diff mbox series

[2/2] arm64/mm: Use CONT_SHIFT to define CONT_PTE_SHIFT

Message ID 20200908071931.47767-2-gshan@redhat.com
State New, archived
Headers show
Series [1/2] arm64/mm: Remove CONT_RANGE_OFFSET | expand

Commit Message

Gavin Shan Sept. 8, 2020, 7:19 a.m. UTC
The macro CONT_PTE_SHIFT actually depends on CONT_SHIFT, which has
been defined in page-def.h, based on CONFIG_ARM64_CONT_SHIFT. Lets
reflect the dependency.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
 arch/arm64/include/asm/pgtable-hwdef.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

Comments

Anshuman Khandual Sept. 10, 2020, 6:17 a.m. UTC | #1
On 09/08/2020 12:49 PM, Gavin Shan wrote:
> The macro CONT_PTE_SHIFT actually depends on CONT_SHIFT, which has
> been defined in page-def.h, based on CONFIG_ARM64_CONT_SHIFT. Lets
> reflect the dependency.
> 
> Signed-off-by: Gavin Shan <gshan@redhat.com>
> ---
>  arch/arm64/include/asm/pgtable-hwdef.h | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
> index 8a399e666837..0bd9469f4323 100644
> --- a/arch/arm64/include/asm/pgtable-hwdef.h
> +++ b/arch/arm64/include/asm/pgtable-hwdef.h
> @@ -81,14 +81,12 @@
>  /*
>   * Contiguous page definitions.
>   */
> +#define CONT_PTE_SHIFT		(CONT_SHIFT + PAGE_SHIFT)
>  #ifdef CONFIG_ARM64_64K_PAGES
> -#define CONT_PTE_SHIFT		(5 + PAGE_SHIFT)
>  #define CONT_PMD_SHIFT		(5 + PMD_SHIFT)
>  #elif defined(CONFIG_ARM64_16K_PAGES)
> -#define CONT_PTE_SHIFT		(7 + PAGE_SHIFT)
>  #define CONT_PMD_SHIFT		(5 + PMD_SHIFT)
>  #else
> -#define CONT_PTE_SHIFT		(4 + PAGE_SHIFT)
>  #define CONT_PMD_SHIFT		(4 + PMD_SHIFT)
>  #endif
Could not a similar CONT_PMD be created from a new CONFIG_ARM64_CONT_PMD
config option, which would help unify CONT_PMD_SHIFT here as well ?
Gavin Shan Sept. 10, 2020, 8:31 a.m. UTC | #2
Hi Anshuman,

On 9/10/20 4:17 PM, Anshuman Khandual wrote:
> On 09/08/2020 12:49 PM, Gavin Shan wrote:
>> The macro CONT_PTE_SHIFT actually depends on CONT_SHIFT, which has
>> been defined in page-def.h, based on CONFIG_ARM64_CONT_SHIFT. Lets
>> reflect the dependency.
>>
>> Signed-off-by: Gavin Shan <gshan@redhat.com>
>> ---
>>   arch/arm64/include/asm/pgtable-hwdef.h | 4 +---
>>   1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
>> index 8a399e666837..0bd9469f4323 100644
>> --- a/arch/arm64/include/asm/pgtable-hwdef.h
>> +++ b/arch/arm64/include/asm/pgtable-hwdef.h
>> @@ -81,14 +81,12 @@
>>   /*
>>    * Contiguous page definitions.
>>    */
>> +#define CONT_PTE_SHIFT		(CONT_SHIFT + PAGE_SHIFT)
>>   #ifdef CONFIG_ARM64_64K_PAGES
>> -#define CONT_PTE_SHIFT		(5 + PAGE_SHIFT)
>>   #define CONT_PMD_SHIFT		(5 + PMD_SHIFT)
>>   #elif defined(CONFIG_ARM64_16K_PAGES)
>> -#define CONT_PTE_SHIFT		(7 + PAGE_SHIFT)
>>   #define CONT_PMD_SHIFT		(5 + PMD_SHIFT)
>>   #else
>> -#define CONT_PTE_SHIFT		(4 + PAGE_SHIFT)
>>   #define CONT_PMD_SHIFT		(4 + PMD_SHIFT)
>>   #endif
> Could not a similar CONT_PMD be created from a new CONFIG_ARM64_CONT_PMD
> config option, which would help unify CONT_PMD_SHIFT here as well ?
> 

