[char-misc-next] mei: use kvmalloc for read buffer

From: Alexander Usyskin
Date: Sun Oct 13 2024 - 08:05:49 EST


Read buffer is allocated according to max message size,
reported by the firmware and may reach 64K in systems
with pxp client.
Contiguous 64k allocation may fail under memory pressure.
Read buffer is used as in-driver message storage and
not required to be contiguous.
Use kvmalloc to allow kernel to allocate non-contiguous
memory in this case.

Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
---
drivers/misc/mei/client.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 9d090fa07516..be011cef12e5 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -321,7 +321,7 @@ void mei_io_cb_free(struct mei_cl_cb *cb)
return;

list_del(&cb->list);
- kfree(cb->buf.data);
+ kvfree(cb->buf.data);
kfree(cb->ext_hdr);
kfree(cb);
}
@@ -497,7 +497,7 @@ struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length,
if (length == 0)
return cb;

- cb->buf.data = kmalloc(roundup(length, MEI_SLOT_SIZE), GFP_KERNEL);
+ cb->buf.data = kvmalloc(roundup(length, MEI_SLOT_SIZE), GFP_KERNEL);
if (!cb->buf.data) {
mei_io_cb_free(cb);
return NULL;
--
2.43.0