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2017-07-18x86/mm: Use proper encryption attributes with /dev/memTom Lendacky
When accessing memory using /dev/mem (or /dev/kmem) use the proper encryption attributes when mapping the memory. To insure the proper attributes are applied when reading or writing /dev/mem, update the xlate_dev_mem_ptr() function to use memremap() which will essentially perform the same steps of applying __va for RAM or using ioremap() if not RAM. To insure the proper attributes are applied when mmapping /dev/mem, update the phys_mem_access_prot() to call phys_mem_access_encrypted(), a new function which will check if the memory should be mapped encrypted or not. If it is not to be mapped encrypted then the VMA protection value is updated to remove the encryption bit. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Toshimitsu Kani <toshi.kani@hpe.com> Cc: kasan-dev@googlegroups.com Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/c917f403ab9f61cbfd455ad6425ed8429a5e7b54.1500319216.git.thomas.lendacky@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-18x86/mm/pat: Set write-protect cache mode for full PAT supportTom Lendacky
For processors that support PAT, set the write-protect cache mode (_PAGE_CACHE_MODE_WP) entry to the actual write-protect value (x05). Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Borislav Petkov <bp@suse.de> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Toshimitsu Kani <toshi.kani@hpe.com> Cc: kasan-dev@googlegroups.com Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/ade53b63d4dbffbfc3cb08fb62024647059c8688.1500319216.git.thomas.lendacky@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-05x86/mm/pat: Don't report PAT on CPUs that don't support itMikulas Patocka
The pat_enabled() logic is broken on CPUs which do not support PAT and where the initialization code fails to call pat_init(). Due to that the enabled flag stays true and pat_enabled() returns true wrongfully. As a consequence the mappings, e.g. for Xorg, are set up with the wrong caching mode and the required MTRR setups are omitted. To cure this the following changes are required: 1) Make pat_enabled() return true only if PAT initialization was invoked and successful. 2) Invoke init_cache_modes() unconditionally in setup_arch() and remove the extra callsites in pat_disable() and the pat disabled code path in pat_init(). Also rename __pat_enabled to pat_disabled to reflect the real purpose of this variable. Fixes: 9cd25aac1f44 ("x86/mm/pat: Emulate PAT when it is disabled") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Bernhard Held <berny156@gmx.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: "Luis R. Rodriguez" <mcgrof@suse.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1707041749300.3456@file01.intranet.prod.int.rdu2.redhat.com
2017-06-01Revert "x86/PAT: Fix Xorg regression on CPUs that don't support PAT"Ingo Molnar
This reverts commit cbed27cdf0e3f7ea3b2259e86b9e34df02be3fe4. As Andy Lutomirski observed: "I think this patch is bogus. pat_enabled() sure looks like it's supposed to return true if PAT is *enabled*, and these days PAT is 'enabled' even if there's no HW PAT support." Reported-by: Bernhard Held <berny156@gmx.de> Reported-by: Chris Wilson <chris@chris-wilson.co.uk> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: stable@vger.kernel.org # v4.2+ Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-24x86/PAT: Fix Xorg regression on CPUs that don't support PATMikulas Patocka
In the file arch/x86/mm/pat.c, there's a '__pat_enabled' variable. The variable is set to 1 by default and the function pat_init() sets __pat_enabled to 0 if the CPU doesn't support PAT. However, on AMD K6-3 CPUs, the processor initialization code never calls pat_init() and so __pat_enabled stays 1 and the function pat_enabled() returns true, even though the K6-3 CPU doesn't support PAT. The result of this bug is that a kernel warning is produced when attempting to start the Xserver and the Xserver doesn't start (fork() returns ENOMEM). Another symptom of this bug is that the framebuffer driver doesn't set the K6-3 MTRR registers: x86/PAT: Xorg:3891 map pfn expected mapping type uncached-minus for [mem 0xe4000000-0xe5ffffff], got write-combining ------------[ cut here ]------------ WARNING: CPU: 0 PID: 3891 at arch/x86/mm/pat.c:1020 untrack_pfn+0x5c/0x9f ... x86/PAT: Xorg:3891 map pfn expected mapping type uncached-minus for [mem 0xe4000000-0xe5ffffff], got write-combining To fix the bug change pat_enabled() so that it returns true only if PAT initialization was actually done. Also, I changed boot_cpu_has(X86_FEATURE_PAT) to this_cpu_has(X86_FEATURE_PAT) in pat_ap_init(), so that we check the PAT feature on the processor that is being initialized. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> 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: Josh Poimboeuf <jpoimboe@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> Cc: stable@vger.kernel.org # v4.2+ Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1704181501450.26399@file01.intranet.prod.int.rdu2.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28x86/boot/e820: Remove unnecessary #include <linux/ioport.h> from asm/e820/api.hIngo Molnar
