FAILED: patch "[PATCH] firmware: stratix10-svc: Add mutex in stratix10 memory" failed to apply to 5.15-stable tree

FAILED: patch "[PATCH] firmware: stratix10-svc: Add mutex in stratix10 memory" failed to apply to 5.15-stable tree

[gregkh]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 85f96cbbbc67b59652b2c1ec394b8ddc0ddf1b0b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026010654-kimono-starlight-7676@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 85f96cbbbc67b59652b2c1ec394b8ddc0ddf1b0b Mon Sep 17 00:00:00 2001
From: Mahesh Rao <mahesh.rao@altera.com>
Date: Mon, 27 Oct 2025 22:54:40 +0800
Subject: [PATCH] firmware: stratix10-svc: Add mutex in stratix10 memory
 management

Add mutex lock to stratix10_svc_allocate_memory and
stratix10_svc_free_memory for thread safety. This prevents race
conditions and ensures proper synchronization during memory operations.
This is required for parallel communication with the Stratix10 service
channel.

Fixes: 7ca5ce896524f ("firmware: add Intel Stratix10 service layer driver")
Cc: stable@vger.kernel.org
Signed-off-by: Mahesh Rao <mahesh.rao@altera.com>
Reviewed-by: Matthew Gerlach <matthew.gerlach@altera.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>

diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-svc.c
index 5a32c1054bee..9372a17d89b7 100644
--- a/drivers/firmware/stratix10-svc.c
+++ b/drivers/firmware/stratix10-svc.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2017-2018, Intel Corporation
+ * Copyright (C) 2025, Altera Corporation
  */
 
 #include <linux/completion.h>
@@ -172,6 +173,12 @@ struct stratix10_svc_chan {
 static LIST_HEAD(svc_ctrl);
 static LIST_HEAD(svc_data_mem);
 
+/**
+ * svc_mem_lock protects access to the svc_data_mem list for
+ * concurrent multi-client operations
+ */
+static DEFINE_MUTEX(svc_mem_lock);
+
 /**
  * svc_pa_to_va() - translate physical address to virtual address
  * @addr: to be translated physical address
@@ -184,6 +191,7 @@ static void *svc_pa_to_va(unsigned long addr)
 	struct stratix10_svc_data_mem *pmem;
 
 	pr_debug("claim back P-addr=0x%016x\n", (unsigned int)addr);
+	guard(mutex)(&svc_mem_lock);
 	list_for_each_entry(pmem, &svc_data_mem, node)
 		if (pmem->paddr == addr)
 			return pmem->vaddr;
@@ -1002,6 +1010,7 @@ int stratix10_svc_send(struct stratix10_svc_chan *chan, void *msg)
 			p_data->flag = ct->flags;
 		}
 	} else {
+		guard(mutex)(&svc_mem_lock);
 		list_for_each_entry(p_mem, &svc_data_mem, node)
 			if (p_mem->vaddr == p_msg->payload) {
 				p_data->paddr = p_mem->paddr;
@@ -1084,6 +1093,7 @@ void *stratix10_svc_allocate_memory(struct stratix10_svc_chan *chan,
 	if (!pmem)
 		return ERR_PTR(-ENOMEM);
 
+	guard(mutex)(&svc_mem_lock);
 	va = gen_pool_alloc(genpool, s);
 	if (!va)
 		return ERR_PTR(-ENOMEM);
@@ -1112,6 +1122,7 @@ EXPORT_SYMBOL_GPL(stratix10_svc_allocate_memory);
 void stratix10_svc_free_memory(struct stratix10_svc_chan *chan, void *kaddr)
 {
 	struct stratix10_svc_data_mem *pmem;
+	guard(mutex)(&svc_mem_lock);
 
 	list_for_each_entry(pmem, &svc_data_mem, node)
 		if (pmem->vaddr == kaddr) {