Re: [PATCH v4] mtd: rawnand: cadence: support 64-bit slave dma interface

[Valentin Korenblit <vkorenblit@sequans.com>]

Hi Miquel,

On 10/18/22 11:17, Miquel Raynal wrote:
> Hi Valentin,
>
> vkorenblit@sequans.com wrote on Tue, 18 Oct 2022 11:16:31 +0200:
>
>> 32-bit accesses on 64-bit sdma trigger sdma_err in intr_status register.
>>
>> Check dma capabilities before reading/writing from/to sdma interface.
>>
>> Link: https://secure-web.cisco.com/1Zuwps3Jm-Qybygq3UAIg4d4S5heggZX1ow8KENGLYXasfYvc72QPuxCC1kbg9_YPoqVYqfCQVlokpkras6hyjajt6RxKCmlzNhUsTu6vdTgufT8upiLvVnbScXuhDTKV539Fk3pwIluw0CMUbizt16dze_fAdyNKJxwNbEzZIq8DIpD8kK9qUCTdhHSEXza7Ytk_EmwCBawUQFBNNV2CzKBaw-vx5t7gbuvlT1IL9WV4bA3nzUs4NLiN1TV2lBuyA28Duk2i-aouwPb5o3UwDHhHxyCQuGos0F-sSxMREQr2Uj4lgR8lfIpFbk6O8o7J3K2i8rXA4TqUYcRD4BxWWNk3nBHVJxW2oVqX6sjS3Vh32VxOnsoXhttu_3UFm3qziOiukq8jXcvoFPvD6kwJutnujcsJzeGzEBSBfUxSHdgZYFyBbHwqqBC298e3uUV-/https%3A%2F%2Flists.01.org%2Fhyperkitty%2Flist%2Fkbuild-all%40lists.01.org%2Fthread%2F3NMACGIM5NDUBPXRT5RTBZON6LQE5A3B%2F
> What happened to the link? I guess there is some security software
> interaction here? Should we take the one from your v3?

I copy/pasted the link that I received in Arnd's email.

Maybe this is better:

https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org/thread/3NMACGIM5NDUBPXRT5RTBZON6LQE5A3B/

Do you want me to do a v5 with it?