There's a completely unnecessary inclusion of linux/ioport.h near the end of the asm/e820/api.h file. Remove it and fix up unrelated code that learned to rely on this spurious inclusion of a generic header. No change in functionality. Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28x86/boot/e820: Move asm/e820.h to asm/e820/api.hIngo Molnar
In line with asm/e820/types.h, move the e820 API declarations to asm/e820/api.h and update all usage sites. This is just a mechanical, obviously correct move & replace patch, there will be subsequent changes to clean up the code and to make better use of the new header organization. Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-09x86/pat, mm: Make track_pfn_insert() return voidBorislav Petkov
It only returns 0 so we can save us the testing of its retval everywhere. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: mcgrof@suse.com Cc: dri-devel@lists.freedesktop.org Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Airlie <airlied@redhat.com> Cc: dan.j.williams@intel.com Cc: torvalds@linux-foundation.org Link: http://lkml.kernel.org/r/20161026174839.rusfxkm3xt4ennhe@pd.tnic Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-26x86/io: add interface to reserve io memtype for a resource range. (v1.1)Dave Airlie
A recent change to the mm code in: 87744ab3832b mm: fix cache mode tracking in vm_insert_mixed() started enforcing checking the memory type against the registered list for amixed pfn insertion mappings. It happens that the drm drivers for a number of gpus relied on this being broken. Currently the driver only inserted VRAM mappings into the tracking table when they came from the kernel, and userspace mappings never landed in the table. This led to a regression where all the mapping end up as UC instead of WC now. I've considered a number of solutions but since this needs to be fixed in fixes and not next, and some of the solutions were going to introduce overhead that hadn't been there before I didn't consider them viable at this stage. These mainly concerned hooking into the TTM io reserve APIs, but these API have a bunch of fast paths I didn't want to unwind to add this to. The solution I've decided on is to add a new API like the arch_phys_wc APIs (these would have worked but wc_del didn't take a range), and use them from the drivers to add a WC compatible mapping to the table for all VRAM on those GPUs. This means we can then create userspace mapping that won't get degraded to UC. v1.1: use CONFIG_X86_PAT + add some comments in io.h Cc: Toshi Kani <toshi.kani@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: x86@kernel.org Cc: mcgrof@suse.com Cc: Dan Williams <dan.j.williams@intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-09-09mm: fix cache mode of dax pmd mappingsDan Williams
track_pfn_insert() in vmf_insert_pfn_pmd() is marking dax mappings as uncacheable rendering them impractical for application usage. DAX-pte mappings are cached and the goal of establishing DAX-pmd mappings is to attain more performance, not dramatically less (3 orders of magnitude). track_pfn_insert() relies on a previous call to reserve_memtype() to establish the expected page_cache_mode for the range. While memremap() arranges for reserve_memtype() to be called, devm_memremap_pages() does not. So, teach track_pfn_insert() and untrack_pfn() how to handle tracking without a vma, and arrange for devm_memremap_pages() to establish the write-back-cache reservation in the memtype tree. Cc: <stable@vger.kernel.org> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Toshi Kani <toshi.kani@hpe.com> Reported-by: Kai Zhang <kai.ka.zhang@oracle.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-08-01Merge branch 'x86-headers-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 header cleanups from Ingo Molnar: "This tree is a cleanup of the x86 tree reducing spurious uses of module.h - which should improve build performance a bit" * 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, crypto: Restore MODULE_LICENSE() to glue_helper.c so it loads x86/apic: Remove duplicated include from probe_64.c x86/ce4100: Remove duplicated include from ce4100.c x86/headers: Include spinlock_types.h in x8664_ksyms_64.c for missing spinlock_t x86/platform: Delete extraneous MODULE_* tags fromm ts5500 x86: Audit and remove any remaining unnecessary uses of module.h x86/kvm: Audit and remove any unnecessary uses of module.h x86/xen: Audit and remove any unnecessary uses of module.h x86/platform: Audit and remove any unnecessary uses of module.h x86/lib: Audit and remove any unnecessary uses of module.h x86/kernel: Audit and remove any unnecessary uses of module.h x86/mm: Audit and remove any unnecessary uses of module.h x86: Don't use module.h just for AUTHOR / LICENSE tags
