> On Feb 8, 2022, at 9:24 AM, Bart Van Assche <bvanassche@xxxxxxx> wrote:
>
> Set .cmd_size in the SCSI host template instead of using the SCSI pointer.
> 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/imm.c | 88 ++++++++++++++++++++++++----------------------
> drivers/scsi/imm.h | 11 ++++++
> 2 files changed, 56 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/scsi/imm.c b/drivers/scsi/imm.c
> index 8afdb4dba2be..3d86e3a52866 100644
> --- a/drivers/scsi/imm.c
> +++ b/drivers/scsi/imm.c
> @@ -66,7 +66,7 @@ static void got_it(imm_struct *dev)
> {
> dev->base = dev->dev->port->base;
> if (dev->cur_cmd)
> - dev->cur_cmd->SCp.phase = 1;
> + imm_scsi_pointer(dev->cur_cmd)->phase = 1;
> else
> wake_up(dev->waiting);
> }
> @@ -618,13 +618,14 @@ static inline int imm_send_command(struct scsi_cmnd *cmd)
> * The driver appears to remain stable if we speed up the parallel port
> * i/o in this function, but not elsewhere.
> */
> -static int imm_completion(struct scsi_cmnd *cmd)
> +static int imm_completion(struct scsi_cmnd *const cmd)
> {
> /* Return codes:
> * -1 Error
> * 0 Told to schedule
> * 1 Finished data transfer
> */
> + struct scsi_pointer *scsi_pointer = imm_scsi_pointer(cmd);
> imm_struct *dev = imm_dev(cmd->device->host);
> unsigned short ppb = dev->base;
> unsigned long start_jiffies = jiffies;
> @@ -660,44 +661,43 @@ static int imm_completion(struct scsi_cmnd *cmd)
> * a) Drive status is screwy (!ready && !present)
> * b) Drive is requesting/sending more data than expected
> */
> - if (((r & 0x88) != 0x88) || (cmd->SCp.this_residual <= 0)) {
> + if ((r & 0x88) != 0x88 || scsi_pointer->this_residual <= 0) {
> imm_fail(dev, DID_ERROR);
> return -1; /* ERROR_RETURN */
> }
> /* determine if we should use burst I/O */
> if (dev->rd == 0) {
> - fast = (bulk
> - && (cmd->SCp.this_residual >=
> - IMM_BURST_SIZE)) ? IMM_BURST_SIZE : 2;
> - status = imm_out(dev, cmd->SCp.ptr, fast);
> + fast = bulk && scsi_pointer->this_residual >=
> + IMM_BURST_SIZE ? IMM_BURST_SIZE : 2;
> + status = imm_out(dev, scsi_pointer->ptr, fast);
> } else {
> - fast = (bulk
> - && (cmd->SCp.this_residual >=
> - IMM_BURST_SIZE)) ? IMM_BURST_SIZE : 1;
> - status = imm_in(dev, cmd->SCp.ptr, fast);
> + fast = bulk && scsi_pointer->this_residual >=
> + IMM_BURST_SIZE ? IMM_BURST_SIZE : 1;
> + status = imm_in(dev, scsi_pointer->ptr, fast);
> }
>
> - cmd->SCp.ptr += fast;
> - cmd->SCp.this_residual -= fast;
> + scsi_pointer->ptr += fast;
> + scsi_pointer->this_residual -= fast;
>
> if (!status) {
> imm_fail(dev, DID_BUS_BUSY);
> return -1; /* ERROR_RETURN */
> }
> - if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
> + if (scsi_pointer->buffer && !scsi_pointer->this_residual) {
> /* if scatter/gather, advance to the next segment */
> - if (cmd->SCp.buffers_residual--) {
> - cmd->SCp.buffer = sg_next(cmd->SCp.buffer);
> - cmd->SCp.this_residual =
> - cmd->SCp.buffer->length;
> - cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
> + if (scsi_pointer->buffers_residual--) {
> + scsi_pointer->buffer =
> + sg_next(scsi_pointer->buffer);
> + scsi_pointer->this_residual =
> + scsi_pointer->buffer->length;
> + scsi_pointer->ptr = sg_virt(scsi_pointer->buffer);
>
> /*
> * Make sure that we transfer even number of bytes
> * otherwise it makes imm_byte_out() messy.
