From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>,
Dave Hansen <dave.hansen@intel.com>,
Andy Lutomirski <luto@amacapital.net>,
Michal Hocko <mhocko@kernel.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCHv2 07/10] x86/mm: Fold p4d page table layer at runtime
Date: Tue, 18 Jul 2017 17:15:14 +0300 [thread overview]
Message-ID: <20170718141517.52202-8-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <20170718141517.52202-1-kirill.shutemov@linux.intel.com>
This patch changes page table helpers to fold p4d at runtime.
The logic is the same as in <asm-generic/pgtable-nop4d.h>.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
arch/x86/include/asm/paravirt.h | 3 ++-
arch/x86/include/asm/pgalloc.h | 5 ++++-
arch/x86/include/asm/pgtable.h | 10 +++++++++-
3 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 9ccac1926587..511f300abd42 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -613,7 +613,8 @@ static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
static inline void pgd_clear(pgd_t *pgdp)
{
- set_pgd(pgdp, __pgd(0));
+ if (!p4d_folded)
+ set_pgd(pgdp, __pgd(0));
}
#endif /* CONFIG_PGTABLE_LEVELS == 5 */
diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
index b2d0cd8288aa..5c42262169d0 100644
--- a/arch/x86/include/asm/pgalloc.h
+++ b/arch/x86/include/asm/pgalloc.h
@@ -155,6 +155,8 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
#if CONFIG_PGTABLE_LEVELS > 4
static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
{
+ if (p4d_folded)
+ return;
paravirt_alloc_p4d(mm, __pa(p4d) >> PAGE_SHIFT);
set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(p4d)));
}
@@ -179,7 +181,8 @@ extern void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d);
static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
unsigned long address)
{
- ___p4d_free_tlb(tlb, p4d);
+ if (!p4d_folded)
+ ___p4d_free_tlb(tlb, p4d);
}
#endif /* CONFIG_PGTABLE_LEVELS > 4 */
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 77037b6f1caa..4516a1bdcc31 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -53,7 +53,7 @@ extern struct mm_struct *pgd_page_get_mm(struct page *page);
#ifndef __PAGETABLE_P4D_FOLDED
#define set_pgd(pgdp, pgd) native_set_pgd(pgdp, pgd)
-#define pgd_clear(pgd) native_pgd_clear(pgd)
+#define pgd_clear(pgd) (!p4d_folded ? native_pgd_clear(pgd) : 0)
#endif
#ifndef set_p4d
@@ -847,6 +847,8 @@ static inline unsigned long p4d_index(unsigned long address)
#if CONFIG_PGTABLE_LEVELS > 4
static inline int pgd_present(pgd_t pgd)
{
+ if (p4d_folded)
+ return 1;
return pgd_flags(pgd) & _PAGE_PRESENT;
}
@@ -864,16 +866,22 @@ static inline unsigned long pgd_page_vaddr(pgd_t pgd)
/* to find an entry in a page-table-directory. */
static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
{
+ if (p4d_folded)
+ return (p4d_t *)pgd;
return (p4d_t *)pgd_page_vaddr(*pgd) + p4d_index(address);
}
static inline int pgd_bad(pgd_t pgd)
{
+ if (p4d_folded)
+ return 0;
return (pgd_flags(pgd) & ~_PAGE_USER) != _KERNPG_TABLE;
}
static inline int pgd_none(pgd_t pgd)
{
+ if (p4d_folded)
+ return 0;
/*
* There is no need to do a workaround for the KNL stray
* A/D bit erratum here. PGDs only point to page tables
--
2.11.0
--
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next prev parent reply other threads:[~2017-07-18 14:16 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-18 14:15 [PATCHv2 00/10] Boot-time switching between 4- and 5-level paging Kirill A. Shutemov
2017-07-18 14:15 ` [PATCHv2 01/10] x86/kasan: Use the same shadow offset for " Kirill A. Shutemov
2017-07-18 14:15 ` [PATCHv2 02/10] x86/xen: Provide pre-built page tables only for XEN_PV and XEN_PVH Kirill A. Shutemov
2017-07-18 14:15 ` [PATCHv2 03/10] x86/boot/compressed/64: Detect and handle 5-level paging at boot-time Kirill A. Shutemov
2017-07-18 14:15 ` [PATCHv2 04/10] x86/mm: Make virtual memory layout movable for CONFIG_X86_5LEVEL Kirill A. Shutemov
2017-07-18 14:15 ` [PATCHv2 05/10] x86/mm: Make PGDIR_SHIFT and PTRS_PER_P4D variable Kirill A. Shutemov
2017-07-18 14:15 ` [PATCHv2 06/10] x86/mm: Handle boot-time paging mode switching at early boot Kirill A. Shutemov
2017-07-18 14:15 ` Kirill A. Shutemov [this message]
2017-07-18 14:15 ` [PATCHv2 08/10] x86/mm: Replace compile-time checks for 5-level with runtime-time Kirill A. Shutemov
2017-07-18 14:24 ` Juergen Gross
2017-07-18 15:16 ` Kirill A. Shutemov
2017-07-25 9:05 ` Kirill A. Shutemov
2017-07-26 7:28 ` Juergen Gross
2017-07-26 16:43 ` Kirill A. Shutemov
2017-07-27 8:27 ` Juergen Gross
2017-08-01 7:46 ` Juergen Gross
2017-08-01 14:44 ` Kirill A. Shutemov
2017-08-01 17:14 ` Juergen Gross
2017-08-01 19:11 ` Kirill A. Shutemov
2017-08-02 7:44 ` Juergen Gross
2017-08-02 8:17 ` Kirill A. Shutemov
2017-08-02 8:30 ` Juergen Gross
2017-07-18 14:15 ` [PATCHv2 09/10] x86/mm: Allow to boot without la57 if CONFIG_X86_5LEVEL=y Kirill A. Shutemov
2017-07-18 14:15 ` [PATCHv2 10/10] x86/mm: Offset boot-time paging mode switching cost Kirill A. Shutemov
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