Re: [PATCH v2] mmc: fsl_esdhc_spl: Add support for loading proper U-Boot from unaligned location

[Jaehoon Chung <jh80.chung@samsung.com>]

On 6/20/22 19:54, Pali Rohár wrote:
> This allows to concatenate SPL and proper U-Boot without extra alignment.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>

Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>

Best Regards,
Jaehoon Chung


> ---
> Changes in v2:
> * Rebased on top of the U-Boot next branch, commit 98c4828740f4944462b7d9608b95d5b73850c7b0
> ---
>  drivers/mmc/fsl_esdhc_spl.c | 27 +++++++++++++++++++++++----
>  1 file changed, 23 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mmc/fsl_esdhc_spl.c b/drivers/mmc/fsl_esdhc_spl.c
> index 760f13d24018..54bf8152ca7a 100644
> --- a/drivers/mmc/fsl_esdhc_spl.c
> +++ b/drivers/mmc/fsl_esdhc_spl.c
> @@ -58,10 +58,10 @@ void __noreturn mmc_boot(void)
>  {
>  	__attribute__((noreturn)) void (*uboot)(void);
>  	uint blk_start, blk_cnt, err;
> +	u32 blk_off;
>  #ifndef CONFIG_FSL_CORENET
>  	uchar *tmp_buf;
>  	u32 blklen;
> -	u32 blk_off;
>  	uchar val;
>  #ifndef CONFIG_SPL_FSL_PBL
>  	u32 val32;
> @@ -155,10 +155,21 @@ again:
>  	* Load U-Boot image from mmc into RAM
>  	*/
>  	code_len = CONFIG_SYS_MMC_U_BOOT_SIZE;
> -	blk_start = ALIGN(offset, mmc->read_bl_len) / mmc->read_bl_len;
> -	blk_cnt = ALIGN(code_len, mmc->read_bl_len) / mmc->read_bl_len;
> +	blk_start = offset / mmc->read_bl_len;
> +	blk_off = offset % mmc->read_bl_len;
> +	blk_cnt = ALIGN(code_len, mmc->read_bl_len) / mmc->read_bl_len + 1;
> +	if (blk_off) {
> +		err = mmc->block_dev.block_read(&mmc->block_dev,
> +						blk_start, 1, tmp_buf);
> +		if (err != 1) {
> +			puts("spl: mmc read failed!!\n");
> +			hang();
> +		}
> +		blk_start++;
> +	}
>  	err = mmc->block_dev.block_read(&mmc->block_dev, blk_start, blk_cnt,
> -					(uchar *)CONFIG_SYS_MMC_U_BOOT_DST);
> +					(uchar *)CONFIG_SYS_MMC_U_BOOT_DST +
> +					(blk_off ? (mmc->read_bl_len - blk_off) : 0));
>  	if (err != blk_cnt) {
>  		puts("spl: mmc read failed!!\n");
>  #ifndef CONFIG_FSL_CORENET
> @@ -166,6 +177,14 @@ again:
>  #endif
>  		hang();
>  	}
> +	/*
> +	 * SDHC DMA may erase bytes at dst + bl_len - blk_off - 8
> +	 * due to unaligned access. So copy leading bytes from tmp_buf
> +	 * after SDHC DMA transfer.
> +	 */
> +	if (blk_off)
> +		memcpy((uchar *)CONFIG_SYS_MMC_U_BOOT_DST,
> +		       tmp_buf + blk_off, mmc->read_bl_len - blk_off);
>  
>  	/*
>  	* Clean d-cache and invalidate i-cache, to