I was thinking of it, to have CONFIG_ARM64_CONT_PMD and defined the
following macros in arch/arm64/include/asm/page-def.h:

    #define CONT_PMD_SHIFT	CONFIG_ARM64_CONT_PMD_SHIFT
    #define CONT_PMD_SIZE        (_AC(1, UL) << (CONT_PMD_SHIFT + PMD_SHIFT)
    #define CONT_PMD_MASK        (~(CONT_PMD_SIZE - 1))

PMD_SHIFT is variable because PMD could be folded into PUD or PGD,
depending on the kernel configuration. PMD_SHIFT is declared
in arch/arm64/include/asm/pgtable-types.h, which isn't supposed
to be included in "page-def.h".

So the peroper way to handle this might be drop the continuous page
macros in page-def.h and introduce the following ones into pgtable-hwdef.h.
I will post v2 to do this if it sounds good to you.

    #define CONT_PTE_SHIFT         (CONFIG_ARM64_CONT_PTE_SHIFT + PAGE_SHIFT)
    #define CONT_PMD_SHIFT         (CONFIG_ARM64_CONT_PMD_SHIFT + PMD_SHIFT)

Thanks,
Gavin
Anshuman Khandual Sept. 10, 2020, 9:28 a.m. UTC | #3
On 09/10/2020 02:01 PM, Gavin Shan wrote:
> Hi Anshuman,
> 
> On 9/10/20 4:17 PM, Anshuman Khandual wrote:
>> On 09/08/2020 12:49 PM, Gavin Shan wrote:
>>> The macro CONT_PTE_SHIFT actually depends on CONT_SHIFT, which has
>>> been defined in page-def.h, based on CONFIG_ARM64_CONT_SHIFT. Lets
>>> reflect the dependency.
>>>
>>> Signed-off-by: Gavin Shan <gshan@redhat.com>
>>> ---
>>>   arch/arm64/include/asm/pgtable-hwdef.h | 4 +---
>>>   1 file changed, 1 insertion(+), 3 deletions(-)
>>>
>>> diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
>>> index 8a399e666837..0bd9469f4323 100644
>>> --- a/arch/arm64/include/asm/pgtable-hwdef.h
>>> +++ b/arch/arm64/include/asm/pgtable-hwdef.h
>>> @@ -81,14 +81,12 @@
>>>   /*
>>>    * Contiguous page definitions.
>>>    */
>>> +#define CONT_PTE_SHIFT        (CONT_SHIFT + PAGE_SHIFT)
>>>   #ifdef CONFIG_ARM64_64K_PAGES
>>> -#define CONT_PTE_SHIFT        (5 + PAGE_SHIFT)
>>>   #define CONT_PMD_SHIFT        (5 + PMD_SHIFT)
>>>   #elif defined(CONFIG_ARM64_16K_PAGES)
>>> -#define CONT_PTE_SHIFT        (7 + PAGE_SHIFT)
>>>   #define CONT_PMD_SHIFT        (5 + PMD_SHIFT)
>>>   #else
>>> -#define CONT_PTE_SHIFT        (4 + PAGE_SHIFT)
>>>   #define CONT_PMD_SHIFT        (4 + PMD_SHIFT)
>>>   #endif
>> Could not a similar CONT_PMD be created from a new CONFIG_ARM64_CONT_PMD
>> config option, which would help unify CONT_PMD_SHIFT here as well ?
>>
> 
> I was thinking of it, to have CONFIG_ARM64_CONT_PMD and defined the
> following macros in arch/arm64/include/asm/page-def.h:
> 
>    #define CONT_PMD_SHIFT    CONFIG_ARM64_CONT_PMD_SHIFT
>    #define CONT_PMD_SIZE        (_AC(1, UL) << (CONT_PMD_SHIFT + PMD_SHIFT)
>    #define CONT_PMD_MASK        (~(CONT_PMD_SIZE - 1))
> 
> PMD_SHIFT is variable because PMD could be folded into PUD or PGD,
> depending on the kernel configuration. PMD_SHIFT is declared

