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>

1 files changed, 4 insertions, 22 deletions

diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
index 8e5e74121a78..2bb006bdc31c 100644
--- a/arch/m68k/mm/motorola.c
+++ b/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);
 	}
 }