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2020-06-05kmap: consolidate kmap_prot definitionsIra Weiny1-0/+4
Most architectures define kmap_prot to be PAGE_KERNEL. Let sparc and xtensa define there own and define PAGE_KERNEL as the default if not overridden. [akpm@linux-foundation.org: coding style fixes] Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian König <christian.koenig@amd.com> Cc: Chris Zankel <chris@zankel.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200507150004.1423069-16-ira.weiny@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-05parisc/kmap: remove duplicate kmap codeIra Weiny1-3/+7
parisc reimplements the kmap calls except to flush its dcache. This is arguably an abuse of kmap but regardless it is messy and confusing. Remove the duplicate code and have parisc define ARCH_HAS_FLUSH_ON_KUNMAP for a kunmap_flush_on_unmap() architecture specific call to flush the cache. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian König <christian.koenig@amd.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chris Zankel <chris@zankel.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200507150004.1423069-14-ira.weiny@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-05arch/kmap: define kmap_atomic_prot() for all arch'sIra Weiny1-3/+4
To support kmap_atomic_prot(), all architectures need to support protections passed to their kmap_atomic_high() function. Pass protections into kmap_atomic_high() and change the name to kmap_atomic_high_prot() to match. Then define kmap_atomic_prot() as a core function which calls kmap_atomic_high_prot() when needed. Finally, redefine kmap_atomic() as a wrapper of kmap_atomic_prot() with the default kmap_prot exported by the architectures. Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian König <christian.koenig@amd.com> Cc: Chris Zankel <chris@zankel.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200507150004.1423069-11-ira.weiny@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-05arch/kunmap_atomic: consolidate duplicate codeIra Weiny1-4/+9
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 <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian König <christian.koenig@amd.com> Cc: Chris Zankel <chris@zankel.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Guenter Roeck <linux@roeck-us.net> Link: http://lkml.kernel.org/r/20200507150004.1423069-8-ira.weiny@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-05arch/kmap_atomic: consolidate duplicate codeIra Weiny1-0/+23
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 <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian König <christian.koenig@amd.com> Cc: Chris Zankel <chris@zankel.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200507150004.1423069-7-ira.weiny@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-05arch/kunmap: remove duplicate kunmap implementationsIra Weiny1-0/+14
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 <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian König <christian.koenig@amd.com> Cc: Chris Zankel <chris@zankel.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200507150004.1423069-5-ira.weiny@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-05arch/kmap: remove redundant arch specific kmapsIra Weiny1-0/+18
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 <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian König <christian.koenig@amd.com> Cc: Chris Zankel <chris@zankel.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200507150004.1423069-4-ira.weiny@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28mm: convert totalram_pages and totalhigh_pages variables to atomicArun KS1-2/+26
totalram_pages and totalhigh_pages are made static inline function. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes better to remove the lock and convert variables to atomic, with preventing poteintial store-to-read tearing as a bonus. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Suggested-by: Michal Hocko <mhocko@suse.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-18mm: Allow arch code to override copy_highpage()Khalid Aziz1-0/+4
Some architectures can support metadata for memory pages and when a page is copied, its metadata must also be copied. Sparc processors from M7 onwards support metadata for memory pages. This metadata provides tag based protection for access to memory pages. To maintain this protection, the tag data must be copied to the new page when a page is migrated across NUMA nodes. This patch allows arch specific code to override default copy_highpage() and copy metadata along with page data upon migration. Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com> Cc: Khalid Aziz <khalid@gonehiking.org> Reviewed-by: Anthony Yznaga <anthony.yznaga@oracle.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-10kmap_atomic_to_page() has no users, remove itNicolas Pitre1-1/+0
