the inverse config i.e !(CONFIG_HUGETLB_PAGE && CONFIG_CMA). Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Barry Song <song.bao.hua@hisilicon.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/1593578521-24672-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-03arm64/mm: Redefine CONT_{PTE, PMD}_SHIFTGavin Shan
Currently, the value of CONT_{PTE, PMD}_SHIFT is off from standard {PAGE, PMD}_SHIFT. In turn, we have to consider adding {PAGE, PMD}_SHIFT when using CONT_{PTE, PMD}_SHIFT in the function hugetlbpage_init(). It's a bit confusing. This redefines CONT_{PTE, PMD}_SHIFT with {PAGE, PMD}_SHIFT included so that the later values needn't be added when using the former ones in function hugetlbpage_init(). Note that the values of CONT_{PTES, PMDS} are unchanged. Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Link: https://lkml.org/lkml/2020/5/6/190 Link: https://lore.kernel.org/r/20200630062428.194235-1-gshan@redhat.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-06-04arm64: add support for folded p4d page tablesMike Rapoport
Implement primitives necessary for the 4th level folding, add walks of p4d level where appropriate, replace 5level-fixup.h with pgtable-nop4d.h and remove __ARCH_USE_5LEVEL_HACK. [arnd@arndb.de: fix gcc-10 shift warning] Link: http://lkml.kernel.org/r/20200429185657.4085975-1-arnd@arndb.de Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: James Morse <james.morse@arm.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200414153455.21744-4-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03hugetlbfs: remove hugetlb_add_hstate() warning for existing hstateMike Kravetz
hugetlb_add_hstate() prints a warning if the hstate already exists. This was originally done as part of kernel command line parsing. If 'hugepagesz=' was specified more than once, the warning pr_warn("hugepagesz= specified twice, ignoring\n"); would be printed. Some architectures want to enable all huge page sizes. They would call hugetlb_add_hstate for all supported sizes. However, this was done after command line processing and as a result hstates could have already been created for some sizes. To make sure no warning were printed, there would often be code like: if (!size_to_hstate(size) hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT) The only time we want to print the warning is as the result of command line processing. So, remove the warning from hugetlb_add_hstate and add it to the single arch independent routine processing "hugepagesz=". After this, calls to size_to_hstate() in arch specific code can be removed and hugetlb_add_hstate can be called without worrying about warning messages. [mike.kravetz@oracle.com: fix hugetlb initialization] Link: http://lkml.kernel.org/r/4c36c6ce-3774-78fa-abc4-b7346bf24348@oracle.com Link: http://lkml.kernel.org/r/20200428205614.246260-5-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Anders Roxell <anders.roxell@linaro.org> Acked-by: Mina Almasry <almasrymina@google.com> Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390] Acked-by: Will Deacon <will@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Longpeng <longpeng2@huawei.com> Cc: Nitesh Narayan Lal <nitesh@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Qian Cai <cai@lca.pw> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: http://lkml.kernel.org/r/20200417185049.275845-4-mike.kravetz@oracle.com Link: http://lkml.kernel.org/r/20200428205614.246260-4-mike.kravetz@oracle.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03hugetlbfs: move hugepagesz= parsing to arch independent codeMike Kravetz
Now that architectures provide arch_hugetlb_valid_size(), parsing of "hugepagesz=" can be done in architecture independent code. Create a single routine to handle hugepagesz= parsing and remove all arch specific routines. We can also remove the interface hugetlb_bad_size() as this is no longer used outside arch independent code. This also provides consistent behavior of hugetlbfs command line options. The hugepagesz= option should only be specified once for a specific size, but some architectures allow multiple instances. This appears to be more of an oversight when code was added by some architectures to set up ALL huge pages sizes. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Sandipan Das <sandipan@linux.ibm.com> Reviewed-by: Peter Xu <peterx@redhat.com> Acked-by: Mina Almasry <almasrymina@google.com> Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390] Acked-by: Will Deacon <will@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Longpeng <longpeng2@huawei.com> Cc: Nitesh Narayan Lal <nitesh@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Qian Cai <cai@lca.pw> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: http://lkml.kernel.org/r/20200417185049.275845-3-mike.kravetz@oracle.com Link: http://lkml.kernel.org/r/20200428205614.246260-3-mike.kravetz@oracle.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03hugetlbfs: add arch_hugetlb_valid_sizeMike Kravetz
