[PATCH v2 10/11] firewire-sbp-target: Add sbp_scsi_cmnd.{c,h}

[Chris Boot <bootc@bootc.net>]

Miscellaneous functions for dealing with SCSI commands, status, sense
data and data read/write. This is where the real grunt work of pushing
data in and out of the FireWire bus happens.

Signed-off-by: Chris Boot <bootc@bootc.net>
Cc: Andy Grover <agrover@redhat.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
---
 drivers/target/sbp/sbp_scsi_cmnd.c |  360 ++++++++++++++++++++++++++++++++++++
 drivers/target/sbp/sbp_scsi_cmnd.h |    6 +
 2 files changed, 366 insertions(+), 0 deletions(-)
 create mode 100644 drivers/target/sbp/sbp_scsi_cmnd.c
 create mode 100644 drivers/target/sbp/sbp_scsi_cmnd.h

diff --git a/drivers/target/sbp/sbp_scsi_cmnd.c b/drivers/target/sbp/sbp_scsi_cmnd.c
new file mode 100644
index 0000000..e0b4b71
--- /dev/null
+++ b/drivers/target/sbp/sbp_scsi_cmnd.c
@@ -0,0 +1,360 @@
+/*
+ * SBP2 target driver (SCSI over IEEE1394 in target mode)
+ *
+ * Copyright (C) 2011  Chris Boot <bootc@bootc.net>
+ *
+ * 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
+ * (at your option) 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#define KMSG_COMPONENT "sbp_target"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/firewire.h>
+#include <linux/firewire-constants.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_tcq.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_fabric.h>
+#include <target/target_core_fabric_configfs.h>
+#include <target/target_core_configfs.h>
+
+#include "sbp_base.h"
+#include "sbp_target_agent.h"
+#include "sbp_scsi_cmnd.h"
+
+/*
+ * Wraps fw_run_transaction taking into account page size and max payload, and
+ * retries the transaction if it fails
+ */
+static int sbp_run_transaction(struct sbp_target_request *req, int tcode,
+	unsigned long long offset, void *payload, size_t length)
+{
+	struct sbp_login_descriptor *login = req->agent->login;
+	struct sbp_session *sess = login->sess;
+	int ret, speed, max_payload, pg_size, seg_off = 0, seg_len;
+
+	speed = CMDBLK_ORB_SPEED(be32_to_cpu(req->orb.misc));
+	max_payload = 4 << CMDBLK_ORB_MAX_PAYLOAD(be32_to_cpu(req->orb.misc));
+	pg_size = CMDBLK_ORB_PG_SIZE(be32_to_cpu(req->orb.misc));
+
+	if (pg_size) {
+		pr_err("sbp_run_transaction: page size ignored\n");
+		pg_size = 0x100 << pg_size;
+	}
+
+	while (seg_off < length) {
+		seg_len = length - seg_off;
+		if (seg_len > max_payload)
+			seg_len = max_payload;
+
+		/* FIXME: take page_size into account */
+
+		/* FIXME: retry failed data transfers */
+		ret = fw_run_transaction(sess->card, tcode,
+				sess->node_id, sess->generation, speed,
+				offset + seg_off, payload + seg_off, seg_len);
+		if (ret != RCODE_COMPLETE) {
+			pr_debug("sbp_run_transaction: txn failed: %x\n", ret);
+			return -EIO;
+		}
+
+		seg_off += seg_len;
+	}
+
+	return 0;
+}
+
+static int sbp_fetch_command(struct sbp_target_request *req)
+{
+	int ret, cmd_len, copy_len;
+
+	cmd_len = scsi_command_size(req->orb.command_block);
+
+	req->cmd_buf = kmalloc(cmd_len, GFP_KERNEL);
+	if (!req->cmd_buf)
+		return -ENOMEM;
+
+	memcpy(req->cmd_buf, req->orb.command_block,
+		min_t(int, cmd_len, sizeof(req->orb.command_block)));
+
+	if (cmd_len > sizeof(req->orb.command_block)) {
+		pr_debug("sbp_fetch_command: filling in long command\n");
