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Commit ad3fe525 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Ingo Molnar
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x86/mm: Unify pgtable_l5_enabled usage in early boot code 



Usually pgtable_l5_enabled is defined using cpu_feature_enabled().
cpu_feature_enabled() is not available in early boot code. We use
several different preprocessor tricks to get around it. It's messy.

Unify them all.

If cpu_feature_enabled() is not yet available, USE_EARLY_PGTABLE_L5 can
be defined before all includes. It makes pgtable_l5_enabled rely on
__pgtable_l5_enabled variable instead. This approach fits all early
users.

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180518103528.59260-3-kirill.shutemov@linux.intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 30bbf728

arch/x86/boot/compressed/kaslr.c

+2 −2
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ 
#include <linux/decompress/mm.h>



#ifdef CONFIG_X86_5LEVEL

unsigned int pgtable_l5_enabled __ro_after_init;

unsigned int __pgtable_l5_enabled;

unsigned int pgdir_shift __ro_after_init = 39;

unsigned int ptrs_per_p4d __ro_after_init = 1;

#endif
@@ -734,7 +734,7 @@ void choose_random_location(unsigned long input, 


#ifdef CONFIG_X86_5LEVEL

	if (__read_cr4() & X86_CR4_LA57) {

		pgtable_l5_enabled = 1;

		__pgtable_l5_enabled = 1;

		pgdir_shift = 48;

		ptrs_per_p4d = 512;

	}

arch/x86/boot/compressed/misc.h

+2 −4
Original line number Diff line number Diff line
@@ -12,10 +12,8 @@ 
#undef CONFIG_PARAVIRT_SPINLOCKS

#undef CONFIG_KASAN



#ifdef CONFIG_X86_5LEVEL

/* cpu_feature_enabled() cannot be used that early */

#define pgtable_l5_enabled __pgtable_l5_enabled

#endif

/* cpu_feature_enabled() cannot be used this early */

#define USE_EARLY_PGTABLE_L5



#include <linux/linkage.h>

#include <linux/screen_info.h>

arch/x86/include/asm/pgtable_64_types.h

+10 −3
Original line number Diff line number Diff line
@@ -22,12 +22,19 @@ typedef struct { pteval_t pte; } pte_t; 


#ifdef CONFIG_X86_5LEVEL

extern unsigned int __pgtable_l5_enabled;

#ifndef pgtable_l5_enabled



#ifdef USE_EARLY_PGTABLE_L5

/*

 * cpu_feature_enabled() is not available in early boot code.

 * Use variable instead.

 */

#define pgtable_l5_enabled __pgtable_l5_enabled

#else

#define pgtable_l5_enabled cpu_feature_enabled(X86_FEATURE_LA57)

#endif

#endif /* USE_EARLY_PGTABLE_L5 */

#else

#define pgtable_l5_enabled 0

#endif

#endif /* CONFIG_X86_5LEVEL */



extern unsigned int pgdir_shift;

extern unsigned int ptrs_per_p4d;

arch/x86/kernel/head64.c

+5 −7
Original line number Diff line number Diff line
@@ -6,6 +6,10 @@ 
 */



#define DISABLE_BRANCH_PROFILING



/* cpu_feature_enabled() cannot be used this early */

#define USE_EARLY_PGTABLE_L5



#include <linux/init.h>

#include <linux/linkage.h>

#include <linux/types.h>
@@ -32,11 +36,6 @@ 
#include <asm/microcode.h>

#include <asm/kasan.h>



#ifdef CONFIG_X86_5LEVEL

#undef pgtable_l5_enabled

#define pgtable_l5_enabled __pgtable_l5_enabled

#endif



/*

 * Manage page tables very early on.

 */
@@ -46,7 +45,6 @@ pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); 


#ifdef CONFIG_X86_5LEVEL

unsigned int __pgtable_l5_enabled __ro_after_init;

EXPORT_SYMBOL(__pgtable_l5_enabled);

unsigned int pgdir_shift __ro_after_init = 39;

EXPORT_SYMBOL(pgdir_shift);

unsigned int ptrs_per_p4d __ro_after_init = 1;
@@ -88,7 +86,7 @@ static bool __head check_la57_support(unsigned long physaddr) 
	if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31))))

		return false;



	*fixup_int(&pgtable_l5_enabled, physaddr) = 1;

	*fixup_int(&__pgtable_l5_enabled, physaddr) = 1;

	*fixup_int(&pgdir_shift, physaddr) = 48;

	*fixup_int(&ptrs_per_p4d, physaddr) = 512;

	*fixup_long(&page_offset_base, physaddr) = __PAGE_OFFSET_BASE_L5;

arch/x86/mm/kasan_init_64.c

+2 −4
Original line number Diff line number Diff line
@@ -2,10 +2,8 @@ 
#define DISABLE_BRANCH_PROFILING

#define pr_fmt(fmt) "kasan: " fmt



#ifdef CONFIG_X86_5LEVEL

/* Too early to use cpu_feature_enabled() */

#define pgtable_l5_enabled __pgtable_l5_enabled

#endif

/* cpu_feature_enabled() cannot be used this early */

#define USE_EARLY_PGTABLE_L5



#include <linux/bootmem.h>

#include <linux/kasan.h>