Patch series "Clean up hugetlb boot command line processing", v4. Longpeng(Mike) reported a weird message from hugetlb command line processing and proposed a solution [1]. While the proposed patch does address the specific issue, there are other related issues in command line processing. As hugetlbfs evolved, updates to command line processing have been made to meet immediate needs and not necessarily in a coordinated manner. The result is that some processing is done in arch specific code, some is done in arch independent code and coordination is problematic. Semantics can vary between architectures. The patch series does the following: - Define arch specific arch_hugetlb_valid_size routine used to validate passed huge page sizes. - Move hugepagesz= command line parsing out of arch specific code and into an arch independent routine. - Clean up command line processing to follow desired semantics and document those semantics. [1] https://lore.kernel.org/linux-mm/20200305033014.1152-1-longpeng2@huawei.com This patch (of 3): The architecture independent routine hugetlb_default_setup sets up the default huge pages size. It has no way to verify if the passed value is valid, so it accepts it and attempts to validate at a later time. This requires undocumented cooperation between the arch specific and arch independent code. For architectures that support more than one huge page size, provide a routine arch_hugetlb_valid_size to validate a huge page size. hugetlb_default_setup can use this to validate passed values. arch_hugetlb_valid_size will also be used in a subsequent patch to move processing of the "hugepagesz=" in arch specific code to a common routine in arch independent code. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390] Acked-by: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Longpeng <longpeng2@huawei.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Mina Almasry <almasrymina@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Nitesh Narayan Lal <nitesh@redhat.com> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Qian Cai <cai@lca.pw> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: http://lkml.kernel.org/r/20200428205614.246260-1-mike.kravetz@oracle.com Link: http://lkml.kernel.org/r/20200428205614.246260-2-mike.kravetz@oracle.com Link: http://lkml.kernel.org/r/20200417185049.275845-1-mike.kravetz@oracle.com Link: http://lkml.kernel.org/r/20200417185049.275845-2-mike.kravetz@oracle.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-07arm64: hugetlb: avoid potential NULL dereferenceMark Rutland
The static analyzer in GCC 10 spotted that in huge_pte_alloc() we may pass a NULL pmdp into pte_alloc_map() when pmd_alloc() returns NULL: | CC arch/arm64/mm/pageattr.o | CC arch/arm64/mm/hugetlbpage.o | from arch/arm64/mm/hugetlbpage.c:10: | arch/arm64/mm/hugetlbpage.c: In function ‘huge_pte_alloc’: | ./arch/arm64/include/asm/pgtable-types.h:28:24: warning: dereference of NULL ‘pmdp’ [CWE-690] [-Wanalyzer-null-dereference] | ./arch/arm64/include/asm/pgtable.h:436:26: note: in expansion of macro ‘pmd_val’ | arch/arm64/mm/hugetlbpage.c:242:10: note: in expansion of macro ‘pte_alloc_map’ | |arch/arm64/mm/hugetlbpage.c:232:10: | |./arch/arm64/include/asm/pgtable-types.h:28:24: | ./arch/arm64/include/asm/pgtable.h:436:26: note: in expansion of macro ‘pmd_val’ | arch/arm64/mm/hugetlbpage.c:242:10: note: in expansion of macro ‘pte_alloc_map’ This can only occur when the kernel cannot allocate a page, and so is unlikely to happen in practice before other systems start failing. We can avoid this by bailing out if pmd_alloc() fails, as we do earlier in the function if pud_alloc() fails. Fixes: 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Kyrill Tkachov <kyrylo.tkachov@arm.com> Cc: <stable@vger.kernel.org> # 4.5.x- Cc: Will Deacon <will@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-06-03arm64/hugetlb: Use macros for contiguous huge page sizesAnshuman Khandual
Replace all open encoded contiguous huge page size computations with available macro encodings CONT_PTE_SIZE and CONT_PMD_SIZE. There are other instances where these macros are used in the file and this change makes it consistently use the same mnemonic. Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Steve Capper <steve.capper@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174Thomas Gleixner
Based on 1 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 distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 655 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-05arm64/mm: enable HugeTLB migration for contiguous bit HugeTLB pagesAnshuman Khandual
