Re: [PATCH v2 29/44] mesh: Move the SCSI pointer to private command data

[Hannes Reinecke <hare@xxxxxxx>]

On 2/8/22 18:24, Bart Van Assche wrote:
> Set .cmd_size in the SCSI host template instead of using the SCSI pointer
> from struct scsi_cmnd. This patch prepares for removal of the SCSI pointer
> from struct scsi_cmnd.
>
> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
>   drivers/scsi/mesh.c | 20 +++++++++++++-------
>   drivers/scsi/mesh.h | 11 +++++++++++
>   2 files changed, 24 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/scsi/mesh.c b/drivers/scsi/mesh.c
> index ca133e0a140a..de9ae36def42 100644
> --- a/drivers/scsi/mesh.c
> +++ b/drivers/scsi/mesh.c
> @@ -586,10 +586,12 @@ static void mesh_done(struct mesh_state *ms, int start_next)
>   	ms->current_req = NULL;
>   	tp->current_req = NULL;
>   	if (cmd) {
> +		struct scsi_pointer *scsi_pointer = mesh_scsi_pointer(cmd);
> +
>   		set_host_byte(cmd, ms->stat);
> -		set_status_byte(cmd, cmd->SCp.Status);
> +		set_status_byte(cmd, scsi_pointer->Status);
>   		if (ms->stat == DID_OK)
> -			scsi_msg_to_host_byte(cmd, cmd->SCp.Message);
> +			scsi_msg_to_host_byte(cmd, scsi_pointer->Message);
>   		if (DEBUG_TARGET(cmd)) {
>   			printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
>   			       cmd->result, ms->data_ptr, scsi_bufflen(cmd));
> @@ -603,7 +605,7 @@ static void mesh_done(struct mesh_state *ms, int start_next)
>   			}
>   #endif
>   		}
> -		cmd->SCp.this_residual -= ms->data_ptr;
> +		scsi_pointer->this_residual -= ms->data_ptr;
>   		scsi_done(cmd);
>   	}
>   	if (start_next) {
> @@ -1171,7 +1173,7 @@ static void handle_msgin(struct mesh_state *ms)
>   	if (ms->n_msgin < msgin_length(ms))
>   		goto reject;
>   	if (cmd)
> -		cmd->SCp.Message = code;
> +		mesh_scsi_pointer(cmd)->Message = code;
>   	switch (code) {
>   	case COMMAND_COMPLETE:
>   		break;
> @@ -1262,7 +1264,7 @@ static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd)
>   	if (cmd) {
>   		int nseg;
>   
> -		cmd->SCp.this_residual = scsi_bufflen(cmd);
> +		mesh_scsi_pointer(cmd)->this_residual = scsi_bufflen(cmd);
>   
>   		nseg = scsi_dma_map(cmd);
>   		BUG_ON(nseg < 0);
> @@ -1592,10 +1594,13 @@ static void cmd_complete(struct mesh_state *ms)
>   			break;
>   		case statusing:
>   			if (cmd) {
> -				cmd->SCp.Status = mr->fifo;
> +				struct scsi_pointer *scsi_pointer =
> +					mesh_scsi_pointer(cmd);
> +
> +				scsi_pointer->Status = mr->fifo;
>   				if (DEBUG_TARGET(cmd))
>   					printk(KERN_DEBUG "mesh: status is %x\n",
> -					       cmd->SCp.Status);
> +					       scsi_pointer->Status);
>   			}
>   			ms->msgphase = msg_in;
>   			break;
> @@ -1837,6 +1842,7 @@ static struct scsi_host_template mesh_template = {
>   	.sg_tablesize			= SG_ALL,
>   	.cmd_per_lun			= 2,
>   	.max_segment_size		= 65535,
> +	.cmd_size			= sizeof(struct mesh_cmd_priv),
>   };
>   
>   static int mesh_probe(struct macio_dev *mdev, const struct of_device_id *match)
> diff --git a/drivers/scsi/mesh.h b/drivers/scsi/mesh.h
> index ee53c05ace95..1afa8b37295b 100644
> --- a/drivers/scsi/mesh.h
> +++ b/drivers/scsi/mesh.h
> @@ -8,6 +8,17 @@
>   #ifndef _MESH_H
>   #define _MESH_H
>   
> +struct mesh_cmd_priv {
> +	struct scsi_pointer scsi_pointer;
> +};
> +
> +static inline struct scsi_pointer *mesh_scsi_pointer(struct scsi_cmnd *cmd)
> +{
> +	struct mesh_cmd_priv *mcmd = scsi_cmd_priv(cmd);
> +
> +	return &mcmd->scsi_pointer;
> +}
> +
>   /*
>    * Registers in the MESH controller.
>    */

Also here, please use 'struct scsi_pointer' directly.

Cheers,

Hannes
--
Dr. Hannes Reinecke                Kernel Storage Architect
hare@xxxxxxx                              +49 911 74053 688
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