2016-07-14x86/mm: Audit and remove any unnecessary uses of module.hPaul Gortmaker
Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance for the presence of either and replace accordingly where needed. Note that some bool/obj-y instances remain since module.h is the header for some exception table entry stuff, and for things like __init_or_module (code that is tossed when MODULES=n). Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.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/20160714001901.31603-3-paul.gortmaker@windriver.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-08x86/mm/pat, /dev/mem: Remove superfluous error messageJiri Kosina
Currently it's possible for broken (or malicious) userspace to flood a kernel log indefinitely with messages a-la Program dmidecode tried to access /dev/mem between f0000->100000 because range_is_allowed() is case of CONFIG_STRICT_DEVMEM being turned on dumps this information each and every time devmem_is_allowed() fails. Reportedly userspace that is able to trigger contignuous flow of these messages exists. It would be possible to rate limit this message, but that'd have a questionable value; the administrator wouldn't get information about all the failing accessess, so then the information would be both superfluous and incomplete at the same time :) Returning EPERM (which is what is actually happening) is enough indication for userspace what has happened; no need to log this particular error as some sort of special condition. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> 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/alpine.LNX.2.00.1607081137020.24757@cbobk.fhfr.pm Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13x86/mm/pat: Fix BUG_ON() in mmap_mem() on QEMU/i386Toshi Kani
The following BUG_ON() crash was reported on QEMU/i386: kernel BUG at arch/x86/mm/physaddr.c:79! Call Trace: phys_mem_access_prot_allowed mmap_mem ? mmap_region mmap_region do_mmap vm_mmap_pgoff SyS_mmap_pgoff do_int80_syscall_32 entry_INT80_32 after commit: edfe63ec97ed ("x86/mtrr: Fix Xorg crashes in Qemu sessions") PAT is now set to disabled state when MTRRs are disabled. Thus, reactivating the __pa(high_memory) check in phys_mem_access_prot_allowed(). When CONFIG_DEBUG_VIRTUAL is set, __pa() calls __phys_addr(), which in turn calls slow_virt_to_phys() for 'high_memory'. Because 'high_memory' is set to (the max direct mapped virt addr + 1), it is not a valid virtual address. Hence, slow_virt_to_phys() returns 0 and hit the BUG_ON. Using __pa_nodebug() instead of __pa() will fix this BUG_ON. However, this code block, originally written for Pentiums and earlier, is no longer adequate since a 32-bit Xen guest has MTRRs disabled and supports ZONE_HIGHMEM. In this setup, this code sets UC attribute for accessing RAM in high memory range. Delete this code block as it has been unused for a long time. Reported-by: kernel test robot <ying.huang@linux.intel.com> Reviewed-by: Borislav Petkov <bp@suse.de> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1460403360-25441-1-git-send-email-toshi.kani@hpe.com Link: https://lkml.org/lkml/2016/4/1/608 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-29x86/xen, pat: Remove PAT table init code from XenToshi Kani
Xen supports PAT without MTRRs for its guests. In order to enable WC attribute, it was necessary for xen_start_kernel() to call pat_init_cache_modes() to update PAT table before starting guest kernel. Now that the kernel initializes PAT table to the BIOS handoff state when MTRR is disabled, this Xen-specific PAT init code is no longer necessary. Delete it from xen_start_kernel(). Also change __init_cache_modes() to a static function since PAT table should not be tweaked by other modules. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Juergen Gross <jgross@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: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Toshi Kani <toshi.kani@hp.com> Cc: elliott@hpe.com Cc: paul.gortmaker@windriver.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1458769323-24491-7-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-29x86/mm/pat: Replace cpu_has_pat with boot_cpu_has()Toshi Kani