Removal started in commit 5bbeed12bdc3 ("sparc32: drop unused kmap_atomic_to_page"). Let's do it across the whole tree. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-19sched/preempt, mm/kmap: Explicitly disable/enable preemption in kmap_atomic_*David Hildenbrand1-0/+2
The existing code relies on pagefault_disable() implicitly disabling preemption, so that no schedule will happen between kmap_atomic() and kunmap_atomic(). Let's make this explicit, to prepare for pagefault_disable() not touching preemption anymore. Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Link: http://lkml.kernel.org/r/1431359540-32227-5-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-07mm: BUG when __kmap_atomic_idx equals KM_TYPE_NRChintan Pandya1-1/+1
__kmap_atomic_idx is per_cpu variable. Each CPU can use KM_TYPE_NR entries from FIXMAP i.e. from 0 to KM_TYPE_NR - 1. Allowing __kmap_atomic_idx to over- shoot to KM_TYPE_NR can mess up with next CPU's 0th entry which is a bug. Hence BUG_ON if __kmap_atomic_idx >= KM_TYPE_NR. Fix the off-by-on in this test. Signed-off-by: Chintan Pandya <cpandya@codeaurora.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: remove unused memclear_highpage_flush()Kirill A. Shutemov1-6/+0
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: add support for direct_IO to highmem pagesMel Gorman1-0/+7
The patch "mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages" added support for using direct_IO to write swap pages but it is insufficient for highmem pages. To support highmem pages, this patch kmaps() the page before calling the direct_IO() handler. As direct_IO deals with virtual addresses an additional helper is necessary for get_kernel_pages() to lookup the struct page for a kmap virtual address. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-24highmem: remove the deprecated form of kmap_atomicCong Wang1-40/+1
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-24Merge tag 'bug-for-3.4' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull <linux/bug.h> cleanup from Paul Gortmaker: "The changes shown here are to unify linux's BUG support under the one <linux/bug.h> file. Due to historical reasons, we have some BUG code in bug.h and some in kernel.h -- i.e. the support for BUILD_BUG in linux/kernel.h predates the addition of linux/bug.h, but old code in kernel.h wasn't moved to bug.h at that time. As a band-aid, kernel.h was including <asm/bug.h> to pseudo link them. This has caused confusion[1] and general yuck/WTF[2] reactions. Here is an example that violates the principle of least surprise: CC lib/string.o lib/string.c: In function 'strlcat': lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON' make[2]: *** [lib/string.o] Error 1 $ $ grep linux/bug.h lib/string.c #include <linux/bug.h> $ We've included <linux/bug.h> for the BUG infrastructure and yet we still get a compile fail! [We've not kernel.h for BUILD_BUG_ON.] Ugh - very confusing for someone who is new to kernel development. With the above in mind, the goals of this changeset are: 1) find and fix any include/*.h files that were relying on the implicit presence of BUG code. 2) find and fix any C files that were consuming kernel.h and hence relying on implicitly getting some/all BUG code. 3) Move the BUG related code living in kernel.h to <linux/bug.h> 4) remove the asm/bug.h from kernel.h to finally break the chain. During development, the order was more like 3-4, build-test, 1-2. But to ensure that git history for bisect doesn't get needless build failures introduced, the commits have been reorderd to fix the problem areas in advance. [1] https://lkml.org/lkml/2012/1/3/90 [2] https://lkml.org/lkml/2012/1/17/414" Fix up conflicts (new radeon file, reiserfs header cleanups) as per Paul and linux-next. * tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: kernel.h: doesn't explicitly use bug.h, so don't include it. bug: consolidate BUILD_BUG_ON with other bug code BUG: headers with BUG/BUG_ON etc. need linux/bug.h bug.h: add include of it to various implicit C users lib: fix implicit users of kernel.h for TAINT_WARN spinlock: macroize assert_spin_locked to avoid bug.h dependency x86: relocate get/set debugreg fcns to include/asm/debugreg.
