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2024-08-25x86/mtrr: Remove obsolete declaration for mtrr_bp_restore()Gaosheng Cui1-2/+0
mtrr_bp_restore() has been removed in commit 0b9a6a8bedbf ("x86/mtrr: Add a stop_machine() handler calling only cache_cpu_init()"), but the declaration was left behind. Remove it. Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20240824120234.2516830-1-cuigaosheng1@huawei.com
2023-06-01x86/mtrr: Remove unused codeJuergen Gross1-4/+0
mtrr_centaur_report_mcr() isn't used by anyone, so it can be removed. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20230502120931.20719-17-jgross@suse.com Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2023-06-01x86/mtrr: Don't let mtrr_type_lookup() return MTRR_TYPE_INVALIDJuergen Gross1-2/+5
mtrr_type_lookup() should always return a valid memory type. In case there is no information available, it should return the default UC. This will remove the last case where mtrr_type_lookup() can return MTRR_TYPE_INVALID, so adjust the comment in include/uapi/asm/mtrr.h. Note that removing the MTRR_TYPE_INVALID #define from that header could break user code, so it has to stay. At the same time the mtrr_type_lookup() stub for the !CONFIG_MTRR case should set uniform to 1, as if the memory range would be covered by no MTRR at all. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20230502120931.20719-15-jgross@suse.com Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2023-06-01x86/mtrr: Support setting MTRR state for software defined MTRRsJuergen Gross1-0/+8
When running virtualized, MTRR access can be reduced (e.g. in Xen PV guests or when running as a SEV-SNP guest under Hyper-V). Typically, the hypervisor will not advertize the MTRR feature in CPUID data, resulting in no MTRR memory type information being available for the kernel. This has turned out to result in problems (Link tags below): - Hyper-V SEV-SNP guests using uncached mappings where they shouldn't - Xen PV dom0 mapping memory as WB which should be UC- instead Solve those problems by allowing an MTRR static state override, overwriting the empty state used today. In case such a state has been set, don't call get_mtrr_state() in mtrr_bp_init(). The set state will only be used by mtrr_type_lookup(), as in all other cases mtrr_enabled() is being checked, which will return false. Accept the overwrite call only for selected cases when running as a guest. Disable X86_FEATURE_MTRR in order to avoid any MTRR modifications by just refusing them. [ bp: Massage. ] Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/all/4fe9541e-4d4c-2b2a-f8c8-2d34a7284930@nerdbynature.de/ Link: https://lore.kernel.org/lkml/BYAPR21MB16883ABC186566BD4D2A1451D7FE9@BYAPR21MB1688.namprd21.prod.outlook.com Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2023-06-01x86/mtrr: Replace size_or_mask and size_and_mask with a much easier conceptJuergen Gross1-2/+30
Replace size_or_mask and size_and_mask with the much easier concept of high reserved bits. While at it, instead of using constants in the MTRR code, use some new [ bp: - Drop mtrr_set_mask() - Unbreak long lines - Move struct mtrr_state_type out of the uapi header as it doesn't belong there. It also fixes a HDRTEST breakage "unknown type name ‘bool’" as Reported-by: kernel test robot <lkp@intel.com> - Massage. ] Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230502120931.20719-3-jgross@suse.com Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2022-11-10x86/mtrr: Add a stop_machine() handler calling only cache_cpu_init()Juergen Gross1-6/+2
Instead of having a stop_machine() handler for either a specific MTRR register or all state at once, add a handler just for calling cache_cpu_init() if appropriate. Add functions for calling stop_machine() with this handler as well. Add a generic replacement for mtrr_bp_restore() and a wrapper for mtrr_bp_init(). Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20221102074713.21493-13-jgross@suse.com Signed-off-by: Borislav Petkov <bp@suse.de>
2022-11-10x86/mtrr: Let cache_aps_delayed_init replace mtrr_aps_delayed_initJuergen Gross1-2/+0
In order to prepare decoupling MTRR and PAT replace the MTRR-specific mtrr_aps_delayed_init flag with a more generic cache_aps_delayed_init one. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20221102074713.21493-12-jgross@suse.com Signed-off-by: Borislav Petkov <bp@suse.de>
2022-11-10x86/mtrr: Disentangle MTRR init from PAT initJuergen Gross1-0/+2
