+ nios2-add-support-for-folded-p4d-page-tables.patch added to -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: nios2: add support for folded p4d page tables
has been added to the -mm tree.  Its filename is
     nios2-add-support-for-folded-p4d-page-tables.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/nios2-add-support-for-folded-p4d-page-tables.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/nios2-add-support-for-folded-p4d-page-tables.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Mike Rapoport <rppt@linux.ibm.com>
Subject: nios2: add support for folded p4d page tables

Implement primitives necessary for the 4th level folding, add walks of p4d
level where appropriate and remove usage of __ARCH_USE_5LEVEL_HACK.

Link: http://lkml.kernel.org/r/20200414153455.21744-7-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: James Morse <james.morse@arm.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/nios2/include/asm/pgtable.h |    3 +--
 arch/nios2/mm/fault.c            |    9 +++++++--
 arch/nios2/mm/ioremap.c          |    6 +++++-
 3 files changed, 13 insertions(+), 5 deletions(-)

--- a/arch/nios2/include/asm/pgtable.h~nios2-add-support-for-folded-p4d-page-tables
+++ a/arch/nios2/include/asm/pgtable.h
@@ -22,7 +22,6 @@
 #include <asm/tlbflush.h>
 
 #include <asm/pgtable-bits.h>
-#define __ARCH_USE_5LEVEL_HACK
 #include <asm-generic/pgtable-nopmd.h>
 
 #define FIRST_USER_ADDRESS	0UL
@@ -100,7 +99,7 @@ extern pte_t invalid_pte_table[PAGE_SIZE
  */
 static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval)
 {
-	pmdptr->pud.pgd.pgd = pmdval.pud.pgd.pgd;
+	*pmdptr = pmdval;
 }
 
 /* to find an entry in a page-table-directory */
--- a/arch/nios2/mm/fault.c~nios2-add-support-for-folded-p4d-page-tables
+++ a/arch/nios2/mm/fault.c
@@ -242,6 +242,7 @@ vmalloc_fault:
 		 */
 		int offset = pgd_index(address);
 		pgd_t *pgd, *pgd_k;
+		p4d_t *p4d, *p4d_k;
 		pud_t *pud, *pud_k;
 		pmd_t *pmd, *pmd_k;
 		pte_t *pte_k;
@@ -253,8 +254,12 @@ vmalloc_fault:
 			goto no_context;
 		set_pgd(pgd, *pgd_k);
 
-		pud = pud_offset(pgd, address);
-		pud_k = pud_offset(pgd_k, address);
+		p4d = p4d_offset(pgd, address);
+		p4d_k = p4d_offset(pgd_k, address);
+		if (!p4d_present(*p4d_k))
+			goto no_context;
+		pud = pud_offset(p4d, address);
+		pud_k = pud_offset(p4d_k, address);
 		if (!pud_present(*pud_k))
 			goto no_context;
 		pmd = pmd_offset(pud, address);
--- a/arch/nios2/mm/ioremap.c~nios2-add-support-for-folded-p4d-page-tables
+++ a/arch/nios2/mm/ioremap.c
@@ -86,11 +86,15 @@ static int remap_area_pages(unsigned lon
 	if (address >= end)
 		BUG();
 	do {
+		p4d_t *p4d;
 		pud_t *pud;
 		pmd_t *pmd;
 
 		error = -ENOMEM;
-		pud = pud_alloc(&init_mm, dir, address);
+		p4d = p4d_alloc(&init_mm, dir, address);
+		if (!p4d)
+			break;
+		pud = pud_alloc(&init_mm, p4d, address);
 		if (!pud)
 			break;
 		pmd = pmd_alloc(&init_mm, pud, address);
_

Patches currently in -mm which might be from rppt@linux.ibm.com are

h8300-remove-usage-of-__arch_use_5level_hack.patch
arm-add-support-for-folded-p4d-page-tables.patch
arm64-add-support-for-folded-p4d-page-tables.patch
hexagon-remove-__arch_use_5level_hack.patch
ia64-add-support-for-folded-p4d-page-tables.patch
nios2-add-support-for-folded-p4d-page-tables.patch
openrisc-add-support-for-folded-p4d-page-tables.patch
powerpc-add-support-for-folded-p4d-page-tables.patch
sh-drop-__pxd_offset-macros-that-duplicate-pxd_index-ones.patch
sh-add-support-for-folded-p4d-page-tables.patch
unicore32-remove-__arch_use_5level_hack.patch
asm-generic-remove-pgtable-nop4d-hackh.patch
mm-remove-__arch_has_5level_hack-and-include-asm-generic-5level-fixuph.patch
mm-memblock-replace-dereferences-of-memblock_regionnid-with-api-calls.patch
mm-make-early_pfn_to_nid-and-related-defintions-close-to-each-other.patch
mm-remove-config_have_memblock_node_map-option.patch
mm-free_area_init-use-maximal-zone-pfns-rather-than-zone-sizes.patch
mm-use-free_area_init-instead-of-free_area_init_nodes.patch
alpha-simplify-detection-of-memory-zone-boundaries.patch
arm-simplify-detection-of-memory-zone-boundaries.patch
arm64-simplify-detection-of-memory-zone-boundaries-for-uma-configs.patch
csky-simplify-detection-of-memory-zone-boundaries.patch
m68k-mm-simplify-detection-of-memory-zone-boundaries.patch
parisc-simplify-detection-of-memory-zone-boundaries.patch
sparc32-simplify-detection-of-memory-zone-boundaries.patch
unicore32-simplify-detection-of-memory-zone-boundaries.patch
xtensa-simplify-detection-of-memory-zone-boundaries.patch
mm-remove-early_pfn_in_nid-and-config_nodes_span_other_nodes.patch
mm-free_area_init-allow-defining-max_zone_pfn-in-descending-order.patch
mm-rename-free_area_init_node-to-free_area_init_memoryless_node.patch
mm-clean-up-free_area_init_node-and-its-helpers.patch
mm-simplify-find_min_pfn_with_active_regions.patch
docs-vm-update-memory-models-documentation.patch