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path: root/arch/x86/realmode/init.c
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2015-02-04x86: Store a per-cpu shadow copy of CR4Andy Lutomirski
Context switches and TLB flushes can change individual bits of CR4. CR4 reads take several cycles, so store a shadow copy of CR4 in a per-cpu variable. To avoid wasting a cache line, I added the CR4 shadow to cpu_tlbstate, which is already touched in switch_mm. The heaviest users of the cr4 shadow will be switch_mm and __switch_to_xtra, and __switch_to_xtra is called shortly after switch_mm during context switch, so the cacheline is likely to be hot. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Vince Weaver <vince@deater.net> Cc: "hillf.zj" <hillf.zj@alibaba-inc.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/3a54dd3353fffbf84804398e00dfdc5b7c1afd7d.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-12-18x86, realmode: Pointer walk cleanups, pull out invariant use of __pa()H. Peter Anvin
The pointer arithmetic in this function was really bizarre, where in fact all we really wanted was a simple pointer array walk. Use the much more idiomatic construction for that (*ptr++). Factor an invariant use of __pa() out of the relocation loop. At least on 64 bits it seems gcc isn't capable of doing that automatically. Change the scope of a couple of variables to make it extra obvious that they are extremely local temp variables. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/n/tip-rd908t9c8kvcojdabtmm94mb@git.kernel.org
2013-02-01Merge remote-tracking branch 'origin/x86/mm' into x86/mm2H. Peter Anvin
Explicitly merging these two branches due to nontrivial conflicts and to allow further work. Resolved Conflicts: arch/x86/kernel/head32.c arch/x86/kernel/head64.c arch/x86/mm/init_64.c arch/x86/realmode/init.c Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-29x86, realmode: Separate real_mode reserve and setupYinghai Lu
After we switch to use #PF handler help to set page table, init_level4_pgt will only have entries set after init_mem_mapping(). We need to move copying init_level4_pgt to trampoline_pgd after that. So split reserve and setup, and move the setup after init_mem_mapping() Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1359058816-7615-11-git-send-email-yinghai@kernel.org Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Acked-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-29x86, 64bit, realmode: Use init_level4_pgt to set trampoline_pgd directlyYinghai Lu
with #PF handler way to set early page table, level3_ident will go away with 64bit native path. So just use entries in init_level4_pgt to set them in trampoline_pgd. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1359058816-7615-10-git-send-email-yinghai@kernel.org Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Acked-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-29x86, realmode: Set real_mode permissions earlyYinghai Lu
Trampoline code is executed by APs with kernel low mapping on 64bit. We need to set trampoline code to EXEC early before we boot APs. Found the problem after switching to #PF handler set page table, and we do not set initial kernel low mapping with EXEC anymore in arch/x86/kernel/head_64.S. Change to use early_initcall instead that will make sure trampoline will have EXEC set. -v2: Merge two comments according to Borislav Petkov <bp@alien8.de> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1359058816-7615-7-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-16x86: Use __pa_symbol instead of __pa on C visible symbolsAlexander Duyck
When I made an attempt at separating __pa_symbol and __pa I found that there were a number of cases where __pa was used on an obvious symbol. I also caught one non-obvious case as _brk_start and _brk_end are based on the address of __brk_base which is a C visible symbol. In mark_rodata_ro I was able to reduce the overhead of kernel symbol to virtual memory translation by using a combination of __va(__pa_symbol()) instead of page_address(virt_to_page()). Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Link: http://lkml.kernel.org/r/20121116215640.8521.80483.stgit@ahduyck-cp1.jf.intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-16x86, realmode: Change EFER to a single u64 fieldH. Peter Anvin
Change EFER to be a single u64 field instead of two u32 fields; change the order to maintain alignment. Note that on x86-64 cr4 is really also a 64-bit quantity, although we can only set the low 32 bits from the trampoline code since it is still executing in 32-bit mode at that point. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
2012-05-16x86, realmode: Move kernel/realmode.c to realmode/init.cH. Peter Anvin
Keep all the realmode code together, including initialization (only the rm/ subdirectory is actually built as real-mode code, anyway.) Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>