Even CONT_PMD_SHIFT via the new CONFIG_ARM64_CONT_PMD_SHIFT will
be a variable as well depending on page size.

> in arch/arm64/include/asm/pgtable-types.h, which isn't supposed
> to be included in "page-def.h".

Are there build failures if <pgtable-types.h> is included from <page-def.h> ?

> 
> So the peroper way to handle this might be drop the continuous page
> macros in page-def.h and introduce the following ones into pgtable-hwdef.h.
> I will post v2 to do this if it sounds good to you.

Sure, go ahead if that builds. But unifying both these macros seems cleaner.

> 
>    #define CONT_PTE_SHIFT         (CONFIG_ARM64_CONT_PTE_SHIFT + PAGE_SHIFT)
>    #define CONT_PMD_SHIFT         (CONFIG_ARM64_CONT_PMD_SHIFT + PMD_SHIFT)
> 
> Thanks,
> Gavin
> 
>
Gavin Shan Sept. 10, 2020, 9:56 a.m. UTC | #4
Hi Anshuman,

On 9/10/20 7:28 PM, Anshuman Khandual wrote:
> On 09/10/2020 02:01 PM, Gavin Shan wrote:
>> On 9/10/20 4:17 PM, Anshuman Khandual wrote:
>>> On 09/08/2020 12:49 PM, Gavin Shan wrote:
>>>> The macro CONT_PTE_SHIFT actually depends on CONT_SHIFT, which has
>>>> been defined in page-def.h, based on CONFIG_ARM64_CONT_SHIFT. Lets
>>>> reflect the dependency.
>>>>
>>>> Signed-off-by: Gavin Shan <gshan@redhat.com>
>>>> ---
>>>>    arch/arm64/include/asm/pgtable-hwdef.h | 4 +---
>>>>    1 file changed, 1 insertion(+), 3 deletions(-)
>>>>
>>>> diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
>>>> index 8a399e666837..0bd9469f4323 100644
>>>> --- a/arch/arm64/include/asm/pgtable-hwdef.h
>>>> +++ b/arch/arm64/include/asm/pgtable-hwdef.h
>>>> @@ -81,14 +81,12 @@
>>>>    /*
>>>>     * Contiguous page definitions.
>>>>     */
>>>> +#define CONT_PTE_SHIFT        (CONT_SHIFT + PAGE_SHIFT)
>>>>    #ifdef CONFIG_ARM64_64K_PAGES
>>>> -#define CONT_PTE_SHIFT        (5 + PAGE_SHIFT)
>>>>    #define CONT_PMD_SHIFT        (5 + PMD_SHIFT)
>>>>    #elif defined(CONFIG_ARM64_16K_PAGES)
>>>> -#define CONT_PTE_SHIFT        (7 + PAGE_SHIFT)
>>>>    #define CONT_PMD_SHIFT        (5 + PMD_SHIFT)
>>>>    #else
>>>> -#define CONT_PTE_SHIFT        (4 + PAGE_SHIFT)
>>>>    #define CONT_PMD_SHIFT        (4 + PMD_SHIFT)
>>>>    #endif
>>> Could not a similar CONT_PMD be created from a new CONFIG_ARM64_CONT_PMD
>>> config option, which would help unify CONT_PMD_SHIFT here as well ?
>>>
>>
>> I was thinking of it, to have CONFIG_ARM64_CONT_PMD and defined the
>> following macros in arch/arm64/include/asm/page-def.h:
>>
>>     #define CONT_PMD_SHIFT    CONFIG_ARM64_CONT_PMD_SHIFT
>>     #define CONT_PMD_SIZE        (_AC(1, UL) << (CONT_PMD_SHIFT + PMD_SHIFT)
>>     #define CONT_PMD_MASK        (~(CONT_PMD_SIZE - 1))
>>
>> PMD_SHIFT is variable because PMD could be folded into PUD or PGD,
>> depending on the kernel configuration. PMD_SHIFT is declared
> 
> Even CONT_PMD_SHIFT via the new CONFIG_ARM64_CONT_PMD_SHIFT will
> be a variable as well depending on page size.
> 