Let arm64 subscribe to the previously added framework in which architecture can inform whether a given huge page size is supported for migration. This just overrides the default function arch_hugetlb_migration_supported() and enables migration for all possible HugeTLB page sizes on arm64. With this, HugeTLB migration support on arm64 now covers all possible HugeTLB options. CONT PTE PMD CONT PMD PUD -------- --- -------- --- 4K: 64K 2M 32M 1G 16K: 2M 32M 1G 64K: 2M 512M 16G Link: http://lkml.kernel.org/r/1545121450-1663-6-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-06arm64: hugetlb: Register hugepages during arch initAllen Pais
Add hstate for each supported hugepage size using arch initcall. * no hugepage parameters Without hugepage parameters, only a default hugepage size is available for dynamic allocation. It's different, for example, from x86_64 and sparc64 where all supported hugepage sizes are available. * only default_hugepagesz= is specified and set not to HPAGE_SIZE In spite of the fact that default_hugepagesz= is set to a valid hugepage size, it's treated as unsupported and reverted to HPAGE_SIZE. Such behaviour is also different from x86_64 and sparc64. Acked-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Tom Saeger <tom.saeger@oracle.com> Signed-off-by: Dmitry Klochkov <dmitry.klochkov@oracle.com> Signed-off-by: Allen Pais <allen.pais@oracle.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-09-24arm64: hugetlb: Avoid unnecessary clearing in huge_ptep_set_access_flagsSteve Capper
For contiguous hugetlb, huge_ptep_set_access_flags performs a get_clear_flush (which then flushes the TLBs) even when no change of ptes is necessary. Unfortunately, this behaviour can lead to back-to-back page faults being generated when running with multiple threads that access the same contiguous huge page. Thread 1 | Thread 2 -----------------------------+------------------------------ hugetlb_fault | huge_ptep_set_access_flags | -> invalidate pte range | hugetlb_fault continue processing | wait for hugetlb_fault_mutex release mutex and return | huge_ptep_set_access_flags | -> invalidate pte range hugetlb_fault ... This patch changes huge_ptep_set_access_flags s.t. we first read the contiguous range of ptes (whilst preserving dirty information); the pte range is only then invalidated where necessary and this prevents further spurious page faults. Fixes: d8bdcff28764 ("arm64: hugetlb: Add break-before-make logic for contiguous entries") Reported-by: Lei Zhang <zhang.lei@jp.fujitsu.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-09-24arm64: hugetlb: Fix handling of young ptesSteve Capper
In the contiguous bit hugetlb break-before-make code we assume that all hugetlb pages are young. In fact, remove_migration_pte is able to place an old hugetlb pte so this assumption is not valid. This patch fixes the contiguous hugetlb scanning code to preserve young ptes. Fixes: d8bdcff28764 ("arm64: hugetlb: Add break-before-make logic for contiguous entries") Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-08-01mm: do not initialize TLB stack vma's with vma_init()Linus Torvalds
Commit 2c4541e24c55 ("mm: use vma_init() to initialize VMAs on stack and data segments") tried to initialize various left-over ad-hoc vma's "properly", but actually made things worse for the temporary vma's used for TLB flushing. vma_init() doesn't actually initialize all of the vma, just a few fields, so doing something like - struct vm_area_struct vma = { .vm_mm = tlb->mm, }; + struct vm_area_struct vma; + + vma_init(&vma, tlb->mm); was actually very bad: instead of having a nicely initialized vma with every field but "vm_mm" zeroed, you'd have an entirely uninitialized vma with only a couple of fields initialized. And they weren't even fields that the code in question mostly cared about. The flush_tlb_range() function takes a "struct vma" rather than a "struct mm_struct", because a few architectures actually care about what kind of range it is - being able to only do an ITLB flush if it's a range that doesn't have data accesses enabled, for example. And all the normal users already have the vma for doing the range invalidation. But a few people want to call flush_tlb_range() with a range they just made up, so they also end up using a made-up vma. x86 just has a special "flush_tlb_mm_range()" function for this, but other architectures (arm and ia64) do the "use fake vma" thing instead, and thus got caught up in the vma_init() changes. At the same time, the TLB flushing code really doesn't care about most other fields in the vma, so vma_init() is just unnecessary and pointless. This fixes things by having an explicit "this is just an initializer for the TLB flush" initializer macro, which is used by the arm/arm64/ia64 people who mis-use this interface with just a dummy vma. Fixes: 2c4541e24c55 ("mm: use vma_init() to initialize VMAs on stack and data segments") Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26mm: use vma_init() to initialize VMAs on stack and data segmentsKirill A. Shutemov
