mm: pgtable: add shortcuts for accessing kernel PMD and PTE

The powerpc 32-bit implementation of pgtable has nice shortcuts for
accessing kernel PMD and PTE for a given virtual address.  Make these
helpers available for all architectures.

[rppt@linux.ibm.com: microblaze: fix page table traversal in setup_rt_frame()]
  Link: http://lkml.kernel.org/r/20200518191511.GD1118872@kernel.org
[akpm@linux-foundation.org: s/pmd_ptr_k/pmd_off_k/ in various powerpc places]

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-9-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/arc/mm/highmem.c

@@ -92,17 +92,9 @@ EXPORT_SYMBOL(kunmap_atomic_high);
 
 static noinline pte_t * __init alloc_kmap_pgtable(unsigned long kvaddr)
 {
-	pgd_t *pgd_k;
-	p4d_t *p4d_k;
-	pud_t *pud_k;
-	pmd_t *pmd_k;
+	pmd_t *pmd_k = pmd_off_k(kvaddr);
 	pte_t *pte_k;
 
-	pgd_k = pgd_offset_k(kvaddr);
-	p4d_k = p4d_offset(pgd_k, kvaddr);
-	pud_k = pud_offset(p4d_k, kvaddr);
-	pmd_k = pmd_offset(pud_k, kvaddr);
-
 	pte_k = (pte_t *)memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
 	if (!pte_k)
 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",

arch/arm/mach-sa1100/assabet.c

@@ -632,7 +632,7 @@ static void __init map_sa1100_gpio_regs( void )
 	int prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_DOMAIN(DOMAIN_IO);
 	pmd_t *pmd;
 
-	pmd = pmd_offset(pud_offset(p4d_offset(pgd_offset_k(virt), virt), virt), virt);
+	pmd = pmd_off_k(virt);
 	*pmd = __pmd(phys | prot);
 	flush_pmd_entry(pmd);
 }

arch/arm/mm/highmem.c

@@ -18,15 +18,15 @@
 static inline void set_fixmap_pte(int idx, pte_t pte)
 {
 	unsigned long vaddr = __fix_to_virt(idx);
-	pte_t *ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
+	pte_t *ptep = virt_to_kpte(vaddr);
 
 	set_pte_ext(ptep, pte, 0);
 	local_flush_tlb_kernel_page(vaddr);
 }
 
 static inline pte_t get_fixmap_pte(unsigned long vaddr)
 {
-	pte_t *ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
+	pte_t *ptep = virt_to_kpte(vaddr);
 
 	return *ptep;
 }

arch/arm/mm/ioremap.c

@@ -141,16 +141,8 @@ void __check_vmalloc_seq(struct mm_struct *mm)
 static void unmap_area_sections(unsigned long virt, unsigned long size)
 {
 	unsigned long addr = virt, end = virt + (size & ~(SZ_1M - 1));
-	pgd_t *pgd;
-	p4d_t *p4d;
-	pud_t *pud;
-	pmd_t *pmdp;
-
-	flush_cache_vunmap(addr, end);
-	pgd = pgd_offset_k(addr);
-	p4d = p4d_offset(pgd, addr);
-	pud = pud_offset(p4d, addr);
-	pmdp = pmd_offset(pud, addr);
+	pmd_t *pmdp = pmd_off_k(addr);
+
 	do {
 		pmd_t pmd = *pmdp;
 
@@ -191,21 +183,14 @@ remap_area_sections(unsigned long virt, unsigned long pfn,
 		    size_t size, const struct mem_type *type)
 {
 	unsigned long addr = virt, end = virt + size;
-	pgd_t *pgd;
-	p4d_t *p4d;
-	pud_t *pud;
-	pmd_t *pmd;
+	pmd_t *pmd = pmd_off_k(addr);
 
 	/*
 	 * Remove and free any PTE-based mapping, and
 	 * sync the current kernel mapping.
 	 */
 	unmap_area_sections(virt, size);
 
