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| author |   Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2018-02-14 14:16:53 +0300 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2018-02-14 13:11:14 +0100 |
| commit | c65e774fb3f6af212641538694b9778ff9ab4300 (patch) | |
| tree | 3c4da88dd0658874ea3fc7de3cc96ee27d711ef9 /arch/x86/mm | |
| parent | x86/mm: Make LDT_BASE_ADDR dynamic (diff) | |
| download | linux-dev-c65e774fb3f6af212641538694b9778ff9ab4300.tar.xz linux-dev-c65e774fb3f6af212641538694b9778ff9ab4300.zip | |
x86/mm: Make PGDIR_SHIFT and PTRS_PER_P4D variable
For boot-time switching between 4- and 5-level paging we need to be able
to fold p4d page table level at runtime. It requires variable
PGDIR_SHIFT and PTRS_PER_P4D.
The change doesn't affect the kernel image size much:
text data bss dec hex filename
8628091 4734304 1368064 14730459 e0c4db vmlinux.before
8628393 4734340 1368064 14730797 e0c62d vmlinux.after
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@suse.de>
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/20180214111656.88514-7-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/dump_pagetables.c | 12 | ||||
| -rw-r--r-- | arch/x86/mm/init_64.c | 2 | ||||
| -rw-r--r-- | arch/x86/mm/kasan_init_64.c | 2 |
3 files changed, 7 insertions, 9 deletions
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index a89f2dbc3531..420058b05d39 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -428,14 +428,15 @@ static void walk_pud_level(struct seq_file *m, struct pg_state *st, p4d_t addr, #define p4d_none(a) pud_none(__pud(p4d_val(a))) #endif -#if PTRS_PER_P4D > 1 - static void walk_p4d_level(struct seq_file *m, struct pg_state *st, pgd_t addr, unsigned long P) { int i; p4d_t *start, *p4d_start; pgprotval_t prot; + if (PTRS_PER_P4D == 1) + return walk_pud_level(m, st, __p4d(pgd_val(addr)), P); + p4d_start = start = (p4d_t *)pgd_page_vaddr(addr); for (i = 0; i < PTRS_PER_P4D; i++) { @@ -455,11 +456,8 @@ static void walk_p4d_level(struct seq_file *m, struct pg_state *st, pgd_t addr, } } -#else -#define walk_p4d_level(m,s,a,p) walk_pud_level(m,s,__p4d(pgd_val(a)),p) -#define pgd_large(a) p4d_large(__p4d(pgd_val(a))) -#define pgd_none(a) p4d_none(__p4d(pgd_val(a))) -#endif +#define pgd_large(a) (pgtable_l5_enabled ? pgd_large(a) : p4d_large(__p4d(pgd_val(a)))) +#define pgd_none(a) (pgtable_l5_enabled ? pgd_none(a) : p4d_none(__p4d(pgd_val(a)))) static inline bool is_hypervisor_range(int idx) { diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 1ab42c852069..6a4b20bc7527 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -143,7 +143,7 @@ void sync_global_pgds(unsigned long start, unsigned long end) * With folded p4d, pgd_none() is always false, we need to * handle synchonization on p4d level. */ - BUILD_BUG_ON(pgd_none(*pgd_ref)); + MAYBE_BUILD_BUG_ON(pgd_none(*pgd_ref)); p4d_ref = p4d_offset(pgd_ref, addr); if (p4d_none(*p4d_ref)) diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index af6f2f9c6a26..12ec90f62457 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -19,7 +19,7 @@ extern struct range pfn_mapped[E820_MAX_ENTRIES]; -static p4d_t tmp_p4d_table[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE); +static p4d_t tmp_p4d_table[MAX_PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE); static __init void *early_alloc(size_t size, int nid, bool panic) { |