ide-atapi: add a buffer-arg to ide_queue_pc_tail

This is in preparation of removing ide_atapi_pc. Expose the buffer as an
argument to ide_queue_pc_tail with later replacing it with local buffer
or even kmalloc'ed one if needed due to stack usage constraints.

Also, add the possibility of passing a NULL-ptr buffer for cmds which
don't transfer data besides the cdb. While at it, switch to local buffer
in idetape_get_mode_sense_results().

There should be no functional change resulting from this patch.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>

1 files changed, 18 insertions, 19 deletions

diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index f09a263b72f..1f7f50473a4 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -770,7 +770,7 @@ static int idetape_flush_tape_buffers(ide_drive_t *drive)
 	int rc;
 
 	idetape_create_write_filemark_cmd(drive, &pc, 0);
-	rc = ide_queue_pc_tail(drive, tape->disk, &pc, pc.req_xfer);
+	rc = ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0);
 	if (rc)
 		return rc;
 	idetape_wait_ready(drive, 60 * 5 * HZ);
@@ -793,7 +793,7 @@ static int idetape_read_position(ide_drive_t *drive)
 	debug_log(DBG_PROCS, "Enter %s\n", __func__);
 
 	idetape_create_read_position_cmd(&pc);
-	if (ide_queue_pc_tail(drive, tape->disk, &pc, pc.req_xfer))
+	if (ide_queue_pc_tail(drive, tape->disk, &pc, pc.buf, pc.req_xfer))
 		return -1;
 	position = tape->first_frame;
 	return position;
@@ -846,12 +846,12 @@ static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 		__ide_tape_discard_merge_buffer(drive);
 	idetape_wait_ready(drive, 60 * 5 * HZ);
 	idetape_create_locate_cmd(drive, &pc, block, partition, skip);
-	retval = ide_queue_pc_tail(drive, disk, &pc, pc.req_xfer);
+	retval = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 	if (retval)
 		return (retval);
 
 	idetape_create_read_position_cmd(&pc);
-	return ide_queue_pc_tail(drive, disk, &pc, pc.req_xfer);
+	return ide_queue_pc_tail(drive, disk, &pc, pc.buf, pc.req_xfer);
 }
 
 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
@@ -1047,12 +1047,12 @@ static int idetape_rewind_tape(ide_drive_t *drive)
 	debug_log(DBG_SENSE, "Enter %s\n", __func__);
 
 	idetape_create_rewind_cmd(drive, &pc);
-	retval = ide_queue_pc_tail(drive, disk, &pc, pc.req_xfer);
+	retval = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 	if (retval)
 		return retval;
 
 	idetape_create_read_position_cmd(&pc);
-	retval = ide_queue_pc_tail(drive, disk, &pc, pc.req_xfer);
+	retval = ide_queue_pc_tail(drive, disk, &pc, pc.buf, pc.req_xfer);
 	if (retval)
 		return retval;
 	return 0;
@@ -1120,7 +1120,7 @@ static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
 	case MTBSF:
 		idetape_create_space_cmd(&pc, mt_count - count,
 					 IDETAPE_SPACE_OVER_FILEMARK);
-		return ide_queue_pc_tail(drive, disk, &pc, pc.req_xfer);
+		return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 	case MTFSFM:
 	case MTBSFM:
 		if (!sprev)
@@ -1259,7 +1259,7 @@ static int idetape_write_filemark(ide_drive_t *drive)
 
 	/* Write a filemark */
 	idetape_create_write_filemark_cmd(drive, &pc, 1);
-	if (ide_queue_pc_tail(drive, tape->disk, &pc, pc.req_xfer)) {
+	if (ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0)) {
 		printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
 		return -EIO;
 	}
@@ -1344,11 +1344,11 @@ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
 			IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
 	case MTEOM:
 		idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
-		return ide_queue_pc_tail(drive, disk, &pc, pc.req_xfer);
+		return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 	case MTERASE:
 		(void)idetape_rewind_tape(drive);
 		idetape_create_erase_cmd(&pc);
-		return ide_queue_pc_tail(drive, disk, &pc, pc.req_xfer);
+		return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 	case MTSETBLK:
 		if (mt_count) {
 			if (mt_count < tape->blk_size ||
@@ -1457,7 +1457,7 @@ static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
 	struct ide_atapi_pc pc;
 
 	idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
-	if (ide_queue_pc_tail(drive, tape->disk, &pc, pc.req_xfer)) {
+	if (ide_queue_pc_tail(drive, tape->disk, &pc, pc.buf, pc.req_xfer)) {
 		printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
 		if (tape->blk_size == 0) {
 			printk(KERN_WARNING "ide-tape: Cannot deal with zero "
@@ -1610,17 +1610,16 @@ static void idetape_get_inquiry_results(ide_drive_t *drive)
 	char fw_rev[4], vendor_id[8], product_id[16];
 
 	idetape_create_inquiry_cmd(&pc);
-	pc.buf = &pc_buf[0];
 	pc.buf_size = sizeof(pc_buf);
 
-	if (ide_queue_pc_tail(drive, tape->disk, &pc, pc.req_xfer)) {
+	if (ide_queue_pc_tail(drive, tape->disk, &pc, pc_buf, pc.req_xfer)) {
 		printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
 				tape->name);
 		return;
 	}
-	memcpy(vendor_id, &pc.buf[8], 8);
-	memcpy(product_id, &pc.buf[16], 16);
-	memcpy(fw_rev, &pc.buf[32], 4);
+	memcpy(vendor_id, &pc_buf[8], 8);
+	memcpy(product_id, &pc_buf[16], 16);
+	memcpy(fw_rev, &pc_buf[32], 4);
 
 	ide_fixstring(vendor_id, 8, 0);
 	ide_fixstring(product_id, 16, 0);
@@ -1638,11 +1637,11 @@ static void idetape_get_mode_sense_results(ide_drive_t *drive)
 {
 	idetape_tape_t *tape = drive->driver_data;
 	struct ide_atapi_pc pc;
-	u8 *caps;
+	u8 buf[24], *caps;
 	u8 speed, max_speed;
 
 	idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
-	if (ide_queue_pc_tail(drive, tape->disk, &pc, pc.req_xfer)) {
+	if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
 		printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
 				" some default values\n");
 		tape->blk_size = 512;
@@ -1651,7 +1650,7 @@ static void idetape_get_mode_sense_results(ide_drive_t *drive)
 		put_unaligned(6*52, (u16 *)&tape->caps[16]);
 		return;
 	}
-	caps = pc.buf + 4 + pc.buf[3];
+	caps = buf + 4 + buf[3];
 
 	/* convert to host order and save for later use */
 	speed = be16_to_cpup((__be16 *)&caps[14]);