>
>> Signed-off-by: Valentin Korenblit <vkorenblit@sequans.com>
>> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
>>
>> ---
>>
>> Changes v1 -> v2:
>> 	- Replaced ioread64_rep by cadence_nand_readsq (suggested by Arnd)
>> 	- Replaced iowrite64_rep by cadence_nand_writesq (suggested by Arnd)
>> 	- Do not try to access 64-bit sdma if __raw_readq/__raw_writeq are not defined
>>
>> Changes v2 -> v3:
>> 	- Use readsq/writesq on 64-bit architectures (Arnd)
>> 	- Detect issue on init instead of 1st transfer
>>
>> Changes v3 -> v4:
>> 	- Updated link and reviewed tag (Arnd)
>> ---
>>   .../mtd/nand/raw/cadence-nand-controller.c    | 70 +++++++++++++++----
>>   1 file changed, 58 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/mtd/nand/raw/cadence-nand-controller.c b/drivers/mtd/nand/raw/cadence-nand-controller.c
>> index 9dac3ca69d57..7661a5cf1883 100644
>> --- a/drivers/mtd/nand/raw/cadence-nand-controller.c
>> +++ b/drivers/mtd/nand/raw/cadence-nand-controller.c
>> @@ -1184,6 +1184,14 @@ static int cadence_nand_hw_init(struct cdns_nand_ctrl *cdns_ctrl)
>>   	if (cadence_nand_read_bch_caps(cdns_ctrl))
>>   		return -EIO;
>>   
>> +#ifndef CONFIG_64BIT
>> +	if (cdns_ctrl->caps2.data_dma_width == 8) {
>> +		dev_err(cdns_ctrl->dev,
>> +			"cannot access 64-bit dma on !64-bit architectures");
>> +		return -EIO;
>> +	}
>> +#endif
>> +
>>   	/*
>>   	 * Set IO width access to 8.
>>   	 * It is because during SW device discovering width access
>> @@ -1882,17 +1890,36 @@ static int cadence_nand_read_buf(struct cdns_nand_ctrl *cdns_ctrl,
>>   		return status;
>>   
>>   	if (!cdns_ctrl->caps1->has_dma) {
>> -		int len_in_words = len >> 2;
>> +		u8 data_dma_width = cdns_ctrl->caps2.data_dma_width;
>> +
>> +		int len_in_words = (data_dma_width == 4) ? len >> 2 : len >> 3;
>>   
>>   		/* read alingment data */
>> -		ioread32_rep(cdns_ctrl->io.virt, buf, len_in_words);
>> +		if (data_dma_width == 4)
>> +			ioread32_rep(cdns_ctrl->io.virt, buf, len_in_words);
>> +#ifdef CONFIG_64BIT
>> +		else
>> +			readsq(cdns_ctrl->io.virt, buf, len_in_words);
>> +#endif
>> +
>>   		if (sdma_size > len) {
>> +			int read_bytes = (data_dma_width == 4) ?
>> +				len_in_words << 2 : len_in_words << 3;
>> +
>>   			/* read rest data from slave DMA interface if any */
>> -			ioread32_rep(cdns_ctrl->io.virt, cdns_ctrl->buf,
>> -				     sdma_size / 4 - len_in_words);
>> +			if (data_dma_width == 4)
>> +				ioread32_rep(cdns_ctrl->io.virt,
>> +					     cdns_ctrl->buf,
>> +					     sdma_size / 4 - len_in_words);
>> +#ifdef CONFIG_64BIT
>> +			else
>> +				readsq(cdns_ctrl->io.virt, cdns_ctrl->buf,
>> +				       sdma_size / 8 - len_in_words);
>> +#endif
>> +
>>   			/* copy rest of data */
>> -			memcpy(buf + (len_in_words << 2), cdns_ctrl->buf,
>> -			       len - (len_in_words << 2));
>> +			memcpy(buf + read_bytes, cdns_ctrl->buf,
>> +			       len - read_bytes);
>>   		}
>>   		return 0;
>>   	}
>> @@ -1936,16 +1963,35 @@ static int cadence_nand_write_buf(struct cdns_nand_ctrl *cdns_ctrl,
>>   		return status;
>>   
>>   	if (!cdns_ctrl->caps1->has_dma) {
>> -		int len_in_words = len >> 2;
>> +		u8 data_dma_width = cdns_ctrl->caps2.data_dma_width;
>> +
>> +		int len_in_words = (data_dma_width == 4) ? len >> 2 : len >> 3;
>> +
>> +		if (data_dma_width == 4)
>> +			iowrite32_rep(cdns_ctrl->io.virt, buf, len_in_words);
>> +#ifdef CONFIG_64BIT
>> +		else
>> +			writesq(cdns_ctrl->io.virt, buf, len_in_words);
>> +#endif
>>   
>> -		iowrite32_rep(cdns_ctrl->io.virt, buf, len_in_words);
>>   		if (sdma_size > len) {
>> +			int written_bytes = (data_dma_width == 4) ?
>> +				len_in_words << 2 : len_in_words << 3;
>> +
>>   			/* copy rest of data */
>> -			memcpy(cdns_ctrl->buf, buf + (len_in_words << 2),
>> -			       len - (len_in_words << 2));
>> +			memcpy(cdns_ctrl->buf, buf + written_bytes,
>> +			       len - written_bytes);
>> +
>>   			/* write all expected by nand controller data */
>> -			iowrite32_rep(cdns_ctrl->io.virt, cdns_ctrl->buf,
>> -				      sdma_size / 4 - len_in_words);
>> +			if (data_dma_width == 4)
>> +				iowrite32_rep(cdns_ctrl->io.virt,
>> +					      cdns_ctrl->buf,
>> +					      sdma_size / 4 - len_in_words);
>> +#ifdef CONFIG_64BIT
>> +			else
>> +				writesq(cdns_ctrl->io.virt, cdns_ctrl->buf,
>> +					sdma_size / 8 - len_in_words);
>> +#endif
>>   		}
>>   
>>   		return 0;
>
> Thanks,
> Miquèl

Best regards,

Valentin

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