Skip to content

L
linux
Commit e7734ef1 authored by Ahmed S. Darwish's avatar Ahmed S. Darwish Committed by Martin K. Petersen
Browse files
Options

scsi: NCR5380: Remove context check 

NCR5380_poll_politely2() uses in_interrupt() and irqs_disabled() to check
if it is safe to sleep.

Such usage in drivers is phased out and Linus clearly requested that code
which changes behaviour depending on context should either be separated, or
the context be explicitly conveyed in an argument passed by the caller.

Below is a context analysis of NCR5380_poll_politely2() uppermost callers:

  - NCR5380_maybe_reset_bus(), task, invoked during device probe.
    -> NCR5380_poll_politely()
    -> do_abort()

  - NCR5380_select(), task, but can only sleep in the "release, then
    re-acquire" regions of the spinlock held by its caller.
    Sleeping invocations (lock released):
    -> NCR5380_poll_politely2()

    Atomic invocations (lock acquired):
    -> NCR5380_reselect()
       -> NCR5380_poll_politely()
       -> do_abort()
       -> NCR5380_transfer_pio()

  - NCR5380_intr(), interrupt handler
    -> NCR5380_dma_complete()
       -> NCR5380_transfer_pio()
	  -> NCR5380_poll_politely()
    -> NCR5380_reselect() (see above)

  - NCR5380_information_transfer(), task, but can only sleep in the
    "release, then re-acquire" regions of the caller-held spinlock.
    Sleeping invocations (lock released):
      - NCR5380_transfer_pio() -> NCR5380_poll_politely()
      - NCR5380_poll_politely()

    Atomic invocations (lock acquired):
      - NCR5380_transfer_dma()
	-> NCR5380_dma_recv_setup()
           => generic_NCR5380_precv() -> NCR5380_poll_politely()
	   => macscsi_pread() -> NCR5380_poll_politely()

	-> NCR5380_dma_send_setup()
 	   => generic_NCR5380_psend -> NCR5380_poll_politely2()
	   => macscsi_pwrite() -> NCR5380_poll_politely()

	-> NCR5380_poll_politely2()
        -> NCR5380_dma_complete()
           -> NCR5380_transfer_pio()
	      -> NCR5380_poll_politely()
      - NCR5380_transfer_pio() -> NCR5380_poll_politely

  - NCR5380_reselect(), atomic, always called with hostdata spinlock
    held.

Since NCR5380_poll_politely2() already takes a "wait" argument in jiffies,
use it to determine if the function can sleep. Modify atomic callers, which
passed an unused wait value in terms of HZ, to pass zero.

