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: Finn Thain <fthain@telegraphics.com.au>
Co-developed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 6 insertions, 6 deletions

diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c
index 29e4cdcade72..2df2f38a9b12 100644
--- a/drivers/scsi/g_NCR5380.c
+++ b/drivers/scsi/g_NCR5380.c
@@ -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__);
 	}