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| author | Andy Lutomirski <luto@kernel.org> | 2017-06-29 08:53:21 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-07-05 10:52:58 +0200 |
| commit | 660da7c9228f685b2ebe664f9fd69aaddcc420b5 (patch) | |
| tree | 363dd4d5cc99b8d78cf66d8f6c3973a1d852dcb5 /arch/x86/include/asm/tlbflush.h | |
| parent | 0790c9aad84901ca1bdc14746175549c8b5da215 (diff) | |
| download | linux-660da7c9228f685b2ebe664f9fd69aaddcc420b5.tar.bz2 | |
x86/mm: Enable CR4.PCIDE on supported systems
We can use PCID if the CPU has PCID and PGE and we're not on Xen.
By itself, this has no effect. A followup patch will start using PCID.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Nadav Amit <nadav.amit@gmail.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.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: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/6327ecd907b32f79d5aa0d466f04503bbec5df88.1498751203.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/tlbflush.h')
| -rw-r--r-- | arch/x86/include/asm/tlbflush.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index 06e997a36d49..6397275008db 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -243,6 +243,14 @@ static inline void __flush_tlb_all(void) __flush_tlb_global(); else __flush_tlb(); + + /* + * Note: if we somehow had PCID but not PGE, then this wouldn't work -- + * we'd end up flushing kernel translations for the current ASID but + * we might fail to flush kernel translations for other cached ASIDs. + * + * To avoid this issue, we force PCID off if PGE is off. + */ } static inline void __flush_tlb_one(unsigned long addr) |