+		copy_len = cmd_len - sizeof(req->orb.command_block);
+
+		ret = sbp_run_transaction(req, TCODE_READ_BLOCK_REQUEST,
+			req->orb_pointer + sizeof(req->orb),
+			req->cmd_buf + sizeof(req->orb.command_block),
+			copy_len);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int sbp_fetch_page_table(struct sbp_target_request *req)
+{
+	int pg_tbl_sz, ret;
+	struct sbp_page_table_entry *pg_tbl;
+
+	if (!CMDBLK_ORB_PG_TBL_PRESENT(be32_to_cpu(req->orb.misc)))
+		return 0;
+
+	pg_tbl_sz = CMDBLK_ORB_DATA_SIZE(be32_to_cpu(req->orb.misc)) *
+		sizeof(struct sbp_page_table_entry);
+
+	pg_tbl = kmalloc(pg_tbl_sz, GFP_KERNEL);
+	if (!pg_tbl)
+		return -ENOMEM;
+
+	ret = sbp_run_transaction(req, TCODE_READ_BLOCK_REQUEST,
+		sbp2_pointer_to_addr(&req->orb.data_descriptor),
+		pg_tbl, pg_tbl_sz);
+	if (ret) {
+		kfree(pg_tbl);
+		return ret;
+	}
+
+	req->pg_tbl = pg_tbl;
+	return 0;
+}
+
+static void sbp_calc_data_length_direction(struct sbp_target_request *req,
+	u32 *data_len, enum dma_data_direction *data_dir)
+{
+	int data_size, direction, idx;
+
+	data_size = CMDBLK_ORB_DATA_SIZE(be32_to_cpu(req->orb.misc));
+	direction = CMDBLK_ORB_DIRECTION(be32_to_cpu(req->orb.misc));
+
+	if (!data_size) {
+		*data_len = 0;
+		*data_dir = DMA_NONE;
+		return;
+	}
+
+	*data_dir = direction ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+	if (req->pg_tbl) {
+		*data_len = 0;
+		for (idx = 0; idx < data_size; idx++) {
+			*data_len += be16_to_cpu(
+					req->pg_tbl[idx].segment_length);
+		}
+	} else {
+		*data_len = data_size;
+	}
+}
+
+void sbp_handle_command(struct sbp_target_request *req)
+{
+	struct sbp_login_descriptor *login = req->agent->login;
+	struct sbp_session *sess = login->sess;
+	int ret, unpacked_lun;
+	u32 data_length;
+	enum dma_data_direction data_dir;
+
+	ret = sbp_fetch_command(req);
+	if (ret) {
+		pr_debug("sbp_handle_command: fetch command failed: %d\n", ret);
+		req->status.status |= cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_TRANSPORT_FAILURE) |
+			STATUS_BLOCK_DEAD(0) |
+			STATUS_BLOCK_LEN(1) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_UNSPECIFIED_ERROR));
+		sbp_send_status(req);
+		sbp_free_request(req);
+		return;
+	}
+
+	ret = sbp_fetch_page_table(req);
+	if (ret) {
+		pr_debug("sbp_handle_command: fetch page table failed: %d\n",
+			ret);
+		req->status.status |= cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_TRANSPORT_FAILURE) |
+			STATUS_BLOCK_DEAD(0) |
+			STATUS_BLOCK_LEN(1) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_UNSPECIFIED_ERROR));
+		sbp_send_status(req);
+		sbp_free_request(req);
+		return;
+	}
+
+	unpacked_lun = req->agent->login->lun->unpacked_lun;
+	sbp_calc_data_length_direction(req, &data_length, &data_dir);
+
+	pr_debug("sbp_handle_command unpacked_lun:%d data_len:%d data_dir:%d\n",
+			unpacked_lun, data_length, data_dir);
+
+	target_submit_cmd(&req->se_cmd, sess->se_sess, req->cmd_buf,
+			req->sense_buf, unpacked_lun, data_length,
+			MSG_SIMPLE_TAG, data_dir, 0);
+}
+
+/*
+ * DMA_TO_DEVICE = read from initiator (SCSI WRITE)
+ * DMA_FROM_DEVICE = write to initiator (SCSI READ)
+ */
+int sbp_rw_data(struct sbp_target_request *req)
+{
+	int ret, tcode;
+
+	tcode = (req->se_cmd.data_direction == DMA_TO_DEVICE) ?
