summaryrefslogtreecommitdiffstats
path: root/arch/x86/mm/pageattr.c
AgeCommit message (Collapse)AuthorFilesLines
2016-01-29x86/mm/pat: Avoid truncation when converting cpa->numpages to addressMatt Fleming1-2/+2
There are a couple of nasty truncation bugs lurking in the pageattr code that can be triggered when mapping EFI regions, e.g. when we pass a cpa->pgd pointer. Because cpa->numpages is a 32-bit value, shifting left by PAGE_SHIFT will truncate the resultant address to 32-bits. Viorel-Cătălin managed to trigger this bug on his Dell machine that provides a ~5GB EFI region which requires 1236992 pages to be mapped. When calling populate_pud() the end of the region gets calculated incorrectly in the following buggy expression, end = start + (cpa->numpages << PAGE_SHIFT); And only 188416 pages are mapped. Next, populate_pud() gets invoked for a second time because of the loop in __change_page_attr_set_clr(), only this time no pages get mapped because shifting the remaining number of pages (1048576) by PAGE_SHIFT is zero. At which point the loop in __change_page_attr_set_clr() spins forever because we fail to map progress. Hitting this bug depends very much on the virtual address we pick to map the large region at and how many pages we map on the initial run through the loop. This explains why this issue was only recently hit with the introduction of commit a5caa209ba9c ("x86/efi: Fix boot crash by mapping EFI memmap entries bottom-up at runtime, instead of top-down") It's interesting to note that safe uses of cpa->numpages do exist in the pageattr code. If instead of shifting ->numpages we multiply by PAGE_SIZE, no truncation occurs because PAGE_SIZE is a UL value, and so the result is unsigned long. To avoid surprises when users try to convert very large cpa->numpages values to addresses, change the data type from 'int' to 'unsigned long', thereby making it suitable for shifting by PAGE_SHIFT without any type casting. The alternative would be to make liberal use of casting, but that is far more likely to cause problems in the future when someone adds more code and fails to cast properly; this bug was difficult enough to track down in the first place. Reported-and-tested-by: Viorel-Cătălin Răpițeanu <rapiteanu.catalin@gmail.com> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Link: https://bugzilla.kernel.org/show_bug.cgi?id=110131 Link: http://lkml.kernel.org/r/1454067370-10374-1-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-12x86/mm/pat: Make split_page_count() check for empty levels to fix ↵Dave Jones1-0/+3
/proc/meminfo output In CONFIG_PAGEALLOC_DEBUG=y builds, we disable 2M pages. Unfortunatly when we split up mappings during boot, split_page_count() doesn't take this into account, and starts decrementing an empty direct_pages_count[] level. This results in /proc/meminfo showing crazy things like: DirectMap2M: 18446744073709543424 kB Signed-off-by: Dave Jones <davej@codemonkey.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-08x86/mm: Micro-optimise clflush_cache_range()Chris Wilson1-4/+6
Whilst inspecting the asm for clflush_cache_range() and some perf profiles that required extensive flushing of single cachelines (from part of the intel-gpu-tools GPU benchmarks), we noticed that gcc was reloading boot_cpu_data.x86_clflush_size on every iteration of the loop. We can manually hoist that read which perf regarded as taking ~25% of the function time for a single cacheline flush. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Borislav Petkov <bp@suse.de> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Sai Praneeth <sai.praneeth.prakhya@intel.com> Link: http://lkml.kernel.org/r/1452246933-10890-1-git-send-email-chris@chris-wilson.co.uk Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-11-29x86/mm/pat: Ensure cpa->pfn only contains page frame numbersMatt Fleming1-11/+6
The x86 pageattr code is confused about the data that is stored in cpa->pfn, sometimes it's treated as a page frame number, sometimes it's treated as an unshifted physical address, and in one place it's treated as a pte. The result of this is that the mapping functions do not map the intended physical address. This isn't a problem in practice because most of the addresses we're mapping in the EFI code paths are already mapped in 'trampoline_pgd' and so the pageattr mapping functions don't actually do anything in this case. But when we move to using a separate page table for the EFI runtime this will be an issue. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1448658575-17029-3-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-03Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds1-29/+50
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm changes from Ingo Molnar: "The main changes are: continued PAT work by Toshi Kani, plus a new boot time warning about insecure RWX kernel mappings, by Stephen Smalley. The new CONFIG_DEBUG_WX=y warning is marked default-y if CONFIG_DEBUG_RODATA=y is already eanbled, as a special exception, as these bugs are hard to notice and this check already found several live bugs" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Warn on W^X mappings x86/mm: Fix no-change case in try_preserve_large_page() x86/mm: Fix __split_large_page() to handle large PAT bit x86/mm: Fix try_preserve_large_page() to handle large PAT bit x86/mm: Fix gup_huge_p?d() to handle large PAT bit x86/mm: Fix slow_virt_to_phys() to handle large PAT bit x86/mm: Fix page table dump to show PAT bit x86/asm: Add pud_pgprot() and pmd_pgprot() x86/asm: Fix pud/pmd interfaces to handle large PAT bit x86/asm: Add pud/pmd mask interfaces to handle large PAT bit x86/asm: Move PUD_PAGE macros to page_types.h x86/vdso32: Define PGTABLE_LEVELS to 32bit VDSO
