[PATCH] sr: Use {get,put}_unaligned_be*() instead of open-coding these functions

[PATCH] sr: Use {get,put}_unaligned_be*() instead of open-coding these functions

[Bart Van Assche]

This patch makes the sr code slightly easier to read.

Cc: Merlijn Wajer <merlijn@archive.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/sr.c | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index d2fe3fa470f9..7727893238c7 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -51,6 +51,8 @@
 #include <linux/pm_runtime.h>
 #include <linux/uaccess.h>
 
+#include <asm/unaligned.h>
+
 #include <scsi/scsi.h>
 #include <scsi/scsi_dbg.h>
 #include <scsi/scsi_device.h>
@@ -344,10 +346,8 @@ static int sr_done(struct scsi_cmnd *SCpnt)
 		case ILLEGAL_REQUEST:
 			if (!(SCpnt->sense_buffer[0] & 0x90))
 				break;
-			error_sector = (SCpnt->sense_buffer[3] << 24) |
-				(SCpnt->sense_buffer[4] << 16) |
-				(SCpnt->sense_buffer[5] << 8) |
-				SCpnt->sense_buffer[6];
+			error_sector =
+				get_unaligned_be32(&SCpnt->sense_buffer[3]);
 			if (SCpnt->request->bio != NULL)
 				block_sectors =
 					bio_sectors(SCpnt->request->bio);
@@ -495,13 +495,9 @@ static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt)
 		SCpnt->sdb.length = this_count * s_size;
 	}
 
-	SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
-	SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
-	SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
-	SCpnt->cmnd[5] = (unsigned char) block & 0xff;
+	put_unaligned_be32(block, &SCpnt->cmnd[2]);
 	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
-	SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
-	SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
+	put_unaligned_be16(this_count, &SCpnt->cmnd[7]);
 
 	/*
 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
@@ -854,8 +850,7 @@ static void get_sectorsize(struct scsi_cd *cd)
 	} else {
 		long last_written;
 
-		cd->capacity = 1 + ((buffer[0] << 24) | (buffer[1] << 16) |
-				    (buffer[2] << 8) | buffer[3]);
+		cd->capacity = 1 + get_unaligned_be32(&buffer[0]);
 		/*
 		 * READ_CAPACITY doesn't return the correct size on
 		 * certain UDF media.  If last_written is larger, use
@@ -866,8 +861,7 @@ static void get_sectorsize(struct scsi_cd *cd)
 		if (!cdrom_get_last_written(&cd->cdi, &last_written))
 			cd->capacity = max_t(long, cd->capacity, last_written);
 
-		sector_size = (buffer[4] << 24) |
-		    (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
+		sector_size = get_unaligned_be32(&buffer[4]);
 		switch (sector_size) {
 			/*
 			 * HP 4020i CD-Recorder reports 2340 byte sectors
@@ -955,13 +949,13 @@ static void get_capabilities(struct scsi_cd *cd)
 	}
 
 	n = data.header_length + data.block_descriptor_length;
-	cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
+	cd->cdi.speed = get_unaligned_be16(&buffer[n + 8]) / 176;
 	cd->readcd_known = 1;
 	cd->readcd_cdda = buffer[n + 5] & 0x01;
 	/* print some capability bits */
 	sr_printk(KERN_INFO, cd,
 		  "scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
-		  ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
+		  get_unaligned_be16(&buffer[n + 14]) / 176,
 		  cd->cdi.speed,
 		  buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
 		  buffer[n + 3] & 0x20 ? "dvd-ram " : "",

Re: [PATCH] sr: Use {get,put}_unaligned_be*() instead of open-coding these functions

[Martin K. Petersen]

On Sun, 26 Apr 2020 18:48:44 -0700, Bart Van Assche wrote:

> This patch makes the sr code slightly easier to read.

Applied to 5.8/scsi-queue, thanks!

[1/1] scsi: sr: Use {get,put}_unaligned_be*() instead of open-coding these functions
      https://git.kernel.org/mkp/scsi/c/655da8e57a46

-- 
Martin K. Petersen	Oracle Linux Engineering