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2016-03-29x86/mtrr: Fix PAT init handling when MTRR is disabledToshi Kani
get_mtrr_state() calls pat_init() on BSP even if MTRR is disabled. This results in calling pat_init() on BSP only since APs do not call pat_init() when MTRR is disabled. This inconsistency between BSP and APs leads to undefined behavior. Make BSP's calling condition to pat_init() consistent with AP's, mtrr_ap_init() and mtrr_aps_init(). 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/1458769323-24491-6-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27x86/mm/mtrr: Generalize runtime disabling of MTRRsLuis R. Rodriguez
It is possible to enable CONFIG_MTRR and CONFIG_X86_PAT and end up with a system with MTRR functionality disabled but PAT functionality enabled. This can happen, for instance, when the Xen hypervisor is used where MTRRs are not supported but PAT is. This can happen on Linux as of commit 47591df50512 ("xen: Support Xen pv-domains using PAT") by Juergen, introduced in v3.19. Technically, we should assume the proper CPU bits would be set to disable MTRRs but we can't always rely on this. At least on the Xen Hypervisor, for instance, only X86_FEATURE_MTRR was disabled as of Xen 4.4 through Xen commit 586ab6a [0], but not X86_FEATURE_K6_MTRR, X86_FEATURE_CENTAUR_MCR, or X86_FEATURE_CYRIX_ARR for instance. Roger Pau Monné has clarified though that although this is technically true we will never support PVH on these CPU types so Xen has no need to disable these bits on those systems. As per Roger, AMD K6, Centaur and VIA chips don't have the necessary hardware extensions to allow running PVH guests [1]. As per Toshi it is also possible for the BIOS to disable MTRR support, in such cases get_mtrr_state() would update the MTRR state as per the BIOS, we need to propagate this information as well. x86 MTRR code relies on quite a bit of checks for mtrr_if being set to check to see if MTRRs did get set up. Instead, lets provide a generic getter for that. This also adds a few checks where they were not before which could potentially safeguard ourselves against incorrect usage of MTRR where this was not desirable. Where possible match error codes as if MTRRs were disabled on arch/x86/include/asm/mtrr.h. Lastly, since disabling MTRRs can happen at run time and we could end up with PAT enabled, best record now in our logs when MTRRs are disabled. [0] ~/devel/xen (git::stable-4.5)$ git describe --contains 586ab6a 4.4.0-rc1~18 [1] http://lists.xenproject.org/archives/html/xen-devel/2015-03/msg03460.html Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Antonino Daplas <adaplas@gmail.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: Dave Hansen <dave.hansen@linux.intel.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.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: Peter Zijlstra <peterz@infradead.org> Cc: Roger Pau Monné <roger.pau@citrix.com> Cc: Stefan Bader <stefan.bader@canonical.com> Cc: Suresh Siddha <sbsiddha@gmail.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: bhelgaas@google.com Cc: david.vrabel@citrix.com Cc: jbeulich@suse.com Cc: konrad.wilk@oracle.com Cc: venkatesh.pallipadi@intel.com Cc: ville.syrjala@linux.intel.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/1426893517-2511-3-git-send-email-mcgrof@do-not-panic.com Link: http://lkml.kernel.org/r/1432628901-18044-12-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2010-02-01x86, mtrr: Constify struct mtrr_opsEmese Revfy
This is part of the ops structure constification effort started by Arjan van de Ven et al. Benefits of this constification: * prevents modification of data that is shared (referenced) by many other structure instances at runtime * detects/prevents accidental (but not intentional) modification attempts on archs that enforce read-only kernel data at runtime * potentially better optimized code as the compiler can assume that the const data cannot be changed * the compiler/linker move const data into .rodata and therefore exclude them from false sharing Signed-off-by: Emese Revfy <re.emese@gmail.com> LKML-Reference: <4B65D712.3080804@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-07-04x86: Clean up mtrr/mtrr.hJaswinder Singh Rajput
Fix: ERROR: do not use C99 // comments ERROR: "foo * bar" should be "foo *bar" X 2 Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <20090703164225.GA21447@elte.hu> [ More tidyups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-15x86, mtrr: replace MTRRdefType_MSR with msr-index's MSR_MTRRdefTypeJaswinder Singh Rajput
Use standard msr-index.h's MSR declaration and no need to declare again. [ Impact: cleanup, no object code change ] Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-15x86, mtrr: replace MTRRfix4K_C0000_MSR with msr-index's MSR_MTRRfix4K_C0000Jaswinder Singh Rajput
Use standard msr-index.h's MSR declaration and no need to declare again. [ Impact: cleanup, no object code change ] Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-15x86, mtrr: remove mtrr MSRs double declarationJaswinder Singh Rajput
Removed MTRR MSR from mtrr/mtrr.h as these are already declared in msr-index.h and nobody is using them: MTRRfix16K_A0000_MSR MTRRfix4K_C8000_MSR MTRRfix4K_D0000_MSR MTRRfix4K_D8000_MSR MTRRfix4K_E0000_MSR MTRRfix4K_E8000_MSR MTRRfix4K_F0000_MSR MTRRfix4K_F8000_MSR Use standard msr-index.h's MSR declaration and no need to declare again [ Impact: cleanup, no object code change ] Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-15x86, mtrr: replace MTRRfix16K_80000_MSR with msr-index's MSR_MTRRfix16K_80000Jaswinder Singh Rajput
