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Groups > linux.kernel > #1599448
| Path | csiph.com!aioe.org!bofh.it!news.nic.it!robomod |
|---|---|
| From | "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> |
| Newsgroups | linux.kernel |
| Subject | [PATCH 4/6] x86/ident_map: Add 5-level paging support |
| Date | Mon, 13 Mar 2017 15:40:02 +0100 |
| Message-ID | <tkziG-1PZ-5@gated-at.bofh.it> (permalink) |
| References | <tkziG-1PZ-3@gated-at.bofh.it> |
| X-Extloop1 | 1 |
| X-Ironport-Av | E=Sophos;i="5.36,159,1486454400"; d="scan'208";a="1141542284" |
| X-Mailer | git-send-email 2.11.0 |
| Sender | robomod@news.nic.it |
| List-ID | <linux-kernel.vger.kernel.org> |
| X-Mailing-List | linux-kernel@vger.kernel.org |
| Approved | robomod@news.nic.it |
| Lines | 96 |
| Organization | linux.* mail to news gateway |
| X-Original-Cc | Andi Kleen <ak@linux.intel.com>, Dave Hansen <dave.hansen@intel.com>, Andy Lutomirski <luto@amacapital.net>, Michal Hocko <mhocko@suse.com>, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> |
| X-Original-Date | Mon, 13 Mar 2017 17:33:07 +0300 |
| X-Original-Message-ID | <20170313143309.16020-5-kirill.shutemov@linux.intel.com> |
| X-Original-References | <20170313143309.16020-1-kirill.shutemov@linux.intel.com> |
| X-Original-Sender | linux-kernel-owner@vger.kernel.org |
| Xref | csiph.com linux.kernel:1599448 |
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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(). pgd entry has to point pud page table in
this case.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
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 4473cb4f8b90..1c3f166bd8c3 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.
+ * pgd entry has to point pud page table in this case.
+ */
+ pud_t *pud = pud_offset(p4d, 0);
+ set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
+ }
}
return 0;
--
2.11.0
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[PATCH 0/6] x86: 5-level paging enabling for v4.12, Part 1 "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-13 15:40 +0100 [PATCH 4/6] x86/ident_map: Add 5-level paging support "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-13 15:40 +0100 [PATCH 1/6] x86/mm: Extend headers with basic definitions to support 5-level paging "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-13 15:40 +0100 [PATCH 5/6] x86/vmalloc: Add 5-level paging support "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-13 15:40 +0100 [PATCH 3/6] x86/gup: Add 5-level paging support "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-13 15:40 +0100 [PATCH 6/6] x86/power: Add 5-level paging support "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-13 15:40 +0100 [PATCH 2/6] x86/mm: Convert trivial cases of page table walk to 5-level paging "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-13 15:40 +0100 Re: [PATCH 0/6] x86: 5-level paging enabling for v4.12, Part 1 Linus Torvalds <torvalds@linux-foundation.org> - 2017-03-13 20:50 +0100
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