diff mbox series

arm64: Define only {pud/pmd}_{set/clear}_huge when usefull

Message ID 73ec95f40cafbbb69bdfb43a7f53876fd845b0ce.1620990479.git.christophe.leroy@csgroup.eu
State Not Applicable
Headers show
Series arm64: Define only {pud/pmd}_{set/clear}_huge when usefull | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch powerpc/merge (1fab3666d738e4af3a7450c44441310e4d7a7e53)
snowpatch_ozlabs/build-ppc64le success Build succeeded
snowpatch_ozlabs/build-ppc64be success Build succeeded
snowpatch_ozlabs/build-ppc64e success Build succeeded
snowpatch_ozlabs/build-pmac32 success Build succeeded
snowpatch_ozlabs/checkpatch warning total: 0 errors, 1 warnings, 0 checks, 44 lines checked
snowpatch_ozlabs/needsstable success Patch has no Fixes tags

Commit Message

Christophe Leroy May 14, 2021, 11:08 a.m. UTC
When PUD and/or PMD are folded, those functions are useless
and we now have a stub in linux/pgtable.h

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/arm64/mm/mmu.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

Comments

Andrew Morton May 14, 2021, 9:42 p.m. UTC | #1
On Fri, 14 May 2021 11:08:53 +0000 (UTC) Christophe Leroy <christophe.leroy@csgroup.eu> wrote:

> When PUD and/or PMD are folded, those functions are useless
> and we now have a stub in linux/pgtable.h

OK, help me out here please.  What patch does this fix?
Nathan Chancellor May 15, 2021, 3:58 a.m. UTC | #2
On Fri, May 14, 2021 at 02:42:00PM -0700, Andrew Morton wrote:
> On Fri, 14 May 2021 11:08:53 +0000 (UTC) Christophe Leroy <christophe.leroy@csgroup.eu> wrote:
> 
> > When PUD and/or PMD are folded, those functions are useless
> > and we now have a stub in linux/pgtable.h
> 
> OK, help me out here please.  What patch does this fix?
> 

Naresh's original report is here it seems:

https://lore.kernel.org/r/CA+G9fYv79t0+2W4Rt3wDkBShc4eY3M3utC5BHqUgGDwMYExYMw@mail.gmail.com/

I can reproduce the failure that he reported with
ARCH=arm64 allmodconfig and this patch resolves it for me.

Cheers,
Nathan
Christophe Leroy May 15, 2021, 6:28 a.m. UTC | #3
Le 14/05/2021 à 23:42, Andrew Morton a écrit :
> On Fri, 14 May 2021 11:08:53 +0000 (UTC) Christophe Leroy <christophe.leroy@csgroup.eu> wrote:
> 
>> When PUD and/or PMD are folded, those functions are useless
>> and we now have a stub in linux/pgtable.h
> 
> OK, help me out here please.  What patch does this fix?
> 

Both this one and the x86 one from the day before fix 1cff41494b15cd82c1ec418bb5c ("mm/pgtable: add 
stubs for {pmd/pub}_{set/clear}_huge")

I think both the x86 fix and the arm64 fix should be squashed into that patch at the end.

I checked, the only other architecture involving pud_set_huge() and friends is powerpc, and powerpc 
doesn't have this problem as it only defined those for book3s/64 platforms which have 4 level page 
tables by definition.

Thanks
Christophe
diff mbox series

Patch

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 6dd9369e3ea0..98af085afe90 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1337,6 +1337,7 @@  void *__init fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
 	return dt_virt;
 }
 
+#if CONFIG_PGTABLE_LEVELS > 3
 int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot)
 {
 	pud_t new_pud = pfn_pud(__phys_to_pfn(phys), mk_pud_sect_prot(prot));
@@ -1351,6 +1352,16 @@  int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot)
 	return 1;
 }
 
+int pud_clear_huge(pud_t *pudp)
+{
+	if (!pud_sect(READ_ONCE(*pudp)))
+		return 0;
+	pud_clear(pudp);
+	return 1;
+}
+#endif
+
+#if CONFIG_PGTABLE_LEVELS > 2
 int pmd_set_huge(pmd_t *pmdp, phys_addr_t phys, pgprot_t prot)
 {
 	pmd_t new_pmd = pfn_pmd(__phys_to_pfn(phys), mk_pmd_sect_prot(prot));
@@ -1365,14 +1376,6 @@  int pmd_set_huge(pmd_t *pmdp, phys_addr_t phys, pgprot_t prot)
 	return 1;
 }
 
-int pud_clear_huge(pud_t *pudp)
-{
-	if (!pud_sect(READ_ONCE(*pudp)))
-		return 0;
-	pud_clear(pudp);
-	return 1;
-}
-
 int pmd_clear_huge(pmd_t *pmdp)
 {
 	if (!pmd_sect(READ_ONCE(*pmdp)))
@@ -1380,6 +1383,7 @@  int pmd_clear_huge(pmd_t *pmdp)
 	pmd_clear(pmdp);
 	return 1;
 }
+#endif
 
 int pmd_free_pte_page(pmd_t *pmdp, unsigned long addr)
 {