2015-10-27Merge tag 'efi-next' of ↵Ingo Molnar1-3/+6
git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into core/efi Pull EFI fix from Matt Fleming: - Fix a kernel panic by not passing EFI virtual mapping addresses to __pa() in the x86 pageattr code. Since these virtual addreses are not part of the direct mapping or kernel text mapping, passing them to __pa() will trigger a BUG_ON() when CONFIG_DEBUG_VIRTUAL is enabled. (Sai Praneeth Prakhya) Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-25x86/efi: Fix kernel panic when CONFIG_DEBUG_VIRTUAL is enabledSai Praneeth1-3/+6
When CONFIG_DEBUG_VIRTUAL is enabled, all accesses to __pa(address) are monitored to see whether address falls in direct mapping or kernel text mapping (see Documentation/x86/x86_64/mm.txt for details), if it does not, the kernel panics. During 1:1 mapping of EFI runtime services we access virtual addresses which are == physical addresses, thus the 1:1 mapping and these addresses do not fall in either of the above two regions and hence when passed as arguments to __pa() kernel panics as reported by Dave Hansen here https://lkml.kernel.org/r/5462999A.7090706@intel.com. So, before calling __pa() virtual addresses should be validated which results in skipping call to split_page_count() and that should be fine because it is used to keep track of everything *but* 1:1 mappings. Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Reported-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Glenn P Williamson <glenn.p.williamson@intel.com> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2015-09-22x86/mm: Fix no-change case in try_preserve_large_page()Toshi Kani1-1/+1
try_preserve_large_page() checks if new_prot is the same as old_prot. If so, it simply sets do_split to 0, and returns with no-operation. However, old_prot is set as a 4KB pgprot value while new_prot is a large page pgprot value. Now that old_prot is initially set from p?d_pgprot() as a large page pgprot value, fix it by not overwriting old_prot with a 4KB pgprot value. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Konrad Wilk <konrad.wilk@oracle.com> Cc: Robert Elliot <elliott@hpe.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1442514264-12475-12-git-send-email-toshi.kani@hpe.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-22x86/mm: Fix __split_large_page() to handle large PAT bitToshi Kani1-12/+19
__split_large_page() is called from __change_page_attr() to change the mapping attribute by splitting a given large page into smaller pages. This function uses pte_pfn() and pte_pgprot() for PUD/PMD, which do not handle the large PAT bit properly. Fix __split_large_page() by using the corresponding pud/pmd pfn/ pgprot interfaces. Also remove '#ifdef CONFIG_X86_64', which is not necessary. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Konrad Wilk <konrad.wilk@oracle.com> Cc: Robert Elliot <elliott@hpe.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1442514264-12475-11-git-send-email-toshi.kani@hpe.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-22x86/mm: Fix try_preserve_large_page() to handle large PAT bitToshi Kani1-10/+14
try_preserve_large_page() is called from __change_page_attr() to change the mapping attribute of a given large page. This function uses pte_pfn() and pte_pgprot() for PUD/PMD, which do not handle the large PAT bit properly. Fix try_preserve_large_page() by using the corresponding pud/pmd prot/pfn interfaces. Also remove '#ifdef CONFIG_X86_64', which is not necessary. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Konrad Wilk <konrad.wilk@oracle.com> Cc: Robert Elliot <elliott@hpe.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1442514264-12475-10-git-send-email-toshi.kani@hpe.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-22x86/mm: Fix slow_virt_to_phys() to handle large PAT bitToshi Kani1-7/+17
slow_virt_to_phys() calls lookup_address() to obtain *pte and its level. It then calls pte_pfn() to obtain a physical address for any level. However, this physical address is not correct when the large PAT bit is set because pte_pfn() does not mask the large PAT bit properly for PUD/PMD. Fix slow_virt_to_phys() to use pud_pfn() and pmd_pfn() for 1GB and 2MB mapping levels. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Konrad Wilk <konrad.wilk@oracle.com> Cc: Robert Elliot <elliott@hpe.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1442514264-12475-8-git-send-email-toshi.kani@hpe.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-08-25x86/mm/pat: Make mm/pageattr[-test].c explicitly non-modularPaul Gortmaker1-1/+0
The file pageattr.c is obj-y and it includes pageattr-test.c based on CPA_DEBUG (a bool), meaning that no code here is currently being built as a module by anyone. Lets remove the couple traces of modularity so that when reading the code there is no doubt it is builtin-only. Since module_init translates to device_initcall in the non-modular case, the init ordering remains unchanged with this commit. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1440459295-21814-3-git-send-email-paul.gortmaker@windriver.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07x86/mm/pat: Add set_memory_wt() for Write-Through typeToshi Kani1-13/+49
