Re: [PATCH v2 11/12] scsi: ufs: Simplify transfer request header initialization

Re: [PATCH v2 11/12] scsi: ufs: Simplify transfer request header initialization

[Kumar, Udit]

Hi Bart,

On 7/28/2023 1:11 AM, Bart Van Assche wrote:
> Make the code that initializes UTP transfer request headers easier to
> read by using bitfields instead of __le32 where appropriate.
>
> Cc: Bao D. Nguyen <quic_nguyenb@quicinc.com>
> Cc: Eric Biggers <ebiggers@google.com>
> Cc: Avri Altman <avri.altman@wdc.com>
> Cc: Bean Huo <beanhuo@micron.com>
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
>   [...]
>   
> +static void ufshcd_check_header_layout(void)
> +{
> +	BUILD_BUG_ON(((u8 *)&(struct request_desc_header){
> +				.cci = 3})[0] != 3);
> +
> +	BUILD_BUG_ON(((u8 *)&(struct request_desc_header){
> +				.ehs_length = 2})[1] != 2);
> +
> +	BUILD_BUG_ON(((u8 *)&(struct request_desc_header){
> +				.enable_crypto = 1})[2]
> +		     != 0x80);
> +
> +	BUILD_BUG_ON((((u8 *)&(struct request_desc_header){
> +					.command_type = 5,
> +					.data_direction = 3,
> +					.interrupt = 1,
> +				})[3]) != ((5 << 4) | (3 << 1) | 1));
> +
> +	BUILD_BUG_ON(((__le32 *)&(struct request_desc_header){
> +				.dunl = cpu_to_le32(0xdeadbeef)})[1] !=
> +		cpu_to_le32(0xdeadbeef));
> +
> +	BUILD_BUG_ON(((u8 *)&(struct request_desc_header){
> +				.ocs = 4})[8] != 4);
> +
> +	BUILD_BUG_ON(((u8 *)&(struct request_desc_header){
> +				.cds = 5})[9] != 5);
> +
> +	BUILD_BUG_ON(((__le32 *)&(struct request_desc_header){
> +				.dunu = cpu_to_le32(0xbadcafe)})[3] !=
> +		cpu_to_le32(0xbadcafe));
> +}
> +

While building next-20230801 for ARM64 architecture,

this patch is giving compilation error

In function ‘ufshcd_check_header_layout’,
     inlined from ‘ufshcd_core_init’ at drivers/ufs/core/ufshcd.c:10629:2:
././include/linux/compiler_types.h:397:38: error: call to 
‘__compiletime_assert_554’ declared with attribute error: BUILD_BUG_ON 
failed: ((u8 *)&(struct request_desc_header){ .enable_crypto = 1})[2] != 
0x80
   397 |  _compiletime_assert(condition, msg, __compiletime_assert_, 
__COUNTER__)


compiler information

wget 
https://developer.arm.com/-/media/Files/downloads/gnu-a/9.2-2019.12/binrel/gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu.tar.xz

tar -Jxvf gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu.tar.xz

Build steps

make ARCH=arm64 CROSS_COMPILE=aarch64-none-linux-gnu- defconfig

make ARCH=arm64 CROSS_COMPILE=aarch64-none-linux-gnu- Image


>   [...]

Re: [PATCH v2 11/12] scsi: ufs: Simplify transfer request header initialization

[Bart Van Assche]

On 8/2/23 04:25, Kumar, Udit wrote:
> While building next-20230801 for ARM64 architecture,
> 
> this patch is giving compilation error
> 
> In function ‘ufshcd_check_header_layout’,
>      inlined from ‘ufshcd_core_init’ at drivers/ufs/core/ufshcd.c:10629:2:
> ././include/linux/compiler_types.h:397:38: error: call to 
> ‘__compiletime_assert_554’ declared with attribute error: BUILD_BUG_ON 
> failed: ((u8 *)&(struct request_desc_header){ .enable_crypto = 1})[2] != 
> 0x80
>    397 |  _compiletime_assert(condition, msg, __compiletime_assert_, 
> __COUNTER__)
> 
> 
> compiler information
> 
> wget 
> https://developer.arm.com/-/media/Files/downloads/gnu-a/9.2-2019.12/binrel/gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu.tar.xz

Does this patch help: 
https://lore.kernel.org/linux-scsi/20230801232204.1481902-1-bvanassche@acm.org/?

Thanks,

Bart.

RE: [PATCH v2 11/12] scsi: ufs: Simplify transfer request header initialization

[Kumar, Udit]

Thanks Bart

>
>On 8/2/23 04:25, Kumar, Udit wrote:
>> While building next-20230801 for ARM64 architecture,
>>
>> this patch is giving compilation error
>>
>> In function ‘ufshcd_check_header_layout’,
>>      inlined from ‘ufshcd_core_init’ at drivers/ufs/core/ufshcd.c:10629:2:
>> ././include/linux/compiler_types.h:397:38: error: call to
>> ‘__compiletime_assert_554’ declared with attribute error: BUILD_BUG_ON
>> failed: ((u8 *)&(struct request_desc_header){ .enable_crypto = 1})[2]
>> !=
>> 0x80
>>    397 |  _compiletime_assert(condition, msg, __compiletime_assert_,
>> __COUNTER__)
>>
>>
>> compiler information
>>
>> wget
>> https://developer.arm.com/-/media/Files/downloads/gnu-a/9.2-2019.12/bi
>> nrel/gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu.tar.xz
>
>Does this patch help:
>https://lore.kernel.org/linux-scsi/20230801232204.1481902-1-
>bvanassche@acm.org/?

Yes , build works for me with this patch.
You just skipped based upon compiler version  but 
what about checks you want to do in this function. 


>Thanks,
>
>Bart.

Re: [PATCH v2 11/12] scsi: ufs: Simplify transfer request header initialization

[Bart Van Assche]

On 8/2/23 09:44, Kumar, Udit wrote:
>> Does this patch help:
>> https://lore.kernel.org/linux-scsi/20230801232204.1481902-1-
>> bvanassche@acm.org/?
> 
> Yes , build works for me with this patch.
> You just skipped based upon compiler version  but
> what about checks you want to do in this function.

These checks verify that the layout of the structures matches the layout 
from the UFS standard. I want these checks to performed at compile time. 
I'm not sure how to let gcc 9 or older perform these checks at compile time.

Thanks,

Bart.