Borislav Petkov suggested: > Please use on init paths boot_cpu_has(X86_FEATURE_PAT) and on fast > paths static_cpu_has(X86_FEATURE_PAT). No more of that cpu_has_XXX > ugliness. Replace the use of cpu_has_pat on init paths with boot_cpu_has(). Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.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: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert Elliott <elliott@hpe.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: konrad.wilk@oracle.com Cc: paul.gortmaker@windriver.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1458769323-24491-4-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-29x86/mm/pat: Add pat_disable() interfaceToshi Kani
In preparation for fixing a regression caused by: 9cd25aac1f44 ("x86/mm/pat: Emulate PAT when it is disabled") ... PAT needs to provide an interface that prevents the OS from initializing the PAT MSR. PAT MSR initialization must be done on all CPUs using the specific sequence of operations defined in the Intel SDM. This requires MTRRs to be enabled since pat_init() is called as part of MTRR init from mtrr_rendezvous_handler(). Make pat_disable() as the interface that prevents the OS from initializing the PAT MSR. MTRR will call this interface when it cannot provide the SDM-defined sequence to initialize PAT. This also assures that pat_disable() called from pat_bsp_init() will set the PAT table properly when CPU does not support PAT. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> 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: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert Elliott <elliott@hpe.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: konrad.wilk@oracle.com Cc: paul.gortmaker@windriver.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1458769323-24491-3-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-29x86/mm/pat: Add support of non-default PAT MSR settingToshi Kani
In preparation for fixing a regression caused by: 9cd25aac1f44 ("x86/mm/pat: Emulate PAT when it is disabled")' ... PAT needs to support a case that PAT MSR is initialized with a non-default value. When pat_init() is called and PAT is disabled, it initializes the PAT table with the BIOS default value. Xen, however, sets PAT MSR with a non-default value to enable WC. This causes inconsistency between the PAT table and PAT MSR when PAT is set to disable on Xen. Change pat_init() to handle the PAT disable cases properly. Add init_cache_modes() to handle two cases when PAT is set to disable. 1. CPU supports PAT: Set PAT table to be consistent with PAT MSR. 2. CPU does not support PAT: Set PAT table to be consistent with PWT and PCD bits in a PTE. Note, __init_cache_modes(), renamed from pat_init_cache_modes(), will be changed to a static function in a later patch. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> 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: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Toshi Kani <toshi.kani@hp.com> Cc: elliott@hpe.com Cc: konrad.wilk@oracle.com Cc: paul.gortmaker@windriver.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1458769323-24491-2-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-17Merge branch 'x86/cleanups' into x86/urgentIngo Molnar
Pull in some merge window leftovers. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-24x86: Fix misspellings in commentsAdam Buchbinder
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: trivial@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-09x86/mm: Honour passed pgprot in track_pfn_insert() and track_pfn_remap()Matthew Wilcox
track_pfn_insert() overwrites the pgprot that is passed in with a value based on the VMA's page_prot. This is a problem for people trying to do clever things with the new vm_insert_pfn_prot() as it will simply overwrite the passed protection flags. If we use the current value of the pgprot as the base, then it will behave as people are expecting. Also fix track_pfn_remap() in the same way. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1453742717-10326-2-git-send-email-matthew.r.wilcox@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-15mm, dax: convert vmf_insert_pfn_pmd() to pfn_tDan Williams
Similar to the conversion of vm_insert_mixed() use pfn_t in the vmf_insert_pfn_pmd() to tag the resulting pte with _PAGE_DEVICE when the pfn is backed by a devm_memremap_pages() mapping. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave@sr71.net> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-05x86/mm/pat: Change free_memtype() to support shrinking caseToshi Kani
