Commit 7edd053b authored by Fabio M. De Francesco's avatar Fabio M. De Francesco Committed by Martin K. Petersen
Browse files

scsi: ips: Replace kmap_atomic() with kmap_local_page() 



kmap_atomic() is deprecated in favor of kmap_local_page(). Therefore,
replace kmap_atomic() with kmap_local_page() in ips_is_passthru(). In the
meantime remove an unnecessary comment, align code, and remove spaces.

kmap_atomic() is implemented like a kmap_local_page() which also disables
page-faults and preemption (the latter only for !PREEMPT_RT kernels).  The
code within the mapping/unmapping in ips_is_passthru() is already in atomic
context because of a call to local_irq_save() and kmap_local_page() can be
called in atomic context too (including interrupts).

Therefore, a mere replacement of the old API with the new one is all it is
required (i.e., there is no need to explicitly add any calls to
pagefault_disable() and/or preempt_disable()).

Suggested-by: default avatarIra Weiny <ira.weiny@intel.com>
Signed-off-by: default avatarFabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: default avatarIra Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20230103173131.21259-1-fmdefrancesco@gmail.com


Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 1eeedfad

drivers/scsi/ips.c

+5 −6
Original line number Diff line number Diff line
@@ -1499,17 +1499,16 @@ static int ips_is_passthru(struct scsi_cmnd *SC) 
                struct scatterlist *sg = scsi_sglist(SC);

                char  *buffer;



                /* kmap_atomic() ensures addressability of the user buffer.*/

                /* local_irq_save() protects the KM_IRQ0 address slot.     */

                local_irq_save(flags);

                buffer = kmap_atomic(sg_page(sg)) + sg->offset;

		buffer = kmap_local_page(sg_page(sg)) + sg->offset;

		if (buffer && buffer[0] == 'C' && buffer[1] == 'O' &&

		    buffer[2] == 'P' && buffer[3] == 'P') {

                        kunmap_atomic(buffer - sg->offset);

			kunmap_local(buffer);

                        local_irq_restore(flags);

                        return 1;

                }

                kunmap_atomic(buffer - sg->offset);

		kunmap_local(buffer);

                local_irq_restore(flags);

	}

	return 0;