Now that reserve_ram_pages_type() accepts the WT type, add set_memory_wt(), set_memory_array_wt() and set_pages_array_wt() in order to be able to set memory to Write-Through page cache mode. Also, extend ioremap_change_attr() to accept the WT type. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Elliott@hp.com Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: arnd@arndb.de Cc: hch@lst.de Cc: hmh@hmh.eng.br Cc: jgross@suse.com Cc: konrad.wilk@oracle.com Cc: linux-mm <linux-mm@kvack.org> Cc: linux-nvdimm@lists.01.org Cc: stefan.bader@canonical.com Cc: yigal@plexistor.com Link: http://lkml.kernel.org/r/1433436928-31903-13-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07x86/mm/pat: Remove pat_enabled() checksBorislav Petkov1-3/+0
Now that we emulate a PAT table when PAT is disabled, there's no need for those checks anymore as the PAT abstraction will handle those cases too. Based on a conglomerate patch from Toshi Kani. Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Toshi Kani <toshi.kani@hp.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Elliott@hp.com Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: arnd@arndb.de Cc: hch@lst.de Cc: hmh@hmh.eng.br Cc: jgross@suse.com Cc: konrad.wilk@oracle.com Cc: linux-mm <linux-mm@kvack.org> Cc: linux-nvdimm@lists.01.org Cc: stefan.bader@canonical.com Cc: yigal@plexistor.com Link: http://lkml.kernel.org/r/1433436928-31903-4-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-03x86/mm: Decouple <linux/vmalloc.h> from <asm/io.h>Stephen Rothwell1-0/+1
Nothing in <asm/io.h> uses anything from <linux/vmalloc.h>, so remove it from there and fix up the resulting build problems triggered on x86 {64|32}-bit {def|allmod|allno}configs. The breakages were triggering in places where x86 builds relied on vmalloc() facilities but did not include <linux/vmalloc.h> explicitly and relied on the implicit inclusion via <asm/io.h>. Also add: - <linux/init.h> to <linux/io.h> - <asm/pgtable_types> to <asm/io.h> ... which were two other implicit header file dependencies. Suggested-by: David Miller <davem@davemloft.net> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> [ Tidied up the changelog. ] Acked-by: David Miller <davem@davemloft.net> Acked-by: Takashi Iwai <tiwai@suse.de> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Vinod Koul <vinod.koul@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Colin Cross <ccross@android.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: James E.J. Bottomley <JBottomley@odin.com> Cc: Jaroslav Kysela <perex@perex.cz> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Kees Cook <keescook@chromium.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Kristen Carlson Accardi <kristen@linux.intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Suma Ramars <sramars@cisco.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27x86/mm/pat: Wrap pat_enabled into a function APILuis R. Rodriguez1-1/+1
We use pat_enabled in x86-specific code to see if PAT is enabled or not but we're granting full access to it even though readers do not need to set it. If, for instance, we granted access to it to modules later they then could override the variable setting... no bueno. This renames pat_enabled to a new static variable __pat_enabled. Folks are redirected to use pat_enabled() now. Code that sets this can only be internal to pat.c. Apart from the early kernel parameter "nopat" to disable PAT, we also have a few cases that disable it later and make use of a helper pat_disable(). It is wrapped under an ifdef but since that code cannot run unless PAT was enabled its not required to wrap it with ifdefs, unwrap that. Likewise, since "nopat" doesn't really change non-PAT systems just remove that ifdef as well. Although we could add and use an early_param_off(), these helpers don't use __read_mostly but we want to keep __read_mostly for __pat_enabled as this is a hot path -- upon boot, for instance, a simple guest may see ~4k accesses to pat_enabled(). Since __read_mostly early boot params are not that common we don't add a helper for them just yet. Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Walls <awalls@md.metrocast.net> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dave Airlie <airlied@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Doug Ledford <dledford@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kyle McMartin <kyle@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1430425520-22275-3-git-send-email-mcgrof@do-not-panic.com Link: http://lkml.kernel.org/r/1432628901-18044-13-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11x86/mm/pageattr: Remove an unused variable in slow_virt_to_phys()Dexuan Cui1-2/+0
The patch doesn't change any logic. Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1429776428-4475-1-git-send-email-decui@microsoft.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11x86/mm: Add ioremap_uc() helper to map memory uncacheable (not UC-)Luis R. Rodriguez1-0/+3