Make sure to initialize all VMAs properly, not only those which come from vm_area_cachep. Link: http://lkml.kernel.org/r/20180724121139.62570-3-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-16arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tablesWill Deacon
In many cases, page tables can be accessed concurrently by either another CPU (due to things like fast gup) or by the hardware page table walker itself, which may set access/dirty bits. In such cases, it is important to use READ_ONCE/WRITE_ONCE when accessing page table entries so that entries cannot be torn, merged or subject to apparent loss of coherence due to compiler transformations. Whilst there are some scenarios where this cannot happen (e.g. pinned kernel mappings for the linear region), the overhead of using READ_ONCE /WRITE_ONCE everywhere is minimal and makes the code an awful lot easier to reason about. This patch consistently uses these macros in the arch code, as well as explicitly namespacing pointers to page table entries from the entries themselves by using adopting a 'p' suffix for the former (as is sometimes used elsewhere in the kernel source). Tested-by: Yury Norov <ynorov@caviumnetworks.com> Tested-by: Richard Ruigrok <rruigrok@codeaurora.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-22arm64: hugetlb: Cleanup setup_hugepageszSteve Capper
Replace a lot of if statements with switch and case labels to make it much clearer which huge page sizes are supported. Also, we prevent PUD_SIZE from being used on systems not running with 4KB PAGE_SIZE. Before if one supplied PUD_SIZE in these circumstances, then unusuable huge page sizes would be in use. Fixes: 084bd29810a5 ("ARM64: mm: HugeTLB support.") Cc: David Woods <dwoods@mellanox.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-22arm64: Re-enable support for contiguous hugepagesPunit Agrawal
also known as - Revert "Revert "Revert "commit 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit")""" Now that our hugetlb implementation is compliant with the break-before-make requirements of the architecture and we have addressed some of the issues in core code required for properly dealing with hardware poisoning of contiguous hugepages let's re-enable support for contiguous hugepages. This reverts commit 6ae979ab39a368c18ceb0424bf824d172d6ab56f. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-22arm64: hugetlb: Override set_huge_swap_pte_at() to support contiguous hugepagesPunit Agrawal
The default implementation of set_huge_swap_pte_at() does not support hugepages consisting of contiguous ptes. Override it to add support for contiguous hugepages. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Cc: David Woods <dwoods@mellanox.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-22arm64: hugetlb: Override huge_pte_clear() to support contiguous hugepagesPunit Agrawal
The default huge_pte_clear() implementation does not clear contiguous page table entries when it encounters contiguous hugepages that are supported on arm64. Fix this by overriding the default implementation to clear all the entries associated with contiguous hugepages. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Cc: David Woods <dwoods@mellanox.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-22arm64: hugetlb: Handle swap entries in huge_pte_offset() for contiguous ↵Punit Agrawal
hugepages huge_pte_offset() was updated to correctly handle swap entries for hugepages. With the addition of the size parameter, it is now possible to disambiguate whether the request is for a regular hugepage or a contiguous hugepage. Fix huge_pte_offset() for contiguous hugepages by using the size to find the correct page table entry. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Cc: David Woods <dwoods@mellanox.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-22arm64: hugetlb: Add break-before-make logic for contiguous entriesSteve Capper
It has become apparent that one has to take special care when modifying attributes of memory mappings that employ the contiguous bit. Both the requirement and the architecturally correct "Break-Before-Make" technique of updating contiguous entries can be found described in: ARM DDI 0487A.k_iss10775, "Misprogramming of the Contiguous bit", page D4-1762. The huge pte accessors currently replace the attributes of contiguous pte entries in place thus can, on certain platforms, lead to TLB conflict aborts or even erroneous results returned from TLB lookups. This patch adds two helper functions - * get_clear_flush(.) - clears a contiguous entry and returns the head pte (whilst taking care to retain dirty bit information that could have been modified by DBM). * clear_flush(.) that clears a contiguous entry A tlb invalidate is performed to then ensure that there is no possibility of multiple tlb entries being present for the same region. Cc: David Woods <dwoods@mellanox.com> Signed-off-by: Steve Capper <steve.capper@arm.com> (Added helper clear_flush(), updated commit log, and some cleanup) Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> [catalin.marinas@arm.com: remove CONFIG_ARM64_HW_AFDBM check] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-22arm64: hugetlb: Spring clean huge pte accessorsSteve Capper