+		TCODE_READ_BLOCK_REQUEST :
+		TCODE_WRITE_BLOCK_REQUEST;
+
+	if (req->pg_tbl) {
+		int idx, offset = 0, data_size;
+
+		data_size = CMDBLK_ORB_DATA_SIZE(be32_to_cpu(req->orb.misc));
+
+		for (idx = 0; idx < data_size; idx++) {
+			struct sbp_page_table_entry *pte = &req->pg_tbl[idx];
+			int pte_len = be16_to_cpu(pte->segment_length);
+			u64 pte_offset =
+				(u64)be16_to_cpu(pte->segment_base_hi) << 32 |
+				be32_to_cpu(pte->segment_base_lo);
+
+			ret = sbp_run_transaction(req, tcode, pte_offset,
+					req->data_buf + offset, pte_len);
+			if (ret)
+				break;
+
+			offset += pte_len;
+		}
+	} else {
+		ret = sbp_run_transaction(req, tcode,
+				sbp2_pointer_to_addr(&req->orb.data_descriptor),
+				req->data_buf, req->se_cmd.data_length);
+	}
+
+	return ret;
+}
+
+int sbp_send_status(struct sbp_target_request *req)
+{
+	int ret, length;
+	struct sbp_login_descriptor *login = req->agent->login;
+
+	length = (((be32_to_cpu(req->status.status) >> 24) & 0x07) + 1) * 4;
+
+	ret = sbp_run_transaction(req, TCODE_WRITE_BLOCK_REQUEST,
+			login->status_fifo_addr, &req->status, length);
+	if (ret) {
+		pr_debug("sbp_send_status: write failed: %d\n", ret);
+		return ret;
+	}
+
+	pr_debug("sbp_send_status: status write complete for ORB: 0x%llx\n",
+			req->orb_pointer);
+
+	return 0;
+}
+
+static void sbp_sense_mangle(struct sbp_target_request *req)
+{
+	struct se_cmd *se_cmd = &req->se_cmd;
+	u8 *sense = req->sense_buf;
+	u8 *status = req->status.data;
+
+	WARN_ON(se_cmd->scsi_sense_length < 18);
+
+	switch (sense[0] & 0x7f) { 		/* sfmt */
+	case 0x70: /* current, fixed */
+		status[0] = 0 << 6;
+		break;
+	case 0x71: /* deferred, fixed */
+		status[0] = 1 << 6;
+		break;
+	case 0x72: /* current, descriptor */
+	case 0x73: /* deferred, descriptor */
+	default:
+		/*
+		 * TODO: SBP-3 specifies what we should do with descriptor
+		 * format sense data
+		 */
+		pr_err("sbp_send_sense: unknown sense format: 0x%x\n",
+			sense[0]);
+		req->status.status |= cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_DEAD(0) |
+			STATUS_BLOCK_LEN(1) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_REQUEST_ABORTED));
+		return;
+	}
+
+	status[0] |= se_cmd->scsi_status & 0x3f;/* status */
+	status[1] =
+		(sense[0] & 0x80) |		/* valid */
+		((sense[2] & 0xe0) >> 1) |	/* mark, eom, ili */
+		(sense[2] & 0x0f);		/* sense_key */
+	status[2] = se_cmd->scsi_asc;		/* sense_code */
+	status[3] = se_cmd->scsi_ascq;		/* sense_qualifier */
+
+	/* information */
+	status[4] = sense[3];
+	status[5] = sense[4];
+	status[6] = sense[5];
+	status[7] = sense[6];
+
+	/* CDB-dependent */
+	status[8] = sense[8];
+	status[9] = sense[9];
+	status[10] = sense[10];
+	status[11] = sense[11];
+
+	/* fru */
+	status[12] = sense[14];
+
+	/* sense_key-dependent */
+	status[13] = sense[15];
+	status[14] = sense[16];
+	status[15] = sense[17];
+
+	req->status.status |= cpu_to_be32(
+		STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+		STATUS_BLOCK_DEAD(0) |
+		STATUS_BLOCK_LEN(5) |
+		STATUS_BLOCK_SBP_STATUS(SBP_STATUS_OK));
+}
+
+int sbp_send_sense(struct sbp_target_request *req)
+{
+	struct se_cmd *se_cmd = &req->se_cmd;
+
+	if (se_cmd->scsi_sense_length) {
+		sbp_sense_mangle(req);
+	} else {
+		req->status.status |= cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_DEAD(0) |
+			STATUS_BLOCK_LEN(1) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_OK));
+	}
+
+	return sbp_send_status(req);
+}
+
+void sbp_free_request(struct sbp_target_request *req)
+{
+	kfree(req->pg_tbl);
+	kfree(req->cmd_buf);
+	kfree(req->data_buf);
+	kfree(req);
+}
diff --git a/drivers/target/sbp/sbp_scsi_cmnd.h b/drivers/target/sbp/sbp_scsi_cmnd.h
new file mode 100644
index 0000000..5e82b25
--- /dev/null
+++ b/drivers/target/sbp/sbp_scsi_cmnd.h
@@ -0,0 +1,6 @@
+
+void sbp_handle_command(struct sbp_target_request *req);
+int sbp_rw_data(struct sbp_target_request *req);
+int sbp_send_status(struct sbp_target_request *req);
+int sbp_send_sense(struct sbp_target_request *req);
+void sbp_free_request(struct sbp_target_request *req);
-- 
1.7.9