ioremap_nocache() currently uses UC- by default. Our goal is to eventually make UC the default. Linux maps UC- to PCD=1, PWT=0 page attributes on non-PAT systems. Linux maps UC to PCD=1, PWT=1 page attributes on non-PAT systems. On non-PAT and PAT systems a WC MTRR has different effects on pages with either of these attributes. In order to help with a smooth transition its best to enable use of UC (PCD,1, PWT=1) on a region as that ensures a WC MTRR will have no effect on a region, this however requires us to have an way to declare a region as UC and we currently do not have a way to do this. WC MTRR on non-PAT system with PCD=1, PWT=0 (UC-) yields WC. WC MTRR on non-PAT system with PCD=1, PWT=1 (UC) yields UC. WC MTRR on PAT system with PCD=1, PWT=0 (UC-) yields WC. WC MTRR on PAT system with PCD=1, PWT=1 (UC) yields UC. A flip of the default ioremap_nocache() behaviour from UC- to UC can therefore regress a memory region from effective memory type WC to UC if MTRRs are used. Use of MTRRs should be phased out and in the best case only arch_phys_wc_add() use will remain, even if this happens arch_phys_wc_add() will have an effect on non-PAT systems and changes to default ioremap_nocache() behaviour could regress drivers. Now, ideally we'd use ioremap_nocache() on the regions in which we'd need uncachable memory types and avoid any MTRRs on those regions. There are however some restrictions on MTRRs use, such as the requirement of having the base and size of variable sized MTRRs to be powers of two, which could mean having to use a WC MTRR over a large area which includes a region in which write-combining effects are undesirable. Add ioremap_uc() to help with the both phasing out of MTRR use and also provide a way to blacklist small WC undesirable regions in devices with mixed regions which are size-implicated to use large WC MTRRs. Use of ioremap_uc() helps phase out MTRR use by avoiding regressions with an eventual flip of default behaviour or ioremap_nocache() from UC- to UC. Drivers working with WC MTRRs can use the below table to review and consider the use of ioremap*() and similar helpers to ensure appropriate behaviour long term even if default ioremap_nocache() behaviour changes from UC- to UC. Although ioremap_uc() is being added we leave set_memory_uc() to use UC- as only initial memory type setup is required to be able to accommodate existing device drivers and phase out MTRR use. It should also be clarified that set_memory_uc() cannot be used with IO memory, even though its use will not return any errors, it really has no effect. ---------------------------------------------------------------------- MTRR Non-PAT PAT Linux ioremap value Effective memory type ---------------------------------------------------------------------- Non-PAT | PAT PAT |PCD ||PWT ||| WC 000 WB _PAGE_CACHE_MODE_WB WC | WC WC 001 WC _PAGE_CACHE_MODE_WC WC* | WC WC 010 UC- _PAGE_CACHE_MODE_UC_MINUS WC* | WC WC 011 UC _PAGE_CACHE_MODE_UC UC | UC ---------------------------------------------------------------------- Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Antonino Daplas <adaplas@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dave Airlie <airlied@redhat.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Travis <travis@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Suresh Siddha <sbsiddha@gmail.com> Cc: Thierry Reding <treding@nvidia.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Ville Syrjälä <syrjala@sci.fi> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-fbdev@vger.kernel.org Link: http://lkml.kernel.org/r/1430343851-967-2-git-send-email-mcgrof@do-not-panic.com Link: http://lkml.kernel.org/r/1431332153-18566-9-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11x86/mm: Do not flush last cacheline twice in clflush_cache_range()Ross Zwisler1-7/+6
The current algorithm used in clflush_cache_range() can cause the last cache line of the buffer to be flushed twice. Fix that algorithm so that each cache line will only be flushed once. Reported-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Link: http://lkml.kernel.org/r/1430259192-18802-1-git-send-email-ross.zwisler@linux.intel.com Link: http://lkml.kernel.org/r/1431332153-18566-5-git-send-email-bp@alien8.de [ Changed it to 'void *' to simplify the type conversions. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-05x86/mm: Simplify enabling direct_gbpagesLuis R. Rodriguez1-2/+0
direct_gbpages can be force enabled as an early parameter but not really have taken effect when DEBUG_PAGEALLOC or KMEMCHECK is enabled. You can also enable direct_gbpages right now if you have an x86_64 architecture but your CPU doesn't really have support for this feature. In both cases PG_LEVEL_1G won't actually be enabled but direct_gbpages is used in other areas under the assumptions that PG_LEVEL_1G was set. Fix this by putting together all requirements which make this feature sensible to enable under, and only enable both finally flipping on PG_LEVEL_1G and leaving PG_LEVEL_1G set when this is true. We only enable this feature then to be possible on sensible builds defined by the new ENABLE_DIRECT_GBPAGES. If the CPU has support for it you can either enable this by using the DIRECT_GBPAGES option or using the early kernel parameter. If a platform had support for this you can always force disable it as well. Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: JBeulich@suse.com Cc: Jan Beulich <JBeulich@suse.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Lindgren <tony@atomide.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: julia.lawall@lip6.fr Link: http://lkml.kernel.org/r/1425518654-3403-3-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-28x86/mm: Unexport set_memory_ro() and set_memory_rw()Daniel Borkmann1-2/+0
This effectively unexports set_memory_ro() and set_memory_rw() functions, and thus reverts: a03352d2c1dc ("x86: export set_memory_ro and set_memory_rw"). They have been introduced for debugging purposes in e1000e, but no module user is in mainline kernel (anymore?) and we explicitly do not want modules to use these functions, as they i.e. protect eBPF (interpreted & JIT'ed) images from malicious modifications or bugs. Outside of eBPF scope, I believe also other set_memory_*() functions should be unexported on x86 for modules. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Bruce Allan <bruce.w.allan@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jesse Brandeburg <jesse.brandeburg@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Link: http://lkml.kernel.org/r/a064393a0a5d319eebde5c761cfd743132d4f213.1425040940.git.daniel@iogearbox.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-12-16Merge tag 'stable/for-linus-3.19-rc0b-tag' of ↵Linus Torvalds1-0/+20
