CasperSecurity
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_GENERIC_PGALLOC_H
#define __ASM_GENERIC_PGALLOC_H
#ifdef CONFIG_MMU
#define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO)
#define GFP_PGTABLE_USER (GFP_PGTABLE_KERNEL | __GFP_ACCOUNT)
/**
* __pte_alloc_one_kernel - allocate a page for PTE-level kernel page table
* @mm: the mm_struct of the current context
*
* This function is intended for architectures that need
* anything beyond simple page allocation.
*
* Return: pointer to the allocated memory or %NULL on error
*/
static inline pte_t *__pte_alloc_one_kernel(struct mm_struct *mm)
{
return (pte_t *)__get_free_page(GFP_PGTABLE_KERNEL);
}
#ifndef __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
/**
* pte_alloc_one_kernel - allocate a page for PTE-level kernel page table
* @mm: the mm_struct of the current context
*
* Return: pointer to the allocated memory or %NULL on error
*/
static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
{
return __pte_alloc_one_kernel(mm);
}
#endif
/**
* pte_free_kernel - free PTE-level kernel page table page
* @mm: the mm_struct of the current context
* @pte: pointer to the memory containing the page table
*/
static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
free_page((unsigned long)pte);
}
/**
* __pte_alloc_one - allocate a page for PTE-level user page table
* @mm: the mm_struct of the current context
* @gfp: GFP flags to use for the allocation
*
* Allocates a page and runs the pgtable_pte_page_ctor().
*
* This function is intended for architectures that need
* anything beyond simple page allocation or must have custom GFP flags.
*
* Return: `struct page` initialized as page table or %NULL on error
*/
static inline pgtable_t __pte_alloc_one(struct mm_struct *mm, gfp_t gfp)
{
struct page *pte;
pte = alloc_page(gfp);
if (!pte)
return NULL;
if (!pgtable_pte_page_ctor(pte)) {
__free_page(pte);
return NULL;
}
return pte;
}
#ifndef __HAVE_ARCH_PTE_ALLOC_ONE
/**
* pte_alloc_one - allocate a page for PTE-level user page table
* @mm: the mm_struct of the current context
*
* Allocates a page and runs the pgtable_pte_page_ctor().
*
* Return: `struct page` initialized as page table or %NULL on error
*/
static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
{
return __pte_alloc_one(mm, GFP_PGTABLE_USER);
}
#endif
/*
* Should really implement gc for free page table pages. This could be
* done with a reference count in struct page.
*/
/**
* pte_free - free PTE-level user page table page
* @mm: the mm_struct of the current context
* @pte_page: the `struct page` representing the page table
*/
static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
{
pgtable_pte_page_dtor(pte_page);
__free_page(pte_page);
}
#if CONFIG_PGTABLE_LEVELS > 2
#ifndef __HAVE_ARCH_PMD_ALLOC_ONE
/**
* pmd_alloc_one - allocate a page for PMD-level page table
* @mm: the mm_struct of the current context
*
* Allocates a page and runs the pgtable_pmd_page_ctor().
* Allocations use %GFP_PGTABLE_USER in user context and
* %GFP_PGTABLE_KERNEL in kernel context.
*
* Return: pointer to the allocated memory or %NULL on error
*/
static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
{
struct page *page;
gfp_t gfp = GFP_PGTABLE_USER;
if (mm == &init_mm)
gfp = GFP_PGTABLE_KERNEL;
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);
}
#endif
#ifndef __HAVE_ARCH_PMD_FREE
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);
}
#endif
#endif /* CONFIG_PGTABLE_LEVELS > 2 */
#if CONFIG_PGTABLE_LEVELS > 3
#ifndef __HAVE_ARCH_PUD_ALLOC_ONE
/**
* pud_alloc_one - allocate a page for PUD-level page table
* @mm: the mm_struct of the current context
*
* Allocates a page using %GFP_PGTABLE_USER for user context and
* %GFP_PGTABLE_KERNEL for kernel context.
*
* Return: pointer to the allocated memory or %NULL on error
*/
static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
{
gfp_t gfp = GFP_PGTABLE_USER;
if (mm == &init_mm)
gfp = GFP_PGTABLE_KERNEL;
return (pud_t *)get_zeroed_page(gfp);
}
#endif
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);
}
#endif /* CONFIG_PGTABLE_LEVELS > 3 */
#ifndef __HAVE_ARCH_PGD_FREE
static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
free_page((unsigned long)pgd);
}
#endif
#endif /* CONFIG_MMU */
#endif /* __ASM_GENERIC_PGALLOC_H */