Using mremap() to shrink the map size of a VM_PFNMAP range causes the following error message, and leaves the pfn range allocated. x86/PAT: test:3493 freeing invalid memtype [mem 0x483200000-0x4863fffff] This is because rbt_memtype_erase(), called from free_memtype() with spin_lock held, only supports to free a whole memtype node in memtype_rbroot. Therefore, this patch changes rbt_memtype_erase() to support a request that shrinks the size of a memtype node for mremap(). memtype_rb_exact_match() is renamed to memtype_rb_match(), and is enhanced to support EXACT_MATCH and END_MATCH in @match_type. Since the memtype_rbroot tree allows overlapping ranges, rbt_memtype_erase() checks with EXACT_MATCH first, i.e. free a whole node for the munmap case. If no such entry is found, it then checks with END_MATCH, i.e. shrink the size of a node from the end for the mremap case. On the mremap case, rbt_memtype_erase() proceeds in two steps, 1) remove the node, and then 2) insert the updated node. This allows proper update of augmented values, subtree_max_end, in the tree. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: stsp@list.ru Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1450832064-10093-3-git-send-email-toshi.kani@hpe.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-05x86/mm/pat: Add untrack_pfn_moved for mremapToshi Kani
mremap() with MREMAP_FIXED on a VM_PFNMAP range causes the following WARN_ON_ONCE() message in untrack_pfn(). WARNING: CPU: 1 PID: 3493 at arch/x86/mm/pat.c:985 untrack_pfn+0xbd/0xd0() Call Trace: [<ffffffff817729ea>] dump_stack+0x45/0x57 [<ffffffff8109e4b6>] warn_slowpath_common+0x86/0xc0 [<ffffffff8109e5ea>] warn_slowpath_null+0x1a/0x20 [<ffffffff8106a88d>] untrack_pfn+0xbd/0xd0 [<ffffffff811d2d5e>] unmap_single_vma+0x80e/0x860 [<ffffffff811d3725>] unmap_vmas+0x55/0xb0 [<ffffffff811d916c>] unmap_region+0xac/0x120 [<ffffffff811db86a>] do_munmap+0x28a/0x460 [<ffffffff811dec33>] move_vma+0x1b3/0x2e0 [<ffffffff811df113>] SyS_mremap+0x3b3/0x510 [<ffffffff817793ee>] entry_SYSCALL_64_fastpath+0x12/0x71 MREMAP_FIXED moves a pfnmap from old vma to new vma. untrack_pfn() is called with the old vma after its pfnmap page table has been removed, which causes follow_phys() to fail. The new vma has a new pfnmap to the same pfn & cache type with VM_PAT set. Therefore, we only need to clear VM_PAT from the old vma in this case. Add untrack_pfn_moved(), which clears VM_PAT from a given old vma. move_vma() is changed to call this function with the old vma when VM_PFNMAP is set. move_vma() then calls do_munmap(), and untrack_pfn() is a no-op since VM_PAT is cleared. Reported-by: Stas Sergeev <stsp@list.ru> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1450832064-10093-2-git-send-email-toshi.kani@hpe.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-07x86/mm/pat: Extend set_page_memtype() to support Write-Through typeToshi Kani
As set_memory_wb() calls free_ram_pages_type(), which then calls set_page_memtype() with -1, _PGMT_DEFAULT is used for tracking the WB type. _PGMT_WB is defined but unused. Thus, rename _PGMT_DEFAULT to _PGMT_WB to clarify the usage, and release the slot used by _PGMT_WB. Furthermore, change free_ram_pages_type() to call set_page_memtype() with _PGMT_WB, and get_page_memtype() to return _PAGE_CACHE_MODE_WB for _PGMT_WB. Then, define _PGMT_WT in the freed slot. This allows set_page_memtype() to track 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/1433436928-31903-12-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07x86/mm/pat: Add pgprot_writethrough()Toshi Kani
Add pgprot_writethrough() for setting page protection flags to Write-Through mode. 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/1433436928-31903-11-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07x86/mm/pat: Change reserve_memtype() for Write-Through typeToshi Kani
When a target range is in RAM, reserve_ram_pages_type() verifies the requested type. Change it to fail WT and WP requests with -EINVAL since set_page_memtype() is limited to handle three types: WB, WC and UC-. 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/1433436928-31903-6-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07x86/mm/pat: Use 7th PAT MSR slot for Write-Through PAT typeToshi Kani
