1 files changed, 40 insertions, 7 deletions

diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 0706322154cb..0a0e984e5673 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -98,9 +98,12 @@ static int mei_cl_irq_read_msg(struct mei_cl *cl,
 	struct mei_device *dev = cl->dev;
 	struct mei_cl_cb *cb;
 
+	struct mei_ext_hdr_vtag *vtag_hdr = NULL;
+	struct mei_ext_hdr_gsc_f2h *gsc_f2h = NULL;
+
 	size_t buf_sz;
 	u32 length;
-	int ext_len;
+	u32 ext_len;
 
 	length = mei_hdr->length;
 	ext_len = 0;
@@ -122,18 +125,24 @@ static int mei_cl_irq_read_msg(struct mei_cl *cl,
 	}
 
 	if (mei_hdr->extended) {
-		struct mei_ext_hdr *ext;
-		struct mei_ext_hdr_vtag *vtag_hdr = NULL;
-
-		ext = mei_ext_begin(meta);
+		struct mei_ext_hdr *ext = mei_ext_begin(meta);
 		do {
 			switch (ext->type) {
 			case MEI_EXT_HDR_VTAG:
 				vtag_hdr = (struct mei_ext_hdr_vtag *)ext;
 				break;
+			case MEI_EXT_HDR_GSC:
+				gsc_f2h = (struct mei_ext_hdr_gsc_f2h *)ext;
+				cb->ext_hdr = kzalloc(sizeof(*gsc_f2h), GFP_KERNEL);
+				if (!cb->ext_hdr) {
+					cb->status = -ENOMEM;
+					goto discard;
+				}
+				break;
 			case MEI_EXT_HDR_NONE:
 				fallthrough;
 			default:
+				cl_err(dev, cl, "unknown extended header\n");
 				cb->status = -EPROTO;
 				break;
 			}
@@ -141,12 +150,14 @@ static int mei_cl_irq_read_msg(struct mei_cl *cl,
 			ext = mei_ext_next(ext);
 		} while (!mei_ext_last(meta, ext));
 
-		if (!vtag_hdr) {
-			cl_dbg(dev, cl, "vtag not found in extended header.\n");
+		if (!vtag_hdr && !gsc_f2h) {
+			cl_dbg(dev, cl, "no vtag or gsc found in extended header.\n");
 			cb->status = -EPROTO;
 			goto discard;
 		}
+	}
 
+	if (vtag_hdr) {
 		cl_dbg(dev, cl, "vtag: %d\n", vtag_hdr->vtag);
 		if (cb->vtag && cb->vtag != vtag_hdr->vtag) {
 			cl_err(dev, cl, "mismatched tag: %d != %d\n",
@@ -157,6 +168,28 @@ static int mei_cl_irq_read_msg(struct mei_cl *cl,
 		cb->vtag = vtag_hdr->vtag;
 	}
 
+	if (gsc_f2h) {
+		u32 ext_hdr_len = mei_ext_hdr_len(&gsc_f2h->hdr);
+
+		if (!dev->hbm_f_gsc_supported) {
+			cl_err(dev, cl, "gsc extended header is not supported\n");
+			cb->status = -EPROTO;
+			goto discard;
+		}
+
+		if (length) {
+			cl_err(dev, cl, "no data allowed in cb with gsc\n");
+			cb->status = -EPROTO;
+			goto discard;
+		}
+		if (ext_hdr_len > sizeof(*gsc_f2h)) {
+			cl_err(dev, cl, "gsc extended header is too big %u\n", ext_hdr_len);
+			cb->status = -EPROTO;
+			goto discard;
+		}
+		memcpy(cb->ext_hdr, gsc_f2h, ext_hdr_len);
+	}
+
 	if (!mei_cl_is_connected(cl)) {
 		cl_dbg(dev, cl, "not connected\n");
 		cb->status = -ENODEV;