[PATCHv2 11/29] x86/ident_map: add 5-level paging support
From: Kirill A. Shutemov <hidden>
Date: 2016-12-27 01:55:00
Also in:
linux-mm, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 mm · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
Nothing special: just handle one more level. Signed-off-by: Kirill A. Shutemov <redacted> --- arch/x86/mm/ident_map.c | 42 +++++++++++++++++++++++++++++++++++------- 1 file changed, 35 insertions(+), 7 deletions(-)
diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c
index 4473cb4f8b90..f1a620b9f2ef 100644
--- a/arch/x86/mm/ident_map.c
+++ b/arch/x86/mm/ident_map.c@@ -45,6 +45,34 @@ static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page, return 0; } +static int ident_p4d_init(struct x86_mapping_info *info, p4d_t *p4d_page, + unsigned long addr, unsigned long end) +{ + unsigned long next; + + for (; addr < end; addr = next) { + p4d_t *p4d = p4d_page + p4d_index(addr); + pud_t *pud; + + next = (addr & P4D_MASK) + P4D_SIZE; + if (next > end) + next = end; + + if (p4d_present(*p4d)) { + pud = pud_offset(p4d, 0); + ident_pud_init(info, pud, addr, next); + continue; + } + pud = (pud_t *)info->alloc_pgt_page(info->context); + if (!pud) + return -ENOMEM; + ident_pud_init(info, pud, addr, next); + set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE)); + } + + return 0; +} + int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page, unsigned long pstart, unsigned long pend) {
@@ -55,27 +83,27 @@ int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page, for (; addr < end; addr = next) { pgd_t *pgd = pgd_page + pgd_index(addr); - pud_t *pud; + p4d_t *p4d; next = (addr & PGDIR_MASK) + PGDIR_SIZE; if (next > end) next = end; if (pgd_present(*pgd)) { - pud = pud_offset(pgd, 0); - result = ident_pud_init(info, pud, addr, next); + p4d = p4d_offset(pgd, 0); + result = ident_p4d_init(info, p4d, addr, next); if (result) return result; continue; } - pud = (pud_t *)info->alloc_pgt_page(info->context); - if (!pud) + p4d = (p4d_t *)info->alloc_pgt_page(info->context); + if (!p4d) return -ENOMEM; - result = ident_pud_init(info, pud, addr, next); + result = ident_p4d_init(info, p4d, addr, next); if (result) return result; - set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE)); + set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE)); } return 0;
--
2.11.0
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