[PATCH] drivers/sgi-gru: Use pxdp_get() for page table access

[PATCH] drivers/sgi-gru: Use pxdp_get() for page table access

[Anshuman Khandual]

Replace all READ_ONCE() with a standard page table accessors i.e pxdp_get()
that default into READ_ONCE() in cases where platforms do not override.

Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 drivers/misc/sgi-gru/grufault.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
index 3557d78ee47a..60e55facd8d7 100644
--- a/drivers/misc/sgi-gru/grufault.c
+++ b/drivers/misc/sgi-gru/grufault.c
@@ -212,19 +212,19 @@ static int atomic_pte_lookup(struct vm_area_struct *vma, unsigned long vaddr,
 	pte_t pte;
 
 	pgdp = pgd_offset(vma->vm_mm, vaddr);
-	if (unlikely(pgd_none(*pgdp)))
+	if (unlikely(pgd_none(pgdp_get(pgdp))))
 		goto err;
 
 	p4dp = p4d_offset(pgdp, vaddr);
-	if (unlikely(p4d_none(*p4dp)))
+	if (unlikely(p4d_none(p4dp_get(p4dp))))
 		goto err;
 
 	pudp = pud_offset(p4dp, vaddr);
-	if (unlikely(pud_none(*pudp)))
+	if (unlikely(pud_none(pudp_get(pudp))))
 		goto err;
 
 	pmdp = pmd_offset(pudp, vaddr);
-	if (unlikely(pmd_none(*pmdp)))
+	if (unlikely(pmd_none(pmdp_get(pmdp))))
 		goto err;
 #ifdef CONFIG_X86_64
 	if (unlikely(pmd_leaf(*pmdp)))
-- 
2.30.2

Re: [PATCH] drivers/sgi-gru: Use pxdp_get() for page table access

[Anshuman Khandual]

On 08/10/25 9:51 AM, Anshuman Khandual wrote:
> Replace all READ_ONCE() with a standard page table accessors i.e pxdp_get()
> that default into READ_ONCE() in cases where platforms do not override.
> 
> Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
>  drivers/misc/sgi-gru/grufault.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
> index 3557d78ee47a..60e55facd8d7 100644
> --- a/drivers/misc/sgi-gru/grufault.c
> +++ b/drivers/misc/sgi-gru/grufault.c
> @@ -212,19 +212,19 @@ static int atomic_pte_lookup(struct vm_area_struct *vma, unsigned long vaddr,
>  	pte_t pte;
>  
>  	pgdp = pgd_offset(vma->vm_mm, vaddr);
> -	if (unlikely(pgd_none(*pgdp)))
> +	if (unlikely(pgd_none(pgdp_get(pgdp))))
>  		goto err;
>  
>  	p4dp = p4d_offset(pgdp, vaddr);
> -	if (unlikely(p4d_none(*p4dp)))
> +	if (unlikely(p4d_none(p4dp_get(p4dp))))
>  		goto err;
>  
>  	pudp = pud_offset(p4dp, vaddr);
> -	if (unlikely(pud_none(*pudp)))
> +	if (unlikely(pud_none(pudp_get(pudp))))
>  		goto err;
>  
>  	pmdp = pmd_offset(pudp, vaddr);
> -	if (unlikely(pmd_none(*pmdp)))
> +	if (unlikely(pmd_none(pmdp_get(pmdp))))
>  		goto err;
>  #ifdef CONFIG_X86_64
>  	if (unlikely(pmd_leaf(*pmdp)))

Please ignore this patch as it does not replace any READ_ONCE()
based page table accesses in this file. My bad.