Assign Write-Through type to the PA7 slot in the PAT MSR when the processor is not affected by PAT errata. The PA7 slot is chosen to improve robustness in the presence of errata that might cause the high PAT bit to be ignored. This way a buggy PA7 slot access will hit the PA3 slot, which is UC, so at worst we lose performance without causing a correctness issue. The following Intel processors are affected by the PAT errata. Errata CPUID ---------------------------------------------------- Pentium 2, A52 family 0x6, model 0x5 Pentium 3, E27 family 0x6, model 0x7, 0x8 Pentium 3 Xenon, G26 family 0x6, model 0x7, 0x8, 0xa Pentium M, Y26 family 0x6, model 0x9 Pentium M 90nm, X9 family 0x6, model 0xd Pentium 4, N46 family 0xf, model 0x0 Instead of making sharp boundary checks, we remain conservative and exclude all Pentium 2, 3, M and 4 family processors. For those, _PAGE_CACHE_MODE_WT is redirected to UC- per the default setup in __cachemode2pte_tbl[]. 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: https://lkml.kernel.org/r/1433187393-22688-2-git-send-email-toshi.kani@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07x86/mm/pat: Remove pat_enabled() checksBorislav Petkov
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>
2015-06-07x86/mm/pat: Emulate PAT when it is disabledBorislav Petkov
In the case when PAT is disabled on the command line with "nopat" or when virtualization doesn't support PAT (correctly) - see 9d34cfdf4796 ("x86: Don't rely on VMWare emulating PAT MSR correctly"). we emulate it using the PWT and PCD cache attribute bits. Get rid of boot_pat_state while at it. Based on a conglomerate patch from Toshi Kani. Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Toshi Kani <toshi.kani@hp.com> Acked-by: Juergen Gross <jgross@suse.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: 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/1433436928-31903-3-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07x86/mm/pat: Untangle pat_init()Borislav Petkov
Split it into a BSP and AP version which makes the PAT initialization path actually readable again. 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/1433436928-31903-2-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27x86/mm/pat: Export pat_enabled()Luis R. Rodriguez
Two Linux device drivers cannot work with PAT and the work required to make them work is significant. There is not enough motivation to convert these drivers over to use PAT properly, the compromise reached is to let drivers that cannot be ported to PAT check if PAT was enabled and if so fail on probe with a recommendation to boot with the "nopat" kernel parameter. 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: 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: 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/1430425520-22275-4-git-send-email-mcgrof@do-not-panic.com Link: http://lkml.kernel.org/r/1432628901-18044-14-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27x86/mm/pat: Wrap pat_enabled into a function APILuis R. Rodriguez
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>
2015-05-27x86/mm/pat: Convert to pr_*() usageLuis R. Rodriguez
Use pr_info() instead of the old printk to prefix the component where things are coming from. With this readers will know exactly where the message is coming from. We use pr_* helpers but define pr_fmt to the empty string for easier grepping for those error messages. We leave the users of dprintk() in place, this will print only when the debugpat kernel parameter is enabled. We want to leave those enabled as a debug feature, but also make them use the same prefix. Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> [ Kill pr_fmt. ] 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: 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: 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> Cc: cocci@systeme.lip6.fr Cc: plagnioj@jcrosoft.com Cc: tomi.valkeinen@ti.com Link: http://lkml.kernel.org/r/1430425520-22275-2-git-send-email-mcgrof@do-not-panic.com Link: http://lkml.kernel.org/r/1432628901-18044-9-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27x86/mm/mtrr: Enhance MTRR checks in kernel mapping helpersToshi Kani
This patch adds the argument 'uniform' to mtrr_type_lookup(), which gets set to 1 when a given range is covered uniformly by MTRRs, i.e. the range is fully covered by a single MTRR entry or the default type. Change pud_set_huge() and pmd_set_huge() to honor the 'uniform' flag to see if it is safe to create a huge page mapping in the range. This allows them to create a huge page mapping in a range covered by a single MTRR entry of any memory type. It also detects a non-optimal request properly. They continue to check with the WB type since it does not effectively change the uniform mapping even if a request spans multiple MTRR entries. pmd_set_huge() logs a warning message to a non-optimal request so that driver writers will be aware of such a case. Drivers should make a mapping request aligned to a single MTRR entry when the range is covered by MTRRs. Signed-off-by: Toshi Kani <toshi.kani@hp.com> [ Realign, flesh out comments, improve warning message. ] 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: 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: dave.hansen@intel.com Cc: linux-mm <linux-mm@kvack.org> Cc: pebolle@tiscali.nl Link: http://lkml.kernel.org/r/1431714237-880-7-git-send-email-toshi.kani@hp.com Link: http://lkml.kernel.org/r/1432628901-18044-8-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-19x86/mm/pat: Ensure different messages in STRICT_DEVMEM and PAT casesPavel Machek
