diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2018-02-14 21:25:35 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-02-16 10:48:47 +0100 |
| commit | b16e770bfa5344f1cd4f7b4ecd7bbae25001e120 (patch) | |
| tree | 47ba333dc01234e8e5d026296536d58b56a2b76f /arch/x86/boot/compressed | |
| parent | 4c2b4058ab32581931c2caf760b689fd4b019a87 (diff) | |
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@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180214182542.69302-3-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/boot/compressed')
| -rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index d02a838c0ce4..66e42a098d70 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 |