Upcoming changes to the lazy_mmu API will cause
arch_flush_lazy_mmu_mode() to be called when leaving a nested
lazy_mmu section.

Move the relevant logic from arch_leave_lazy_mmu_mode() to
arch_flush_lazy_mmu_mode() and have the former call the latter.

Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
---
 .../powerpc/include/asm/book3s/64/tlbflush-hash.h | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
index 146287d9580f..7704dbe8e88d 100644
--- a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
+++ b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
@@ -41,6 +41,16 @@ static inline void arch_enter_lazy_mmu_mode(void)
 	batch->active = 1;
 }
 
+static inline void arch_flush_lazy_mmu_mode(void)
+{
+	struct ppc64_tlb_batch *batch;
+
+	batch = this_cpu_ptr(&ppc64_tlb_batch);
+
+	if (batch->index)
+		__flush_tlb_pending(batch);
+}
+
 static inline void arch_leave_lazy_mmu_mode(void)
 {
 	struct ppc64_tlb_batch *batch;
@@ -49,14 +59,11 @@ static inline void arch_leave_lazy_mmu_mode(void)
 		return;
 	batch = this_cpu_ptr(&ppc64_tlb_batch);
 
-	if (batch->index)
-		__flush_tlb_pending(batch);
+	arch_flush_lazy_mmu_mode();
 	batch->active = 0;
 	preempt_enable();
 }
 
-#define arch_flush_lazy_mmu_mode()      do {} while (0)
-
 extern void hash__tlbiel_all(unsigned int action);
 
 extern void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize,
-- 
2.47.0

On 15.10.25 10:27, Kevin Brodsky wrote:
> Upcoming changes to the lazy_mmu API will cause
> arch_flush_lazy_mmu_mode() to be called when leaving a nested
> lazy_mmu section.
> 
> Move the relevant logic from arch_leave_lazy_mmu_mode() to
> arch_flush_lazy_mmu_mode() and have the former call the latter.
> 
> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
> ---
>   .../powerpc/include/asm/book3s/64/tlbflush-hash.h | 15 +++++++++++----
>   1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
> index 146287d9580f..7704dbe8e88d 100644
> --- a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
> +++ b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
> @@ -41,6 +41,16 @@ static inline void arch_enter_lazy_mmu_mode(void)
>   	batch->active = 1;
>   }
>   
> +static inline void arch_flush_lazy_mmu_mode(void)
> +{
> +	struct ppc64_tlb_batch *batch;
> +
> +	batch = this_cpu_ptr(&ppc64_tlb_batch);

The downside is the double this_cpu_ptr() now on the 
arch_leave_lazy_mmu_mode() path.

You could just have a helper function that is called by either or just 
... leave arch_leave_lazy_mmu_mode() alone and just replicate the two 
statements here in arch_flush_lazy_mmu_mode().

I would do just that :)

-- 
Cheers

David / dhildenb

On 23/10/2025 21:36, David Hildenbrand wrote:
> On 15.10.25 10:27, Kevin Brodsky wrote:
>> [...]
>>
>> diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
>> b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
>> index 146287d9580f..7704dbe8e88d 100644
>> --- a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
>> +++ b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
>> @@ -41,6 +41,16 @@ static inline void arch_enter_lazy_mmu_mode(void)
>>       batch->active = 1;
>>   }
>>   +static inline void arch_flush_lazy_mmu_mode(void)
>> +{
>> +    struct ppc64_tlb_batch *batch;
>> +
>> +    batch = this_cpu_ptr(&ppc64_tlb_batch);
>
> The downside is the double this_cpu_ptr() now on the
> arch_leave_lazy_mmu_mode() path.

This is only temporary, patch 9 removes it from arch_enter(). I don't
think having a redundant this_cpu_ptr() for a few commits is really a
concern?

Same idea for patch 4/10.

- Kevin

On 24.10.25 14:09, Kevin Brodsky wrote:
> On 23/10/2025 21:36, David Hildenbrand wrote:
>> On 15.10.25 10:27, Kevin Brodsky wrote:
>>> [...]
>>>
>>> diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
>>> b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
>>> index 146287d9580f..7704dbe8e88d 100644
>>> --- a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
>>> +++ b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
>>> @@ -41,6 +41,16 @@ static inline void arch_enter_lazy_mmu_mode(void)
>>>        batch->active = 1;
>>>    }
>>>    +static inline void arch_flush_lazy_mmu_mode(void)
>>> +{
>>> +    struct ppc64_tlb_batch *batch;
>>> +
>>> +    batch = this_cpu_ptr(&ppc64_tlb_batch);
>>
>> The downside is the double this_cpu_ptr() now on the
>> arch_leave_lazy_mmu_mode() path.
> 
> This is only temporary, patch 9 removes it from arch_enter(). I don't
> think having a redundant this_cpu_ptr() for a few commits is really a
> concern?

Oh, right. Consider mentioning in the patch description

"Note that follow-up patches will remove the double this_cpu_ptr() on 
the arch_leave_lazy_mmu_mode() path again."

-- 
Cheers

David / dhildenb

On 24/10/2025 16:42, David Hildenbrand wrote:
> On 24.10.25 14:09, Kevin Brodsky wrote:
>> On 23/10/2025 21:36, David Hildenbrand wrote:
>>> On 15.10.25 10:27, Kevin Brodsky wrote:
>>>> [...]
>>>>
>>>> diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
>>>> b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
>>>> index 146287d9580f..7704dbe8e88d 100644
>>>> --- a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
>>>> +++ b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
>>>> @@ -41,6 +41,16 @@ static inline void arch_enter_lazy_mmu_mode(void)
>>>>        batch->active = 1;
>>>>    }
>>>>    +static inline void arch_flush_lazy_mmu_mode(void)
>>>> +{
>>>> +    struct ppc64_tlb_batch *batch;
>>>> +
>>>> +    batch = this_cpu_ptr(&ppc64_tlb_batch);
>>>
>>> The downside is the double this_cpu_ptr() now on the
>>> arch_leave_lazy_mmu_mode() path.
>>
>> This is only temporary, patch 9 removes it from arch_enter(). I don't
>> think having a redundant this_cpu_ptr() for a few commits is really a
>> concern?
>
> Oh, right. Consider mentioning in the patch description
>
> "Note that follow-up patches will remove the double this_cpu_ptr() on
> the arch_leave_lazy_mmu_mode() path again." 

Sounds good, will do.

- Kevin