arm64: add support for folded p4d page tables

Implement primitives necessary for the 4th level folding, add walks of p4d
level where appropriate, replace 5level-fixup.h with pgtable-nop4d.h and
remove __ARCH_USE_5LEVEL_HACK.

[arnd@arndb.de: fix gcc-10 shift warning]
  Link: http://lkml.kernel.org/r/20200429185657.4085975-1-arnd@arndb.de
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: 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>
Link: http://lkml.kernel.org/r/20200414153455.21744-4-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 7 deletions

diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
index f87a32484ea8..2339811f317b 100644
--- a/arch/arm64/mm/kasan_init.c
+++ b/arch/arm64/mm/kasan_init.c
@@ -84,17 +84,17 @@ static pmd_t *__init kasan_pmd_offset(pud_t *pudp, unsigned long addr, int node,
 	return early ? pmd_offset_kimg(pudp, addr) : pmd_offset(pudp, addr);
 }
 
-static pud_t *__init kasan_pud_offset(pgd_t *pgdp, unsigned long addr, int node,
+static pud_t *__init kasan_pud_offset(p4d_t *p4dp, unsigned long addr, int node,
 				      bool early)
 {
-	if (pgd_none(READ_ONCE(*pgdp))) {
+	if (p4d_none(READ_ONCE(*p4dp))) {
 		phys_addr_t pud_phys = early ?
 				__pa_symbol(kasan_early_shadow_pud)
 					: kasan_alloc_zeroed_page(node);
-		__pgd_populate(pgdp, pud_phys, PMD_TYPE_TABLE);
+		__p4d_populate(p4dp, pud_phys, PMD_TYPE_TABLE);
 	}
 
-	return early ? pud_offset_kimg(pgdp, addr) : pud_offset(pgdp, addr);
+	return early ? pud_offset_kimg(p4dp, addr) : pud_offset(p4dp, addr);
 }
 
 static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr,
@@ -126,11 +126,11 @@ static void __init kasan_pmd_populate(pud_t *pudp, unsigned long addr,
 	} while (pmdp++, addr = next, addr != end && pmd_none(READ_ONCE(*pmdp)));
 }
 
-static void __init kasan_pud_populate(pgd_t *pgdp, unsigned long addr,
+static void __init kasan_pud_populate(p4d_t *p4dp, unsigned long addr,
 				      unsigned long end, int node, bool early)
 {
 	unsigned long next;
-	pud_t *pudp = kasan_pud_offset(pgdp, addr, node, early);
+	pud_t *pudp = kasan_pud_offset(p4dp, addr, node, early);
 
 	do {
 		next = pud_addr_end(addr, end);
@@ -138,6 +138,18 @@ static void __init kasan_pud_populate(pgd_t *pgdp, unsigned long addr,
 	} while (pudp++, addr = next, addr != end && pud_none(READ_ONCE(*pudp)));
 }
 
+static void __init kasan_p4d_populate(pgd_t *pgdp, unsigned long addr,
+				      unsigned long end, int node, bool early)
+{
+	unsigned long next;
+	p4d_t *p4dp = p4d_offset(pgdp, addr);
+
+	do {
+		next = p4d_addr_end(addr, end);
+		kasan_pud_populate(p4dp, addr, next, node, early);
+	} while (p4dp++, addr = next, addr != end);
+}
+
 static void __init kasan_pgd_populate(unsigned long addr, unsigned long end,
 				      int node, bool early)
 {
@@ -147,7 +159,7 @@ static void __init kasan_pgd_populate(unsigned long addr, unsigned long end,
 	pgdp = pgd_offset_k(addr);
 	do {
 		next = pgd_addr_end(addr, end);
-		kasan_pud_populate(pgdp, addr, next, node, early);
+		kasan_p4d_populate(pgdp, addr, next, node, early);
 	} while (pgdp++, addr = next, addr != end);
 }