-	pgd = pgd_offset_k(addr);
-	p4d = p4d_offset(pgd, addr);
-	pud = pud_offset(p4d, addr);
-	pmd = pmd_offset(pud, addr);
 	do {
 		pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
 		pfn += SZ_1M >> PAGE_SHIFT;
@@ -225,21 +210,13 @@ remap_area_supersections(unsigned long virt, unsigned long pfn,
 			 size_t size, const struct mem_type *type)
 {
 	unsigned long addr = virt, end = virt + size;
-	pgd_t *pgd;
-	p4d_t *p4d;
-	pud_t *pud;
-	pmd_t *pmd;
+	pmd_t *pmd = pmd_off_k(addr);
 
 	/*
 	 * Remove and free any PTE-based mapping, and
 	 * sync the current kernel mapping.
 	 */
 	unmap_area_sections(virt, size);
-
-	pgd = pgd_offset_k(virt);
-	p4d = p4d_offset(pgd, addr);
-	pud = pud_offset(p4d, addr);
-	pmd = pmd_offset(pud, addr);
 	do {
 		unsigned long super_pmd_val, i;
 

arch/arm/mm/mm.h

@@ -35,11 +35,6 @@ static inline pte_t get_top_pte(unsigned long va)
 	return *ptep;
 }
 
-static inline pmd_t *pmd_off_k(unsigned long virt)
-{
-	return pmd_offset(pud_offset(p4d_offset(pgd_offset_k(virt), virt), virt), virt);
-}
-
 struct mem_type {
 	pteval_t prot_pte;
 	pteval_t prot_pte_s2;

arch/arm/mm/mmu.c

@@ -356,12 +356,7 @@ static pte_t *pte_offset_late_fixmap(pmd_t *dir, unsigned long addr)
 
 static inline pmd_t * __init fixmap_pmd(unsigned long addr)
 {
-	pgd_t *pgd = pgd_offset_k(addr);
-	p4d_t *p4d = p4d_offset(pgd, addr);
-	pud_t *pud = pud_offset(p4d, addr);
-	pmd_t *pmd = pmd_offset(pud, addr);
-
-	return pmd;
+	return pmd_off_k(addr);
 }
 
 void __init early_fixmap_init(void)

arch/hexagon/include/asm/fixmap.h

@@ -15,8 +15,4 @@
 
 #include <asm-generic/fixmap.h>
 
-#define kmap_get_fixmap_pte(vaddr) \
-	pte_offset_kernel(pmd_offset(pud_offset(p4d_offset(pgd_offset_k(vaddr), \
-				(vaddr)), (vaddr)), (vaddr)), (vaddr))
-
 #endif

arch/m68k/mm/motorola.c

@@ -54,17 +54,8 @@ static inline void nocache_page(void *vaddr)
 	unsigned long addr = (unsigned long)vaddr;
 
 	if (CPU_IS_040_OR_060) {
-		pgd_t *dir;
-		p4d_t *p4dp;
-		pud_t *pudp;
-		pmd_t *pmdp;
-		pte_t *ptep;
-
-		dir = pgd_offset_k(addr);
-		p4dp = p4d_offset(dir, addr);
-		pudp = pud_offset(p4dp, addr);
-		pmdp = pmd_offset(pudp, addr);
-		ptep = pte_offset_kernel(pmdp, addr);
+		pte_t *ptep = virt_to_kpte(addr);
+
 		*ptep = pte_mknocache(*ptep);
 	}
 }
@@ -74,17 +65,8 @@ static inline void cache_page(void *vaddr)
 	unsigned long addr = (unsigned long)vaddr;
 
 	if (CPU_IS_040_OR_060) {
-		pgd_t *dir;
-		p4d_t *p4dp;
-		pud_t *pudp;
-		pmd_t *pmdp;
-		pte_t *ptep;
-
-		dir = pgd_offset_k(addr);
-		p4dp = p4d_offset(dir, addr);
-		pudp = pud_offset(p4dp, addr);
-		pmdp = pmd_offset(pudp, addr);
-		ptep = pte_offset_kernel(pmdp, addr);
+		pte_t *ptep = virt_to_kpte(addr);
+
 		*ptep = pte_mkcache(*ptep);
 	}
 }

arch/microblaze/kernel/signal.c

@@ -159,9 +159,6 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
 	int err = 0, sig = ksig->sig;
 	unsigned long address = 0;
 #ifdef CONFIG_MMU
-	pgd_t *pgdp;
-	p4d_t *p4dp;
-	pud_t *pudp;
 	pmd_t *pmdp;
 	pte_t *ptep;
 #endif
@@ -197,10 +194,7 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
 