2012-03-20highmem: kill all __kmap_atomic()Cong Wang1-8/+3
[swarren@nvidia.com: highmem: Fix ARM build break due to __kmap_atomic rename] Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-20include/linux/highmem.h: remove the second argument of k[un]map_atomic()Cong Wang1-14/+14
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-20highmem: mark k[un]map_atomic() with two arguments as deprecatedCong Wang1-6/+46
For backward compatibility, we still keep the deprecated form, and will warn the users if they still use the deprecated one, like this: drivers/block/drbd/drbd_bitmap.c: In function ‘bm_page_io_async’: drivers/block/drbd/drbd_bitmap.c:973:3: warning: ‘kmap_atomic_deprecated’ is deprecated (declared at /home/wangcong/linux-2.6/include/linux/highmem.h:124) drivers/block/drbd/drbd_bitmap.c:977:3: warning: ‘kunmap_atomic_deprecated’ is deprecated (declared at /home/wangcong/linux-2.6/include/linux/highmem.h:144) Thanks to Nick Bowler for the cpp trick! Cc: Cesar Eduardo Barros <cesarb@cesarb.net> Cc: Nick Bowler <nbowler@elliptictech.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-05BUG: headers with BUG/BUG_ON etc. need linux/bug.hPaul Gortmaker1-0/+1
If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any other BUG variant in a static inline (i.e. not in a #define) then that header really should be including <linux/bug.h> and not just expecting it to be implicitly present. We can make this change risk-free, since if the files using these headers didn't have exposure to linux/bug.h already, they would have been causing compile failures/warnings. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2010-12-17highmem: Use this_cpu_xx_return() operationsChristoph Lameter1-5/+8
Use this_cpu operations to optimize access primitives for highmem. The main effect is the avoidance of address calculations through the use of a segment prefix. V3->V4 - kmap_atomic_idx: Do not return a value. - Use __this_cpu_dec without HIGHMEM_DEBUG Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Catalin Marinas <catalin.marinas@arm.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-11-12include/linux/highmem.h needs hardirq.hCatalin Marinas1-0/+1
Commit 3e4d3af501cc ("mm: stack based kmap_atomic()") introduced the kmap_atomic_idx_push() function which warns on in_irq() with CONFIG_DEBUG_HIGHMEM enabled. This patch includes linux/hardirq.h for the in_irq definition. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28mm: fix race in kunmap_atomic()Peter Zijlstra1-0/+5
Christoph reported a nice splat which illustrated a race in the new stack based kmap_atomic implementation. The problem is that we pop our stack slot before we're completely done resetting its state -- in particular clearing the PTE (sometimes that's CONFIG_DEBUG_HIGHMEM). If an interrupt happens before we actually clear the PTE used for the last slot, that interrupt can reuse the slot in a dirty state, which triggers a BUG in kmap_atomic(). Fix this by introducing kmap_atomic_idx() which reports the current slot index without actually releasing it and use that to find the PTE and delay the _pop() until after we're completely done. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reported-by: Christoph Hellwig <hch@infradead.org> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28mm,x86: fix kmap_atomic_push vs ioremap_32.cPeter Zijlstra1-21/+25
It appears i386 uses kmap_atomic infrastructure regardless of CONFIG_HIGHMEM which results in a compile error when highmem is disabled. Cure this by providing the needed few bits for both CONFIG_HIGHMEM and CONFIG_X86_32. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reported-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27mm: stack based kmap_atomic()Peter Zijlstra1-22/+39
Keep the current interface but ignore the KM_type and use a stack based approach. The advantage is that we get rid of crappy code like: #define __KM_PTE \ (in_nmi() ? KM_NMI_PTE : \ in_irq() ? KM_IRQ_PTE : \ KM_PTE0) and in general can stop worrying about what context we're in and what kmap slots might be appropriate for that. The downside is that FRV kmap_atomic() gets more expensive. For now we use a CPP trick suggested by Andrew: #define kmap_atomic(page, args...) __kmap_atomic(page) to avoid having to touch all kmap_atomic() users in a single patch. [ not compiled on: - mn10300: the arch doesn't actually build with highmem to begin with ] [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c] Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Airlie <airlied@linux.ie> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27mm: strictly nested kmap_atomic()Peter Zijlstra1-2/+2
Ensure kmap_atomic() usage is strictly nested Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10gcc-4.6: mm: fix unused but set warningsAndi Kleen1-1/+5
No real bugs, just some dead code and some fixups. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10kmap_atomic: make kunmap_atomic() harder to misuseCesar Eduardo Barros1-1/+9
