[PATCH v3 05/14] nios2: add support for folded p4d page tables

From: Mike Rapoport <rppt@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: Rich Felker <dalias@libc.org>,
	linux-ia64@vger.kernel.org,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	linux-sh@vger.kernel.org,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	linux-mm@kvack.org, Paul Mackerras <paulus@samba.org>,
	linux-hexagon@vger.kernel.org, Will Deacon <will@kernel.org>,
	kvmarm@lists.cs.columbia.edu, Jonas Bonn <jonas@southpole.se>,
	linux-arch@vger.kernel.org, Brian Cain <bcain@codeaurora.org>,
	Marc Zyngier <maz@kernel.org>,
	Russell King <linux@armlinux.org.uk>,
	Ley Foon Tan <ley.foon.tan@intel.com>,
	Mike Rapoport <rppt@linux.ibm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	uclinux-h8-devel@lists.sourceforge.jp,
	Fenghua Yu <fenghua.yu@intel.com>, Arnd Bergmann <arnd@arndb.de>,
	kvm-ppc@vger.kernel.org,
	Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
	openrisc@lists.librecores.org, Stafford Horne <shorne@gmail.com>,
	Guan Xuetao <gxt@pku.edu.cn>,
	linux-arm-kernel@lists.infradead.org,
	Christophe Leroy <christophe.leroy@c-s.fr>,
	Tony Luck <tony.luck@intel.com>,
	Yoshinori Sato <ysato@users.sourceforge.jp>,
	Michael Ellerman <mpe@ellerman.id.au>,
	nios2-dev@lists.rocketboards.org,
	Andrew Morton <akpm@linux-foundation.org>,
	linuxppc-dev@lists.ozlabs.org, Mike Rapoport <rppt@kernel.org>
Subject: [PATCH v3 05/14] nios2: add support for folded p4d page tables
Date: Thu, 27 Feb 2020 08:45:59 +0000	[thread overview]
Message-ID: <20200227084608.18223-6-rppt@kernel.org> (raw)
In-Reply-To: <20200227084608.18223-1-rppt@kernel.org>

From: Mike Rapoport <rppt@linux.ibm.com>

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

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 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(-)

diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h
index 99985d8b7166..54305aa09b74 100644
--- a/arch/nios2/include/asm/pgtable.h
+++ b/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/sizeof(pte_t)];
  */
 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 */
diff --git a/arch/nios2/mm/fault.c b/arch/nios2/mm/fault.c
index 6a2e716b959f..d3da995665c3 100644
--- a/arch/nios2/mm/fault.c
+++ b/arch/nios2/mm/fault.c
@@ -245,6 +245,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause,
 		 */
 		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;
@@ -256,8 +257,12 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause,
 			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);
diff --git a/arch/nios2/mm/ioremap.c b/arch/nios2/mm/ioremap.c
index 819bdfcc2e71..fe821efb9a99 100644
--- a/arch/nios2/mm/ioremap.c
+++ b/arch/nios2/mm/ioremap.c
@@ -86,11 +86,15 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
 	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);
-- 
2.24.0
