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

Mike Rapoport
2020-02-27T08:45:59Z

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