Re: [PATCH v3 6/9] mm: add hw_pte_val for HW PTE storage

[Muhammad Usama Anjum <usama.anjum@xxxxxxx>]

On 01/10/2026 12:19 pm, David Hildenbrand (Arm) wrote:
> On 9/22/26 19:12, Muhammad Usama Anjum wrote:
>> Atomic PTE updates need an lvalue for the bits stored in an HW PTE.
>> pte_val() only accepts a SW PTE value, so it cannot operate directly on
>> a distinct hw_pte_t.
>>
>> Add hw_pte_val() to expose the underlying pte_val() lvalue. Access the
>> wrapper's __pte member when hw_pte_t is distinct, and use pte_val()
>> directly when it remains an alias of pte_t.
>>
>> Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxx>
>> ---
>> Changes in v3:
>> - Moved from the arm64 series to generic series as it makes more sense
>>   to add this in generic with all other changes. Usually we only add
>>   code where its get used. But this whole series wouldn't get used
>>   until an arch started using HW PTEs.
>> ---
>>  include/linux/pgtable_types.h | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/include/linux/pgtable_types.h b/include/linux/pgtable_types.h
>> index d6c5a7548550b..ee4eace5c3e1c 100644
>> --- a/include/linux/pgtable_types.h
>> +++ b/include/linux/pgtable_types.h
>> @@ -9,9 +9,13 @@
>>  #ifdef CONFIG_ARCH_HAS_HW_PTE_T
>>  typedef struct __hw_pte_t { pte_t __pte; } hw_pte_t;
>>  #define __pte_from_hw(pte)  ((pte).__pte)
>> +
>> +#define hw_pte_val(x)  pte_val((x).__pte)
>>  #else
>>  #define hw_pte_t pte_t
>>  #define __pte_from_hw(pte)  (pte)
>> +
>> +#define hw_pte_val(x)  pte_val(x)
>>  #endif
> 
> I was just about to say: this series doesn't add any users. You should add 
> that
> detail to the patch description: "prepare for usage in arch code" or sth like 
> that.
> 
> With that
> 
> Acked-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>

I'll add to the description. Thanks for reviewing.

-- 
Thanks,
Usama