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull additional xen update from David Vrabel: "Xen: additional features for 3.19-rc0 - Linear p2m for x86 PV guests which simplifies the p2m code, improves performance and will allow for > 512 GB PV guests in the future. A last-minute, configuration specific issue was discovered with this change which is why it was not included in my previous pull request. This is now been fixed and tested" * tag 'stable/for-linus-3.19-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: switch to post-init routines in xen mmu.c earlier Revert "swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single" xen: annotate xen_set_identity_and_remap_chunk() with __init xen: introduce helper functions to do safe read and write accesses xen: Speed up set_phys_to_machine() by using read-only mappings xen: switch to linear virtual mapped sparse p2m list xen: Hide get_phys_to_machine() to be able to tune common path x86: Introduce function to get pmd entry pointer xen: Delay invalidating extra memory xen: Delay m2p_override initialization xen: Delay remapping memory of pv-domain xen: use common page allocation function in p2m.c xen: Make functions static xen: fix some style issues in p2m.c
2014-12-13mm/debug-pagealloc: make debug-pagealloc boottime configurableJoonsoo Kim1-1/+1
Now, we have prepared to avoid using debug-pagealloc in boottime. So introduce new kernel-parameter to disable debug-pagealloc in boottime, and makes related functions to be disabled in this case. Only non-intuitive part is change of guard page functions. Because guard page is effective only if debug-pagealloc is enabled, turning off according to debug-pagealloc is reasonable thing to do. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Dave Hansen <dave@sr71.net> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Jungsoo Son <jungsoo.son@lge.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds1-34/+50
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm tree changes from Ingo Molnar: "The biggest change is full PAT support from Jürgen Gross: The x86 architecture offers via the PAT (Page Attribute Table) a way to specify different caching modes in page table entries. The PAT MSR contains 8 entries each specifying one of 6 possible cache modes. A pte references one of those entries via 3 bits: _PAGE_PAT, _PAGE_PWT and _PAGE_PCD. The Linux kernel currently supports only 4 different cache modes. The PAT MSR is set up in a way that the setting of _PAGE_PAT in a pte doesn't matter: the top 4 entries in the PAT MSR are the same as the 4 lower entries. This results in the kernel not supporting e.g. write-through mode. Especially this cache mode would speed up drivers of video cards which now have to use uncached accesses. OTOH some old processors (Pentium) don't support PAT correctly and the Xen hypervisor has been using a different PAT MSR configuration for some time now and can't change that as this setting is part of the ABI. This patch set abstracts the cache mode from the pte and introduces tables to translate between cache mode and pte bits (the default cache mode "write back" is hard-wired to PAT entry 0). The tables are statically initialized with values being compatible to old processors and current usage. As soon as the PAT MSR is changed (or - in case of Xen - is read at boot time) the tables are changed accordingly. Requests of mappings with special cache modes are always possible now, in case they are not supported there will be a fallback to a compatible but slower mode. Summing it up, this patch set adds the following features: - capability to support WT and WP cache modes on processors with full PAT support - processors with no or uncorrect PAT support are still working as today, even if WT or WP cache mode are selected by drivers for some pages - reduction of Xen special handling regarding cache mode Another change is a boot speedup on ridiculously large RAM systems, plus other smaller fixes" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) x86: mm: Move PAT only functions to mm/pat.c xen: Support Xen pv-domains using PAT x86: Enable PAT to use cache mode translation tables x86: Respect PAT bit when copying pte values between large and normal pages x86: Support PAT bit in pagetable dump for lower levels x86: Clean up pgtable_types.h x86: Use new cache mode type in memtype related functions x86: Use new cache mode type in mm/ioremap.c x86: Use new cache mode type in setting page attributes x86: Remove looking for setting of _PAGE_PAT_LARGE in pageattr.c x86: Use new cache mode type in track_pfn_remap() and track_pfn_insert() x86: Use new cache mode type in mm/iomap_32.c x86: Use new cache mode type in asm/pgtable.h x86: Use new cache mode type in arch/x86/mm/init_64.c x86: Use new cache mode type in arch/x86/pci x86: Use new cache mode type in drivers/video/fbdev/vermilion x86: Use new cache mode type in drivers/video/fbdev/gbefb.c x86: Use new cache mode type in include/asm/fb.h x86: Make page cache mode a real type x86: mm: Use 2GB memory block size on large-memory x86-64 systems ...