This patch aims to re-structure the huge pte accessors without affecting their functionality. Control flow is changed to reduce indentation and expanded use is made of post for loop variable modification. It is then much easier to add break-before-make semantics in a subsequent patch. Cc: David Woods <dwoods@mellanox.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-22arm64: hugetlb: Introduce pte_pgprot helperSteve Capper
Rather than xor pte bits in various places, use this helper function. Cc: David Woods <dwoods@mellanox.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-22arm64: hugetlb: set_huge_pte_at Add WARN_ON on !pte_presentSteve Capper
This patch adds a WARN_ON to set_huge_pte_at as the accessor assumes that entries to be written down are all present. (There are separate accessors to clear huge ptes). We will need to handle the !pte_present case where memory offlining is used on hugetlb pages. swap and migration entries will be supplied to set_huge_pte_at in this case. Cc: David Woods <dwoods@mellanox.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-07-06mm/hugetlb: add size parameter to huge_pte_offset()Punit Agrawal
A poisoned or migrated hugepage is stored as a swap entry in the page tables. On architectures that support hugepages consisting of contiguous page table entries (such as on arm64) this leads to ambiguity in determining the page table entry to return in huge_pte_offset() when a poisoned entry is encountered. Let's remove the ambiguity by adding a size parameter to convey additional information about the requested address. Also fixup the definition/usage of huge_pte_offset() throughout the tree. Link: http://lkml.kernel.org/r/20170522133604.11392-4-punit.agrawal@arm.com Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Acked-by: Steve Capper <steve.capper@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> (odd fixer:METAG ARCHITECTURE) Cc: Ralf Baechle <ralf@linux-mips.org> (supporter:MIPS) Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-06arm64: hugetlb: remove spurious calls to huge_ptep_offset()Steve Capper
We don't need to call huge_ptep_offset as our accessors are already supplied with the pte_t *. This patch removes those spurious calls. [punit.agrawal@arm.com: resolve rebase conflicts due to patch re-ordering] Link: http://lkml.kernel.org/r/20170524115409.31309-3-punit.agrawal@arm.com Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Cc: David Woods <dwoods@mellanox.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-06arm64: hugetlb: refactor find_num_contig()Steve Capper
Patch series "Support for contiguous pte hugepages", v4. This patchset updates the hugetlb code to fix issues arising from contiguous pte hugepages (such as on arm64). Compared to v3, This version addresses a build failure on arm64 by including two cleanup patches. Other than the arm64 cleanups, the rest are generic code changes. The remaining arm64 support based on these patches will be posted separately. The patches are based on v4.12-rc2. Previous related postings can be found at [0], [1], [2], and [3]. The patches fall into three categories - * Patch 1-2 - arm64 cleanups required to greatly simplify changing huge_pte_offset() prototype in Patch 5. Catalin, Will - are you happy for these patches to go via mm? * Patches 3-4 address issues with gup * Patches 5-8 relate to passing a size argument to hugepage helpers to disambiguate the size of the referred page. These changes are required to enable arch code to properly handle swap entries for contiguous pte hugepages. The changes to huge_pte_offset() (patch 5) touch multiple architectures but I've managed to minimise these changes for the other affected functions - huge_pte_clear() and set_huge_pte_at(). These patches gate the enabling of contiguous hugepages support on arm64 which has been requested for systems using !4k page granule. The ARM64 architecture supports two flavours of hugepages - * Block mappings at the pud/pmd level These are regular hugepages where a pmd or a pud page table entry points to a block of memory. Depending on the PAGE_SIZE in use the following size of block mappings are supported - PMD PUD --- --- 4K: 2M 1G 16K: 32M 64K: 512M For certain applications/usecases such as HPC and large enterprise workloads, folks are using 64k page size but the minimum hugepage size of 512MB isn't very practical. To overcome this ... * Using the Contiguous bit The architecture provides a contiguous bit in the translation table entry which acts as a hint to the mmu to indicate that it is one of a contiguous set of entries that can be cached in a single TLB entry. We use the contiguous bit