Use standard msr-index.h's MSR declaration and no need to declare again [ Impact: cleanup, no object code change ] Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-15x86, mtrr: replace MTRRfix64K_00000_MSR with msr-index's MSR_MTRRfix64K_00000Jaswinder Singh Rajput
Use standard msr-index.h's MSR declaration and no need to declare again. [ Impact: cleanup, no object code change ] Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-15x86, mtrr: replace MTRRcap_MSR with msr-index's MSR_MTRRcapJaswinder Singh Rajput
Use standard msr-index.h's MSR declaration and no need to declare again. [ Impact: cleanup, no object code change ] Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-17x86: MTRR workaround for system with stange var MTRRsYinghai Lu
Impact: don't trim e820 according to wrong mtrr Ozan reports that his server emits strange warning. it turns out the BIOS sets the MTRRs incorrectly. Ignore those strange ranges, and don't trim e820, just emit one warning about BIOS Reported-by: Ozan Çağlayan <ozan@pardus.org.tr> Signed-off-by: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <49BEE1E7.7020706@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-13x86: separate mtrr cleanup/mtrr_e820 trim to separate fileYinghai Lu
Impact: cleanup mtrr main.c is too big, seperate mtrr cleanup and mtrr e820 trim code to another file. Signed-off-by: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <49B87C7B.80809@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-31x86: Export some definition of MTRRSheng Yang
For KVM can reuse the type define, and need them to support shadow MTRR. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31x86: Rename mtrr_state struct and macro namesSheng Yang
Prepare for exporting them. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2008-05-25x86: mtrr cleanup for converting continuous to discrete layout, v8Yinghai Lu
some BIOS like to use continus MTRR layout, and X driver can not add WB entries for graphical cards when 4g or more RAM installed. the patch will change MTRR to discrete. mtrr_chunk_size= could be used to have smaller continuous block to hold holes. default is 256m, could be set according to size of graphics card memory. mtrr_gran_size= could be used to send smallest mtrr block to avoid run out of MTRRs v2: fix -1 for UC checking v3: default to disable, and need use enable_mtrr_cleanup to enable this feature skip the var state change warning. remove next_basek in range_to_mtrr() v4: correct warning mask. v5: CONFIG_MTRR_SANITIZER v6: fix 1g, 2g, 512 aligment with extra hole v7: gran_sizek to prevent running out of MTRRs. v8: fix hole_basek caculation caused when removing next_basek gran_sizek using when basek is 0. need to apply [PATCH] x86: fix trimming e820 with MTRR holes. right after this one. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-04x86: add cpu mtrr init function definitions to mtrr.hHarvey Harrison
mtrr.h was included everywhere needed. Fixes the following sparse warnings. Also, the return types in the extern definitions were incorrect. arch/x86/kernel/cpu/mtrr/amd.c:113:12: warning: symbol 'amd_init_mtrr' was not declared. Should it be static? arch/x86/kernel/cpu/mtrr/cyrix.c:268:12: warning: symbol 'cyrix_init_mtrr' was not declared. Should it be static? arch/x86/kernel/cpu/mtrr/centaur.c:218:12: warning: symbol 'centaur_init_mtrr' was not declared. Should it be static? Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86, 32-bit: trim memory not covered by wb mtrrsJesse Barnes
On some machines, buggy BIOSes don't properly setup WB MTRRs to cover all available RAM, meaning the last few megs (or even gigs) of memory will be marked uncached. Since Linux tends to allocate from high memory addresses first, this causes the machine to be unusably slow as soon as the kernel starts really using memory (i.e. right around init time). This patch works around the problem by scanning the MTRRs at boot and figuring out whether the current end_pfn value (setup by early e820 code) goes beyond the highest WB MTRR range, and if so, trimming it to match. A fairly obnoxious KERN_WARNING is printed too, letting the user know that not all of their memory is available due to a likely BIOS bug. Something similar could be done on i386 if needed, but the boot ordering would be slightly different, since the MTRR code on i386 depends on the boot_cpu_data structure being setup. This patch fixes a bug in the last patch that caused the code to run on non-Intel machines (AMD machines apparently don't need it and it's untested on other non-Intel machines, so best keep it off). Further enhancements and fixes from: Yinghai Lu <Yinghai.Lu@Sun.COM> Andi Kleen <ak@suse.de> Signed-off-by: Jesse Barnes <jesse.barnes@intel.com> Tested-by: Justin Piszcz <jpiszcz@lucidpixels.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: mtrr use type bool [RESEND AGAIN]Paul Jimenez
This is a janitorish patch to 1) remove private TRUE/FALSE #def's in favor of using the standard enum from linux/stddef.h and 2) switch the variables holding those values to type 'bool' (from linux/types.h) since it both seems more appropriate and allows for potentially better optimization. As a truly minor aside, I removed a couple of comments documenting a 'do_safe' parameter that seems to no longer exist. Signed-off-by: Paul Jimenez <pj@place.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-11i386: move kernel/cpu/mtrrThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>