[Qemu-devel] [PATCH] virtio-input: const_le16 and const_le32 not build time constant

[Qemu-devel] [PATCH] virtio-input: const_le16 and const_le32 not build time constant

[Michael Mueller]

As the implementation of const_le16 and const_le32 is not build time constant
on big endian systems this need to be fixed.

  CC    hw/input/virtio-input-hid.o
hw/input/virtio-input-hid.c:340:13: error: initializer element is not constant
hw/input/virtio-input-hid.c:340:13: error: (near initialization for ‘virtio_keyboard_config[1].u.ids.bustype’)
...

Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
---
 include/hw/virtio/virtio-input.h | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/hw/virtio/virtio-input.h b/include/hw/virtio/virtio-input.h
index a265519..bcee355 100644
--- a/include/hw/virtio/virtio-input.h
+++ b/include/hw/virtio/virtio-input.h
@@ -14,8 +14,14 @@ typedef struct virtio_input_config virtio_input_config;
 typedef struct virtio_input_event virtio_input_event;
 
 #if defined(HOST_WORDS_BIGENDIAN)
-# define const_le32(_x) bswap32(_x)
-# define const_le16(_x) bswap32(_x)
+# define const_le32(_x)                          \
+    (((_x & 0x000000ffU) << 24) |                \
+     ((_x & 0x0000ff00U) <<  8) |                \
+     ((_x & 0x00ff0000U) >>  8) |                \
+     ((_x & 0xff000000U) >> 24))
+# define const_le16(_x)                          \
+    (((_x & 0x00ff) << 8) |                      \
+     ((_x & 0xff00) >> 8))
 #else
 # define const_le32(_x) (_x)
 # define const_le16(_x) (_x)
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH] virtio-input: const_le16 and const_le32 not build time constant

[Alexander Graf]

On 01.06.15 15:51, Michael Mueller wrote:
> As the implementation of const_le16 and const_le32 is not build time constant
> on big endian systems this need to be fixed.
> 
>   CC    hw/input/virtio-input-hid.o
> hw/input/virtio-input-hid.c:340:13: error: initializer element is not constant
> hw/input/virtio-input-hid.c:340:13: error: (near initialization for ‘virtio_keyboard_config[1].u.ids.bustype’)
> ...
> 
> Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>

Thanks a lot for this patch. It fixes current compile breakage on
upstream QEMU for me - or on any big endian system for that matter.

For the time being I've included it into my ppc-next tree, but I'd
prefer if this gets merged directly before I flush it (for
bisectability's sake).


Alex

> ---
>  include/hw/virtio/virtio-input.h | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/include/hw/virtio/virtio-input.h b/include/hw/virtio/virtio-input.h
> index a265519..bcee355 100644
> --- a/include/hw/virtio/virtio-input.h
> +++ b/include/hw/virtio/virtio-input.h
> @@ -14,8 +14,14 @@ typedef struct virtio_input_config virtio_input_config;
>  typedef struct virtio_input_event virtio_input_event;
>  
>  #if defined(HOST_WORDS_BIGENDIAN)
> -# define const_le32(_x) bswap32(_x)
> -# define const_le16(_x) bswap32(_x)
> +# define const_le32(_x)                          \
> +    (((_x & 0x000000ffU) << 24) |                \
> +     ((_x & 0x0000ff00U) <<  8) |                \
> +     ((_x & 0x00ff0000U) >>  8) |                \
> +     ((_x & 0xff000000U) >> 24))
> +# define const_le16(_x)                          \
> +    (((_x & 0x00ff) << 8) |                      \
> +     ((_x & 0xff00) >> 8))
>  #else
>  # define const_le32(_x) (_x)
>  # define const_le16(_x) (_x)
> 

Re: [Qemu-devel] [PATCH] virtio-input: const_le16 and const_le32 not build time constant

[Christian Borntraeger]

