[PATCH] x86: squash lines for simple wrapper functions

[PATCH] x86: squash lines for simple wrapper functions

[Masahiro Yamada]

Remove unneeded variables and assignments.  I am also removing
unnecessary parentheses while I am here.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 arch/x86/kernel/apic/apic_flat_64.c  | 16 +++-------------
 arch/x86/kernel/apic/apic_numachip.c |  5 +----
 arch/x86/kernel/apic/x2apic_uv_x.c   |  5 +----
 arch/x86/mm/pat_rbtree.c             |  4 +---
 arch/x86/platform/uv/bios_uv.c       |  7 ++-----
 arch/x86/platform/uv/tlb_uv.c        |  6 +-----
 6 files changed, 9 insertions(+), 34 deletions(-)

diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c
index 5b2ae10..c7228f9 100644
--- a/arch/x86/kernel/apic/apic_flat_64.c
+++ b/arch/x86/kernel/apic/apic_flat_64.c
@@ -116,27 +116,17 @@ static void flat_send_IPI_all(int vector)
 
 static unsigned int flat_get_apic_id(unsigned long x)
 {
-	unsigned int id;
-
-	id = (((x)>>24) & 0xFFu);
-
-	return id;
+	return ((x) >> 24) & 0xFFu;
 }
 
 static unsigned long set_apic_id(unsigned int id)
 {
-	unsigned long x;
-
-	x = ((id & 0xFFu)<<24);
-	return x;
+	return (id & 0xFFu) << 24;
 }
 
 static unsigned int read_xapic_id(void)
 {
-	unsigned int id;
-
-	id = flat_get_apic_id(apic_read(APIC_ID));
-	return id;
+	return flat_get_apic_id(apic_read(APIC_ID));
 }
 
 static int flat_apic_id_registered(void)
diff --git a/arch/x86/kernel/apic/apic_numachip.c b/arch/x86/kernel/apic/apic_numachip.c
index 714d4fd..fce51bf 100644
--- a/arch/x86/kernel/apic/apic_numachip.c
+++ b/arch/x86/kernel/apic/apic_numachip.c
@@ -40,10 +40,7 @@ static unsigned int numachip1_get_apic_id(unsigned long x)
 
 static unsigned long numachip1_set_apic_id(unsigned int id)
 {
-	unsigned long x;
-
-	x = ((id & 0xffU) << 24);
-	return x;
+	return (id & 0xffU) << 24;
 }
 
 static unsigned int numachip2_get_apic_id(unsigned long x)
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index cb0673c..6a4d4b9 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -533,11 +533,8 @@ static unsigned int x2apic_get_apic_id(unsigned long x)
 
 static unsigned long set_apic_id(unsigned int id)
 {
-	unsigned long x;
-
 	/* maskout x2apic_extra_bits ? */
-	x = id;
-	return x;
+	return id;
 }
 
 static unsigned int uv_read_apic_id(void)
diff --git a/arch/x86/mm/pat_rbtree.c b/arch/x86/mm/pat_rbtree.c
index de391b7..159b52c 100644
--- a/arch/x86/mm/pat_rbtree.c
+++ b/arch/x86/mm/pat_rbtree.c
@@ -254,9 +254,7 @@ struct memtype *rbt_memtype_erase(u64 start, u64 end)
 
 struct memtype *rbt_memtype_lookup(u64 addr)
 {
-	struct memtype *data;
-	data = memtype_rb_lowest_match(&memtype_rbroot, addr, addr + PAGE_SIZE);
-	return data;
+	return memtype_rb_lowest_match(&memtype_rbroot, addr, addr + PAGE_SIZE);
 }
 
 #if defined(CONFIG_DEBUG_FS)
diff --git a/arch/x86/platform/uv/bios_uv.c b/arch/x86/platform/uv/bios_uv.c
index 23f2f3e..b4d5e95 100644
--- a/arch/x86/platform/uv/bios_uv.c
+++ b/arch/x86/platform/uv/bios_uv.c
@@ -149,11 +149,8 @@ EXPORT_SYMBOL_GPL(uv_bios_change_memprotect);
 s64
 uv_bios_reserved_page_pa(u64 buf, u64 *cookie, u64 *addr, u64 *len)
 {
-	s64 ret;
-
-	ret = uv_bios_call_irqsave(UV_BIOS_GET_PARTITION_ADDR, (u64)cookie,
-					(u64)addr, buf, (u64)len, 0);
-	return ret;
+	return uv_bios_call_irqsave(UV_BIOS_GET_PARTITION_ADDR, (u64)cookie,
+				    (u64)addr, buf, (u64)len, 0);
 }
 EXPORT_SYMBOL_GPL(uv_bios_reserved_page_pa);
 
diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
index fdb4d42..276e1b7 100644
--- a/arch/x86/platform/uv/tlb_uv.c
+++ b/arch/x86/platform/uv/tlb_uv.c
@@ -580,11 +580,7 @@ static int uv1_wait_completion(struct bau_desc *bau_desc,
  */
 static unsigned long uv2_3_read_status(unsigned long offset, int rshft, int desc)
 {
-	unsigned long descriptor_status;
-
-	descriptor_status =
-		((read_lmmr(offset) >> rshft) & UV_ACT_STATUS_MASK) << 1;
-	return descriptor_status;
+	return ((read_lmmr(offset) >> rshft) & UV_ACT_STATUS_MASK) << 1;
 }
 