kunmap_atomic() is currently at level -4 on Rusty's "Hard To Misuse" list[1] ("Follow common convention and you'll get it wrong"), except in some architectures when CONFIG_DEBUG_HIGHMEM is set[2][3]. kunmap() takes a pointer to a struct page; kunmap_atomic(), however, takes takes a pointer to within the page itself. This seems to once in a while trip people up (the convention they are following is the one from kunmap()). Make it much harder to misuse, by moving it to level 9 on Rusty's list[4] ("The compiler/linker won't let you get it wrong"). This is done by refusing to build if the type of its first argument is a pointer to a struct page. The real kunmap_atomic() is renamed to kunmap_atomic_notypecheck() (which is what you would call in case for some strange reason calling it with a pointer to a struct page is not incorrect in your code). The previous version of this patch was compile tested on x86-64. [1] http://ozlabs.org/~rusty/index.cgi/tech/2008-04-01.html [2] In these cases, it is at level 5, "Do it right or it will always break at runtime." [3] At least mips and powerpc look very similar, and sparc also seems to share a common ancestor with both; there seems to be quite some degree of copy-and-paste coding here. The include/asm/highmem.h file for these three archs mention x86 CPUs at its top. [4] http://ozlabs.org/~rusty/index.cgi/tech/2008-03-30.html [5] As an aside, could someone tell me why mn10300 uses unsigned long as the first parameter of kunmap_atomic() instead of void *? Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Cc: Russell King <linux@arm.linux.org.uk> (arch/arm) Cc: Ralf Baechle <ralf@linux-mips.org> (arch/mips) Cc: David Howells <dhowells@redhat.com> (arch/frv, arch/mn10300) Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> (arch/mn10300) Cc: Kyle McMartin <kyle@mcmartin.ca> (arch/parisc) Cc: Helge Deller <deller@gmx.de> (arch/parisc) Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> (arch/parisc) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> (arch/powerpc) Cc: Paul Mackerras <paulus@samba.org> (arch/powerpc) Cc: "David S. Miller" <davem@davemloft.net> (arch/sparc) Cc: Thomas Gleixner <tglx@linutronix.de> (arch/x86) Cc: Ingo Molnar <mingo@redhat.com> (arch/x86) Cc: "H. Peter Anvin" <hpa@zytor.com> (arch/x86) Cc: Arnd Bergmann <arnd@arndb.de> (include/asm-generic) Cc: Rusty Russell <rusty@rustcorp.com.au> ("Hard To Misuse" list) Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25highmem: remove unneeded #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT for ↵Akinobu Mita1-1/+1
debug_kmap_atomic() In f4112de6b679d84bd9b9681c7504be7bdfb7c7d5 ("mm: introduce debug_kmap_atomic") I said that debug_kmap_atomic() needs CONFIG_TRACE_IRQFLAGS_SUPPORT. It was wrong. (I thought irqs_disabled() is only available when the architecture has CONFIG_TRACE_IRQFLAGS_SUPPORT) Remove the #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT check to enable kmap_atomic() debugging for the architectures which do not have CONFIG_TRACE_IRQFLAGS_SUPPORT. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-02-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/xfs-viptLinus Torvalds1-0/+6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/xfs-vipt: xfs: fix xfs to work with Virtually Indexed architectures sh: add mm API for DMA to vmalloc/vmap areas arm: add mm API for DMA to vmalloc/vmap areas parisc: add mm API for DMA to vmalloc/vmap areas mm: add coherence API for DMA to vmalloc/vmap areas
2010-01-25mm: add coherence API for DMA to vmalloc/vmap areasJames Bottomley1-0/+6
On Virtually Indexed architectures (which don't do automatic alias resolution in their caches), we have to flush via the correct virtual address to prepare pages for DMA. On some architectures (like arm) we cannot prevent the CPU from doing data movein along the alias (and thus giving stale read data), so we not only have to introduce a flush API to push dirty cache lines out, but also an invalidate API to kill inconsistent cache lines that may have moved in before DMA changed the data Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-01-11mm: make totalhigh_pages unsigned longAndreas Fenkart1-1/+1
Makes it consistent with the extern declaration, used when CONFIG_HIGHMEM is set Removes redundant casts in printout messages Signed-off-by: Andreas Fenkart <andreas.fenkart@streamunlimited.com> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-17mm: check the argument of kunmap on architectures without highmemMatthew Wilcox1-1/+3
If you're using a non-highmem architecture, passing an argument with the wrong type to kunmap() doesn't give you a warning because the ifdef doesn't check the type. Using a static inline function solves the problem nicely. Reported-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-03Fix highmem PPC build failureKumar Gala1-15/+14
