Subject: Re: [PATCH 04/15] net: hbl_cn: QP state machine

From: Leon Romanovsky <[email-masked]>
Date: Mon, 17 Jun 2024 16:18:07 +0300

On Thu, Jun 13, 2024 at 11:21:57AM +0300, Omer Shpigelman wrote:
> Add a common QP state machine which handles the moving for a QP from one
> state to another including performing necessary checks, draining
> in-flight transactions, invalidating caches and error reporting.
> 
> Signed-off-by: Omer Shpigelman <[email-masked]>
> Co-developed-by: Abhilash K V <[email-masked]>
> Signed-off-by: Abhilash K V <[email-masked]>
> Co-developed-by: Andrey Agranovich <[email-masked]>
> Signed-off-by: Andrey Agranovich <[email-masked]>
> Co-developed-by: Bharat Jauhari <[email-masked]>
> Signed-off-by: Bharat Jauhari <[email-masked]>
> Co-developed-by: David Meriin <[email-masked]>
> Signed-off-by: David Meriin <[email-masked]>
> Co-developed-by: Sagiv Ozeri <[email-masked]>
> Signed-off-by: Sagiv Ozeri <[email-masked]>
> Co-developed-by: Zvika Yehudai <[email-masked]>
> Signed-off-by: Zvika Yehudai <[email-masked]>
> ---
>  .../ethernet/intel/hbl_cn/common/hbl_cn_qp.c  | 480 +++++++++++++++++-
>  1 file changed, 479 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/intel/hbl_cn/common/hbl_cn_qp.c b/drivers/net/ethernet/intel/hbl_cn/common/hbl_cn_qp.c
> index 9ddc23bf8194..26ebdf448193 100644
> --- a/drivers/net/ethernet/intel/hbl_cn/common/hbl_cn_qp.c
> +++ b/drivers/net/ethernet/intel/hbl_cn/common/hbl_cn_qp.c
> @@ -6,8 +6,486 @@

<...>

> +/* The following table represents the (valid) operations that can be performed on
> + * a QP in order to move it from one state to another
> + * For example: a QP in RTR state can be moved to RTS state using the CN_QP_OP_RTR_2RTS
> + * operation.
> + */
> +static const enum hbl_cn_qp_state_op qp_valid_state_op[CN_QP_NUM_STATE][CN_QP_NUM_STATE] = {
> +	[CN_QP_STATE_RESET] = {
> +		[CN_QP_STATE_RESET]	= CN_QP_OP_2RESET,
> +		[CN_QP_STATE_INIT]	= CN_QP_OP_RST_2INIT,
> +		[CN_QP_STATE_SQD]	= CN_QP_OP_NOP,
> +		[CN_QP_STATE_QPD]	= CN_QP_OP_NOP,
> +	},
> +	[CN_QP_STATE_INIT] = {
> +		[CN_QP_STATE_RESET]	= CN_QP_OP_2RESET,
> +		[CN_QP_STATE_ERR]	= CN_QP_OP_2ERR,
> +		[CN_QP_STATE_INIT]	= CN_QP_OP_NOP,
> +		[CN_QP_STATE_RTR]	= CN_QP_OP_INIT_2RTR,
> +		[CN_QP_STATE_SQD]	= CN_QP_OP_NOP,
> +		[CN_QP_STATE_QPD]	= CN_QP_OP_NOP,
> +	},
> +	[CN_QP_STATE_RTR] = {
> +		[CN_QP_STATE_RESET]	= CN_QP_OP_2RESET,
> +		[CN_QP_STATE_ERR]	= CN_QP_OP_2ERR,
> +		[CN_QP_STATE_RTR]	= CN_QP_OP_RTR_2RTR,
> +		[CN_QP_STATE_RTS]	= CN_QP_OP_RTR_2RTS,
> +		[CN_QP_STATE_SQD]	= CN_QP_OP_NOP,
> +		[CN_QP_STATE_QPD]	= CN_QP_OP_RTR_2QPD,
> +	},
> +	[CN_QP_STATE_RTS] = {
> +		[CN_QP_STATE_RESET]	= CN_QP_OP_2RESET,
> +		[CN_QP_STATE_ERR]	= CN_QP_OP_2ERR,
> +		[CN_QP_STATE_RTS]	= CN_QP_OP_RTS_2RTS,
> +		[CN_QP_STATE_SQD]	= CN_QP_OP_RTS_2SQD,
> +		[CN_QP_STATE_QPD]	= CN_QP_OP_RTS_2QPD,
> +		[CN_QP_STATE_SQERR]	= CN_QP_OP_RTS_2SQERR,
> +	},
> +	[CN_QP_STATE_SQD] = {
> +		[CN_QP_STATE_RESET]	= CN_QP_OP_2RESET,
> +		[CN_QP_STATE_ERR]	= CN_QP_OP_2ERR,
> +		[CN_QP_STATE_SQD]	= CN_QP_OP_SQD_2SQD,
> +		[CN_QP_STATE_RTS]	= CN_QP_OP_SQD_2RTS,
> +		[CN_QP_STATE_QPD]	= CN_QP_OP_SQD_2QPD,
> +		[CN_QP_STATE_SQERR]	= CN_QP_OP_SQD_2SQ_ERR,
> +	},
> +	[CN_QP_STATE_QPD] = {
> +		[CN_QP_STATE_RESET]	= CN_QP_OP_2RESET,
> +		[CN_QP_STATE_ERR]	= CN_QP_OP_2ERR,
> +		[CN_QP_STATE_SQD]	= CN_QP_OP_NOP,
> +		[CN_QP_STATE_QPD]	= CN_QP_OP_NOP,
> +		[CN_QP_STATE_RTR]	= CN_QP_OP_QPD_2RTR,
> +	},
> +	[CN_QP_STATE_SQERR] = {
> +		[CN_QP_STATE_RESET]	= CN_QP_OP_2RESET,
> +		[CN_QP_STATE_ERR]	= CN_QP_OP_2ERR,
> +		[CN_QP_STATE_SQD]	= CN_QP_OP_SQ_ERR_2SQD,
> +		[CN_QP_STATE_SQERR]	= CN_QP_OP_NOP,
> +	},
> +	[CN_QP_STATE_ERR] = {
> +		[CN_QP_STATE_RESET]	= CN_QP_OP_2RESET,
> +		[CN_QP_STATE_ERR]	= CN_QP_OP_2ERR,
> +	}
> +};

I don't understand why IBTA QP state machine is declared in ETH driver
and not in IB driver.

> +

<...>

> +		/* Release lock while we wait before retry.
> +		 * Note, we can assert that we are already locked.
> +		 */
> +		port_funcs->cfg_unlock(cn_port);
> +
> +		msleep(20);
> +
> +		port_funcs->cfg_lock(cn_port);

lock/unlock through ops pointer doesn't look like a good idea.

Thanks