 /*
-- 
1.9.1

Re: [PATCH] x86: squash lines for simple wrapper functions

[Ingo Molnar]

* Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> Remove unneeded variables and assignments.  I am also removing
> unnecessary parentheses while I am here.
> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
> 
>  arch/x86/kernel/apic/apic_flat_64.c  | 16 +++-------------
>  arch/x86/kernel/apic/apic_numachip.c |  5 +----
>  arch/x86/kernel/apic/x2apic_uv_x.c   |  5 +----
>  arch/x86/mm/pat_rbtree.c             |  4 +---
>  arch/x86/platform/uv/bios_uv.c       |  7 ++-----
>  arch/x86/platform/uv/tlb_uv.c        |  6 +-----
>  6 files changed, 9 insertions(+), 34 deletions(-)
> 
> diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c
> index 5b2ae10..c7228f9 100644
> --- a/arch/x86/kernel/apic/apic_flat_64.c
> +++ b/arch/x86/kernel/apic/apic_flat_64.c
> @@ -116,27 +116,17 @@ static void flat_send_IPI_all(int vector)
>  
>  static unsigned int flat_get_apic_id(unsigned long x)
>  {
> -	unsigned int id;
> -
> -	id = (((x)>>24) & 0xFFu);
> -
> -	return id;
> +	return ((x) >> 24) & 0xFFu;

So while we are removing unnecessary things, exactly why does the 'x' need 
parentheses?

>  static unsigned long set_apic_id(unsigned int id)
>  {
> -	unsigned long x;
> -
> -	x = ((id & 0xFFu)<<24);
> -	return x;
> +	return (id & 0xFFu) << 24;

'id' is already unsigned, why does the 'u' have to be stressed in the literal? 
(Ditto for other places as well)

>  static unsigned long numachip1_set_apic_id(unsigned int id)
>  {
> -	unsigned long x;
> -
> -	x = ((id & 0xffU) << 24);
> -	return x;
> +	return (id & 0xffU) << 24;
>  }

Why is the spelling of the literal inconsistent here with the other patterns?

> +++ b/arch/x86/kernel/apic/x2apic_uv_x.c
> @@ -533,11 +533,8 @@ static unsigned int x2apic_get_apic_id(unsigned long x)
>  
>  static unsigned long set_apic_id(unsigned int id)
>  {
> -	unsigned long x;
> -
>  	/* maskout x2apic_extra_bits ? */
> -	x = id;
> -	return x;
> +	return id;
>  }

This was clearly left there to document a quirk and as a placeholder for future 
changes.

Thanks,

	Ingo

Re: [PATCH] x86: squash lines for simple wrapper functions

[Thomas Gleixner]

On Thu, 8 Sep 2016, Ingo Molnar wrote:
> * Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> >  static unsigned long set_apic_id(unsigned int id)
> >  {
> > -	unsigned long x;
> > -
> >  	/* maskout x2apic_extra_bits ? */
> > -	x = id;
> > -	return x;
> > +	return id;
> >  }
> 
> This was clearly left there to document a quirk and as a placeholder for future 
> changes.

Keeping the comment and rewording it to:

	/* CHECKME: Do we need to mask out the xapic extra bits */

should be good enough. The variable dance is not really giving any value.

Thanks,

	tglx

Re: [PATCH] x86: squash lines for simple wrapper functions

[Ingo Molnar]

* Thomas Gleixner <tglx@linutronix.de> wrote:

> On Thu, 8 Sep 2016, Ingo Molnar wrote:
> > * Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> > >  static unsigned long set_apic_id(unsigned int id)
> > >  {
> > > -	unsigned long x;
> > > -
> > >  	/* maskout x2apic_extra_bits ? */
> > > -	x = id;
> > > -	return x;
> > > +	return id;
> > >  }
> > 
> > This was clearly left there to document a quirk and as a placeholder for future 
> > changes.
> 
> Keeping the comment and rewording it to:
> 
> 	/* CHECKME: Do we need to mask out the xapic extra bits */
> 
> should be good enough. The variable dance is not really giving any value.

