forked from Minki/linux
224bb1e5d6
In preparation for fixing a regression caused by:
9cd25aac1f ("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>
25 lines
671 B
C
25 lines
671 B
C
#ifndef _ASM_X86_PAT_H
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#define _ASM_X86_PAT_H
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#include <linux/types.h>
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#include <asm/pgtable_types.h>
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bool pat_enabled(void);
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void pat_disable(const char *reason);
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extern void pat_init(void);
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void __init_cache_modes(u64);
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extern int reserve_memtype(u64 start, u64 end,
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enum page_cache_mode req_pcm, enum page_cache_mode *ret_pcm);
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extern int free_memtype(u64 start, u64 end);
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extern int kernel_map_sync_memtype(u64 base, unsigned long size,
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enum page_cache_mode pcm);
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int io_reserve_memtype(resource_size_t start, resource_size_t end,
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enum page_cache_mode *pcm);
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void io_free_memtype(resource_size_t start, resource_size_t end);
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#endif /* _ASM_X86_PAT_H */
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