Commit-ID: b16e770bfa5344f1cd4f7b4ecd7bbae25001e120
Gitweb: https://git.kernel.org/tip/b16e770bfa5344f1cd4f7b4ecd7bbae25001e120
Author: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
AuthorDate: Wed, 14 Feb 2018 21:25:35 +0300
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 16 Feb 2018 10:48:47 +0100
x86/mm: Initialize 'pgdir_shift' and 'ptrs_per_p4d' at boot-time
Switching between paging modes requires the folding of the p4d page table level
when we only have 4 paging levels, which means we need to adjust 'pgdir_shift'
and 'ptrs_per_p4d' during early boot according to paging mode.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Link: http://lkml.kernel.org/r/20180214182542.69302-3-kirill.shutemov@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/boot/compressed/kaslr.c | 6 ++++--
arch/x86/kernel/head64.c | 6 ++++--
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index d02a838..66e42a0 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -48,8 +48,8 @@
#ifdef CONFIG_X86_5LEVEL
unsigned int pgtable_l5_enabled __ro_after_init;
-unsigned int pgdir_shift __ro_after_init = 48;
-unsigned int ptrs_per_p4d __ro_after_init = 512;
+unsigned int pgdir_shift __ro_after_init = 39;
+unsigned int ptrs_per_p4d __ro_after_init = 1;
#endif
extern unsigned long get_cmd_line_ptr(void);
@@ -732,6 +732,8 @@ void choose_random_location(unsigned long input,
#ifdef CONFIG_X86_5LEVEL
if (__read_cr4() & X86_CR4_LA57) {
pgtable_l5_enabled = 1;
+ pgdir_shift = 48;
+ ptrs_per_p4d = 512;
}
#endif
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index ffb31c5..8a0a485 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -42,9 +42,9 @@ 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 = 48;
+unsigned int pgdir_shift __ro_after_init = 39;
EXPORT_SYMBOL(pgdir_shift);
-unsigned int ptrs_per_p4d __ro_after_init = 512;
+unsigned int ptrs_per_p4d __ro_after_init = 1;
EXPORT_SYMBOL(ptrs_per_p4d);
#endif
@@ -79,6 +79,8 @@ static void __head check_la57_support(unsigned long physaddr)
return;
*fixup_int(&pgtable_l5_enabled, physaddr) = 1;
+ *fixup_int(&pgdir_shift, physaddr) = 48;
+ *fixup_int(&ptrs_per_p4d, physaddr) = 512;
}
#else
static void __head check_la57_support(unsigned long physaddr) {}
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|