 	address = ((unsigned long)frame->tramp);
 #ifdef CONFIG_MMU
-	pgdp = pgd_offset(current->mm, address);
-	p4dp = p4d_offset(pgdp, address);
-	pudp = pud_offset(p4dp, address);
-	pmdp = pmd_offset(pudp, address);
+	pmdp = pmd_off(current->mm, address);
 
 	preempt_disable();
 	ptep = pte_offset_map(pmdp, address);

arch/microblaze/mm/init.c

@@ -50,15 +50,6 @@ unsigned long lowmem_size;
 pte_t *kmap_pte;
 EXPORT_SYMBOL(kmap_pte);
 
-static inline pte_t *virt_to_kpte(unsigned long vaddr)
-{
-	pgd_t *pgd = pgd_offset_k(vaddr);
-	p4d_t *p4d = p4d_offset(pgd, vaddr);
-	pud_t *pud = pud_offset(p4d, vaddr);
-
-	return pte_offset_kernel(pmd_offset(pud, vaddr), vaddr);
-}
-
 static void __init highmem_init(void)
 {
 	pr_debug("%x\n", (u32)PKMAP_BASE);

arch/mips/include/asm/fixmap.h

@@ -69,9 +69,6 @@ enum fixed_addresses {
 
 #include <asm-generic/fixmap.h>
 
-#define kmap_get_fixmap_pte(vaddr)					\
-	pte_offset_kernel(pmd_offset(pud_offset(p4d_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr)), (vaddr))
-
 /*
  * Called from pgtable_init()
  */

arch/mips/mm/c-r3k.c

@@ -239,9 +239,6 @@ static void r3k_flush_cache_page(struct vm_area_struct *vma,
 	unsigned long kaddr = KSEG0ADDR(pfn << PAGE_SHIFT);
 	int exec = vma->vm_flags & VM_EXEC;
 	struct mm_struct *mm = vma->vm_mm;
-	pgd_t *pgdp;
-	p4d_t *p4dp;
-	pud_t *pudp;
 	pmd_t *pmdp;
 	pte_t *ptep;
 
@@ -252,11 +249,8 @@ static void r3k_flush_cache_page(struct vm_area_struct *vma,
 	if (cpu_context(smp_processor_id(), mm) == 0)
 		return;
 
-	pgdp = pgd_offset(mm, addr);
-	p4dp = p4d_offset(pgdp, addr);
-	pudp = pud_offset(p4dp, addr);
-	pmdp = pmd_offset(pudp, addr);
-	ptep = pte_offset(pmdp, addr);
+	pmdp = pmd_off(mm, addr);
+	ptep = pte_offset_kernel(pmdp, addr);
 
 	/* Invalid => no such page in the cache.  */
 	if (!(pte_val(*ptep) & _PAGE_PRESENT))

arch/mips/mm/c-r4k.c

@@ -652,9 +652,6 @@ static inline void local_r4k_flush_cache_page(void *args)
 	int exec = vma->vm_flags & VM_EXEC;
 	struct mm_struct *mm = vma->vm_mm;
 	int map_coherent = 0;
-	pgd_t *pgdp;
-	p4d_t *p4dp;
-	pud_t *pudp;
 	pmd_t *pmdp;
 	pte_t *ptep;
 	void *vaddr;
@@ -667,11 +664,8 @@ static inline void local_r4k_flush_cache_page(void *args)
 		return;
 
 	addr &= PAGE_MASK;
-	pgdp = pgd_offset(mm, addr);
-	p4dp = p4d_offset(pgdp, addr);
-	pudp = pud_offset(p4dp, addr);
-	pmdp = pmd_offset(pudp, addr);
-	ptep = pte_offset(pmdp, addr);
+	pmdp = pmd_off(mm, addr);
+	ptep = pte_offset_kernel(pmdp, addr);
 
 	/*
 	 * If the page isn't marked valid, the page cannot possibly be

arch/mips/mm/c-tx39.c

@@ -168,9 +168,6 @@ static void tx39_flush_cache_page(struct vm_area_struct *vma, unsigned long page
 {
 	int exec = vma->vm_flags & VM_EXEC;
 	struct mm_struct *mm = vma->vm_mm;
-	pgd_t *pgdp;
-	p4d_t *p4dp;
-	pud_t *pudp;
 	pmd_t *pmdp;
 	pte_t *ptep;
 