2014-12-04x86: Introduce function to get pmd entry pointerJuergen Gross1-0/+20
Introduces lookup_pmd_address() to get the address of the pmd entry related to a virtual address in the current address space. This function is needed for support of a virtual mapped sparse p2m list in xen pv domains, as we need the address of the pmd entry, not the one of the pte in that case. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-11-16x86: Respect PAT bit when copying pte values between large and normal pagesJuergen Gross1-10/+23
The PAT bit in the ptes is not moved to the correct position when copying page protection attributes between entries of different sized pages. Translate the ptes according to their page size. Based-on-patch-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: stefan.bader@canonical.com Cc: xen-devel@lists.xensource.com Cc: konrad.wilk@oracle.com Cc: ville.syrjala@linux.intel.com Cc: david.vrabel@citrix.com Cc: jbeulich@suse.com Cc: toshi.kani@hp.com Cc: plagnioj@jcrosoft.com Cc: tomi.valkeinen@ti.com Cc: bhelgaas@google.com Link: http://lkml.kernel.org/r/1415019724-4317-17-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-16x86: Use new cache mode type in memtype related functionsJuergen Gross1-5/+4
Instead of directly using the cache mode bits in the pte switch to using the cache mode type. Based-on-patch-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: stefan.bader@canonical.com Cc: xen-devel@lists.xensource.com Cc: konrad.wilk@oracle.com Cc: ville.syrjala@linux.intel.com Cc: david.vrabel@citrix.com Cc: jbeulich@suse.com Cc: toshi.kani@hp.com Cc: plagnioj@jcrosoft.com Cc: tomi.valkeinen@ti.com Cc: bhelgaas@google.com Link: http://lkml.kernel.org/r/1415019724-4317-14-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-16x86: Use new cache mode type in setting page attributesJuergen Gross1-24/+28
Instead of directly using the cache mode bits in the pte switch to using the cache mode type in the functions for modifying page attributes. Based-on-patch-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: stefan.bader@canonical.com Cc: xen-devel@lists.xensource.com Cc: konrad.wilk@oracle.com Cc: ville.syrjala@linux.intel.com Cc: david.vrabel@citrix.com Cc: jbeulich@suse.com Cc: toshi.kani@hp.com Cc: plagnioj@jcrosoft.com Cc: tomi.valkeinen@ti.com Cc: bhelgaas@google.com Link: http://lkml.kernel.org/r/1415019724-4317-12-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-16x86: Remove looking for setting of _PAGE_PAT_LARGE in pageattr.cJuergen Gross1-1/+1
When modifying page attributes via change_page_attr_set_clr() don't test for setting _PAGE_PAT_LARGE, as this is - never done - PAT support for large pages is not included in the kernel up to now Signed-off-by: Juergen Gross <jgross@suse.com> Cc: stefan.bader@canonical.com Cc: xen-devel@lists.xensource.com Cc: konrad.wilk@oracle.com Cc: ville.syrjala@linux.intel.com Cc: david.vrabel@citrix.com Cc: jbeulich@suse.com Cc: toshi.kani@hp.com Cc: plagnioj@jcrosoft.com Cc: tomi.valkeinen@ti.com Cc: bhelgaas@google.com Link: http://lkml.kernel.org/r/1415019724-4317-11-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-10-29x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAEDexuan Cui1-1/+1
pte_pfn() returns a PFN of long (32 bits in 32-PAE), so "long << PAGE_SHIFT" will overflow for PFNs above 4GB. Due to this issue, some Linux 32-PAE distros, running as guests on Hyper-V, with 5GB memory assigned, can't load the netvsc driver successfully and hence the synthetic network device can't work (we can use the kernel parameter mem=3000M to work around the issue). Cast pte_pfn() to phys_addr_t before shifting. Fixes: "commit d76565344512: x86, mm: Create slow_virt_to_phys()" Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: gregkh@linuxfoundation.org Cc: linux-mm@kvack.org Cc: olaf@aepfle.de Cc: apw@canonical.com Cc: jasowang@redhat.com Cc: dave.hansen@intel.com Cc: riel@redhat.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1414580017-27444-1-git-send-email-decui@microsoft.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-03-31Merge branch 'x86-efi-for-linus' of ↵Linus Torvalds1-17/+39
