From cde9070d9970eef1f7ec2360586c802a16230ad8 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 07:43:50 +0000
Subject: [PATCH] rtl88x2CE_WiFi_linux driver

---
 kernel/arch/powerpc/platforms/pseries/msi.c |   34 ++++++++++++++++++++++++++--------
 1 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/kernel/arch/powerpc/platforms/pseries/msi.c b/kernel/arch/powerpc/platforms/pseries/msi.c
index b749694..6373003 100644
--- a/kernel/arch/powerpc/platforms/pseries/msi.c
+++ b/kernel/arch/powerpc/platforms/pseries/msi.c
@@ -1,14 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp.
  * Copyright 2006-2007 Michael Ellerman, IBM Corp.
- *
- * 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; version 2 of the
- * License.
- *
  */
 
+#include <linux/crash_dump.h>
 #include <linux/device.h>
 #include <linux/irq.h>
 #include <linux/msi.h>
@@ -203,7 +199,8 @@
 	/* Get the top level device in the PE */
 	edev = pdn_to_eeh_dev(PCI_DN(dn));
 	if (edev->pe)
-		edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, list);
+		edev = list_first_entry(&edev->pe->edevs, struct eeh_dev,
+					entry);
 	dn = pci_device_to_OF_node(edev->pdev);
 	if (!dn)
 		return NULL;
@@ -462,7 +459,28 @@
 			return hwirq;
 		}
 
-		virq = irq_create_mapping(NULL, hwirq);
+		/*
+		 * Depending on the number of online CPUs in the original
+		 * kernel, it is likely for CPU #0 to be offline in a kdump
+		 * kernel. The associated IRQs in the affinity mappings
+		 * provided by irq_create_affinity_masks() are thus not
+		 * started by irq_startup(), as per-design for managed IRQs.
+		 * This can be a problem with multi-queue block devices driven
+		 * by blk-mq : such a non-started IRQ is very likely paired
+		 * with the single queue enforced by blk-mq during kdump (see
+		 * blk_mq_alloc_tag_set()). This causes the device to remain
+		 * silent and likely hangs the guest at some point.
+		 *
+		 * We don't really care for fine-grained affinity when doing
+		 * kdump actually : simply ignore the pre-computed affinity
+		 * masks in this case and let the default mask with all CPUs
+		 * be used when creating the IRQ mappings.
+		 */
+		if (is_kdump_kernel())
+			virq = irq_create_mapping(NULL, hwirq);
+		else
+			virq = irq_create_mapping_affinity(NULL, hwirq,
+							   entry->affinity);
 
 		if (!virq) {
 			pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq);

--
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