[PATCH 6.12 396/567] firmware: stratix10-svc: Add mutex in stratix10 memory management

Greg Kroah-Hartman
2026-01-06T17:36:05Z

From: Mahesh Rao <mahesh.rao@altera.com>

commit 85f96cbbbc67b59652b2c1ec394b8ddc0ddf1b0b upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/firmware/stratix10-svc.c | 11 +++++++++++
1 file changed, 11 insertions(+)

--- 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>
@@ -176,6 +177,12 @@ 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
*
@@ -187,6 +194,7 @@ static void *svc_pa_to_va(unsigned long
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;
@@ -996,6 +1004,7 @@ int stratix10_svc_send(struct stratix10_
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;
@@ -1078,6 +1087,7 @@ void *stratix10_svc_allocate_memory(stru
if (!pmem)
return ERR_PTR(-ENOMEM);

+ guard(mutex)(&svc_mem_lock);
va = gen_pool_alloc(genpool, s);
if (!va)
return ERR_PTR(-ENOMEM);
@@ -1106,6 +1116,7 @@ EXPORT_SYMBOL_GPL(stratix10_svc_allocate
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) {