> */
> - if (cmd->SCp.this_residual & 0x01)
> - cmd->SCp.this_residual++;
> + if (scsi_pointer->this_residual & 0x01)
> + scsi_pointer->this_residual++;
> }
> }
> /* Now check to see if the drive is ready to comunicate */
> @@ -762,7 +762,7 @@ static void imm_interrupt(struct work_struct *work)
> }
> #endif
>
> - if (cmd->SCp.phase > 1)
> + if (imm_scsi_pointer(cmd)->phase > 1)
> imm_disconnect(dev);
>
> imm_pb_dismiss(dev);
> @@ -774,8 +774,9 @@ static void imm_interrupt(struct work_struct *work)
> return;
> }
>
> -static int imm_engine(imm_struct *dev, struct scsi_cmnd *cmd)
> +static int imm_engine(imm_struct *dev, struct scsi_cmnd *const cmd)
> {
> + struct scsi_pointer *scsi_pointer = imm_scsi_pointer(cmd);
> unsigned short ppb = dev->base;
> unsigned char l = 0, h = 0;
> int retv, x;
> @@ -786,7 +787,7 @@ static int imm_engine(imm_struct *dev, struct scsi_cmnd *cmd)
> if (dev->failed)
> return 0;
>
> - switch (cmd->SCp.phase) {
> + switch (scsi_pointer->phase) {
> case 0: /* Phase 0 - Waiting for parport */
> if (time_after(jiffies, dev->jstart + HZ)) {
> /*
> @@ -800,7 +801,7 @@ static int imm_engine(imm_struct *dev, struct scsi_cmnd *cmd)
>
> case 1: /* Phase 1 - Connected */
> imm_connect(dev, CONNECT_EPP_MAYBE);
> - cmd->SCp.phase++;
> + scsi_pointer->phase++;
> fallthrough;
>
> case 2: /* Phase 2 - We are now talking to the scsi bus */
> @@ -808,7 +809,7 @@ static int imm_engine(imm_struct *dev, struct scsi_cmnd *cmd)
> imm_fail(dev, DID_NO_CONNECT);
> return 0;
> }
> - cmd->SCp.phase++;
> + scsi_pointer->phase++;
> fallthrough;
>
> case 3: /* Phase 3 - Ready to accept a command */
> @@ -818,23 +819,23 @@ static int imm_engine(imm_struct *dev, struct scsi_cmnd *cmd)
>
> if (!imm_send_command(cmd))
> return 0;
> - cmd->SCp.phase++;
> + scsi_pointer->phase++;
> fallthrough;
>
> case 4: /* Phase 4 - Setup scatter/gather buffers */
> if (scsi_bufflen(cmd)) {
> - cmd->SCp.buffer = scsi_sglist(cmd);
> - cmd->SCp.this_residual = cmd->SCp.buffer->length;
> - cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
> + scsi_pointer->buffer = scsi_sglist(cmd);
> + scsi_pointer->this_residual = scsi_pointer->buffer->length;
> + scsi_pointer->ptr = sg_virt(scsi_pointer->buffer);
> } else {
> - cmd->SCp.buffer = NULL;
> - cmd->SCp.this_residual = 0;
> - cmd->SCp.ptr = NULL;
> + scsi_pointer->buffer = NULL;
> + scsi_pointer->this_residual = 0;
> + scsi_pointer->ptr = NULL;
> }
> - cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
> - cmd->SCp.phase++;
> - if (cmd->SCp.this_residual & 0x01)
> - cmd->SCp.this_residual++;
> + scsi_pointer->buffers_residual = scsi_sg_count(cmd) - 1;
> + scsi_pointer->phase++;
> + if (scsi_pointer->this_residual & 0x01)