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 EFI changes from Ingo Molnar: "The main changes: - Add debug code to the dump EFI pagetable - Borislav Petkov - Make 1:1 runtime mapping robust when booting on machines with lots of memory - Borislav Petkov - Move the EFI facilities bits out of 'x86_efi_facility' and into efi.flags which is the standard architecture independent place to keep EFI state, by Matt Fleming. - Add 'EFI mixed mode' support: this allows 64-bit kernels to be booted from 32-bit firmware. This needs a bootloader that supports the 'EFI handover protocol'. By Matt Fleming" * 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) x86, efi: Abstract x86 efi_early calls x86/efi: Restore 'attr' argument to query_variable_info() x86/efi: Rip out phys_efi_get_time() x86/efi: Preserve segment registers in mixed mode x86/boot: Fix non-EFI build x86, tools: Fix up compiler warnings x86/efi: Re-disable interrupts after calling firmware services x86/boot: Don't overwrite cr4 when enabling PAE x86/efi: Wire up CONFIG_EFI_MIXED x86/efi: Add mixed runtime services support x86/efi: Firmware agnostic handover entry points x86/efi: Split the boot stub into 32/64 code paths x86/efi: Add early thunk code to go from 64-bit to 32-bit x86/efi: Build our own EFI services pointer table efi: Add separate 32-bit/64-bit definitions x86/efi: Delete dead code when checking for non-native x86/mm/pageattr: Always dump the right page table in an oops x86, tools: Consolidate #ifdef code x86/boot: Cleanup header.S by removing some #ifdefs efi: Use NULL instead of 0 for pointer ...
2014-03-31Merge branch 'x86-cpu-for-linus' of ↵Linus Torvalds1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpu handling changes from Ingo Molnar: "Bigger changes: - Intel CPU hardware-enablement: new vector instructions support (AVX-512), by Fenghua Yu. - Support the clflushopt instruction and use it in appropriate places. clflushopt is similar to clflush but with more relaxed ordering, by Ross Zwisler. - MSR accessor cleanups, by Borislav Petkov. - 'forcepae' boot flag for those who have way too much time to spend on way too old Pentium-M systems and want to live way too dangerously, by Chris Bainbridge" * 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, cpu: Add forcepae parameter for booting PAE kernels on PAE-disabled Pentium M Rename TAINT_UNSAFE_SMP to TAINT_CPU_OUT_OF_SPEC x86, intel: Make MSR_IA32_MISC_ENABLE bit constants systematic x86, Intel: Convert to the new bit access MSR accessors x86, AMD: Convert to the new bit access MSR accessors x86: Add another set of MSR accessor functions x86: Use clflushopt in drm_clflush_virt_range x86: Use clflushopt in drm_clflush_page x86: Use clflushopt in clflush_cache_range x86: Add support for the clflushopt instruction x86, AVX-512: Enable AVX-512 States Context Switch x86, AVX-512: AVX-512 Feature Detection
2014-03-13x86, pageattr: Correct WBINVD spelling in commentBorislav Petkov1-3/+3
It is WBINVD, for INValiDate and not "wbindv". Use caps for instruction names, while at it. Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1394633584-5509-4-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-05Merge remote-tracking branch 'tip/x86/efi-mixed' into efi-for-mingoMatt Fleming1-4/+8
Conflicts: arch/x86/kernel/setup.c arch/x86/platform/efi/efi.c arch/x86/platform/efi/efi_64.c
2014-03-04x86/mm/pageattr: Always dump the right page table in an oopsMatt Fleming1-4/+8
Now that we have EFI-specific page tables we need to lookup the pgd when dumping those page tables, rather than assuming that swapper_pgdir is the current pgdir. Remove the double underscore prefix, which is usually reserved for static functions. Acked-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-04x86, pageattr: Export page unmapping interfaceBorislav Petkov1-13/+31
We will use it in efi so expose it. Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-02-27x86: Use clflushopt in clflush_cache_rangeRoss Zwisler1-4/+4
If clflushopt is available on the system, use it instead of clflush in clflush_cache_range. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Link: http://lkml.kernel.org/r/1393441612-19729-3-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-11-02x86/mm/cpa: Map in an arbitrary pgdBorislav Petkov1-7/+46
Add the ability to map pages in an arbitrary pgd. This wires in the remaining stuff so that there's a new interface with which you can map a region into an arbitrary PGD. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-11-02x86/mm/pageattr: Add last levels of error pathBorislav Petkov1-1/+93
We try to free the pagetable pages once we've unmapped our portion. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-11-02x86/mm/pageattr: Add a PUD error unwinding pathBorislav Petkov1-2/+58
In case we encounter an error during the mapping of a region, we want to unwind what we've established so far exactly the way we did the mapping. This is the PUD part kept deliberately small for easier review. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-11-02x86/mm/pageattr: Add a PTE pagetable populating functionBorislav Petkov1-1/+21
