mm: consolidate pgtable_cache_init() and pgd_cache_init()

Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem
cache for page table allocations on several architectures that do not use
PAGE_SIZE tables for one or more levels of the page table hierarchy.

Most architectures do not implement these functions and use __weak default
NOP implementation of pgd_cache_init().  Since there is no such default
for pgtable_cache_init(), its empty stub is duplicated among most
architectures.

Rename the definitions of pgd_cache_init() to pgtable_cache_init() and
drop empty stubs of pgtable_cache_init().

Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Will Deacon <will@kernel.org>		[arm64]
Acked-by: Thomas Gleixner <tglx@linutronix.de>	[x86]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/alpha/include/asm/pgtable.h

@@ -359,11 +359,6 @@ extern void paging_init(void);
 
 #include <asm-generic/pgtable.h>
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()	do { } while (0)
-
 /* We have our own get_unmapped_area to cope with ADDR_LIMIT_32BIT.  */
 #define HAVE_ARCH_UNMAPPED_AREA
 

arch/arc/include/asm/pgtable.h

@@ -395,11 +395,6 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 /* to cope with aliasing VIPT cache */
 #define HAVE_ARCH_UNMAPPED_AREA
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()   do { } while (0)
-
 #endif /* __ASSEMBLY__ */
 
 #endif

arch/arm/include/asm/pgtable-nommu.h

@@ -70,11 +70,6 @@ typedef pte_t *pte_addr_t;
  */
 extern unsigned int kobjsize(const void *objp);
 
-/*
- * No page table caches to initialise.
- */
-#define pgtable_cache_init()	do { } while (0)
-
 /*
  * All 32bit addresses are effectively valid for vmalloc...
  * Sort of meaningless for non-VM targets.

arch/arm/include/asm/pgtable.h

@@ -368,8 +368,6 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 
-#define pgtable_cache_init() do { } while (0)
-
 #endif /* !__ASSEMBLY__ */
 
 #endif /* CONFIG_MMU */

arch/arm64/include/asm/pgtable.h

@@ -861,8 +861,6 @@ extern int kern_addr_valid(unsigned long addr);
 
 #include <asm-generic/pgtable.h>
 
-static inline void pgtable_cache_init(void) { }
-
 /*
  * On AArch64, the cache coherency is handled via the set_pte_at() function.
  */

arch/arm64/mm/pgd.c

@@ -35,7 +35,7 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 		kmem_cache_free(pgd_cache, pgd);
 }
 
-void __init pgd_cache_init(void)
+void __init pgtable_cache_init(void)
 {
 	if (PGD_SIZE == PAGE_SIZE)
 		return;

arch/c6x/include/asm/pgtable.h

@@ -59,11 +59,6 @@ extern unsigned long empty_zero_page;
 
 #define swapper_pg_dir ((pgd_t *) 0)
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()   do { } while (0)
-
 /*
  * c6x is !MMU, so define the simpliest implementation
  */

arch/csky/include/asm/pgtable.h

@@ -296,11 +296,6 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 #define kern_addr_valid(addr)	(1)
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()	do {} while (0)
-
 #define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \
 	remap_pfn_range(vma, vaddr, pfn, size, prot)
 

arch/h8300/include/asm/pgtable.h

@@ -4,7 +4,6 @@
 #define __ARCH_USE_5LEVEL_HACK
 #include <asm-generic/pgtable-nopud.h>
 #include <asm-generic/pgtable.h>
-#define pgtable_cache_init()   do { } while (0)
 extern void paging_init(void);
 #define PAGE_NONE		__pgprot(0)    /* these mean nothing to NO_MM */
 #define PAGE_SHARED		__pgprot(0)    /* these mean nothing to NO_MM */
@@ -34,11 +33,6 @@ static inline int pte_file(pte_t pte) { return 0; }
 extern unsigned int kobjsize(const void *objp);
 extern int is_in_rom(unsigned long);
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()   do { } while (0)
-
 /*
  * All 32bit addresses are effectively valid for vmalloc...
  * Sort of meaningless for non-VM targets.

arch/hexagon/include/asm/pgtable.h

@@ -431,9 +431,6 @@ static inline int pte_exec(pte_t pte)
 
 #define __pte_offset(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 
-/*  I think this is in case we have page table caches; needed by init/main.c  */
-#define pgtable_cache_init()    do { } while (0)
-
 /*
  * Swap/file PTE definitions.  If _PAGE_PRESENT is zero, the rest of the PTE is
  * interpreted as swap information.  The remaining free bits are interpreted as

arch/hexagon/mm/Makefile

@@ -3,5 +3,5 @@
 # Makefile for Hexagon memory management subsystem
 #
 
-obj-y := init.o pgalloc.o ioremap.o uaccess.o vm_fault.o cache.o
+obj-y := init.o ioremap.o uaccess.o vm_fault.o cache.o
 obj-y += copy_to_user.o copy_from_user.o strnlen_user.o vm_tlb.o

