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-rw-r--r--include/asm-generic/pgalloc.h215
1 files changed, 215 insertions, 0 deletions
diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
new file mode 100644
index 0000000000..c75d4a7538
--- /dev/null
+++ b/include/asm-generic/pgalloc.h
@@ -0,0 +1,215 @@
+/* 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 memory for a 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)
+{
+ struct ptdesc *ptdesc = pagetable_alloc(GFP_PGTABLE_KERNEL &
+ ~__GFP_HIGHMEM, 0);
+
+ if (!ptdesc)
+ return NULL;
+ return ptdesc_address(ptdesc);
+}
+
+#ifndef __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
+/**
+ * pte_alloc_one_kernel - allocate memory for a 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 memory
+ * @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)
+{
+ pagetable_free(virt_to_ptdesc(pte));
+}
+
+/**
+ * __pte_alloc_one - allocate memory for a PTE-level user page table
+ * @mm: the mm_struct of the current context
+ * @gfp: GFP flags to use for the allocation
+ *
+ * Allocate memory for a page table and ptdesc and runs pagetable_pte_ctor().
+ *
+ * This function is intended for architectures that need
+ * anything beyond simple page allocation or must have custom GFP flags.
+ *
+ * Return: `struct page` referencing the ptdesc or %NULL on error
+ */
+static inline pgtable_t __pte_alloc_one(struct mm_struct *mm, gfp_t gfp)
+{
+ struct ptdesc *ptdesc;
+
+ ptdesc = pagetable_alloc(gfp, 0);
+ if (!ptdesc)
+ return NULL;
+ if (!pagetable_pte_ctor(ptdesc)) {
+ pagetable_free(ptdesc);
+ return NULL;
+ }
+
+ return ptdesc_page(ptdesc);
+}
+
+#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
+ *
+ * Allocate memory for a page table and ptdesc and runs pagetable_pte_ctor().
+ *
+ * Return: `struct page` referencing the ptdesc 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 memory
+ * @mm: the mm_struct of the current context
+ * @pte_page: the `struct page` referencing the ptdesc
+ */
+static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
+{
+ struct ptdesc *ptdesc = page_ptdesc(pte_page);
+
+ pagetable_pte_dtor(ptdesc);
+ pagetable_free(ptdesc);
+}
+
+
+#if CONFIG_PGTABLE_LEVELS > 2
+
+#ifndef __HAVE_ARCH_PMD_ALLOC_ONE
+/**
+ * pmd_alloc_one - allocate memory for a PMD-level page table
+ * @mm: the mm_struct of the current context
+ *
+ * Allocate memory for a page table and ptdesc and runs pagetable_pmd_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 ptdesc *ptdesc;
+ gfp_t gfp = GFP_PGTABLE_USER;
+
+ if (mm == &init_mm)
+ gfp = GFP_PGTABLE_KERNEL;
+ ptdesc = pagetable_alloc(gfp, 0);
+ if (!ptdesc)
+ return NULL;
+ if (!pagetable_pmd_ctor(ptdesc)) {
+ pagetable_free(ptdesc);
+ return NULL;
+ }
+ return ptdesc_address(ptdesc);
+}
+#endif
+
+#ifndef __HAVE_ARCH_PMD_FREE
+static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
+{
+ struct ptdesc *ptdesc = virt_to_ptdesc(pmd);
+
+ BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
+ pagetable_pmd_dtor(ptdesc);
+ pagetable_free(ptdesc);
+}
+#endif
+
+#endif /* CONFIG_PGTABLE_LEVELS > 2 */
+
+#if CONFIG_PGTABLE_LEVELS > 3
+
+static inline pud_t *__pud_alloc_one(struct mm_struct *mm, unsigned long addr)
+{
+ gfp_t gfp = GFP_PGTABLE_USER;
+ struct ptdesc *ptdesc;
+
+ if (mm == &init_mm)
+ gfp = GFP_PGTABLE_KERNEL;
+ gfp &= ~__GFP_HIGHMEM;
+
+ ptdesc = pagetable_alloc(gfp, 0);
+ if (!ptdesc)
+ return NULL;
+ return ptdesc_address(ptdesc);
+}
+
+#ifndef __HAVE_ARCH_PUD_ALLOC_ONE
+/**
+ * pud_alloc_one - allocate memory for a PUD-level page table
+ * @mm: the mm_struct of the current context
+ *
+ * Allocate memory for a page table 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)
+{
+ return __pud_alloc_one(mm, addr);
+}
+#endif
+
+static inline void __pud_free(struct mm_struct *mm, pud_t *pud)
+{
+ BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
+ pagetable_free(virt_to_ptdesc(pud));
+}
+
+#ifndef __HAVE_ARCH_PUD_FREE
+static inline void pud_free(struct mm_struct *mm, pud_t *pud)
+{
+ __pud_free(mm, pud);
+}
+#endif
+
+#endif /* CONFIG_PGTABLE_LEVELS > 3 */
+
+#ifndef __HAVE_ARCH_PGD_FREE
+static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+ pagetable_free(virt_to_ptdesc(pgd));
+}
+#endif
+
+#endif /* CONFIG_MMU */
+
+#endif /* __ASM_GENERIC_PGALLOC_H */