asm-generic: pgalloc: provide generic pud_alloc_one() and pud_free_one()

Several architectures define pud_alloc_one() as a wrapper for
__get_free_page() and pud_free() as a wrapper for free_page().

Provide a generic implementation in asm-generic/pgalloc.h and use it where
appropriate.

Signed-off-by: Mike Rapoport <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Reviewed-by: Pekka Enberg <[e-mail]>
Cc: Abdul Haleem <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Arnd Bergmann <[e-mail]>
Cc: Christophe Leroy <[e-mail]>
Cc: Joerg Roedel <[e-mail]>
Cc: Joerg Roedel <[e-mail]>
Cc: Max Filippov <[e-mail]>
Cc: Peter Zijlstra (Intel) <[e-mail]>
Cc: Satheesh Rajendran <[e-mail]>
Cc: Stafford Horne <[e-mail]>
Cc: Stephen Rothwell <[e-mail]>
Cc: Steven Rostedt <[e-mail]>
Cc: Geert Uytterhoeven <[e-mail]>
Cc: Matthew Wilcox <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Linus Torvalds <[e-mail]>

arch/arm64/include/asm/pgalloc.h

···
 
 #if CONFIG_PGTABLE_LEVELS > 3
 
-static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
-{
-	return (pud_t *)__get_free_page(GFP_PGTABLE_USER);
-}
-
-static inline void pud_free(struct mm_struct *mm, pud_t *pudp)
-{
-	BUG_ON((unsigned long)pudp & (PAGE_SIZE-1));
-	free_page((unsigned long)pudp);
-}
-
 static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot)
 {
 	set_p4d(p4dp, __p4d(__phys_to_p4d_val(pudp) | prot));

arch/ia64/include/asm/pgalloc.h

···
 	p4d_val(*p4d_entry) = __pa(pud);
 }
 
-static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
-{
-	return (pud_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
-}
-
-static inline void pud_free(struct mm_struct *mm, pud_t *pud)
-{
-	free_page((unsigned long)pud);
-}
 #define __pud_free_tlb(tlb, pud, address)	pud_free((tlb)->mm, pud)
 #endif /* CONFIG_PGTABLE_LEVELS == 4 */
 

arch/mips/include/asm/pgalloc.h

···
 #include <linux/sched.h>
 
 #define __HAVE_ARCH_PMD_ALLOC_ONE
+#define __HAVE_ARCH_PUD_ALLOC_ONE
 #include <asm-generic/pgalloc.h>
 
 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
···
 	if (pud)
 		pud_init((unsigned long)pud, (unsigned long)invalid_pmd_table);
 	return pud;
-}
-
-static inline void pud_free(struct mm_struct *mm, pud_t *pud)
-{
-	free_pages((unsigned long)pud, PUD_ORDER);
 }
 
 static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)

arch/x86/include/asm/pgalloc.h

···
 	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,

include/asm-generic/pgalloc.h

···
 
 #endif /* CONFIG_PGTABLE_LEVELS > 2 */
 
+#if CONFIG_PGTABLE_LEVELS > 3
+
+#ifndef __HAVE_ARCH_PUD_FREE
+/**
+ * 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 */
+
 #endif /* CONFIG_MMU */
 
 #endif /* __ASM_GENERIC_PGALLOC_H */