Defined SCSI device interface, and added SCSI block device

implementation.

1 files changed, 142 insertions, 0 deletions

diff --git a/src/drivers/block/scsi.c b/src/drivers/block/scsi.c
new file mode 100644
index 00000000..7ddc4a11
--- /dev/null
+++ b/src/drivers/block/scsi.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stddef.h>
+#include <string.h>
+#include <byteswap.h>
+#include <gpxe/blockdev.h>
+#include <gpxe/scsi.h>
+
+/** @file
+ *
+ * SCSI block device
+ *
+ */
+
+static inline __attribute__ (( always_inline )) struct scsi_device *
+block_to_scsi ( struct block_device *blockdev ) {
+	return container_of ( blockdev, struct scsi_device, blockdev );
+}
+
+/**
+ * Issue SCSI command
+ *
+ * @v scsi		SCSI device
+ * @v command		SCSI command
+ * @ret rc		Return status code
+ */
+static int scsi_command ( struct scsi_device *scsi,
+			  struct scsi_command *command ) {
+	return scsi->command ( scsi, command );
+}
+
+/**
+ * Read block from SCSI device
+ *
+ * @v blockdev		Block device
+ * @v block		LBA block number
+ * @v buffer		Data buffer
+ * @ret rc		Return status code
+ */
+static int scsi_read ( struct block_device *blockdev, uint64_t block,
+		       void *buffer ) {
+	struct scsi_device *scsi = block_to_scsi ( blockdev );
+	struct scsi_command command;
+	struct scsi_cdb_read_16 *cdb = &command.cdb.read16;
+
+	/* Issue READ (16) */
+	memset ( &command, 0, sizeof ( command ) );
+	cdb->opcode = SCSI_OPCODE_READ_16;
+	cdb->lba = cpu_to_be64 ( block );
+	cdb->len = cpu_to_be32 ( 1 ); /* always a single block */
+	command.data_in = buffer;
+	command.data_in_len = blockdev->blksize;
+	return scsi_command ( scsi, &command );
+}
+
+/**
+ * Write block to SCSI device
+ *
+ * @v blockdev		Block device
+ * @v block		LBA block number
+ * @v buffer		Data buffer
+ * @ret rc		Return status code
+ */
+static int scsi_write ( struct block_device *blockdev, uint64_t block,
+			const void *buffer ) {
+	struct scsi_device *scsi = block_to_scsi ( blockdev );
+	struct scsi_command command;
+	struct scsi_cdb_write_16 *cdb = &command.cdb.write16;
+
+	/* Issue WRITE (16) */
+	memset ( &command, 0, sizeof ( command ) );
+	cdb->opcode = SCSI_OPCODE_WRITE_16;
+	cdb->lba = cpu_to_be64 ( block );
+	cdb->len = cpu_to_be32 ( 1 ); /* always a single block */
+	command.data_out = buffer;
+	command.data_out_len = blockdev->blksize;
+	return scsi_command ( scsi, &command );
+}
+
+/**
+ * Read capacity of SCSI device
+ *
+ * @v blockdev		Block device
+ * @ret rc		Return status code
+ */
+static int scsi_read_capacity ( struct block_device *blockdev ) {
+	struct scsi_device *scsi = block_to_scsi ( blockdev );
+	struct scsi_command command;
+	struct scsi_cdb_read_capacity_16 *cdb = &command.cdb.readcap16;
+	struct scsi_capacity_16 capacity;
+	int rc;
+
+	/* Issue READ CAPACITY (16) */
+	memset ( &command, 0, sizeof ( command ) );
+	cdb->opcode = SCSI_OPCODE_SERVICE_ACTION_IN;
+	cdb->service_action = SCSI_SERVICE_ACTION_READ_CAPACITY_16;
+	cdb->len = cpu_to_be32 ( sizeof ( capacity ) );
+	command.data_in = &capacity;
+	command.data_in_len = sizeof ( capacity );
+
+	if ( ( rc = scsi_command ( scsi, &command ) ) != 0 )
+		return rc;
+
+	/* Fill in block device fields */
+	blockdev->blksize = be32_to_cpu ( capacity.blksize );
+	blockdev->blocks = ( be64_to_cpu ( capacity.lba ) + 1 );
+	return 0;
+}
+
+/**
+ * Initialise SCSI device
+ *
+ * @v scsi		SCSI device
+ * @ret rc		Return status code
+ *
+ * Initialises a SCSI device.  The scsi_device::command and
+ * scsi_device::lun fields must already be filled in.  This function
+ * will configure scsi_device::blockdev, including issuing a READ
+ * CAPACITY call to determine the block size and total device size.
+ */
+int init_scsidev ( struct scsi_device *scsi ) {
+	/** Fill in read and write methods, and get device capacity */
+	scsi->blockdev.read = scsi_read;
+	scsi->blockdev.write = scsi_write;
+	return scsi_read_capacity ( &scsi->blockdev );
+}