Commit f4112de6b679d84bd9b9681c7504be7bdfb7c7d5 ("mm: introduce debug_kmap_atomic") broke PPC builds with CONFIG_HIGHMEM=y: CC init/main.o In file included from include/linux/highmem.h:25, from include/linux/pagemap.h:11, from include/linux/mempolicy.h:63, from init/main.c:53: arch/powerpc/include/asm/highmem.h: In function 'kmap_atomic_prot': arch/powerpc/include/asm/highmem.h:98: error: implicit declaration of function 'debug_kmap_atomic' In file included from include/linux/pagemap.h:11, from include/linux/mempolicy.h:63, from init/main.c:53: include/linux/highmem.h: At top level: include/linux/highmem.h:196: warning: conflicting types for 'debug_kmap_atomic' include/linux/highmem.h:196: error: static declaration of 'debug_kmap_atomic' follows non-static declaration include/asm/highmem.h:98: error: previous implicit declaration of 'debug_kmap_atomic' was here make[1]: *** [init/main.o] Error 1 make: *** [init] Error 2 Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Acked-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: introduce debug_kmap_atomicAkinobu Mita1-0/+12
x86 has debug_kmap_atomic_prot() which is error checking function for kmap_atomic. It is usefull for the other architectures, although it needs CONFIG_TRACE_IRQFLAGS_SUPPORT. This patch exposes it to the other architectures. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-28Allow architectures to override copy_user_highpage()Russell King1-0/+2
With aliasing VIPT cache support, the ARM implementation of clear_user_page() and copy_user_page() sets up a temporary kernel space mapping such that we have the same cache colour as the userspace page. This avoids having to consider any userspace aliases from this operation. However, when highmem is enabled, kmap_atomic() have to setup mappings. The copy_user_highpage() and clear_user_highpage() call these functions before delegating the copies to copy_user_page() and clear_user_page(). The effect of this is that each of the *_user_highpage() functions setup their own kmap mapping, followed by the *_user_page() functions setting up another mapping. This is rather wasteful. Thankfully, copy_user_highpage() can be overriden by architectures by defining __HAVE_ARCH_COPY_USER_HIGHPAGE. However, replacement of clear_user_highpage() is more difficult because its inline definition is not conditional. It seems that you're expected to define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and provide a replacement __alloc_zeroed_user_highpage() implementation instead. The allocation itself is fine, so we don't want to override that. What we really want to do is to override clear_user_highpage() with our own version which doesn't kmap_atomic() unnecessarily. Other VIPT architectures (PARISC and SH) would also like to override this function as well. Acked-by: Hugh Dickins <hugh@veritas.com> Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-02-05mm: fix PageUptodate data raceNick Piggin1-4/+0
After running SetPageUptodate, preceeding stores to the page contents to actually bring it uptodate may not be ordered with the store to set the page uptodate. Therefore, another CPU which checks PageUptodate is true, then reads the page contents can get stale data. Fix this by having an smp_wmb before SetPageUptodate, and smp_rmb after PageUptodate. Many places that test PageUptodate, do so with the page locked, and this would be enough to ensure memory ordering in those places if SetPageUptodate were only called while the page is locked. Unfortunately that is not always the case for some filesystems, but it could be an idea for the future. Also bring the handling of anonymous page uptodateness in line with that of file backed page management, by marking anon pages as uptodate when they _are_ uptodate, rather than when our implementation requires that they be marked as such. Doing allows us to get rid of the smp_wmb's in the page copying functions, which were especially added for anonymous pages for an analogous memory ordering problem. Both file and anonymous pages are handled with the same barriers. FAQ: Q. Why not do this in flush_dcache_page? A. Firstly, flush_dcache_page handles only one side (the smb side) of the ordering protocol; we'd still need smp_rmb somewhere. Secondly, hiding away memory barriers in a completely unrelated function is nasty; at least in the PageUptodate macros, they are located together with (half) the operations involved in the ordering. Thirdly, the smp_wmb is only required when first bringing the page uptodate, wheras flush_dcache_page should be called each time it is written to through the kernel mapping. It is logically the wrong place to put it. Q. Why does this increase my text size / reduce my performance / etc. A. Because it is adding the necessary instructions to eliminate the data-race. Q. Can it be improved? A. Yes, eg. if you were to create a rule that all SetPageUptodate operations run under the page lock, we could avoid the smp_rmb places where PageUptodate is queried under the page lock. Requires audit of all filesystems and at least some would need reworking. That's great you're interested, I'm eagerly awaiting your patches. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05Pagecache zeroing: zero_user_segment, zero_user_segments and zero_userChristoph Lameter1-18/+30