STRICT_DEVMEM and PAT produce same failure accessing /dev/mem, which is quite confusing to the user. Make printk messages different to lessen confusion. Signed-off-by: Pavel Machek <pavel@ucw.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-20x86: Don't rely on VMWare emulating PAT MSR correctlyJuergen Gross
VMWare seems not to emulate the PAT MSR correctly: reaeding MSR_IA32_CR_PAT returns 0 even after writing another value to it. Commit bd809af16e3ab triggers this VMWare bug when the kernel is booted as a VMWare guest. Detect this bug and don't use the read value if it is 0. Fixes: bd809af16e3ab "x86: Enable PAT to use cache mode translation tables" Reported-and-tested-by: Jongman Heo <jongman.heo@samsung.com> Acked-by: Alok N Kataria <akataria@vmware.com> Signed-off-by: Juergen Gross <jgross@suse.com> Link: http://lkml.kernel.org/r/1421039745-14335-1-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-12-10Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds
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 ...
2014-12-08x86: Replace seq_printf() with seq_puts()Rasmus Villemoes
seq_puts is a lot cheaper than seq_printf, so use that to print literal strings. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Link: http://lkml.kernel.org/r/1417208622-12264-1-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-16x86: mm: Move PAT only functions to mm/pat.cThomas Gleixner
Commit e00c8cc93c1a "x86: Use new cache mode type in memtype related functions" broke the ARCH=um build. arch/x86/include/asm/cacheflush.h:67:36: error: return type is an incomplete type static inline enum page_cache_mode get_page_memtype(struct page *pg) The reason is simple. get_page_memtype() and set_page_memtype() require enum page_cache_mode now, which is defined in asm/pgtable_types.h. UM does not include that file for obvious reasons. The simple solution is to move that functions to arch/x86/mm/pat.c where the only callsites of this are located. They should have been there in the first place. Fixes: e00c8cc93c1a "x86: Use new cache mode type in memtype related functions" Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Juergen Gross <jgross@suse.com> Cc: Richard Weinberger <richard@nod.at>
2014-11-16x86: Enable PAT to use cache mode translation tablesJuergen Gross
Update the translation tables from cache mode to pgprot values according to the PAT settings. This enables changing the cache attributes of a PAT index in just one place without having to change at the users side. With this change it is possible to use the same kernel with different PAT configurations, e.g. supporting Xen. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Toshi Kani <toshi.kani@hp.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: stefan.bader@canonical.com Cc: xen-devel@lists.xensource.com Cc: ville.syrjala@linux.intel.com Cc: david.vrabel@citrix.com Cc: jbeulich@suse.com Cc: plagnioj@jcrosoft.com Cc: tomi.valkeinen@ti.com Cc: bhelgaas@google.com Link: http://lkml.kernel.org/r/1415019724-4317-18-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 Gross
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 mm/ioremap.cJuergen Gross
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/1415019724-4317-13-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-16x86: Use new cache mode type in track_pfn_remap() and track_pfn_insert()Juergen Gross
Instead of directly using the cache mode bits in the pte switch to using the cache mode type. As those are the main callers of lookup_memtype(), change this as well. 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/1415019724-4317-10-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-16x86: Use new cache mode type in mm/iomap_32.cJuergen Gross
Instead of directly using the cache mode bits in the pte switch to using the cache mode type. This requires to change io_reserve_memtype() as well. 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/1415019724-4317-9-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-16x86: Use new cache mode type in asm/pgtable.hJuergen Gross
