2022-02-22 05:25:38

by Finn Thain

Subject: [PATCH] mac53c94: Stop using struct scsi_pointer

This driver doesn't use SCp.ptr to save a SCSI command data pointer
which means "scsi pointer" is a complete misnomer here. Only a few
members of struct scsi_pointer are used and the rest waste memory.
Avoid the "struct foo { struct bar; };" silliness.

Signed-off-by: Finn Thain <[email protected]>
---
drivers/scsi/mac53c94.c | 21 ++++++++++-----------
drivers/scsi/mac53c94.h | 10 +++++-----
2 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/mac53c94.c b/drivers/scsi/mac53c94.c
index f3005b38931f..070ebe352f9e 100644
--- a/drivers/scsi/mac53c94.c
+++ b/drivers/scsi/mac53c94.c
@@ -194,7 +194,7 @@ static void mac53c94_interrupt(int irq, void *dev_id)
struct mac53c94_regs __iomem *regs = state->regs;
struct dbdma_regs __iomem *dma = state->dma;
struct scsi_cmnd *const cmd = state->current_req;
- struct scsi_pointer *const scsi_pointer = mac53c94_scsi_pointer(cmd);
+ struct mac53c94_cmd_priv *const mcmd = mac53c94_priv(cmd);
int nb, stat, seq, intr;
static int mac53c94_errors;

@@ -264,10 +264,10 @@ static void mac53c94_interrupt(int irq, void *dev_id)
/* set DMA controller going if any data to transfer */
if ((stat & (STAT_MSG|STAT_CD)) == 0
&& (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) {
- nb = scsi_pointer->this_residual;
+ nb = mcmd->this_residual;
if (nb > 0xfff0)
nb = 0xfff0;
- scsi_pointer->this_residual -= nb;
+ mcmd->this_residual -= nb;
writeb(nb, &regs->count_lo);
writeb(nb >> 8, &regs->count_mid);
writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
@@ -294,13 +294,13 @@ static void mac53c94_interrupt(int irq, void *dev_id)
cmd_done(state, DID_ERROR << 16);
return;
}
- if (scsi_pointer->this_residual != 0
+ if (mcmd->this_residual != 0
&& (stat & (STAT_MSG|STAT_CD)) == 0) {
/* Set up the count regs to transfer more */
- nb = scsi_pointer->this_residual;
+ nb = mcmd->this_residual;
if (nb > 0xfff0)
nb = 0xfff0;
- scsi_pointer->this_residual -= nb;
+ mcmd->this_residual -= nb;
writeb(nb, &regs->count_lo);
writeb(nb >> 8, &regs->count_mid);
writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
@@ -322,8 +322,8 @@ static void mac53c94_interrupt(int irq, void *dev_id)
cmd_done(state, DID_ERROR << 16);
return;
}
- scsi_pointer->Status = readb(&regs->fifo);
- scsi_pointer->Message = readb(&regs->fifo);
+ mcmd->status = readb(&regs->fifo);
+ mcmd->message = readb(&regs->fifo);
writeb(CMD_ACCEPT_MSG, &regs->command);
state->phase = busfreeing;
break;
@@ -331,8 +331,7 @@ static void mac53c94_interrupt(int irq, void *dev_id)
if (intr != INTR_DISCONNECT) {
printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
}
- cmd_done(state, (DID_OK << 16) + (scsi_pointer->Message << 8)
- + scsi_pointer->Status);
+ cmd_done(state, (DID_OK << 16) + (mcmd->message << 8) + mcmd->status);
break;
default:
printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
@@ -390,7 +389,7 @@ static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
dcmds[-1].command = cpu_to_le16(dma_cmd);
dcmds->command = cpu_to_le16(DBDMA_STOP);
- mac53c94_scsi_pointer(cmd)->this_residual = total;
+ mac53c94_priv(cmd)->this_residual = total;
}

static struct scsi_host_template mac53c94_template = {
diff --git a/drivers/scsi/mac53c94.h b/drivers/scsi/mac53c94.h
index 37d7d30f42ef..b4093027f9c3 100644
--- a/drivers/scsi/mac53c94.h
+++ b/drivers/scsi/mac53c94.h
@@ -213,14 +213,14 @@ struct mac53c94_regs {
#define CF4_BBTE 0x01

struct mac53c94_cmd_priv {
- struct scsi_pointer scsi_pointer;
+ int this_residual;
+ int status;
+ int message;
};

-static inline struct scsi_pointer *mac53c94_scsi_pointer(struct scsi_cmnd *cmd)
+static inline struct mac53c94_cmd_priv *mac53c94_priv(struct scsi_cmnd *cmd)
{
- struct mac53c94_cmd_priv *mcmd = scsi_cmd_priv(cmd);
-
- return &mcmd->scsi_pointer;
+ return scsi_cmd_priv(cmd);
}

#endif /* _MAC53C94_H */
--
2.32.0

2022-02-22 08:07:22

by Christoph Hellwig

Subject: Re: [PATCH] mac53c94: Stop using struct scsi_pointer

Looks good,

Reviewed-by: Christoph Hellwig <[email protected]>

2022-02-28 08:53:52

by Martin K. Petersen

Subject: Re: [PATCH] mac53c94: Stop using struct scsi_pointer

Finn,

> This driver doesn't use SCp.ptr to save a SCSI command data pointer
> which means "scsi pointer" is a complete misnomer here. Only a few
> members of struct scsi_pointer are used and the rest waste memory.
> Avoid the "struct foo { struct bar; };" silliness.

Applied to 5.18/scsi-staging, thanks!

--
Martin K. Petersen Oracle Linux Engineering

2022-03-02 06:39:37

by Martin K. Petersen

Subject: Re: [PATCH] mac53c94: Stop using struct scsi_pointer

On Tue, 22 Feb 2022 10:09:42 +1100, Finn Thain wrote:

> This driver doesn't use SCp.ptr to save a SCSI command data pointer
> which means "scsi pointer" is a complete misnomer here. Only a few
> members of struct scsi_pointer are used and the rest waste memory.
> Avoid the "struct foo { struct bar; };" silliness.
>
>

Applied to 5.18/scsi-queue, thanks!

[1/1] mac53c94: Stop using struct scsi_pointer
https://git.kernel.org/mkp/scsi/c/55a94551f61f

--
Martin K. Petersen Oracle Linux Engineering