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) {