Add a main cache_cpu_init() init routine which initializes MTRR and/or PAT support depending on what has been detected on the system. Leave the MTRR-specific initialization in a MTRR-specific init function where the smp_changes_mask setting happens now with caches disabled. This global mask update was done with caches enabled before probably because atomic operations while running uncached might have been quite expensive. But since only systems with a broken BIOS should ever require to set any bit in smp_changes_mask, hurting those devices with a penalty of a few microseconds during boot shouldn't be a real issue. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20221102074713.21493-8-jgross@suse.com Signed-off-by: Borislav Petkov <bp@suse.de>
2022-11-10x86/mtrr: Split MTRR-specific handling from cache dis/enablingJuergen Gross1-0/+4
Split the MTRR-specific actions from cache_disable() and cache_enable() into new functions mtrr_disable() and mtrr_enable(). Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20221102074713.21493-6-jgross@suse.com Signed-off-by: Borislav Petkov <bp@suse.de>
2021-12-22x86/mtrr: Remove the mtrr_bp_init() stubChristoph Hellwig1-7/+1
Add an IS_ENABLED() check in setup_arch() and call pat_disable() directly if MTRRs are not supported. This allows to remove the <asm/memtype.h> include in <asm/mtrr.h>, which pull in lowlevel x86 headers that should not be included for UML builds and will cause build warnings with a following patch. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20211215165612.554426-2-hch@lst.de
2019-12-10x86/mm/pat: Rename <asm/pat.h> => <asm/memtype.h>Ingo Molnar1-1/+1
pat.h is a file whose main purpose is to provide the memtype_*() APIs. PAT is the low level hardware mechanism - but the high level abstraction is memtype. So name the header <memtype.h> as well - this goes hand in hand with memtype.c and memtype_interval.c. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-12-10x86/mm/pat: Disambiguate PAT-disabled boot messagesIngo Molnar1-1/+1
Right now we have these four types of PAT-disabled boot messages: x86/PAT: PAT support disabled. x86/PAT: PAT MSR is 0, disabled. x86/PAT: MTRRs disabled, skipping PAT initialization too. x86/PAT: PAT not supported by CPU. The first message is ambiguous in that it doesn't signal that PAT is off due to a boot option. The second message doesn't really make it clear that this is the MSR value during early bootup and it's the firmware environment that disabled PAT support. The fourth message doesn't really make it clear that we disable PAT support because CONFIG_MTRR is off in the kernel. Clarify, harmonize and fix the spelling in these user-visible messages: x86/PAT: PAT support disabled via boot option. x86/PAT: PAT support disabled by the firmware. x86/PAT: PAT support disabled because CONFIG_MTRR is disabled in the kernel. x86/PAT: PAT not supported by the CPU. Also add a fifth message, in case PAT support is disabled at build time: x86/PAT: PAT support disabled because CONFIG_X86_PAT is disabled in the kernel. Previously we'd just silently return from pat_init() without giving any indication that PAT support is off. Finally, clarify/extend some of the comments related to PAT initialization. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-29x86/mtrr: Fix Xorg crashes in Qemu sessionsToshi Kani1-1/+5
A Xorg failure on qemu32 was reported as a regression [1] caused by commit 9cd25aac1f44 ("x86/mm/pat: Emulate PAT when it is disabled"). This patch fixes the Xorg crash. Negative effects of this regression were the following two failures [2] in Xorg on QEMU with QEMU CPU model "qemu32" (-cpu qemu32), which were triggered by the fact that its virtual CPU does not support MTRRs. #1. copy_process() failed in the check in reserve_pfn_range() copy_process copy_mm dup_mm dup_mmap copy_page_range track_pfn_copy reserve_pfn_range A WC map request was tracked as WC in memtype, which set a PTE as UC (pgprot) per __cachemode2pte_tbl[]. This led to this error in reserve_pfn_range() called from track_pfn_copy(), which obtained a pgprot from a PTE. It converts pgprot to page_cache_mode, which does not necessarily result in the original page_cache_mode since __cachemode2pte_tbl[] redirects multiple types to UC. #2. error path in copy_process() then hit WARN_ON_ONCE in untrack_pfn(). x86/PAT: Xorg:509 map pfn expected mapping type uncached- minus for [mem 0xfd000000-0xfdffffff], got write-combining Call Trace: dump_stack warn_slowpath_common ? untrack_pfn ? untrack_pfn warn_slowpath_null untrack_pfn ? __kunmap_atomic unmap_single_vma ? pagevec_move_tail_fn unmap_vmas exit_mmap mmput copy_process.part.47 _do_fork SyS_clone do_syscall_32_irqs_on entry_INT80_32 These negative effects are caused by two separate bugs, but they can be addressed in separate patches. Fixing the pat_init() issue described below addresses the root cause, and avoids Xorg to hit these cases. When