From 072de836f53be56a70cecf70b43ae43b7ce17376 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 10:08:36 +0000
Subject: [PATCH] mk-rootfs.sh

---
 kernel/drivers/scsi/ibmvscsi/ibmvscsi.c |  134 +++++++++++++++++++++++++++++---------------
 1 files changed, 87 insertions(+), 47 deletions(-)

diff --git a/kernel/drivers/scsi/ibmvscsi/ibmvscsi.c b/kernel/drivers/scsi/ibmvscsi/ibmvscsi.c
index 036508a..29fcc44 100644
--- a/kernel/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/kernel/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -1,24 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* ------------------------------------------------------------
  * ibmvscsi.c
  * (C) Copyright IBM Corporation 1994, 2004
  * Authors: Colin DeVilbiss (devilbis@us.ibm.com)
  *          Santiago Leon (santil@us.ibm.com)
  *          Dave Boutcher (sleddog@us.ibm.com)
- *
- * 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
  *
  * ------------------------------------------------------------
  * Emulation of a SCSI host adapter for Virtual I/O devices
@@ -683,7 +669,7 @@
 }
 
 /**
- * map_sg_data: - Maps dma for a scatterlist and initializes decriptor fields
+ * map_sg_data: - Maps dma for a scatterlist and initializes descriptor fields
  * @cmd:	struct scsi_cmnd with the scatterlist
  * @srp_cmd:	srp_cmd that contains the memory descriptor
  * @dev:	device for which to map dma memory
@@ -821,16 +807,32 @@
 }
 
 /**
+ * ibmvscsi_set_request_limit - Set the adapter request_limit in response to
+ * an adapter failure, reset, or SRP Login. Done under host lock to prevent
+ * race with SCSI command submission.
+ * @hostdata:	adapter to adjust
+ * @limit:	new request limit
+ */
+static void ibmvscsi_set_request_limit(struct ibmvscsi_host_data *hostdata, int limit)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	atomic_set(&hostdata->request_limit, limit);
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+}
+
+/**
  * ibmvscsi_reset_host - Reset the connection to the server
  * @hostdata:	struct ibmvscsi_host_data to reset
 */
 static void ibmvscsi_reset_host(struct ibmvscsi_host_data *hostdata)
 {
 	scsi_block_requests(hostdata->host);
-	atomic_set(&hostdata->request_limit, 0);
+	ibmvscsi_set_request_limit(hostdata, 0);
 
 	purge_requests(hostdata, DID_ERROR);
-	hostdata->reset_crq = 1;
+	hostdata->action = IBMVSCSI_HOST_ACTION_RESET;
 	wake_up(&hostdata->work_wait_q);
 }
 
@@ -1160,13 +1162,13 @@
 		dev_info(hostdata->dev, "SRP_LOGIN_REJ reason %u\n",
 			 evt_struct->xfer_iu->srp.login_rej.reason);
 		/* Login failed.  */
-		atomic_set(&hostdata->request_limit, -1);
+		ibmvscsi_set_request_limit(hostdata, -1);
 		return;
 	default:
 		dev_err(hostdata->dev, "Invalid login response typecode 0x%02x!\n",
 			evt_struct->xfer_iu->srp.login_rsp.opcode);
 		/* Login failed.  */
-		atomic_set(&hostdata->request_limit, -1);
+		ibmvscsi_set_request_limit(hostdata, -1);
 		return;
 	}
 
@@ -1177,11 +1179,12 @@
 	 * This value is set rather than added to request_limit because
 	 * request_limit could have been set to -1 by this client.
 	 */
-	atomic_set(&hostdata->request_limit,
+	ibmvscsi_set_request_limit(hostdata,
 		   be32_to_cpu(evt_struct->xfer_iu->srp.login_rsp.req_lim_delta));
 
 	/* If we had any pending I/Os, kick them */
-	scsi_unblock_requests(hostdata->host);
+	hostdata->action = IBMVSCSI_HOST_ACTION_UNBLOCK;
+	wake_up(&hostdata->work_wait_q);
 }
 
 /**
@@ -1208,13 +1211,13 @@
 	login->req_buf_fmt = cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
 					 SRP_BUF_FORMAT_INDIRECT);
 
-	spin_lock_irqsave(hostdata->host->host_lock, flags);
 	/* Start out with a request limit of 0, since this is negotiated in
 	 * the login request we are just sending and login requests always
 	 * get sent by the driver regardless of request_limit.
 	 */
-	atomic_set(&hostdata->request_limit, 0);
+	ibmvscsi_set_request_limit(hostdata, 0);
 
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
 	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, login_timeout * 2);
 	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 	dev_info(hostdata->dev, "sent SRP login\n");
@@ -1794,12 +1797,12 @@
 		return;
 	case VIOSRP_CRQ_XPORT_EVENT:	/* Hypervisor telling us the connection is closed */
 		scsi_block_requests(hostdata->host);
-		atomic_set(&hostdata->request_limit, 0);
+		ibmvscsi_set_request_limit(hostdata, 0);
 		if (crq->format == 0x06) {
 			/* We need to re-setup the interpartition connection */
 			dev_info(hostdata->dev, "Re-enabling adapter!\n");
 			hostdata->client_migrated = 1;
-			hostdata->reenable_crq = 1;
+			hostdata->action = IBMVSCSI_HOST_ACTION_REENABLE;
 			purge_requests(hostdata, DID_REQUEUE);
 			wake_up(&hostdata->work_wait_q);
 		} else {
@@ -2052,6 +2055,16 @@
 	.show = show_host_config,
 };
 
