linux/arch/x86/include/asm/pgalloc.h
Dan Williams 0a9fe8ca84 x86/mm: Validate kernel_physical_mapping_init() PTE population
The usage of __flush_tlb_all() in the kernel_physical_mapping_init()
path is not necessary. In general flushing the TLB is not required when
updating an entry from the !present state. However, to give confidence
in the future removal of TLB flushing in this path, use the new
set_pte_safe() family of helpers to assert that the !present assumption
is true in this path.

[ mingo: Minor readability edits. ]

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/154395944177.32119.8524957429632012270.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-05 09:03:06 +01:00

235 lines
6.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_PGALLOC_H
#define _ASM_X86_PGALLOC_H
#include <linux/threads.h>
#include <linux/mm.h> /* for struct page */
#include <linux/pagemap.h>
static inline int __paravirt_pgd_alloc(struct mm_struct *mm) { return 0; }
#ifdef CONFIG_PARAVIRT_XXL
#include <asm/paravirt.h>
#else
#define paravirt_pgd_alloc(mm) __paravirt_pgd_alloc(mm)
static inline void paravirt_pgd_free(struct mm_struct *mm, pgd_t *pgd) {}
static inline void paravirt_alloc_pte(struct mm_struct *mm, unsigned long pfn) {}
static inline void paravirt_alloc_pmd(struct mm_struct *mm, unsigned long pfn) {}
static inline void paravirt_alloc_pmd_clone(unsigned long pfn, unsigned long clonepfn,
unsigned long start, unsigned long count) {}
static inline void paravirt_alloc_pud(struct mm_struct *mm, unsigned long pfn) {}
static inline void paravirt_alloc_p4d(struct mm_struct *mm, unsigned long pfn) {}
static inline void paravirt_release_pte(unsigned long pfn) {}
static inline void paravirt_release_pmd(unsigned long pfn) {}
static inline void paravirt_release_pud(unsigned long pfn) {}
static inline void paravirt_release_p4d(unsigned long pfn) {}
#endif
/*
* Flags to use when allocating a user page table page.
*/
extern gfp_t __userpte_alloc_gfp;
#ifdef CONFIG_PAGE_TABLE_ISOLATION
/*
* Instead of one PGD, we acquire two PGDs. Being order-1, it is
* both 8k in size and 8k-aligned. That lets us just flip bit 12
* in a pointer to swap between the two 4k halves.
*/
#define PGD_ALLOCATION_ORDER 1
#else
#define PGD_ALLOCATION_ORDER 0
#endif
/*
* Allocate and free page tables.
*/
extern pgd_t *pgd_alloc(struct mm_struct *);
extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
extern pte_t *pte_alloc_one_kernel(struct mm_struct *, unsigned long);
extern pgtable_t pte_alloc_one(struct mm_struct *, unsigned long);
/* Should really implement gc for free page table pages. This could be
done with a reference count in struct page. */
static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
BUG_ON((unsigned long)pte & (PAGE_SIZE-1));
free_page((unsigned long)pte);
}
static inline void pte_free(struct mm_struct *mm, struct page *pte)
{
pgtable_page_dtor(pte);
__free_page(pte);
}
extern void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte);
static inline void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte,
unsigned long address)
{
___pte_free_tlb(tlb, pte);
}
static inline void pmd_populate_kernel(struct mm_struct *mm,
pmd_t *pmd, pte_t *pte)
{
paravirt_alloc_pte(mm, __pa(pte) >> PAGE_SHIFT);
set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
}
static inline void pmd_populate_kernel_safe(struct mm_struct *mm,
pmd_t *pmd, pte_t *pte)
{
paravirt_alloc_pte(mm, __pa(pte) >> PAGE_SHIFT);
set_pmd_safe(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
}
static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
struct page *pte)
{
unsigned long pfn = page_to_pfn(pte);
paravirt_alloc_pte(mm, pfn);
set_pmd(pmd, __pmd(((pteval_t)pfn << PAGE_SHIFT) | _PAGE_TABLE));
}
#define pmd_pgtable(pmd) pmd_page(pmd)
#if CONFIG_PGTABLE_LEVELS > 2
static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
{
struct page *page;
gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO;
if (mm == &init_mm)
gfp &= ~__GFP_ACCOUNT;
page = alloc_pages(gfp, 0);
if (!page)
return NULL;
if (!pgtable_pmd_page_ctor(page)) {
__free_pages(page, 0);
return NULL;
}
return (pmd_t *)page_address(page);
}
static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
{
BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
pgtable_pmd_page_dtor(virt_to_page(pmd));
free_page((unsigned long)pmd);
}
extern void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd);
static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
unsigned long address)
{
___pmd_free_tlb(tlb, pmd);
}
#ifdef CONFIG_X86_PAE
extern void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd);
#else /* !CONFIG_X86_PAE */
static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
{
paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT);
set_pud(pud, __pud(_PAGE_TABLE | __pa(pmd)));
}
static inline void pud_populate_safe(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
{
paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT);
set_pud_safe(pud, __pud(_PAGE_TABLE | __pa(pmd)));
}
#endif /* CONFIG_X86_PAE */
#if CONFIG_PGTABLE_LEVELS > 3
static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
{
paravirt_alloc_pud(mm, __pa(pud) >> PAGE_SHIFT);
set_p4d(p4d, __p4d(_PAGE_TABLE | __pa(pud)));
}
static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
{
paravirt_alloc_pud(mm, __pa(pud) >> PAGE_SHIFT);
set_p4d_safe(p4d, __p4d(_PAGE_TABLE | __pa(pud)));
}
static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
{
gfp_t gfp = GFP_KERNEL_ACCOUNT;
if (mm == &init_mm)
gfp &= ~__GFP_ACCOUNT;
return (pud_t *)get_zeroed_page(gfp);
}
static inline void pud_free(struct mm_struct *mm, pud_t *pud)
{
BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
free_page((unsigned long)pud);
}
extern void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud);
static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
unsigned long address)
{
___pud_free_tlb(tlb, pud);
}
#if CONFIG_PGTABLE_LEVELS > 4
static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
{
if (!pgtable_l5_enabled())
return;
paravirt_alloc_p4d(mm, __pa(p4d) >> PAGE_SHIFT);
set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(p4d)));
}
static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
{
if (!pgtable_l5_enabled())
return;
paravirt_alloc_p4d(mm, __pa(p4d) >> PAGE_SHIFT);
set_pgd_safe(pgd, __pgd(_PAGE_TABLE | __pa(p4d)));
}
static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
{
gfp_t gfp = GFP_KERNEL_ACCOUNT;
if (mm == &init_mm)
gfp &= ~__GFP_ACCOUNT;
return (p4d_t *)get_zeroed_page(gfp);
}
static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
{
if (!pgtable_l5_enabled())
return;
BUG_ON((unsigned long)p4d & (PAGE_SIZE-1));
free_page((unsigned long)p4d);
}
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)
{
if (pgtable_l5_enabled())
___p4d_free_tlb(tlb, p4d);
}
#endif /* CONFIG_PGTABLE_LEVELS > 4 */
#endif /* CONFIG_PGTABLE_LEVELS > 3 */
#endif /* CONFIG_PGTABLE_LEVELS > 2 */
#endif /* _ASM_X86_PGALLOC_H */