Am 01.06.2015 um 15:51 schrieb Michael Mueller:
> As the implementation of const_le16 and const_le32 is not build time constant
> on big endian systems this need to be fixed.
> 
>   CC    hw/input/virtio-input-hid.o
> hw/input/virtio-input-hid.c:340:13: error: initializer element is not constant
> hw/input/virtio-input-hid.c:340:13: error: (near initialization for ‘virtio_keyboard_config[1].u.ids.bustype’)
> ...
> 
> Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
> ---
>  include/hw/virtio/virtio-input.h | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/include/hw/virtio/virtio-input.h b/include/hw/virtio/virtio-input.h
> index a265519..bcee355 100644
> --- a/include/hw/virtio/virtio-input.h
> +++ b/include/hw/virtio/virtio-input.h
> @@ -14,8 +14,14 @@ typedef struct virtio_input_config virtio_input_config;
>  typedef struct virtio_input_event virtio_input_event;
> 
>  #if defined(HOST_WORDS_BIGENDIAN)
> -# define const_le32(_x) bswap32(_x)
> -# define const_le16(_x) bswap32(_x)
> +# define const_le32(_x)                          \
> +    (((_x & 0x000000ffU) << 24) |                \
> +     ((_x & 0x0000ff00U) <<  8) |                \
> +     ((_x & 0x00ff0000U) >>  8) |                \
> +     ((_x & 0xff000000U) >> 24))
> +# define const_le16(_x)                          \
> +    (((_x & 0x00ff) << 8) |                      \
> +     ((_x & 0xff00) >> 8))
>  #else
>  # define const_le32(_x) (_x)
>  # define const_le16(_x) (_x)
> 

Would be good to have this fixed soon.
I cannot build current qemu/master on s390. This patch fixes it for me.
An alternative solution might be to not use const_le* in the code.

Christian

Re: [Qemu-devel] [PATCH] virtio-input: const_le16 and const_le32 not build time constant

[Peter Maydell]

On 2 June 2015 at 08:31, Christian Borntraeger <borntraeger@de.ibm.com> wrote:
> Am 01.06.2015 um 15:51 schrieb Michael Mueller:
>> As the implementation of const_le16 and const_le32 is not build time constant
>> on big endian systems this need to be fixed.
>>
>>   CC    hw/input/virtio-input-hid.o
>> hw/input/virtio-input-hid.c:340:13: error: initializer element is not constant
>> hw/input/virtio-input-hid.c:340:13: error: (near initialization for ‘virtio_keyboard_config[1].u.ids.bustype’)
>> ...
>>
>> Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
>> ---
>>  include/hw/virtio/virtio-input.h | 10 ++++++++--
>>  1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/include/hw/virtio/virtio-input.h b/include/hw/virtio/virtio-input.h
>> index a265519..bcee355 100644
>> --- a/include/hw/virtio/virtio-input.h
>> +++ b/include/hw/virtio/virtio-input.h
>> @@ -14,8 +14,14 @@ typedef struct virtio_input_config virtio_input_config;
>>  typedef struct virtio_input_event virtio_input_event;
>>
>>  #if defined(HOST_WORDS_BIGENDIAN)
>> -# define const_le32(_x) bswap32(_x)
>> -# define const_le16(_x) bswap32(_x)
>> +# define const_le32(_x)                          \
>> +    (((_x & 0x000000ffU) << 24) |                \
>> +     ((_x & 0x0000ff00U) <<  8) |                \
>> +     ((_x & 0x00ff0000U) >>  8) |                \
>> +     ((_x & 0xff000000U) >> 24))
>> +# define const_le16(_x)                          \
>> +    (((_x & 0x00ff) << 8) |                      \
>> +     ((_x & 0xff00) >> 8))
>>  #else
>>  # define const_le32(_x) (_x)
>>  # define const_le16(_x) (_x)
>>
>
> Would be good to have this fixed soon.
> I cannot build current qemu/master on s390. This patch fixes it for me.
> An alternative solution might be to not use const_le* in the code.

Should now be fixed in master.

-- PMM