Handle last level by unconditionally writing the PTEs into the PTE page while paying attention to the NX bit. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-11-02x86/mm/pageattr: Add a PMD pagetable populating functionBorislav Petkov1-1/+81
Handle PMD-level mappings the same as PUD ones. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-11-02x86/mm/pageattr: Add a PUD pagetable populating functionBorislav Petkov1-1/+86
Add the next level of the pagetable populating function, we handle chunks around a 1G boundary by mapping them with the lower level functions - otherwise we use 1G pages for the mappings, thus using as less amount of pagetable pages as possible. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-11-02x86/mm/pageattr: Add a PGD pagetable populating functionBorislav Petkov1-0/+39
This allocates, if necessary, and populates the corresponding PGD entry with a PUD page. The next population level is a dummy macro which will be removed by the next patch and it is added here to keep the patch small and easily reviewable but not break bisection, at the same time. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-11-02x86/mm/pageattr: Lookup address in an arbitrary PGDBorislav Petkov1-10/+26
This is preparatory work in order to be able to map pages into a specified PGD and not implicitly and only into init_mm. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-30Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds1-5/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm changes from Ingo Molnar: "Misc smaller changes all over the map" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/iommu/dmar: Remove warning for HPET scope type x86/mm/gart: Drop unnecessary check x86/mm/hotplug: Put kernel_physical_mapping_remove() declaration in CONFIG_MEMORY_HOTREMOVE x86/mm/fixmap: Remove unused FIX_CYCLONE_TIMER x86/mm/numa: Simplify some bit mangling x86/mm: Re-enable DEBUG_TLBFLUSH for X86_32 x86/mm/cpa: Cleanup split_large_page() and its callee x86: Drop always empty .text..page_aligned section
2013-04-12x86/mm: Flush lazy MMU when DEBUG_PAGEALLOC is setBoris Ostrovsky1-0/+2
When CONFIG_DEBUG_PAGEALLOC is set page table updates made by kernel_map_pages() are not made visible (via TLB flush) immediately if lazy MMU is on. In environments that support lazy MMU (e.g. Xen) this may lead to fatal page faults, for example, when zap_pte_range() needs to allocate pages in __tlb_remove_page() -> tlb_next_batch(). Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: konrad.wilk@oracle.com Link: http://lkml.kernel.org/r/1365703192-2089-1-git-send-email-boris.ostrovsky@oracle.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-11x86/mm/cpa: Convert noop to functional fixAndrea Arcangeli1-5/+5
Commit: a8aed3e0752b ("x86/mm/pageattr: Prevent PSE and GLOABL leftovers to confuse pmd/pte_present and pmd_huge") introduced a valid fix but one location that didn't trigger the bug that lead to finding those (small) problems, wasn't updated using the right variable. The wrong variable was also initialized for no good reason, that may have been the source of the confusion. Remove the noop initialization accordingly. Commit a8aed3e0752b also erroneously removed one canon_pgprot pass meant to clear pmd bitflags not supported in hardware by older CPUs, that automatically gets corrected by this patch too by applying it to the right variable in the new location. Reported-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Andy Whitcroft <apw@canonical.com> Cc: Mel Gorman <mgorman@suse.de> Link: http://lkml.kernel.org/r/1365600505-19314-1-git-send-email-aarcange@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-10x86/mm/cpa: Cleanup split_large_page() and its calleeBorislav Petkov1-5/+4
So basically we're generating the pte_t * from a struct page and we're handing it down to the __split_large_page() internal version which then goes and gets back struct page * from it because it needs it. Change the caller to hand down struct page * directly and the callee can compute the pte_t itself. Net save is one virt_to_page() call and simpler code. While at it, make __split_large_page() static. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1363886217-24703-1-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-02-26Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-3/+47
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar. * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/pageattr: Prevent PSE and GLOABL leftovers to confuse pmd/pte_present and pmd_huge Revert "x86, mm: Make spurious_fault check explicitly check explicitly check the PRESENT bit" x86/mm/numa: Don't check if node is NUMA_NO_NODE x86, efi: Make "noefi" really disable EFI runtime serivces x86/apic: Fix parsing of the 'lapic' cmdline option