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>

4 files changed, 7 insertions, 25 deletions

diff --git a/arch/mips/mm/c-r3k.c b/arch/mips/mm/c-r3k.c
index 9f4a93f8b996..df6755ca1892 100644
--- a/arch/mips/mm/c-r3k.c
+++ b/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))
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index eeb63aab9d44..49569e5666d7 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/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
diff --git a/arch/mips/mm/c-tx39.c b/arch/mips/mm/c-tx39.c
index 204059d28f21..03dfbb40ec73 100644
--- a/arch/mips/mm/c-tx39.c
+++ b/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
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index 8e8726992720..5fec7f45d79a 100644
--- a/arch/mips/mm/highmem.c
+++ b/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);
 }