+static int ibmvscsi_host_reset(struct Scsi_Host *shost, int reset_type)
+{
+	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
+
+	dev_info(hostdata->dev, "Initiating adapter reset!\n");
+	ibmvscsi_reset_host(hostdata);
+
+	return 0;
+}
+
 static struct device_attribute *ibmvscsi_attrs[] = {
 	&ibmvscsi_host_vhost_loc,
 	&ibmvscsi_host_vhost_name,
@@ -2078,11 +2091,11 @@
 	.eh_host_reset_handler = ibmvscsi_eh_host_reset_handler,
 	.slave_configure = ibmvscsi_slave_configure,
 	.change_queue_depth = ibmvscsi_change_queue_depth,
+	.host_reset = ibmvscsi_host_reset,
 	.cmd_per_lun = IBMVSCSI_CMDS_PER_LUN_DEFAULT,
 	.can_queue = IBMVSCSI_MAX_REQUESTS_DEFAULT,
 	.this_id = -1,
 	.sg_tablesize = SG_ALL,
-	.use_clustering = ENABLE_CLUSTERING,
 	.shost_attrs = ibmvscsi_attrs,
 };
 
@@ -2108,48 +2121,75 @@
 
 static void ibmvscsi_do_work(struct ibmvscsi_host_data *hostdata)
 {
+	unsigned long flags;
 	int rc;
 	char *action = "reset";
 
-	if (hostdata->reset_crq) {
-		smp_rmb();
-		hostdata->reset_crq = 0;
-
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	switch (hostdata->action) {
+	case IBMVSCSI_HOST_ACTION_UNBLOCK:
+		rc = 0;
+		break;
+	case IBMVSCSI_HOST_ACTION_RESET:
+		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 		rc = ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);
+		spin_lock_irqsave(hostdata->host->host_lock, flags);
 		if (!rc)
 			rc = ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0);
 		vio_enable_interrupts(to_vio_dev(hostdata->dev));
-	} else if (hostdata->reenable_crq) {
-		smp_rmb();
+		break;
+	case IBMVSCSI_HOST_ACTION_REENABLE:
 		action = "enable";
+		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 		rc = ibmvscsi_reenable_crq_queue(&hostdata->queue, hostdata);
-		hostdata->reenable_crq = 0;
+		spin_lock_irqsave(hostdata->host->host_lock, flags);
 		if (!rc)
 			rc = ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0);
-	} else
+		break;
+	case IBMVSCSI_HOST_ACTION_NONE:
+	default:
+		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 		return;
+	}
+
+	hostdata->action = IBMVSCSI_HOST_ACTION_NONE;
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 
 	if (rc) {
-		atomic_set(&hostdata->request_limit, -1);
+		ibmvscsi_set_request_limit(hostdata, -1);
 		dev_err(hostdata->dev, "error after %s\n", action);
 	}
 
 	scsi_unblock_requests(hostdata->host);
 }
 
-static int ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata)
+static int __ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata)
 {
 	if (kthread_should_stop())
 		return 1;
-	else if (hostdata->reset_crq) {
-		smp_rmb();
-		return 1;
-	} else if (hostdata->reenable_crq) {
-		smp_rmb();
-		return 1;
+	switch (hostdata->action) {
+	case IBMVSCSI_HOST_ACTION_NONE:
+		return 0;
+	case IBMVSCSI_HOST_ACTION_RESET:
+	case IBMVSCSI_HOST_ACTION_REENABLE:
+	case IBMVSCSI_HOST_ACTION_UNBLOCK:
+	default:
+		break;
 	}
 
-	return 0;
+	return 1;
+}
+
+static int ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata)
+{
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	rc = __ibmvscsi_work_to_do(hostdata);
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+
+	return rc;
 }
 
 static int ibmvscsi_work(void *data)
@@ -2202,7 +2242,7 @@
 	init_waitqueue_head(&hostdata->work_wait_q);
 	hostdata->host = host;
 	hostdata->dev = dev;
-	atomic_set(&hostdata->request_limit, -1);
+	ibmvscsi_set_request_limit(hostdata, -1);
 	hostdata->host->max_sectors = IBMVSCSI_MAX_SECTORS_DEFAULT;
 
 	if (map_persist_bufs(hostdata)) {
@@ -2362,7 +2402,7 @@
 static struct srp_function_template ibmvscsi_transport_functions = {
 };
 
-int __init ibmvscsi_module_init(void)
+static int __init ibmvscsi_module_init(void)
 {
 	int ret;
 
@@ -2384,7 +2424,7 @@
 	return ret;
 }
 
-void __exit ibmvscsi_module_exit(void)
+static void __exit ibmvscsi_module_exit(void)
 {
 	vio_unregister_driver(&ibmvscsi_driver);
 	srp_release_transport(ibmvscsi_transport_template);

--
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