Yeah, sure - my point was that the mindless removal is wrong.

Thanks,

	Ingo

Re: [PATCH] x86: squash lines for simple wrapper functions

[Thomas Gleixner]

On Sat, 10 Sep 2016, Ingo Molnar wrote:
> * Thomas Gleixner <tglx@linutronix.de> wrote:
> 
> > On Thu, 8 Sep 2016, Ingo Molnar wrote:
> > > * Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> > > >  static unsigned long set_apic_id(unsigned int id)
> > > >  {
> > > > -	unsigned long x;
> > > > -
> > > >  	/* maskout x2apic_extra_bits ? */
> > > > -	x = id;
> > > > -	return x;
> > > > +	return id;
> > > >  }
> > > 
> > > This was clearly left there to document a quirk and as a placeholder for future 
> > > changes.
> > 
> > Keeping the comment and rewording it to:
> > 
> > 	/* CHECKME: Do we need to mask out the xapic extra bits */
> > 
> > should be good enough. The variable dance is not really giving any value.
> 
> Yeah, sure - my point was that the mindless removal is wrong.

He kept the comment. The rewording is a bonus.

Re: [PATCH] x86: squash lines for simple wrapper functions

[Ingo Molnar]

* Thomas Gleixner <tglx@linutronix.de> wrote:

> On Sat, 10 Sep 2016, Ingo Molnar wrote:
> > * Thomas Gleixner <tglx@linutronix.de> wrote:
> > 
> > > On Thu, 8 Sep 2016, Ingo Molnar wrote:
> > > > * Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> > > > >  static unsigned long set_apic_id(unsigned int id)
> > > > >  {
> > > > > -	unsigned long x;
> > > > > -
> > > > >  	/* maskout x2apic_extra_bits ? */
> > > > > -	x = id;
> > > > > -	return x;
> > > > > +	return id;
> > > > >  }
> > > > 
> > > > This was clearly left there to document a quirk and as a placeholder for future 
> > > > changes.
> > > 
> > > Keeping the comment and rewording it to:
> > > 
> > > 	/* CHECKME: Do we need to mask out the xapic extra bits */
> > > 
> > > should be good enough. The variable dance is not really giving any value.
> > 
> > Yeah, sure - my point was that the mindless removal is wrong.
> 
> He kept the comment. The rewording is a bonus.

Ok, fair enough.

Thanks,

	Ingo

Re: [PATCH] x86: squash lines for simple wrapper functions

[Masahiro Yamada]

Hi Ingo, Thomas,

Thanks for your review!



2016-09-08 15:33 GMT+09:00 Ingo Molnar <mingo@kernel.org>:

>>  static unsigned int flat_get_apic_id(unsigned long x)
>>  {
>> -     unsigned int id;
>> -
>> -     id = (((x)>>24) & 0xFFu);
>> -
>> -     return id;
>> +     return ((x) >> 24) & 0xFFu;
>
> So while we are removing unnecessary things, exactly why does the 'x' need
> parentheses?


I will change it to:

    return (x >> 24) & 0xFF;





>>  static unsigned long set_apic_id(unsigned int id)
>>  {
>> -     unsigned long x;
>> -
>> -     x = ((id & 0xFFu)<<24);
>> -     return x;
>> +     return (id & 0xFFu) << 24;
>
> 'id' is already unsigned, why does the 'u' have to be stressed in the literal?
> (Ditto for other places as well)


I will change it to:

          return (id & 0xFF) << 24;



>>  static unsigned long numachip1_set_apic_id(unsigned int id)
>>  {
>> -     unsigned long x;
>> -
>> -     x = ((id & 0xffU) << 24);
>> -     return x;
>> +     return (id & 0xffU) << 24;
>>  }
>
> Why is the spelling of the literal inconsistent here with the other patterns?


I think 0xff is more consistent than 0xFF
in arch/x86/kernel/apic/apic_numachip.c


Making the constant literals consistent across files
is a too much churn, I think.



>> +++ b/arch/x86/kernel/apic/x2apic_uv_x.c
>> @@ -533,11 +533,8 @@ static unsigned int x2apic_get_apic_id(unsigned long x)
>>
>>  static unsigned long set_apic_id(unsigned int id)
>>  {
>> -     unsigned long x;
>> -
>>       /* maskout x2apic_extra_bits ? */
>> -     x = id;
>> -     return x;
>> +     return id;
>>  }
>
> This was clearly left there to document a quirk and as a placeholder for future
> changes.
>


As suggested by Thomas, I will change it to:

{
         /* CHECKME: Do we need to mask out the xapic extra bits? */
         return id;
}



(I am adding '?' at the comment line.)




If there is no more comment, I will send v2.



-- 
Best Regards
Masahiro Yamada