the CPU does not support MTRRs, MTRR does not call pat_init(), which leaves PAT enabled without initializing PAT. This pat_init() issue is a long-standing issue, but manifested as issue #1 (and then hit issue #2) with the above-mentioned commit because the memtype now tracks cache attribute with 'page_cache_mode'. This pat_init() issue existed before the commit, but we used pgprot in memtype. Hence, we did not have issue #1 before. But WC request resulted in WT in effect because WC pgrot is actually WT when PAT is not initialized. This is not how it was designed to work. When PAT is set to disable properly, WC is converted to UC. The use of WT can result in a system crash if the target range does not support WT. Fortunately, nobody ran into such issue before. To fix this pat_init() issue, PAT code has been enhanced to provide pat_disable() interface. Call this interface when MTRRs are disabled. By setting PAT to disable properly, PAT bypasses the memtype check, and avoids issue #1. [1]: https://lkml.org/lkml/2016/3/3/828 [2]: https://lkml.org/lkml/2016/3/4/775 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/1458769323-24491-5-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27x86/mm/mtrr: Avoid #ifdeffery with phys_wc_to_mtrr_index()Luis R. Rodriguez1-5/+0
There is only one user but since we're going to bury MTRR next out of access to drivers, expose this last piece of API to drivers in a general fashion only needing io.h for access to helpers. Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Abhilash Kesavan <a.kesavan@samsung.com> Cc: Andrew Morton <akpm@linux-foundation.org> 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: Catalin Marinas <catalin.marinas@arm.com> Cc: Cristian Stoica <cristian.stoica@freescale.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: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 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: Matthias Brugger <matthias.bgg@gmail.com> Cc: Mel Gorman <mgorman@suse.de> 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: dri-devel@lists.freedesktop.org Link: http://lkml.kernel.org/r/1429722736-4473-1-git-send-email-mcgrof@do-not-panic.com Link: http://lkml.kernel.org/r/1432628901-18044-11-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 Kani1-2/+2
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>
2015-05-27x86/mm/mtrr: Use symbolic define as a retval for disabled MTRRsToshi Kani1-1/+1
mtrr_type_lookup() returns verbatim 0xFF when MTRRs are disabled. This patch defines MTRR_TYPE_INVALID to clarify the meaning of this value, and documents its usage. Document the return values of the kernel virtual address mapping helpers pud_set_huge(), pmd_set_huge, pud_clear_huge() and pmd_clear_huge(). There is no functional change in this patch. 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: 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/1431714237-880-5-git-send-email-toshi.kani@hp.com Link: http://lkml.kernel.org/r/1432628901-18044-5-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27x86/mm/mtrr: Fix MTRR state checks in mtrr_type_lookup()Toshi Kani1-0/+4
'mtrr_state.enabled' contains the FE (fixed MTRRs enabled) and E (MTRRs enabled) flags in MSR_MTRRdefType. Intel SDM, section 11.11.2.1, defines these flags as follows: - All MTRRs are disabled when the E flag is clear. The FE flag has no affect when the E flag is clear. - The default type is enabled when the E flag is set. - MTRR variable ranges are enabled when the E flag is set. - MTRR fixed ranges are enabled when both E and FE flags are set. MTRR state checks in __mtrr_type_lookup() do not match with SDM. Hence, this patch makes the following changes: - The current code detects MTRRs disabled when both E and FE flags are clear in mtrr_state.enabled. Fix to detect MTRRs disabled when the E flag is clear. - The current code does not check if the FE bit is set in mtrr_state.enabled when looking at the fixed entries. Fix to check the FE flag. - The current code returns the default type when the E flag is clear in mtrr_state.enabled. However, the default type is UC when the E flag is clear. Remove the code as this case is handled as MTRR disabled with the 1st change. In addition, this patch defines the E and FE flags in mtrr_state.enabled as follows. - FE flag: MTRR_STATE_MTRR_FIXED_ENABLED - E flag: MTRR_STATE_MTRR_ENABLED print_mtrr_state() and x86_get_mtrr_mem_range() are also updated accordingly. 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: 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/1431714237-880-4-git-send-email-toshi.kani@hp.com Link: http://lkml.kernel.org/r/1432628901-18044-4-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-05-31Add arch_phys_wc_{add, del} to manipulate WC MTRRs if neededAndy Lutomirski1-1/+9