in Linux to increase the mapping size at the pmd and pte (last) level. The number of supported contiguous entries varies by page size and level of the page table. Using the contiguous bit allows additional hugepage sizes - CONT PTE PMD CONT PMD PUD -------- --- -------- --- 4K: 64K 2M 32M 1G 16K: 2M 32M 1G 64K: 2M 512M 16G Of these, 64K with 4K and 2M with 64K pages have been explicitly requested by a few different users. Entries with the contiguous bit set are required to be modified all together - which makes things like memory poisoning and migration impossible to do correctly without knowing the size of hugepage being dealt with - the reason for adding size parameter to a few of the hugepage helpers in this series. This patch (of 8): As we regularly check for contiguous pte's in the huge accessors, remove this extra check from find_num_contig. [punit.agrawal@arm.com: resolve rebase conflicts due to patch re-ordering] Link: http://lkml.kernel.org/r/20170524115409.31309-2-punit.agrawal@arm.com Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Cc: David Woods <dwoods@mellanox.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-12arm64: hugetlb: Fix huge_pte_offset to return poisoned page table entriesPunit Agrawal
When memory failure is enabled, a poisoned hugepage pte is marked as a swap entry. huge_pte_offset() does not return the poisoned page table entries when it encounters PUD/PMD hugepages. This behaviour of huge_pte_offset() leads to error such as below when munmap is called on poisoned hugepages. [ 344.165544] mm/pgtable-generic.c:33: bad pmd 000000083af00074. Fix huge_pte_offset() to return the poisoned pte which is then appropriately handled by the generic layer code. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Acked-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: David Woods <dwoods@mellanox.com> Tested-by: Manoj Iyer <manoj.iyer@canonical.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-04-07Revert "Revert "arm64: hugetlb: partial revert of 66b3923a1a0f""Will Deacon
The use of the contiguous bit by our hugetlb implementation violates the break-before-make requirements of the architecture and can lead to silent data corruption or TLB conflict aborts. Once again, disable these hugetlb sizes whilst it gets worked out. This reverts commit ab2e1b89230fa80328262c91d2d0a539a2790d6f. Conflicts: arch/arm64/mm/hugetlbpage.c Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-11arm64: hugetlb: fix the wrong return value for huge_ptep_set_access_flagsHuang Shijie
In current code, the @changed always returns the last one's status for the huge page with the contiguous bit set. This is really not what we want. Even one of the PTEs is changed, we should tell it to the caller. This patch fixes this issue. Fixes: 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit") Cc: <stable@vger.kernel.org> # 4.5.x- Signed-off-by: Huang Shijie <shijie.huang@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-11-09arm64: hugetlb: fix the wrong address for several functionsHuang Shijie
The libhugetlbfs meets several failures since the following functions do not use the correct address: huge_ptep_get_and_clear() huge_ptep_set_access_flags() huge_ptep_set_wrprotect() huge_ptep_clear_flush() This patch fixes the wrong address for them. Signed-off-by: Huang Shijie <shijie.huang@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-11-09arm64: hugetlb: remove the wrong pmd check in find_num_contig()Huang Shijie
The find_num_contig() will return 1 when the pmd is not present. It will cause a kernel dead loop in the following scenaro: 1.) pmd entry is not present. 2.) the page fault occurs: ... hugetlb_fault() --> hugetlb_no_page() --> set_huge_pte_at() 3.) set_huge_pte_at() will only set the first PMD entry, since the find_num_contig just return 1 in this case. So the PMD entries are all empty except the first one. 4.) when kernel accesses the address mapped by the second PMD entry, a new page fault occurs: ... hugetlb_fault() --> huge_ptep_set_access_flags() The second PMD entry is still empty now. 5.) When the kernel returns, the access will cause a page fault again. The kernel will run like the "4)" above. We will see a dead loop since here. The dead loop is caught in the 32M hugetlb page (2M PMD + Contiguous bit). This patch removes wrong pmd check, and fixes this dead loop. This patch also removes the redundant checks for PGD/PUD in the find_num_contig(). Acked-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Huang Shijie <shijie.huang@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-11-09arm64: Fix typo in add_default_hugepagesz() for 64K pagesCatalin Marinas
The default hugepage size when 64K pages are enabled is set to 2MB using the contiguous PTE bit. The add_default_hugepagesz(), however, uses CONT_PMD_SHIFT instead of CONT_PTE_SHIFT. There is no functional change since the values are the same. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-05-31Revert "arm64: hugetlb: partial revert of 66b3923a1a0f"Will Deacon