> + scsi_pointer->this_residual++;
> fallthrough;
>
> case 5: /* Phase 5 - Pre-Data transfer stage */
> @@ -851,7 +852,7 @@ static int imm_engine(imm_struct *dev, struct scsi_cmnd *cmd)
> if ((dev->dp) && (dev->rd))
> if (imm_negotiate(dev))
> return 0;
> - cmd->SCp.phase++;
> + scsi_pointer->phase++;
> fallthrough;
>
> case 6: /* Phase 6 - Data transfer stage */
> @@ -867,7 +868,7 @@ static int imm_engine(imm_struct *dev, struct scsi_cmnd *cmd)
> if (retv == 0)
> return 1;
> }
> - cmd->SCp.phase++;
> + scsi_pointer->phase++;
> fallthrough;
>
> case 7: /* Phase 7 - Post data transfer stage */
> @@ -879,7 +880,7 @@ static int imm_engine(imm_struct *dev, struct scsi_cmnd *cmd)
> w_ctr(ppb, 0x4);
> }
> }
> - cmd->SCp.phase++;
> + scsi_pointer->phase++;
> fallthrough;
>
> case 8: /* Phase 8 - Read status/message */
> @@ -922,7 +923,7 @@ static int imm_queuecommand_lck(struct scsi_cmnd *cmd)
> dev->jstart = jiffies;
> dev->cur_cmd = cmd;
> cmd->result = DID_ERROR << 16; /* default return code */
> - cmd->SCp.phase = 0; /* bus free */
> + imm_scsi_pointer(cmd)->phase = 0; /* bus free */
>
> schedule_delayed_work(&dev->imm_tq, 0);
>
> @@ -961,7 +962,7 @@ static int imm_abort(struct scsi_cmnd *cmd)
> * have tied the SCSI_MESSAGE line high in the interface
> */
>
> - switch (cmd->SCp.phase) {
> + switch (imm_scsi_pointer(cmd)->phase) {
> case 0: /* Do not have access to parport */
> case 1: /* Have not connected to interface */
> dev->cur_cmd = NULL; /* Forget the problem */
> @@ -987,7 +988,7 @@ static int imm_reset(struct scsi_cmnd *cmd)
> {
> imm_struct *dev = imm_dev(cmd->device->host);
>
> - if (cmd->SCp.phase)
> + if (imm_scsi_pointer(cmd)->phase)
> imm_disconnect(dev);
> dev->cur_cmd = NULL; /* Forget the problem */
>
> @@ -1109,6 +1110,7 @@ static struct scsi_host_template imm_template = {
> .sg_tablesize = SG_ALL,
> .can_queue = 1,
> .slave_alloc = imm_adjust_queue,
> + .cmd_size = sizeof(struct imm_cmd_priv),
> };
>
> /***************************************************************************
> diff --git a/drivers/scsi/imm.h b/drivers/scsi/imm.h
> index 7f2bb35b1b87..12cbc7ee8bba 100644
> --- a/drivers/scsi/imm.h
> +++ b/drivers/scsi/imm.h
> @@ -139,6 +139,17 @@ static char *IMM_MODE_STRING[] =
> #define w_ctr(x,y) outb(y, (x)+2)
> #endif
>
> +struct imm_cmd_priv {
> + struct scsi_pointer scsi_pointer;
> +};
> +
> +static inline struct scsi_pointer *imm_scsi_pointer(struct scsi_cmnd *cmd)
> +{
> + struct imm_cmd_priv *icmd = scsi_cmd_priv(cmd);
> +
> + return &icmd->scsi_pointer;
> +}
> +
> static int imm_engine(imm_struct *, struct scsi_cmnd *);
>
> #endif /* _IMM_H */
Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
--
Himanshu Madhani Oracle Linux Engineering
