[v3,12/21] powerpc/mm: Convert early cpu/mmu feature check to use the new helpers

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

This switches early feature checks to use the non static key variant of
the function. In later patches we will be switching cpu_has_feature()
and mmu_has_feature() to use static keys and we can use them only after
static key/jump label is initialized. Any check for feature before jump
label init should be done using this new helper.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/include/asm/book3s/64/mmu.h | 4 ++--
 arch/powerpc/kernel/paca.c               | 2 +-
 arch/powerpc/kernel/setup_64.c           | 4 ++--
 arch/powerpc/mm/hash_utils_64.c          | 6 +++---
 arch/powerpc/mm/init_64.c                | 2 +-
 5 files changed, 9 insertions(+), 9 deletions(-)

v3: Add/remove some sites now that we're rebased on the early MMU init series.

On Thu, 2016-07-28 at 00:18 +1000, Michael Ellerman wrote:
> 
> diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h
> b/arch/powerpc/include/asm/book3s/64/mmu.h
> index 70c995870297..6deda6ecc4f7 100644
> --- a/arch/powerpc/include/asm/book3s/64/mmu.h
> +++ b/arch/powerpc/include/asm/book3s/64/mmu.h
> @@ -116,7 +116,7 @@ extern void hash__early_init_mmu_secondary(void);
>  extern void radix__early_init_mmu_secondary(void);
>  static inline void early_init_mmu_secondary(void)
>  {
> -       if (radix_enabled())
> +       if (__radix_enabled())
>                 return radix__early_init_mmu_secondary();
>         return hash__early_init_mmu_secondary();
>  }

This one can go, no ?

Cheers,
Ben.

On Thu, 2016-07-28 at 00:18 +1000, Michael Ellerman wrote:
> --- a/arch/powerpc/mm/hash_utils_64.c
> +++ b/arch/powerpc/mm/hash_utils_64.c
> @@ -530,7 +530,7 @@ static bool might_have_hea(void)
>          * we will never see an HEA ethernet device.
>          */
>  #ifdef CONFIG_IBMEBUS
> -       return !cpu_has_feature(CPU_FTR_ARCH_207S) &&
> +       return !__cpu_has_feature(CPU_FTR_ARCH_207S) &&
>                 !firmware_has_feature(FW_FEATURE_SPLPAR);
>  #else

All these could go if that function was split. The part that reads the
DT stays in early_init_mmu_devtree (bastically up to "found:" and then
the bit at the end that scans the huge pages).

The rest, which just assigns the various mmu_*_psize can go into
eary_init_mmu(). That means the only conversion needed is the one
below:

>         return false;
> @@ -561,7 +561,7 @@ static void __init htab_init_page_sizes(void)
>          * Not in the device-tree, let's fallback on known size
>          * list for 16M capable GP & GR
>          */
> -       if (mmu_has_feature(MMU_FTR_16M_PAGE))
> +       if (__mmu_has_feature(MMU_FTR_16M_PAGE))
>                 memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
>                        sizeof(mmu_psize_defaults_gp));
>  found:

And the rest can remain.

> @@ -591,7 +591,7 @@ found:
>                 mmu_vmalloc_psize = MMU_PAGE_64K;
>                 if (mmu_linear_psize == MMU_PAGE_4K)
>                         mmu_linear_psize = MMU_PAGE_64K;
> -               if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) {
> +               if (__mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) {
>                         /*
>                          * When running on pSeries using 64k pages
> for ioremap
>                          * would stop us accessing the HEA ethernet.
> So if we

On Thu, 28 Jul 2016 00:18:08 +1000
Michael Ellerman <mpe@ellerman.id.au> wrote:

> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
> 
> This switches early feature checks to use the non static key variant
> of the function. In later patches we will be switching
> cpu_has_feature() and mmu_has_feature() to use static keys and we can
> use them only after static key/jump label is initialized. Any check
> for feature before jump label init should be done using this new
> helper.

Can't convince you to call it *_has_feature_early()?

Any point to a WARN_ON_ONCE() in these guys that trips if they are
used after the jump labels are set up?

Thanks,
Nick

Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:

> On Thu, 2016-07-28 at 00:18 +1000, Michael Ellerman wrote:
>> 
>> diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h
>> b/arch/powerpc/include/asm/book3s/64/mmu.h
>> index 70c995870297..6deda6ecc4f7 100644
>> --- a/arch/powerpc/include/asm/book3s/64/mmu.h
>> +++ b/arch/powerpc/include/asm/book3s/64/mmu.h
>> @@ -116,7 +116,7 @@ extern void hash__early_init_mmu_secondary(void);
>>  extern void radix__early_init_mmu_secondary(void);
>>  static inline void early_init_mmu_secondary(void)
>>  {
>> -       if (radix_enabled())
>> +       if (__radix_enabled())
>>                 return radix__early_init_mmu_secondary();
>>         return hash__early_init_mmu_secondary();
>>  }
>
> This one can go, no ?

Yep.

cheers

Nicholas Piggin <npiggin@gmail.com> writes:

> On Thu, 28 Jul 2016 00:18:08 +1000
> Michael Ellerman <mpe@ellerman.id.au> wrote:
>
>> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>> 
>> This switches early feature checks to use the non static key variant
>> of the function. In later patches we will be switching
>> cpu_has_feature() and mmu_has_feature() to use static keys and we can
>> use them only after static key/jump label is initialized. Any check
>> for feature before jump label init should be done using this new
>> helper.
>
> Can't convince you to call it *_has_feature_early()?

Hmmm, I'll go with early_cpu_has_feature().

Otherwise it reads "does the CPU have feature 'early'".

> Any point to a WARN_ON_ONCE() in these guys that trips if they are
> used after the jump labels are set up?

See patch 20. Though we can't use WARN() as it may be too early in boot
to WARN(), so it just prints() and dumps stack.

cheers