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 <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200627143453.31835-6-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/arm64/include/asm/pgalloc.h

@@ -37,17 +37,6 @@ static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)
 
 #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

@@ -41,15 +41,6 @@ p4d_populate(struct mm_struct *mm, p4d_t * p4d_entry, pud_t * pud)
 	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

@@ -14,6 +14,7 @@
 #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,
@@ -87,11 +88,6 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
 	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)
 {
 	set_p4d(p4d, __p4d((unsigned long)pud));

arch/x86/include/asm/pgalloc.h

@@ -123,21 +123,6 @@ static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d, pud_t *pu
 	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

@@ -145,6 +145,36 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
 
 #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 */