Instead of directly using the cache mode bits in the pte switch to using the cache mode type. This requires changing some callers of is_new_memtype_allowed() to be changed as well. 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/1415019724-4317-8-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-03-07x86: Do not try to sync identity map for non-mapped pagesDave Hansen
kernel_map_sync_memtype() is called from a variety of contexts. The pat.c code that calls it seems to ensure that it is not called for non-ram areas by checking via pat_pagerange_is_ram(). It is important that it only be called on the actual identity map because there *IS* no map to sync for highmem pages, or for memory holes. The ioremap.c uses are not as careful as those from pat.c, and call kernel_map_sync_memtype() on PCI space which is in the middle of the kernel identity map _range_, but is not actually mapped. This patch adds a check to kernel_map_sync_memtype() which probably duplicates some of the checks already in pat.c. But, it is necessary for the ioremap.c uses and shouldn't hurt other callers. I have reproduced this bug and this patch fixes it for me and the original bug reporter: https://lkml.org/lkml/2013/2/5/396 Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20130307163151.D9B58C4E@kernel.stglabs.ibm.com Signed-off-by: Dave Hansen <dave@sr71.net> Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2013-01-25x86, mm: Make DEBUG_VIRTUAL work earlier in bootDave Hansen
The KVM code has some repeated bugs in it around use of __pa() on per-cpu data. Those data are not in an area on which using __pa() is valid. However, they are also called early enough in boot that __vmalloc_start_set is not set, and thus the CONFIG_DEBUG_VIRTUAL debugging does not catch them. This adds a check to also verify __pa() calls against max_low_pfn, which we can use earler in boot than is_vmalloc_addr(). However, if we are super-early in boot, max_low_pfn=0 and this will trip on every call, so also make sure that max_low_pfn is set before we try to use it. With this patch applied, CONFIG_DEBUG_VIRTUAL will actually catch the bug I was chasing (and fix later in this series). I'd love to find a generic way so that any __pa() call on percpu areas could do a BUG_ON(), but there don't appear to be any nice and easy ways to check if an address is a percpu one. Anybody have ideas on a way to do this? Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20130122212430.F46F8159@kernel.stglabs.ibm.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-10-09mm, x86, pat: rework linear pfn-mmap trackingKonstantin Khlebnikov
Replace the generic vma-flag VM_PFN_AT_MMAP with x86-only VM_PAT. We can toss mapping address from remap_pfn_range() into track_pfn_vma_new(), and collect all PAT-related logic together in arch/x86/. This patch also restores orignal frustration-free is_cow_mapping() check in remap_pfn_range(), as it was before commit v2.6.28-rc8-88-g3c8bb73 ("x86: PAT: store vm_pgoff for all linear_over_vma_region mappings - v3") is_linear_pfn_mapping() checks can be removed from mm/huge_memory.c, because it already handled by VM_PFNMAP in VM_NO_THP bit-mask. [suresh.b.siddha@intel.com: Reset the VM_PAT flag as part of untrack_pfn_vma()] Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Venkatesh Pallipadi <venki@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Eric Paris <eparis@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Venkatesh Pallipadi <venki@google.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09x86, pat: separate the pfn attribute tracking for remap_pfn_range and ↵Suresh Siddha
vm_insert_pfn With PAT enabled, vm_insert_pfn() looks up the existing pfn memory attribute and uses it. Expectation is that the driver reserves the memory attributes for the pfn before calling vm_insert_pfn(). remap_pfn_range() (when called for the whole vma) will setup a new attribute (based on the prot argument) for the specified pfn range. This addresses the legacy usage which typically calls remap_pfn_range() with a desired memory attribute. For ranges smaller than the vma size (which is typically not the case), remap_pfn_range() will use the existing memory attribute for the pfn range. Expose two different API's for these different behaviors. track_pfn_insert() for tracking the pfn attribute set by vm_insert_pfn() and track_pfn_remap() for the remap_pfn_range(). This cleanup also prepares the ground for the track/untrack pfn vma routines to take over the ownership of setting PAT specific vm_flag in the 'vma'. [khlebnikov@openvz.org: Clear checks in track_pfn_remap()] [akpm@linux-foundation.org: tweak a few comments] Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Venkatesh Pallipadi <venki@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Eric Paris <eparis@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>