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

From: "Kumar, Udit" <u-kumar1@ti.com>
To: Bart Van Assche <bvanassche@acm.org>,
	"Martin K . Petersen" <martin.petersen@oracle.com>
Cc: <linux-scsi@vger.kernel.org>, Avri Altman <avri.altman@wdc.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	"Bao D . Nguyen" <quic_nguyenb@quicinc.com>,
	Eric Biggers <ebiggers@google.com>, Bean Huo <beanhuo@micron.com>,
	"James E.J. Bottomley" <jejb@linux.ibm.com>,
	Stanley Chu <stanley.chu@mediatek.com>,
	Can Guo <quic_cang@quicinc.com>,
	Manivannan Sadhasivam <mani@kernel.org>,
	Asutosh Das <quic_asutoshd@quicinc.com>,
	Po-Wen Kao <powen.kao@mediatek.com>,
	Yang Li <yang.lee@linux.alibaba.com>,
	Arthur Simchaev <Arthur.Simchaev@wdc.com>,
	Kiwoong Kim <kwmad.kim@samsung.com>, Nishanth Menon <nm@ti.com>,
	<d-gole@ti.com>, <linux-next@vger.kernel.org>, <u-kumar1@ti.com>
Subject: Re: [PATCH v2 11/12] scsi: ufs: Simplify transfer request header initialization
Date: Wed, 2 Aug 2023 16:55:01 +0530	[thread overview]
Message-ID: <97281aba-a78c-7f75-fc15-af43e4df4907@ti.com> (raw)
In-Reply-To: <20230727194457.3152309-12-bvanassche@acm.org>

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

>   [...]