Link: https://lore.kernel.org/r/20201206075157.19067-1-a.darwish@linutronix.de
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: <linux-m68k@lists.linux-m68k.org>
Suggested-by: default avatarFinn Thain <fthain@telegraphics.com.au>
Co-developed-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: default avatarFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: default avatarAhmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 8ca1a40b
Expand all Hide whitespace changes
Inline Side-by-side
Showing with 53 additions and 46 deletions
drivers/scsi/NCR5380.c
View file @ e7734ef1
This diff is collapsed.
drivers/scsi/NCR5380.h
View file @ e7734ef1
......@@ -277,7 +277,8 @@ static const char *NCR5380_info(struct Scsi_Host *instance);
static void NCR5380_reselect(struct Scsi_Host *instance);
static bool NCR5380_select(struct Scsi_Host *, struct scsi_cmnd *);
static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data);
static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data);
static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data,
unsigned int can_sleep);
static int NCR5380_poll_politely2(struct NCR5380_hostdata *,
unsigned int, u8, u8,
unsigned int, u8, u8, unsigned long);
......
drivers/scsi/g_NCR5380.c
View file @ e7734ef1
......@@ -529,14 +529,14 @@ static inline int generic_NCR5380_precv(struct NCR5380_hostdata *hostdata,
if (start == len - 128) {
/* Ignore End of DMA interrupt for the final buffer */
if (NCR5380_poll_politely(hostdata, hostdata->c400_ctl_status,
CSR_HOST_BUF_NOT_RDY, 0, HZ / 64) < 0)
CSR_HOST_BUF_NOT_RDY, 0, 0) < 0)
break;
} else {
if (NCR5380_poll_politely2(hostdata, hostdata->c400_ctl_status,
CSR_HOST_BUF_NOT_RDY, 0,
hostdata->c400_ctl_status,
CSR_GATED_53C80_IRQ,
CSR_GATED_53C80_IRQ, HZ / 64) < 0 ||
CSR_GATED_53C80_IRQ, 0) < 0 ||
NCR5380_read(hostdata->c400_ctl_status) & CSR_HOST_BUF_NOT_RDY)
break;
}
......@@ -565,7 +565,7 @@ static inline int generic_NCR5380_precv(struct NCR5380_hostdata *hostdata,
if (residual == 0 && NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
BASR_END_DMA_TRANSFER,
BASR_END_DMA_TRANSFER,
HZ / 64) < 0)
0) < 0)
scmd_printk(KERN_ERR, hostdata->connected, "%s: End of DMA timeout\n",
__func__);
......@@ -597,7 +597,7 @@ static inline int generic_NCR5380_psend(struct NCR5380_hostdata *hostdata,
CSR_HOST_BUF_NOT_RDY, 0,
hostdata->c400_ctl_status,
CSR_GATED_53C80_IRQ,
CSR_GATED_53C80_IRQ, HZ / 64) < 0 ||
CSR_GATED_53C80_IRQ, 0) < 0 ||
NCR5380_read(hostdata->c400_ctl_status) & CSR_HOST_BUF_NOT_RDY) {
/* Both 128 B buffers are in use */
if (start >= 128)
......@@ -644,13 +644,13 @@ static inline int generic_NCR5380_psend(struct NCR5380_hostdata *hostdata,
if (residual == 0) {
if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG,
TCR_LAST_BYTE_SENT, TCR_LAST_BYTE_SENT,
HZ / 64) < 0)
0) < 0)
scmd_printk(KERN_ERR, hostdata->connected,
"%s: Last Byte Sent timeout\n", __func__);
if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
BASR_END_DMA_TRANSFER, BASR_END_DMA_TRANSFER,
HZ / 64) < 0)
0) < 0)
scmd_printk(KERN_ERR, hostdata->connected, "%s: End of DMA timeout\n",
__func__);
}
......
drivers/scsi/mac_scsi.c
View file @ e7734ef1
......@@ -285,7 +285,7 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
BASR_DRQ | BASR_PHASE_MATCH,
BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) {
BASR_DRQ | BASR_PHASE_MATCH, 0)) {
int bytes;
if (macintosh_config->ident == MAC_MODEL_IIFX)
......@@ -304,7 +304,7 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
BUS_AND_STATUS_REG, BASR_ACK,
BASR_ACK, HZ / 64) < 0)
BASR_ACK, 0) < 0)
scmd_printk(KERN_DEBUG, hostdata->connected,
"%s: !REQ and !ACK\n", __func__);
if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
......@@ -344,7 +344,7 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
BASR_DRQ | BASR_PHASE_MATCH,
BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) {
BASR_DRQ | BASR_PHASE_MATCH, 0)) {
int bytes;
if (macintosh_config->ident == MAC_MODEL_IIFX)
......@@ -362,7 +362,7 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG,
TCR_LAST_BYTE_SENT,
TCR_LAST_BYTE_SENT,
HZ / 64) < 0) {
0) < 0) {
scmd_printk(KERN_ERR, hostdata->connected,
"%s: Last Byte Sent timeout\n", __func__);
result = -1;
......@@ -372,7 +372,7 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
BUS_AND_STATUS_REG, BASR_ACK,
BASR_ACK, HZ / 64) < 0)
BASR_ACK, 0) < 0)
scmd_printk(KERN_DEBUG, hostdata->connected,
"%s: !REQ and !ACK\n", __func__);
if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7