[PATCH 04/26] x86/ident_map: add 5-level paging support

[Kirill A. Shutemov]

Nothing special: just handle one more level.

Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
---
 arch/x86/mm/ident_map.c | 47 ++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 40 insertions(+), 7 deletions(-)

diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c
index 4473cb4f8b90..2c9a62282fb1 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 +83,32 @@ 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));
+               if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+                       set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE));
+               } else {
+                       pud_t *pud = pud_offset(p4d, 0);
+                       set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
+               }
        }
 
        return 0;
-- 
2.11.0