> On Feb 8, 2022, at 9:25 AM, Bart Van Assche <bvanassche@xxxxxxx> 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/ppa.c | 81 ++++++++++++++++++++++++++++------------------
> 1 file changed, 49 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/scsi/ppa.c b/drivers/scsi/ppa.c
> index 003043de23a5..ac948768eba4 100644
> --- a/drivers/scsi/ppa.c
> +++ b/drivers/scsi/ppa.c
> @@ -45,6 +45,17 @@ typedef struct {
>
> #include "ppa.h"
>
> +struct ppa_cmd_priv {
> + struct scsi_pointer scsi_pointer;
> +};
> +
> +static struct scsi_pointer *ppa_scsi_pointer(struct scsi_cmnd *cmd)
> +{
> + struct ppa_cmd_priv *pcmd = scsi_cmd_priv(cmd);
> +
> + return &pcmd->scsi_pointer;
> +}
> +
> static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
> {
> return *(ppa_struct **)&host->hostdata;
> @@ -56,7 +67,7 @@ static void got_it(ppa_struct *dev)
> {
> dev->base = dev->dev->port->base;
> if (dev->cur_cmd)
> - dev->cur_cmd->SCp.phase = 1;
> + ppa_scsi_pointer(dev->cur_cmd)->phase = 1;
> else
> wake_up(dev->waiting);
> }
> @@ -511,13 +522,14 @@ static inline int ppa_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 ppa_completion(struct scsi_cmnd *cmd)
> +static int ppa_completion(struct scsi_cmnd *const cmd)
> {
> /* Return codes:
> * -1 Error
> * 0 Told to schedule
> * 1 Finished data transfer
> */
> + struct scsi_pointer *scsi_pointer = ppa_scsi_pointer(cmd);
> ppa_struct *dev = ppa_dev(cmd->device->host);
> unsigned short ppb = dev->base;
> unsigned long start_jiffies = jiffies;
> @@ -543,7 +555,7 @@ static int ppa_completion(struct scsi_cmnd *cmd)
> if (time_after(jiffies, start_jiffies + 1))
> return 0;
>
> - if ((cmd->SCp.this_residual <= 0)) {
> + if (scsi_pointer->this_residual <= 0) {
> ppa_fail(dev, DID_ERROR);
> return -1; /* ERROR_RETURN */
> }
> @@ -572,28 +584,30 @@ static int ppa_completion(struct scsi_cmnd *cmd)
> }
>
> /* determine if we should use burst I/O */
> - fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
> - ? PPA_BURST_SIZE : 1;
> + fast = bulk && scsi_pointer->this_residual >= PPA_BURST_SIZE ?
> + PPA_BURST_SIZE : 1;
>
> if (r == (unsigned char) 0xc0)
> - status = ppa_out(dev, cmd->SCp.ptr, fast);
> + status = ppa_out(dev, scsi_pointer->ptr, fast);
> else
> - status = ppa_in(dev, cmd->SCp.ptr, fast);
> + status = ppa_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) {
> ppa_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);
> }
> }
> /* Now check to see if the drive is ready to comunicate */
> @@ -658,7 +672,7 @@ static void ppa_interrupt(struct work_struct *work)
> }
> #endif
>
> - if (cmd->SCp.phase > 1)
> + if (ppa_scsi_pointer(cmd)->phase > 1)
> ppa_disconnect(dev);
>
> ppa_pb_dismiss(dev);
> @@ -670,6 +684,7 @@ static void ppa_interrupt(struct work_struct *work)
>
> static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
> {
> + struct scsi_pointer *scsi_pointer = ppa_scsi_pointer(cmd);
> unsigned short ppb = dev->base;
> unsigned char l = 0, h = 0;
> int retv;
> @@ -680,7 +695,7 @@ static int ppa_engine(ppa_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)) {
> /*
> @@ -715,7 +730,7 @@ static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
> return 1; /* Try again in a jiffy */
> }
> }
> - cmd->SCp.phase++;
> + scsi_pointer->phase++;
> }
> fallthrough;
>
> @@ -724,7 +739,7 @@ static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
> ppa_fail(dev, DID_NO_CONNECT);
> return 0;
> }
> - cmd->SCp.phase++;
> + scsi_pointer->phase++;
> fallthrough;
>
> case 3: /* Phase 3 - Ready to accept a command */
> @@ -734,21 +749,22 @@ static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
>
> if (!ppa_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++;
> + scsi_pointer->buffers_residual = scsi_sg_count(cmd) - 1;
> + scsi_pointer->phase++;
> fallthrough;
>
> case 5: /* Phase 5 - Data transfer stage */
> @@ -761,7 +777,7 @@ static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
> return 0;
> if (retv == 0)
> return 1;
> - cmd->SCp.phase++;
> + scsi_pointer->phase++;
> fallthrough;
>
> case 6: /* Phase 6 - Read status/message */
> @@ -798,7 +814,7 @@ static int ppa_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 */
> + ppa_scsi_pointer(cmd)->phase = 0; /* bus free */
>
> schedule_delayed_work(&dev->ppa_tq, 0);
>
> @@ -839,7 +855,7 @@ static int ppa_abort(struct scsi_cmnd *cmd)
> * have tied the SCSI_MESSAGE line high in the interface
> */
>
> - switch (cmd->SCp.phase) {
> + switch (ppa_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 */
> @@ -861,7 +877,7 @@ static int ppa_reset(struct scsi_cmnd *cmd)
> {
> ppa_struct *dev = ppa_dev(cmd->device->host);
>
> - if (cmd->SCp.phase)
> + if (ppa_scsi_pointer(cmd)->phase)
> ppa_disconnect(dev);
> dev->cur_cmd = NULL; /* Forget the problem */
>
> @@ -976,6 +992,7 @@ static struct scsi_host_template ppa_template = {
> .sg_tablesize = SG_ALL,
> .can_queue = 1,
> .slave_alloc = ppa_adjust_queue,
> + .cmd_size = sizeof(struct ppa_cmd_priv),
> };
>
> /***************************************************************************
Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
--
Himanshu Madhani Oracle Linux Engineering
