Merge tag 'dmaengine-5.3-rc1' of git://git.infradead.org/users/vkoul/slave-dma

[linux.git] / include / asm-generic / pgalloc.h

diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
index 948714c1535a4224be5b22b313fae671119c6e9f..8476175c07e7ec54aee9943e86371997ece0a348 100644 (file)
--- a/include/asm-generic/pgalloc.h
+++ b/include/asm-generic/pgalloc.h
@@ -1,13 +1,112 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __ASM_GENERIC_PGALLOC_H
 #define __ASM_GENERIC_PGALLOC_H
-/*
- * an empty file is enough for a nommu architecture
- */
+
 #ifdef CONFIG_MMU
-#error need to implement an architecture specific asm/pgalloc.h
+
+#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_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_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_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_page_dtor(pte_page);
+       __free_page(pte_page);
+}
+
+#else /* CONFIG_MMU */
+
+/* This is enough for a nommu architecture */
 #define check_pgt_cache()          do { } while (0)
 
+#endif /* CONFIG_MMU */
+
 #endif /* __ASM_GENERIC_PGALLOC_H */