FAILED: patch "[PATCH] bus: mhi: ep: Do not allocate event ring element on stack" failed to apply to 6.7-stable tree

FAILED: patch "[PATCH] bus: mhi: ep: Do not allocate event ring element on stack" failed to apply to 6.7-stable tree

[gregkh]

The patch below does not apply to the 6.7-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-6.7.y
git checkout FETCH_HEAD
git cherry-pick -x 987fdb5a43a66764808371b54e6047834170d565
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024012632-computing-eject-1c07@gregkh' --subject-prefix 'PATCH 6.7.y' HEAD^..

Possible dependencies:

987fdb5a43a6 ("bus: mhi: ep: Do not allocate event ring element on stack")

thanks,

greg k-h

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

From 987fdb5a43a66764808371b54e6047834170d565 Mon Sep 17 00:00:00 2001
From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Date: Fri, 1 Sep 2023 13:05:02 +0530
Subject: [PATCH] bus: mhi: ep: Do not allocate event ring element on stack

It is possible that the host controller driver would use DMA framework to
write the event ring element. So avoid allocating event ring element on the
stack as DMA cannot work on vmalloc memory.

Cc: stable@vger.kernel.org
Fixes: 961aeb689224 ("bus: mhi: ep: Add support for sending events to the host")
Link: https://lore.kernel.org/r/20230901073502.69385-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index 600881808982..e2513f5f47a6 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -71,45 +71,77 @@ static int mhi_ep_send_event(struct mhi_ep_cntrl *mhi_cntrl, u32 ring_idx,
 static int mhi_ep_send_completion_event(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_ring *ring,
 					struct mhi_ring_element *tre, u32 len, enum mhi_ev_ccs code)
 {
-	struct mhi_ring_element event = {};
+	struct mhi_ring_element *event;
+	int ret;
+
+	event = kzalloc(sizeof(struct mhi_ring_element), GFP_KERNEL);
+	if (!event)
+		return -ENOMEM;
 
-	event.ptr = cpu_to_le64(ring->rbase + ring->rd_offset * sizeof(*tre));
-	event.dword[0] = MHI_TRE_EV_DWORD0(code, len);
-	event.dword[1] = MHI_TRE_EV_DWORD1(ring->ch_id, MHI_PKT_TYPE_TX_EVENT);
+	event->ptr = cpu_to_le64(ring->rbase + ring->rd_offset * sizeof(*tre));
+	event->dword[0] = MHI_TRE_EV_DWORD0(code, len);
+	event->dword[1] = MHI_TRE_EV_DWORD1(ring->ch_id, MHI_PKT_TYPE_TX_EVENT);
 
-	return mhi_ep_send_event(mhi_cntrl, ring->er_index, &event, MHI_TRE_DATA_GET_BEI(tre));
+	ret = mhi_ep_send_event(mhi_cntrl, ring->er_index, event, MHI_TRE_DATA_GET_BEI(tre));
+	kfree(event);
+
+	return ret;
 }
 
 int mhi_ep_send_state_change_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_state state)
 {
-	struct mhi_ring_element event = {};
+	struct mhi_ring_element *event;
+	int ret;
+
+	event = kzalloc(sizeof(struct mhi_ring_element), GFP_KERNEL);
+	if (!event)
+		return -ENOMEM;
 
-	event.dword[0] = MHI_SC_EV_DWORD0(state);
-	event.dword[1] = MHI_SC_EV_DWORD1(MHI_PKT_TYPE_STATE_CHANGE_EVENT);
+	event->dword[0] = MHI_SC_EV_DWORD0(state);
+	event->dword[1] = MHI_SC_EV_DWORD1(MHI_PKT_TYPE_STATE_CHANGE_EVENT);
 
-	return mhi_ep_send_event(mhi_cntrl, 0, &event, 0);
+	ret = mhi_ep_send_event(mhi_cntrl, 0, event, 0);
+	kfree(event);
+
+	return ret;
 }
 
 int mhi_ep_send_ee_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_ee_type exec_env)
 {
-	struct mhi_ring_element event = {};
+	struct mhi_ring_element *event;
+	int ret;
+
+	event = kzalloc(sizeof(struct mhi_ring_element), GFP_KERNEL);
+	if (!event)
+		return -ENOMEM;
 
-	event.dword[0] = MHI_EE_EV_DWORD0(exec_env);
-	event.dword[1] = MHI_SC_EV_DWORD1(MHI_PKT_TYPE_EE_EVENT);
+	event->dword[0] = MHI_EE_EV_DWORD0(exec_env);
+	event->dword[1] = MHI_SC_EV_DWORD1(MHI_PKT_TYPE_EE_EVENT);
 
-	return mhi_ep_send_event(mhi_cntrl, 0, &event, 0);
+	ret = mhi_ep_send_event(mhi_cntrl, 0, event, 0);
+	kfree(event);
+
+	return ret;
 }
 
 static int mhi_ep_send_cmd_comp_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_ev_ccs code)
 {
 	struct mhi_ep_ring *ring = &mhi_cntrl->mhi_cmd->ring;
-	struct mhi_ring_element event = {};
+	struct mhi_ring_element *event;
+	int ret;
+
+	event = kzalloc(sizeof(struct mhi_ring_element), GFP_KERNEL);
+	if (!event)
+		return -ENOMEM;
 
-	event.ptr = cpu_to_le64(ring->rbase + ring->rd_offset * sizeof(struct mhi_ring_element));
-	event.dword[0] = MHI_CC_EV_DWORD0(code);
-	event.dword[1] = MHI_CC_EV_DWORD1(MHI_PKT_TYPE_CMD_COMPLETION_EVENT);
+	event->ptr = cpu_to_le64(ring->rbase + ring->rd_offset * sizeof(struct mhi_ring_element));
+	event->dword[0] = MHI_CC_EV_DWORD0(code);
+	event->dword[1] = MHI_CC_EV_DWORD1(MHI_PKT_TYPE_CMD_COMPLETION_EVENT);
 
-	return mhi_ep_send_event(mhi_cntrl, 0, &event, 0);
+	ret = mhi_ep_send_event(mhi_cntrl, 0, event, 0);
+	kfree(event);
+
+	return ret;
 }
 
 static int mhi_ep_process_cmd_ring(struct mhi_ep_ring *ring, struct mhi_ring_element *el)