arch/hexagon/mm/pgalloc.c

@@ -1,10 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
- */
-
-#include <linux/init.h>
-
-void __init pgtable_cache_init(void)
-{
-}

arch/ia64/include/asm/pgtable.h

@@ -566,11 +566,6 @@ extern struct page *zero_page_memmap_ptr;
 #define KERNEL_TR_PAGE_SHIFT	_PAGE_SIZE_64M
 #define KERNEL_TR_PAGE_SIZE	(1 << KERNEL_TR_PAGE_SHIFT)
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()	do { } while (0)
-
 /* These tell get_user_pages() that the first gate page is accessible from user-level.  */
 #define FIXADDR_USER_START	GATE_ADDR
 #ifdef HAVE_BUGGY_SEGREL

arch/m68k/include/asm/pgtable_mm.h

@@ -176,9 +176,4 @@ pgprot_t pgprot_dmacoherent(pgprot_t prot);
 #include <asm-generic/pgtable.h>
 #endif /* !__ASSEMBLY__ */
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()	do { } while (0)
-
 #endif /* _M68K_PGTABLE_H */

arch/m68k/include/asm/pgtable_no.h

@@ -44,11 +44,6 @@ extern void paging_init(void);
  */
 #define ZERO_PAGE(vaddr)	(virt_to_page(0))
 
-/*
- * No page table caches to initialise.
- */
-#define pgtable_cache_init()	do { } while (0)
-
 /*
  * All 32bit addresses are effectively valid for vmalloc...
  * Sort of meaningless for non-VM targets.

arch/microblaze/include/asm/pgtable.h

@@ -46,8 +46,6 @@ extern int mem_init_done;
 
 #define swapper_pg_dir ((pgd_t *) NULL)
 
-#define pgtable_cache_init()	do {} while (0)
-
 #define arch_enter_lazy_cpu_mode()	do {} while (0)
 
 #define pgprot_noncached_wc(prot)	prot
@@ -526,11 +524,6 @@ extern unsigned long iopa(unsigned long addr);
 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 #define kern_addr_valid(addr)	(1)
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()	do { } while (0)
-
 void do_page_fault(struct pt_regs *regs, unsigned long address,
 		   unsigned long error_code);
 

arch/mips/include/asm/pgtable.h

@@ -661,9 +661,4 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()	do { } while (0)
-
 #endif /* _ASM_PGTABLE_H */

arch/nds32/include/asm/pgtable.h

@@ -403,8 +403,6 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  * into virtual address `from'
  */
 
-#define pgtable_cache_init()       do { } while (0)
-
 #endif /* !__ASSEMBLY__ */
 
 #endif /* _ASMNDS32_PGTABLE_H */

arch/nios2/include/asm/pgtable.h

@@ -291,8 +291,6 @@ static inline void pte_clear(struct mm_struct *mm,
 
 #include <asm-generic/pgtable.h>
 
-#define pgtable_cache_init()		do { } while (0)
-
 extern void __init paging_init(void);
 extern void __init mmu_init(void);
 

arch/openrisc/include/asm/pgtable.h

@@ -443,11 +443,6 @@ static inline void update_mmu_cache(struct vm_area_struct *vma,
 
 #include <asm-generic/pgtable.h>
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()		do { } while (0)
-
 typedef pte_t *pte_addr_t;
 
 #endif /* __ASSEMBLY__ */

arch/parisc/include/asm/pgtable.h

@@ -132,8 +132,6 @@ static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
 #define PTRS_PER_PTE    (1UL << BITS_PER_PTE)
 
 /* Definitions for 2nd level */
-#define pgtable_cache_init()	do { } while (0)
-
 #define PMD_SHIFT       (PLD_SHIFT + BITS_PER_PTE)
 #define PMD_SIZE	(1UL << PMD_SHIFT)
 #define PMD_MASK	(~(PMD_SIZE-1))

arch/powerpc/include/asm/pgtable.h

@@ -87,7 +87,6 @@ extern unsigned long ioremap_bot;
 unsigned long vmalloc_to_phys(void *vmalloc_addr);
 
 void pgtable_cache_add(unsigned int shift);
-void pgtable_cache_init(void);
 
 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_PPC32)
 void mark_initmem_nx(void);

arch/riscv/include/asm/pgtable.h

@@ -424,11 +424,6 @@ extern void *dtb_early_va;
 extern void setup_bootmem(void);
 extern void paging_init(void);
 
-static inline void pgtable_cache_init(void)
-{
-	/* No page table caches to initialize */
-}
-
 #define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
 #define VMALLOC_END      (PAGE_OFFSET - 1)
 #define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)

arch/s390/include/asm/pgtable.h

@@ -1682,11 +1682,6 @@ extern void s390_reset_cmma(struct mm_struct *mm);
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 
-/*
- * No page table caches to initialise
- */
-static inline void pgtable_cache_init(void) { }
-
 #include <asm-generic/pgtable.h>
 