This reverts commit ff7925848b50050732ac0401e0acf27e8b241d7b. Now that the contiguous-hint hugetlb regression has been debugged and fixed upstream by 66ee95d16a7f ("mm: exclude HugeTLB pages from THP page_mapped() logic"), we can revert the previous partial revert of this feature. Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-05-19arm64: mm: use hugetlb_bad_size()Vaishali Thakkar
Update setup_hugepagesz() to call hugetlb_bad_size() when unsupported hugepage size is found. Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Dominik Dingel <dingel@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-17mm: cleanup *pte_alloc* interfacesKirill A. Shutemov
There are few things about *pte_alloc*() helpers worth cleaning up: - 'vma' argument is unused, let's drop it; - most __pte_alloc() callers do speculative check for pmd_none(), before taking ptl: let's introduce pte_alloc() macro which does the check. The only direct user of __pte_alloc left is userfaultfd, which has different expectation about atomicity wrt pmd. - pte_alloc_map() and pte_alloc_map_lock() are redefined using pte_alloc(). [sudeep.holla@arm.com: fix build for arm64 hugetlbpage] [sfr@canb.auug.org.au: fix arch/arm/mm/mmu.c some more] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-09arm64: hugetlb: partial revert of 66b3923a1a0fWill Deacon
Commit 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit") introduced support for huge pages using the contiguous bit in the PTE as opposed to block mappings, which may be slightly unwieldy (512M) in 64k page configurations. Unfortunately, this support has resulted in some late regressions when running the libhugetlbfs test suite with 64k pages and CONFIG_DEBUG_VM as a result of a BUG: | readback (2M: 64): ------------[ cut here ]------------ | kernel BUG at fs/hugetlbfs/inode.c:446! | Internal error: Oops - BUG: 0 [#1] SMP | Modules linked in: | CPU: 7 PID: 1448 Comm: readback Not tainted 4.5.0-rc7 #148 | Hardware name: linux,dummy-virt (DT) | task: fffffe0040964b00 ti: fffffe00c2668000 task.ti: fffffe00c2668000 | PC is at remove_inode_hugepages+0x44c/0x480 | LR is at remove_inode_hugepages+0x264/0x480 Rather than revert the entire patch, simply avoid advertising the contiguous huge page sizes for now while people are actively working on a fix. This patch can then be reverted once things have been sorted out. Cc: David Woods <dwoods@ezchip.com> Reported-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-21arm64: hugetlb: add support for PTE contiguous bitDavid Woods
The arm64 MMU supports a Contiguous bit which is a hint that the TTE is one of a set of contiguous entries which can be cached in a single TLB entry. Supporting this bit adds new intermediate huge page sizes. The set of huge page sizes available depends on the base page size. Without using contiguous pages the huge page sizes are as follows. 4KB: 2MB 1GB 64KB: 512MB With a 4KB granule, the contiguous bit groups together sets of 16 pages and with a 64KB granule it groups sets of 32 pages. This enables two new huge page sizes in each case, so that the full set of available sizes is as follows. 4KB: 64KB 2MB 32MB 1GB 64KB: 2MB 512MB 16GB If a 16KB granule is used then the contiguous bit groups 128 pages at the PTE level and 32 pages at the PMD level. If the base page size is set to 64KB then 2MB pages are enabled by default. It is possible in the future to make 2MB the default huge page size for both 4KB and 64KB granules. Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com> Reviewed-by: Steve Capper <steve.capper@linaro.org> Signed-off-by: David Woods <dwoods@ezchip.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: hugetlb: remove paragraph about writing to FSFJisheng Zhang
Remove paragraph about writing to the Free Software Foundation's mailing address from GPL notice. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-03Merge tag 'arm64-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes (and cleanups) from Catalin Marinas: "Various arm64 fixes: - suspicious RCU usage warning - BPF (out of bounds array read and endianness conversion) - perf (of_node usage after of_node_put, cpu_pmu->plat_device assignment) - huge pmd/pud check for value 0 - rate-limiting should only take unhandled signals into account Clean-up: - incorrect use of pgprot_t type - unused header include - __init annotation to arm_cpuidle_init - pr_debug instead of pr_error for disabled GICC entries in ACPI/MADT" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: Fix show_unhandled_signal_ratelimited usage ARM64 / SMP: Switch pr_err() to pr_debug() for disabled GICC entry arm64: cpuidle: add __init section marker to arm_cpuidle_init arm64: Don't report clear pmds and puds as huge arm64: perf: fix unassigned cpu_pmu->plat_device when probing PMU PPIs arm64: perf: Don't use of_node after putting it arm64: fix incorrect use of pgprot_t variable arm64/hw_breakpoint.c: remove unnecessary header arm64: bpf: fix endianness conversion bugs arm64: bpf: fix out-of-bounds read in bpf2a64_offset() ARM64: smp: Fix suspicious RCU usage with ipi tracepoints
