On Wed, Feb 14, 2018 at 9:46 PM, Michael S. Tsirkin <m...@redhat.com> wrote:
> On Wed, Feb 14, 2018 at 03:18:44PM +0100, Marc-André Lureau wrote:
>> The function is used for both LE & BE target type, use __force casting.
>>
>> Fixes:
>> $ make C=1 CF=-D__CHECK_ENDIAN__ drivers/firmware/qemu_fw_cfg.o
>>
>> drivers/firmware/qemu_fw_cfg.c:55:33: warning: restricted __be16 degrades to
>> integer
>> drivers/firmware/qemu_fw_cfg.c:55:52: warning: restricted __le16 degrades to
>> integer
>>
>> Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
>> ---
>> drivers/firmware/qemu_fw_cfg.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c
>> index 90f467232777..85e693287d87 100644
>> --- a/drivers/firmware/qemu_fw_cfg.c
>> +++ b/drivers/firmware/qemu_fw_cfg.c
>> @@ -52,7 +52,9 @@ static DEFINE_MUTEX(fw_cfg_dev_lock);
>> /* pick appropriate endianness for selector key */
>> static inline u16 fw_cfg_sel_endianness(u16 key)
>> {
>> - return fw_cfg_is_mmio ? cpu_to_be16(key) : cpu_to_le16(key);
>> + return fw_cfg_is_mmio ?
>> + (u16 __force)cpu_to_be16(key) :
>> + (u16 __force)cpu_to_le16(key);
>> }
>>
>> /* read chunk of given fw_cfg blob (caller responsible for sanity-check) */
>
> Well the caller does cpu_to_le16 on the result ...
> All this makes my head spin.
>
> IMHO what you want is a wrapper that does iowrite and iowritebe
> rather than __force.
iowrite16(key) is the same as iowrite16(cpu_to_le16(key)) ? There is
no iowrite16le()...
Is this equivalent, and not introducing regressions?
static inline u16 fw_cfg_sel_endianness(u16 key)
+static void fw_cfg_sel_endianness(u16 key)
{
- return fw_cfg_is_mmio ? cpu_to_be16(key) : cpu_to_le16(key);
+ if (fw_cfg_is_mmio)
+ iowrite16be(key, fw_cfg_reg_ctrl);
+ else
+ iowrite16(key, fw_cfg_reg_ctrl);
}
/* read chunk of given fw_cfg blob (caller responsible for sanity-check) */
@@ -74,7 +77,7 @@ static inline void fw_cfg_read_blob(u16 key,
}
mutex_lock(&fw_cfg_dev_lock);
- iowrite16(fw_cfg_sel_endianness(key), fw_cfg_reg_ctrl);
+ fw_cfg_sel_endianness(key);
>
>
>> --
>> 2.16.1.73.g5832b7e9f2