Simplify page cache zeroing of segments of pages through 3 functions zero_user_segments(page, start1, end1, start2, end2) Zeros two segments of the page. It takes the position where to start and end the zeroing which avoids length calculations and makes code clearer. zero_user_segment(page, start, end) Same for a single segment. zero_user(page, start, length) Length variant for the case where we know the length. We remove the zero_user_page macro. Issues: 1. Its a macro. Inline functions are preferable. 2. The KM_USER0 macro is only defined for HIGHMEM. Having to treat this special case everywhere makes the code needlessly complex. The parameter for zeroing is always KM_USER0 except in one single case that we open code. Avoiding KM_USER0 makes a lot of code not having to be dealing with the special casing for HIGHMEM anymore. Dealing with kmap is only necessary for HIGHMEM configurations. In those configurations we use KM_USER0 like we do for a series of other functions defined in highmem.h. Since KM_USER0 is depends on HIGHMEM the existing zero_user_page function could not be a macro. zero_user_* functions introduced here can be be inline because that constant is not used when these functions are called. Also extract the flushing of the caches to be outside of the kmap. [akpm@linux-foundation.org: fix nfs and ntfs build] [akpm@linux-foundation.org: fix ntfs build some more] Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Steven French <sfrench@us.ibm.com> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: <linux-ext4@vger.kernel.org> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Anton Altaparmakov <aia21@cantab.net> Cc: Mark Fasheh <mark.fasheh@oracle.com> Cc: David Chinner <dgc@sgi.com> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: Steven French <sfrench@us.ibm.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19Remove alloc_zeroed_user_highpage()Mel Gorman1-15/+0
alloc_zeroed_user_highpage() has no in-tree users and it is not exported. As it is not exported, it can simply be removed. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17Add __GFP_MOVABLE for callers to flag allocations from high memory that may ↵Mel Gorman1-2/+49
be migrated It is often known at allocation time whether a page may be migrated or not. This patch adds a flag called __GFP_MOVABLE and a new mask called GFP_HIGH_MOVABLE. Allocations using the __GFP_MOVABLE can be either migrated using the page migration mechanism or reclaimed by syncing with backing storage and discarding. An API function very similar to alloc_zeroed_user_highpage() is added for __GFP_MOVABLE allocations called alloc_zeroed_user_highpage_movable(). The flags used by alloc_zeroed_user_highpage() are not changed because it would change the semantics of an existing API. After this patch is applied there are no in-kernel users of alloc_zeroed_user_highpage() so it probably should be marked deprecated if this patch is merged. Note that this patch includes a minor cleanup to the use of __GFP_ZERO in shmem.c to keep all flag modifications to inode->mapping in the shmem_dir_alloc() helper function. This clean-up suggestion is courtesy of Hugh Dickens. Additional credit goes to Christoph Lameter and Linus Torvalds for shaping the concept. Credit to Hugh Dickens for catching issues with shmem swap vector and ramfs allocations. [akpm@linux-foundation.org: build fix] [hugh@veritas.com: __GFP_ZERO cleanup] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09fs: deprecate memclear_highpage_flushNate Diller1-2/+1
Now that all the in-tree users are converted over to zero_user_page(), deprecate the old memclear_highpage_flush() call. Signed-off-by: Nate Diller <nate.diller@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09fs: convert core functions to zero_user_pageNate Diller1-9/+19
It's very common for file systems to need to zero part or all of a page, the simplist way is just to use kmap_atomic() and memset(). There's actually a library function in include/linux/highmem.h that does exactly that, but it's confusingly named memclear_highpage_flush(), which is descriptive of *how* it does the work rather than what the *purpose* is. So this patchset renames the function to zero_user_page(), and calls it from the various places that currently open code it. This first patch introduces the new function call, and converts all the core kernel callsites, both the open-coded ones and the old memclear_highpage_flush() ones. Following this patch is a series of conversions for each file system individually, per AKPM, and finally a patch deprecating the old call. The diffstat below shows the entire patchset. [akpm@linux-foundation.org: fix a few things] Signed-off-by: Nate Diller <nate.diller@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-06Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6Linus Torvalds1-0/+5
* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6: (231 commits) [PATCH] i386: Don't delete cpu_devs data to identify different x86 types in late_initcall [PATCH] i386: type may be unused [PATCH] i386: Some additional chipset register values validation. [PATCH] i386: Add missing !X86_PAE dependincy to the 2G/2G split. [PATCH] x86-64: Don't exclude asm-offsets.c in Documentation/dontdiff [PATCH] i386: avoid redundant preempt_disable in __unlazy_fpu [PATCH] i386: white space fixes in i387.h [PATCH] i386: Drop noisy e820 debugging printks [PATCH] x86-64: Fix allnoconfig error in genapic_flat.c [PATCH] x86-64: Shut up warnings for vfat compat ioctls on other file systems [PATCH] x86-64: Share identical video.S between i386 and x86-64 [PATCH] x86-64: Remove CONFIG_REORDER [PATCH] x86-64: Print type and size correctly for unknown compat ioctls [PATCH] i386: Remove copy_*_user BUG_ONs for (size < 0) [PATCH] i386: Little cleanups in smpboot.c [PATCH] x86-64: Don't enable NUMA for a single node in K8 NUMA scanning [PATCH] x86: Use RDTSCP for synchronous get_cycles if possible [PATCH] i386: Add X86_FEATURE_RDTSCP [PATCH] i386: Implement X86_FEATURE_SYNC_RDTSC on i386 [PATCH] i386: Implement alternative_io for i386 ... Fix up trivial conflict in include/linux/highmem.h manually. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-05Convert non-highmem kmap_atomic() to static inline functionGeert Uytterhoeven1-2/+8
Convert kmap_atomic() in the non-highmem case from a macro to a static inline function, for better type-checking and the ability to pass void pointers instead of struct page pointers. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-02[PATCH] i386: PARAVIRT: add kmap_atomic_pte for mapping highpte pagesJeremy Fitzhardinge1-0/+6
Xen and VMI both have special requirements when mapping a highmem pte page into the kernel address space. These can be dealt with by adding a new kmap_atomic_pte() function for mapping highptes, and hooking it into the paravirt_ops infrastructure. Xen specifically wants to map the pte page RO, so this patch exposes a helper function, kmap_atomic_prot, which maps the page with the specified page protections. This also adds a kmap_flush_unused() function to clear out the cached kmap mappings. Xen needs this to clear out any potential stray RW mappings of pages which will become part of a pagetable. [ Zach - vmi.c will need some attention after this patch. It wasn't immediately obvious to me what needs to be done. ] Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Zachary Amsden <zach@vmware.com>
2007-01-08[ARM] pass vma for flush_anon_page()Russell King1-1/+1
Since get_user_pages() may be used with processes other than the current process and calls flush_anon_page(), flush_anon_page() has to cope in some way with non-current processes. It may not be appropriate, or even desirable to flush a region of virtual memory cache in the current process when that is different to the process that we want the flush to occur for. Therefore, pass the vma into flush_anon_page() so that the architecture can work out whether the 'vmaddr' is for the current process or not. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-12-13[PATCH] Pass vma argument to copy_user_highpage().Atsushi Nemoto1-1/+2
To allow a more effective copy_user_highpage() on certain architectures, a vma argument is added to the function and cow_user_page() allowing the implementation of these functions to check for the VM_EXEC bit. The main part of this patch was originally written by Ralf Baechle; Atushi Nemoto did the the debugging. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-13[PATCH] Fix COW D-cache aliasing on forkAtsushi Nemoto1-0/+4
Problem: 1. There is a process containing two thread (T1 and T2). The thread T1 calls fork(). Then dup_mmap() function called on T1 context. static inline int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) ... flush_cache_mm(current->mm); ... /* A */ (write-protect all Copy-On-Write pages) ... /* B */ flush_tlb_mm(current->mm); ... 2. When preemption happens between A and B (or on SMP kernel), the thread T2 can run and modify data on COW pages without page fault (modified data will stay in cache). 3. Some time after fork() completed, the thread T2 may cause a page fault by write-protect on a COW page. 4. Then data of the COW page will be copied to newly allocated physical page (copy_cow_page()). It reads data via kernel mapping. The kernel mapping can have different 'color' with user space mapping of the thread T2 (dcache aliasing). Therefore copy_cow_page() will copy stale data. Then the modified data in cache will be lost. In order to allow architecture code to deal with this problem allow architecture code to override copy_user_highpage() by defining __HAVE_ARCH_COPY_USER_HIGHPAGE in <asm/page.h>. The main part of this patch was originally written by Ralf Baechle; Atushi Nemoto did the the debugging. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] mm: k{,um}map_atomic() vs in_atomic()Peter Zijlstra1-3/+5
Make kmap_atomic/kunmap_atomic denote a pagefault disabled scope. All non trivial implementations already do this anyway. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>