diff mbox series

ARC: mm: remove __ARCH_USE_5LEVEL_HACK

Message ID 20191008213836.19266-1-vgupta@synopsys.com
State New
Headers show
Series ARC: mm: remove __ARCH_USE_5LEVEL_HACK | expand

Commit Message

Vineet Gupta Oct. 8, 2019, 9:38 p.m. UTC 
Add the intermediate p4d accessors to make it 5 level compliant.

Thi sis non-functional change anyways since ARC has software page walker
with 2 lookup levels (pgd -> pte)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/include/asm/pgtable.h |  1 -
 arch/arc/mm/fault.c            | 10 ++++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

Comments

Kirill A. Shutemov Oct. 8, 2019, 11:42 p.m. UTC | #1 
On Tue, Oct 08, 2019 at 09:38:36PM +0000, Vineet Gupta wrote:
> Add the intermediate p4d accessors to make it 5 level compliant.
> 
> Thi sis non-functional change anyways since ARC has software page walker
     ^
     Typo.
> with 2 lookup levels (pgd -> pte)
> 
> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
> ---
>  arch/arc/include/asm/pgtable.h |  1 -
>  arch/arc/mm/fault.c            | 10 ++++++++--
>  2 files changed, 8 insertions(+), 3 deletions(-)

Have you tested it with CONFIG_HIGHMEM=y? alloc_kmap_pgtable() has to be
converted too.
Vineet Gupta Oct. 9, 2019, 6:38 p.m. UTC | #2 
On 10/8/19 4:42 PM, Kirill A. Shutemov wrote:
> On Tue, Oct 08, 2019 at 09:38:36PM +0000, Vineet Gupta wrote:
>> Add the intermediate p4d accessors to make it 5 level compliant.
>>
>> Thi sis non-functional change anyways since ARC has software page walker
>      ^
>      Typo.

Oops, fixed now !

...

> Have you tested it with CONFIG_HIGHMEM=y? alloc_kmap_pgtable() has to be
> converted too.

No I didn't. Fixed that as well.

Thx for looking
-Vineet
diff mbox series

Patch

diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
index 976b5931372e..902d45428cea 100644
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -33,7 +33,6 @@ 
 #define _ASM_ARC_PGTABLE_H
 
 #include <linux/bits.h>
-#define __ARCH_USE_5LEVEL_HACK
 #include <asm-generic/pgtable-nopmd.h>
 #include <asm/page.h>
 #include <asm/mmu.h>	/* to propagate CONFIG_ARC_MMU_VER <n> */
diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
index 3861543b66a0..fb86bc3e9b35 100644
--- a/arch/arc/mm/fault.c
+++ b/arch/arc/mm/fault.c
@@ -30,6 +30,7 @@  noinline static int handle_kernel_vaddr_fault(unsigned long address)
 	 * with the 'reference' page table.
 	 */
 	pgd_t *pgd, *pgd_k;
+	p4d_t *p4d, *p4d_k;
 	pud_t *pud, *pud_k;
 	pmd_t *pmd, *pmd_k;
 
@@ -39,8 +40,13 @@  noinline static int handle_kernel_vaddr_fault(unsigned long address)
 	if (!pgd_present(*pgd_k))
 		goto bad_area;
 
-	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 bad_area;
+
+	pud = pud_offset(p4d, address);
+	pud_k = pud_offset(p4d_k, address);
 	if (!pud_present(*pud_k))
 		goto bad_area;