@@ -182,11 +179,8 @@ static void tx39_flush_cache_page(struct vm_area_struct *vma, unsigned long page
 		return;
 
 	page &= PAGE_MASK;
-	pgdp = pgd_offset(mm, page);
-	p4dp = p4d_offset(pgdp, page);
-	pudp = pud_offset(p4dp, page);
-	pmdp = pmd_offset(pudp, page);
-	ptep = pte_offset(pmdp, page);
+	pmdp = pmd_off(mm, page);
+	ptep = pte_offset_kernel(pmdp, page);
 
 	/*
 	 * If the page isn't marked valid, the page cannot possibly be

arch/mips/mm/highmem.c

@@ -90,5 +90,5 @@ void __init kmap_init(void)
 
 	/* cache the first kmap pte */
 	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
-	kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
+	kmap_pte = virt_to_kpte(kmap_vstart);
 }

arch/nds32/include/asm/pgtable.h

@@ -195,8 +195,6 @@ extern void paging_init(void);
 #define pte_unmap(pte)		do { } while (0)
 #define pte_unmap_nested(pte)	do { } while (0)
 
-#define pmd_off_k(address)	pmd_offset(pud_offset(p4d_offset(pgd_offset_k(address), (address)), (address)), (address))
-
 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
 /*
  * Set a level 1 translation table entry, and clean it out of

arch/nds32/mm/init.c

@@ -98,9 +98,6 @@ static pmd_t *fixmap_pmd_p;
 static void __init fixedrange_init(void)
 {
 	unsigned long vaddr;
-	pgd_t *pgd;
-	p4d_t *p4d;
-	pud_t *pud;
 	pmd_t *pmd;
 #ifdef CONFIG_HIGHMEM
 	pte_t *pte;
@@ -110,10 +107,7 @@ static void __init fixedrange_init(void)
 	 * Fixed mappings:
 	 */
 	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1);
-	pgd = swapper_pg_dir + pgd_index(vaddr);
-	p4d = p4d_offset(pgd, vaddr);
-	pud = pud_offset(p4d, vaddr);
-	pmd = pmd_offset(pud, vaddr);
+	pmd = pmd_off_k(vaddr);
 	fixmap_pmd_p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 	if (!fixmap_pmd_p)
 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
@@ -126,10 +120,7 @@ static void __init fixedrange_init(void)
 	 */
 	vaddr = PKMAP_BASE;
 
-	pgd = swapper_pg_dir + pgd_index(vaddr);
-	p4d = p4d_offset(pgd, vaddr);
-	pud = pud_offset(p4d, vaddr);
-	pmd = pmd_offset(pud, vaddr);
+	pmd = pmd_off_k(vaddr);
 	pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 	if (!pte)
 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",

arch/nds32/mm/proc.c

@@ -15,14 +15,10 @@ extern struct cache_info L1_cache_info[2];
 
 int va_kernel_present(unsigned long addr)
 {
-	p4d_t *p4d;
-	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *ptep, pte;
 
-	p4d = p4d_offset(pgd_offset_k(addr), addr);
-	pud = pud_offset(p4d, addr);
-	pmd = pmd_offset(pud, addr);
+	pmd = pmd_off_k(addr);
 	if (!pmd_none(*pmd)) {
 		ptep = pte_offset_map(pmd, addr);
 		pte = *ptep;

arch/parisc/mm/fixmap.c

@@ -33,11 +33,7 @@ void notrace set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
 void notrace clear_fixmap(enum fixed_addresses idx)
 {
 	unsigned long vaddr = __fix_to_virt(idx);
-	pgd_t *pgd = pgd_offset_k(vaddr);
-	p4d_t *p4d = p4d_offset(pgd, vaddr);
-	pud_t *pud = pud_offset(p4d, vaddr);
-	pmd_t *pmd = pmd_offset(pud, vaddr);
-	pte_t *pte = pte_offset_kernel(pmd, vaddr);
+	pte_t *pte = virt_to_kpte(vaddr);
 
 	if (WARN_ON(pte_none(*pte)))
 		return;