Yes, it depends on the variable PMD_SHIFT.

>> in arch/arm64/include/asm/pgtable-types.h, which isn't supposed
>> to be included in "page-def.h".
> 
> Are there build failures if <pgtable-types.h> is included from <page-def.h> ?
> 

Yes, something like this:

   AS      arch/arm64/kernel/head.o
In file included from ./arch/arm64/include/asm/pgtable-hwdef.h:8,
                  from ./arch/arm64/include/asm/page-def.h:12,
                  from ./arch/arm64/include/asm/page.h:11,
                  from ./arch/arm64/include/asm/proc-fns.h:14,
                  from ./arch/arm64/include/asm/pgtable.h:9,
                  from ./include/linux/pgtable.h:6,
                  from ./arch/arm64/include/asm/io.h:12,
                  from ./include/linux/io.h:13,
                  from drivers/bus/vexpress-config.c:9:
./arch/arm64/include/asm/memory.h:91:55: warning: "PAGE_SHIFT" is not defined, evaluates to 0 [-Wundef]
  #if defined(CONFIG_VMAP_STACK) && (MIN_THREAD_SHIFT < PAGE_SHIFT)
                                                        ^~~~~~~~~~
./arch/arm64/include/asm/memory.h:97:21: warning: "PAGE_SHIFT" is not defined, evaluates to 0 [-Wundef]
  #if THREAD_SHIFT >= PAGE_SHIFT
                      ^~~~~~~~~~


>>
>> So the peroper way to handle this might be drop the continuous page
>> macros in page-def.h and introduce the following ones into pgtable-hwdef.h.
>> I will post v2 to do this if it sounds good to you.
> 
> Sure, go ahead if that builds. But unifying both these macros seems cleaner.
> 

Thanks for your confirmation. v2 is on the way :)

>>
>>     #define CONT_PTE_SHIFT         (CONFIG_ARM64_CONT_PTE_SHIFT + PAGE_SHIFT)
>>     #define CONT_PMD_SHIFT         (CONFIG_ARM64_CONT_PMD_SHIFT + PMD_SHIFT)
>>

Thanks,
Gavin
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
index 8a399e666837..0bd9469f4323 100644
--- a/arch/arm64/include/asm/pgtable-hwdef.h
+++ b/arch/arm64/include/asm/pgtable-hwdef.h
@@ -81,14 +81,12 @@ 
 /*
  * Contiguous page definitions.
  */
+#define CONT_PTE_SHIFT		(CONT_SHIFT + PAGE_SHIFT)
 #ifdef CONFIG_ARM64_64K_PAGES
-#define CONT_PTE_SHIFT		(5 + PAGE_SHIFT)
 #define CONT_PMD_SHIFT		(5 + PMD_SHIFT)
 #elif defined(CONFIG_ARM64_16K_PAGES)
-#define CONT_PTE_SHIFT		(7 + PAGE_SHIFT)
 #define CONT_PMD_SHIFT		(5 + PMD_SHIFT)
 #else
-#define CONT_PTE_SHIFT		(4 + PAGE_SHIFT)
 #define CONT_PMD_SHIFT		(4 + PMD_SHIFT)
 #endif