diff mbox series

[1/2] asm-generic/io.h: suppress endianness warnings for readq() and writeq()

Message ID 20230109131153.991322-1-vladimir.oltean@nxp.com
State New
Headers
Series [1/2] asm-generic/io.h: suppress endianness warnings for readq() and writeq() |

Commit Message

Vladimir Oltean Jan. 9, 2023, 1:11 p.m. UTC 
  Commit c1d55d50139b ("asm-generic/io.h: Fix sparse warnings on
big-endian architectures") missed fixing the 64-bit accessors.

Arnd explains in the attached link why the casts are necessary, even if
__raw_readq() and __raw_writeq() do not take endian-specific types.

Link: https://lore.kernel.org/lkml/9105d6fc-880b-4734-857d-e3d30b87ccf6@app.fastmail.com/
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 include/asm-generic/io.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Vladimir Oltean March 10, 2023, 9:30 a.m. UTC | #1 
Hi Arnd,

On Mon, Jan 09, 2023 at 03:11:52PM +0200, Vladimir Oltean wrote:
> Commit c1d55d50139b ("asm-generic/io.h: Fix sparse warnings on
> big-endian architectures") missed fixing the 64-bit accessors.
> 
> Arnd explains in the attached link why the casts are necessary, even if
> __raw_readq() and __raw_writeq() do not take endian-specific types.
> 
> Link: https://lore.kernel.org/lkml/9105d6fc-880b-4734-857d-e3d30b87ccf6@app.fastmail.com/
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---
>  include/asm-generic/io.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
> index 4c44a29b5e8e..d78c3056c98f 100644
> --- a/include/asm-generic/io.h
> +++ b/include/asm-generic/io.h
> @@ -236,7 +236,7 @@ static inline u64 readq(const volatile void __iomem *addr)
>  
>  	log_read_mmio(64, addr, _THIS_IP_, _RET_IP_);
>  	__io_br();
> -	val = __le64_to_cpu(__raw_readq(addr));
> +	val = __le64_to_cpu((__le64 __force)__raw_readq(addr));
>  	__io_ar(val);
>  	log_post_read_mmio(val, 64, addr, _THIS_IP_, _RET_IP_);
>  	return val;
> @@ -287,7 +287,7 @@ static inline void writeq(u64 value, volatile void __iomem *addr)
>  {
>  	log_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_);
>  	__io_bw();
> -	__raw_writeq(__cpu_to_le64(value), addr);
> +	__raw_writeq((u64 __force)__cpu_to_le64(value), addr);
>  	__io_aw();
>  	log_post_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_);
>  }
> -- 
> 2.34.1
>

Did these patches get lost?
Jonathan Cameron April 4, 2023, 3:35 p.m. UTC | #2 
On Mon,  9 Jan 2023 15:11:52 +0200
Vladimir Oltean <vladimir.oltean@nxp.com> wrote:

> Commit c1d55d50139b ("asm-generic/io.h: Fix sparse warnings on
> big-endian architectures") missed fixing the 64-bit accessors.
> 
> Arnd explains in the attached link why the casts are necessary, even if
> __raw_readq() and __raw_writeq() do not take endian-specific types.
> 
> Link: https://lore.kernel.org/lkml/9105d6fc-880b-4734-857d-e3d30b87ccf6@app.fastmail.com/
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>

Found this when about to send an equivalent patch. Not seeing this in linux-next yet
and would be good to clean the resulting warnings up.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  include/asm-generic/io.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
> index 4c44a29b5e8e..d78c3056c98f 100644
> --- a/include/asm-generic/io.h
> +++ b/include/asm-generic/io.h
> @@ -236,7 +236,7 @@ static inline u64 readq(const volatile void __iomem *addr)
>  
>  	log_read_mmio(64, addr, _THIS_IP_, _RET_IP_);
>  	__io_br();
> -	val = __le64_to_cpu(__raw_readq(addr));
> +	val = __le64_to_cpu((__le64 __force)__raw_readq(addr));
>  	__io_ar(val);
>  	log_post_read_mmio(val, 64, addr, _THIS_IP_, _RET_IP_);
>  	return val;
> @@ -287,7 +287,7 @@ static inline void writeq(u64 value, volatile void __iomem *addr)
>  {
>  	log_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_);
>  	__io_bw();
> -	__raw_writeq(__cpu_to_le64(value), addr);
> +	__raw_writeq((u64 __force)__cpu_to_le64(value), addr);
>  	__io_aw();
>  	log_post_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_);
>  }
Arnd Bergmann April 4, 2023, 4 p.m. UTC | #3 
On Fri, Mar 10, 2023, at 10:30, Vladimir Oltean wrote:
> Hi Arnd,
>
> On Mon, Jan 09, 2023 at 03:11:52PM +0200, Vladimir Oltean wrote:
>> Commit c1d55d50139b ("asm-generic/io.h: Fix sparse warnings on
>> big-endian architectures") missed fixing the 64-bit accessors.
>> 
>> Arnd explains in the attached link why the casts are necessary, even if
>> __raw_readq() and __raw_writeq() do not take endian-specific types.
>> 
>> Link: https://lore.kernel.org/lkml/9105d6fc-880b-4734-857d-e3d30b87ccf6@app.fastmail.com/
>> Suggested-by: Arnd Bergmann <arnd@arndb.de>
>> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>

>>
>
> Did these patches get lost?

Yes, sorry about that. I picked them up for 6.3 now, along with another
one that I just remembered.

     Arnd
diff mbox series

Patch

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 4c44a29b5e8e..d78c3056c98f 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -236,7 +236,7 @@  static inline u64 readq(const volatile void __iomem *addr)
 
 	log_read_mmio(64, addr, _THIS_IP_, _RET_IP_);
 	__io_br();
-	val = __le64_to_cpu(__raw_readq(addr));
+	val = __le64_to_cpu((__le64 __force)__raw_readq(addr));
 	__io_ar(val);
 	log_post_read_mmio(val, 64, addr, _THIS_IP_, _RET_IP_);
 	return val;
@@ -287,7 +287,7 @@  static inline void writeq(u64 value, volatile void __iomem *addr)
 {
 	log_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_);
 	__io_bw();
-	__raw_writeq(__cpu_to_le64(value), addr);
+	__raw_writeq((u64 __force)__cpu_to_le64(value), addr);
 	__io_aw();
 	log_post_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_);
 }