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Message-ID: <tip-ea3b5e60ce804403ca019039d6331368521348de@git.kernel.org>
Date: Tue, 14 Mar 2017 02:38:51 -0700
From: "tip-bot for Kirill A. Shutemov" <tipbot@...or.com>
To: linux-tip-commits@...r.kernel.org
Cc: mingo@...nel.org, torvalds@...ux-foundation.org, brgerst@...il.com,
tglx@...utronix.de, peterz@...radead.org,
linux-kernel@...r.kernel.org, bp@...en8.de, arnd@...db.de,
dvlasenk@...hat.com, akpm@...ux-foundation.org,
kirill.shutemov@...ux.intel.com, luto@...nel.org,
dave.hansen@...el.com, hpa@...or.com, mhocko@...e.com,
jpoimboe@...hat.com
Subject: [tip:x86/mm] x86/mm/ident_map: Add 5-level paging support
Commit-ID: ea3b5e60ce804403ca019039d6331368521348de
Gitweb: http://git.kernel.org/tip/ea3b5e60ce804403ca019039d6331368521348de
Author: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
AuthorDate: Mon, 13 Mar 2017 17:33:07 +0300
Committer: Ingo Molnar <mingo@...nel.org>
CommitDate: Tue, 14 Mar 2017 08:45:08 +0100
x86/mm/ident_map: Add 5-level paging support
Add additional page table level handing. It's mostly mechanical.
The only quirk is that with p4d folded, 'pgd' is equal to 'p4d' in
kernel_ident_mapping_init(). The pgd entry has to point to the pud
page table in this case.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Arnd Bergmann <arnd@...db.de>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Brian Gerst <brgerst@...il.com>
Cc: Dave Hansen <dave.hansen@...el.com>
Cc: Denys Vlasenko <dvlasenk@...hat.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Josh Poimboeuf <jpoimboe@...hat.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Michal Hocko <mhocko@...e.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: linux-arch@...r.kernel.org
Cc: linux-mm@...ck.org
Link: http://lkml.kernel.org/r/20170313143309.16020-5-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
arch/x86/mm/ident_map.c | 51 ++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 44 insertions(+), 7 deletions(-)
diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c
index 4473cb4..04210a2 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 +83,36 @@ 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 {
+ /*
+ * With p4d folded, pgd is equal to p4d.
+ * The pgd entry has to point to the pud page table in this case.
+ */
+ pud_t *pud = pud_offset(p4d, 0);
+ set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
+ }
}
return 0;
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