2015-07-01arm64: Don't report clear pmds and puds as hugeChristoffer Dall
The current pmd_huge() and pud_huge() functions simply check if the table bit is not set and reports the entries as huge in that case. This is counter-intuitive as a clear pmd/pud cannot also be a huge pmd/pud, and it is inconsistent with at least arm and x86. To prevent others from making the same mistake as me in looking at code that calls these functions and to fix an issue with KVM on arm64 that causes memory corruption due to incorrect page reference counting resulting from this mistake, let's change the behavior. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Steve Capper <steve.capper@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Fixes: 084bd29810a5 ("ARM64: mm: HugeTLB support.") Cc: <stable@vger.kernel.org> # 3.11+ Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-24mm/hugetlb: reduce arch dependent code about huge_pmd_unshareZhang Zhen
Currently we have many duplicates in definitions of huge_pmd_unshare. In all architectures this function just returns 0 when CONFIG_ARCH_WANT_HUGE_PMD_SHARE is N. This patch puts the default implementation in mm/hugetlb.c and lets these architectures use the common code. Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: David Rientjes <rientjes@google.com> Cc: James Yang <James.Yang@freescale.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11mm/hugetlb: reduce arch dependent code around follow_huge_*Naoya Horiguchi
Currently we have many duplicates in definitions around follow_huge_addr(), follow_huge_pmd(), and follow_huge_pud(), so this patch tries to remove the m. The basic idea is to put the default implementation for these functions in mm/hugetlb.c as weak symbols (regardless of CONFIG_ARCH_WANT_GENERAL_HUGETL B), and to implement arch-specific code only when the arch needs it. For follow_huge_addr(), only powerpc and ia64 have their own implementation, and in all other architectures this function just returns ERR_PTR(-EINVAL). So this patch sets returning ERR_PTR(-EINVAL) as default. As for follow_huge_(pmd|pud)(), if (pmd|pud)_huge() is implemented to always return 0 in your architecture (like in ia64 or sparc,) it's never called (the callsite is optimized away) no matter how implemented it is. So in such architectures, we don't need arch-specific implementation. In some architecture (like mips, s390 and tile,) their current arch-specific follow_huge_(pmd|pud)() are effectively identical with the common code, so this patch lets these architecture use the common code. One exception is metag, where pmd_huge() could return non-zero but it expects follow_huge_pmd() to always return NULL. This means that we need arch-specific implementation which returns NULL. This behavior looks strange to me (because non-zero pmd_huge() implies that the architecture supports PMD-based hugepage, so follow_huge_pmd() can/should return some relevant value,) but that's beyond this cleanup patch, so let's keep it. Justification of non-trivial changes: - in s390, follow_huge_pmd() checks !MACHINE_HAS_HPAGE at first, and this patch removes the check. This is OK because we can assume MACHINE_HAS_HPAGE is true when follow_huge_pmd() can be called (note that pmd_huge() has the same check and always returns 0 for !MACHINE_HAS_HPAGE.) - in s390 and mips, we use HPAGE_MASK instead of PMD_MASK as done in common code. This patch forces these archs use PMD_MASK, but it's OK because they are identical in both archs. In s390, both of HPAGE_SHIFT and PMD_SHIFT are 20. In mips, HPAGE_SHIFT is defined as (PAGE_SHIFT + PAGE_SHIFT - 3) and PMD_SHIFT is define as (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3), but PTE_ORDER is always 0, so these are identical. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Steve Capper <steve.capper@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04hugetlb: restrict hugepage_migration_support() to x86_64Naoya Horiguchi
Currently hugepage migration is available for all archs which support pmd-level hugepage, but testing is done only for x86_64 and there're bugs for other archs. So to avoid breaking such archs, this patch limits the availability strictly to x86_64 until developers of other archs get interested in enabling this feature. Simply disabling hugepage migration on non-x86_64 archs is not enough to fix the reported problem where sys_move_pages() hits the BUG_ON() in follow_page(FOLL_GET), so let's fix this by checking if hugepage migration is supported in vma_migratable(). Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Hugh Dickins <hughd@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>