Several drivers currently use mtrr_add through various #ifdef guards and/or drm wrappers. The vast majority of them want to add WC MTRRs on x86 systems and don't actually need the MTRR if PAT (i.e. ioremap_wc, etc) are working. arch_phys_wc_add and arch_phys_wc_del are new functions, available on all architectures and configurations, that add WC MTRRs on x86 if needed (and handle errors) and do nothing at all otherwise. They're also easier to use than mtrr_add and mtrr_del, so the call sites can be simplified. As an added benefit, this will avoid wasting MTRRs and possibly warning pointlessly on PAT-supporting systems. Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-12-14UAPI: (Scripted) Disintegrate arch/x86/include/asmDavid Howells1-92/+1
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
2012-03-01x86, mtrr: Use explicit sizing and padding for the 64-bit ioctlsH. Peter Anvin1-10/+18
Specify the data structures for the 64-bit ioctls with explicit sizing and padding so that the x32 kernel will correctly use the 64-bit forms of these ioctls. Note that these ioctls are bogus in both forms on both 32 and 64 bits; even on 64 bits the maximum MTRR size is only 44 bits long. Note that nothing really is supposed to use these ioctls and that the preferred interface is text strings on /proc/mtrr, or better yet, nothing at all (use /sys/bus/pci/devices/*/resource*_wc for write combining; that uses PAT not MTRRs.) Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: H. J. Lu <hjl.tools@gmail.com> Tested-by: Nitin A. Kamble <nitin.a.kamble@intel.com> Link: http://lkml.kernel.org/n/tip-vwvnlu3hjmtkwvij4qxtm90l@git.kernel.org Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-08-21x86, mtrr: make mtrr_aps_delayed_init static boolH. Peter Anvin1-1/+0
mtr_aps_delayed_init was declared u32 and made global, but it only ever takes boolean values and is only ever used in arch/x86/kernel/cpu/mtrr/main.c. Declare it "static bool" and remove external references. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com>
2009-08-21x86, pat/mtrr: Rendezvous all the cpus for MTRR/PAT initSuresh Siddha1-0/+7
SDM Vol 3a section titled "MTRR considerations in MP systems" specifies the need for synchronizing the logical cpu's while initializing/updating MTRR. Currently Linux kernel does the synchronization of all cpu's only when a single MTRR register is programmed/updated. During an AP online (during boot/cpu-online/resume) where we initialize all the MTRR/PAT registers, we don't follow this synchronization algorithm. This can lead to scenarios where during a dynamic cpu online, that logical cpu is initializing MTRR/PAT with cache disabled (cr0.cd=1) etc while other logical HT sibling continue to run (also with cache disabled because of cr0.cd=1 on its sibling). Starting from Westmere, VMX transitions with cr0.cd=1 don't work properly (because of some VMX performance optimizations) and the above scenario (with one logical cpu doing VMX activity and another logical cpu coming online) can result in system crash. Fix the MTRR initialization by doing rendezvous of all the cpus. During boot and resume, we delay the MTRR/PAT init for APs till all the logical cpu's come online and the rendezvous process at the end of AP's bringup, will initialize the MTRR/PAT for all AP's. For dynamic single cpu online, we synchronize all the logical cpus and do the MTRR/PAT init on the AP that is coming online. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-31headers_check fix: x86, mtrr.hJaswinder Singh Rajput1-0/+1
fix the following 'make headers_check' warning: usr/include/asm/mtrr.h:61: found __[us]{8,16,32,64} type without #include <linux/types.h> Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
2009-01-08x86, mtrr: fix types used in userspace exported headerKyle McMartin1-5/+5
Commit 932d27a7913fc6b3c64c6e6082628b0a1561dec9 exported some mtrr structures without using the exportable __uX types, causing userspace build failures. Signed-off-by: Kyle McMartin <kyle@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-31x86: Export some definition of MTRRSheng Yang1-0/+25
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>
2008-10-22x86: Fix ASM_X86__ header guardsH. Peter Anvin1-3/+3
Change header guards named "ASM_X86__*" to "_ASM_X86_*" since: a. the double underscore is ugly and pointless. b. no leading underscore violates namespace constraints. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22x86, um: ... and asm-x86 moveAl Viro1-0/+173
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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