 #endif /* _S390_PAGE_H */

arch/sh/include/asm/pgtable.h

@@ -123,11 +123,6 @@ typedef pte_t *pte_addr_t;
 
 #define pte_pfn(x)		((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
 
-/*
- * Initialise the page table caches
- */
-extern void pgtable_cache_init(void);
-
 struct vm_area_struct;
 struct mm_struct;
 

arch/sh/mm/nommu.c

@@ -97,7 +97,3 @@ void __init page_table_range_init(unsigned long start, unsigned long end,
 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
 {
 }
-
-void pgtable_cache_init(void)
-{
-}

arch/sparc/include/asm/pgtable_32.h

@@ -445,9 +445,4 @@ static inline int io_remap_pfn_range(struct vm_area_struct *vma,
 /* We provide our own get_unmapped_area to cope with VA holes for userland */
 #define HAVE_ARCH_UNMAPPED_AREA
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()	do { } while (0)
-
 #endif /* !(_SPARC_PGTABLE_H) */

arch/sparc/include/asm/pgtable_64.h

@@ -1135,7 +1135,6 @@ unsigned long get_fb_unmapped_area(struct file *filp, unsigned long,
 				   unsigned long);
 #define HAVE_ARCH_FB_UNMAPPED_AREA
 
-void pgtable_cache_init(void);
 void sun4v_register_fault_status(void);
 void sun4v_ktsb_register(void);
 void __init cheetah_ecache_flush_init(void);

arch/um/include/asm/pgtable.h

@@ -32,8 +32,6 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 /* zero page used for uninitialized stuff */
 extern unsigned long *empty_zero_page;
 
-#define pgtable_cache_init() do ; while (0)
-
 /* Just any arbitrary offset to the start of the vmalloc VM area: the
  * current 8MB value just means that there will be a 8MB "hole" after the
  * physical memory until the kernel virtual memory starts.  That means that

arch/unicore32/include/asm/pgtable.h

@@ -285,8 +285,6 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 
 #include <asm-generic/pgtable.h>
 
-#define pgtable_cache_init() do { } while (0)
-
 #endif /* !__ASSEMBLY__ */
 
 #endif /* __UNICORE_PGTABLE_H__ */

arch/x86/include/asm/pgtable_32.h

@@ -29,7 +29,6 @@ extern pgd_t swapper_pg_dir[1024];
 extern pgd_t initial_page_table[1024];
 extern pmd_t initial_pg_pmd[];
 
-static inline void pgtable_cache_init(void) { }
 void paging_init(void);
 void sync_initial_page_table(void);
 

arch/x86/include/asm/pgtable_64.h

@@ -241,8 +241,6 @@ extern void cleanup_highmap(void);
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 
-#define pgtable_cache_init()   do { } while (0)
-
 #define PAGE_AGP    PAGE_KERNEL_NOCACHE
 #define HAVE_PAGE_AGP 1
 

arch/x86/mm/pgtable.c

@@ -357,7 +357,7 @@ static void pgd_prepopulate_user_pmd(struct mm_struct *mm,
 
 static struct kmem_cache *pgd_cache;
 
-void __init pgd_cache_init(void)
+void __init pgtable_cache_init(void)
 {
 	/*
 	 * When PAE kernel is running as a Xen domain, it does not use
@@ -402,10 +402,6 @@ static inline void _pgd_free(pgd_t *pgd)
 }
 #else
 
-void __init pgd_cache_init(void)
-{
-}
-
 static inline pgd_t *_pgd_alloc(void)
 {
 	return (pgd_t *)__get_free_pages(GFP_PGTABLE_USER,

arch/xtensa/include/asm/pgtable.h

@@ -238,7 +238,6 @@ extern void paging_init(void);
 # define swapper_pg_dir NULL
 static inline void paging_init(void) { }
 #endif
-static inline void pgtable_cache_init(void) { }
 
 /*
  * The pmd contains the kernel virtual address of the pte page.

include/asm-generic/pgtable.h

@@ -1126,7 +1126,7 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
 static inline void init_espfix_bsp(void) { }
 #endif
 
-extern void __init pgd_cache_init(void);
+extern void __init pgtable_cache_init(void);
 
 #ifndef __HAVE_ARCH_PFN_MODIFY_ALLOWED
 static inline bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot)

init/main.c

@@ -507,7 +507,7 @@ void __init __weak mem_encrypt_init(void) { }
 
 void __init __weak poking_init(void) { }
 
-void __init __weak pgd_cache_init(void) { }
+void __init __weak pgtable_cache_init(void) { }
 
 bool initcall_debug;
 core_param(initcall_debug, initcall_debug, bool, 0644);
@@ -565,7 +565,6 @@ static void __init mm_init(void)
 	init_espfix_bsp();
 	/* Should be run after espfix64 is set up. */
 	pti_init();
-	pgd_cache_init();
 }
 
 void __init __weak arch_call_rest_init(void)