forked from Minki/linux
99c13b8c88
The pat_enabled() logic is broken on CPUs which do not support PAT and
where the initialization code fails to call pat_init(). Due to that the
enabled flag stays true and pat_enabled() returns true wrongfully.
As a consequence the mappings, e.g. for Xorg, are set up with the wrong
caching mode and the required MTRR setups are omitted.
To cure this the following changes are required:
1) Make pat_enabled() return true only if PAT initialization was
invoked and successful.
2) Invoke init_cache_modes() unconditionally in setup_arch() and
remove the extra callsites in pat_disable() and the pat disabled
code path in pat_init().
Also rename __pat_enabled to pat_disabled to reflect the real purpose of
this variable.
Fixes: 9cd25aac1f ("x86/mm/pat: Emulate PAT when it is disabled")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bernhard Held <berny156@gmx.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: "Luis R. Rodriguez" <mcgrof@suse.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1707041749300.3456@file01.intranet.prod.int.rdu2.redhat.com
25 lines
677 B
C
25 lines
677 B
C
#ifndef _ASM_X86_PAT_H
|
|
#define _ASM_X86_PAT_H
|
|
|
|
#include <linux/types.h>
|
|
#include <asm/pgtable_types.h>
|
|
|
|
bool pat_enabled(void);
|
|
void pat_disable(const char *reason);
|
|
extern void pat_init(void);
|
|
extern void init_cache_modes(void);
|
|
|
|
extern int reserve_memtype(u64 start, u64 end,
|
|
enum page_cache_mode req_pcm, enum page_cache_mode *ret_pcm);
|
|
extern int free_memtype(u64 start, u64 end);
|
|
|
|
extern int kernel_map_sync_memtype(u64 base, unsigned long size,
|
|
enum page_cache_mode pcm);
|
|
|
|
int io_reserve_memtype(resource_size_t start, resource_size_t end,
|
|
enum page_cache_mode *pcm);
|
|
|
|
void io_free_memtype(resource_size_t start, resource_size_t end);
|
|
|
|
#endif /* _ASM_X86_PAT_H */
|