misc: fastrpc: add support for gdsp remoteproc

Some platforms (like lemans) feature one or more GPDSPs (General
Purpose DSPs). Similar to other kinds of Hexagon DSPs, they provide
a FastRPC implementation, allowing code execution in both signed and
unsigned protection domains. Extend the checks to allow domain names
starting with "gdsp" (possibly followed by an index).

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
Signed-off-by: Ling Xu <quic_lxu5@quicinc.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://lore.kernel.org/r/20250912131302.303199-5-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: quic-lxu5

drivers/misc/fastrpc.c

@@ -27,6 +27,7 @@
 #define MDSP_DOMAIN_ID (1)
 #define SDSP_DOMAIN_ID (2)
 #define CDSP_DOMAIN_ID (3)
+#define GDSP_DOMAIN_ID (4)
 #define FASTRPC_MAX_SESSIONS	14
 #define FASTRPC_MAX_VMIDS	16
 #define FASTRPC_ALIGN		128
@@ -2249,6 +2250,8 @@ static int fastrpc_get_domain_id(const char *domain)
 		return MDSP_DOMAIN_ID;
 	else if (!strncmp(domain, "sdsp", 4))
 		return SDSP_DOMAIN_ID;
+	else if (!strncmp(domain, "gdsp", 4))
+		return GDSP_DOMAIN_ID;
 
 	return -EINVAL;
 }
@@ -2318,13 +2321,14 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 	case ADSP_DOMAIN_ID:
 	case MDSP_DOMAIN_ID:
 	case SDSP_DOMAIN_ID:
-		/* Unsigned PD offloading is only supported on CDSP */
+		/* Unsigned PD offloading is only supported on CDSP and GDSP */
 		data->unsigned_support = false;
 		err = fastrpc_device_register(rdev, data, secure_dsp, domain);
 		if (err)
 			goto err_free_data;
 		break;
 	case CDSP_DOMAIN_ID:
+	case GDSP_DOMAIN_ID:
 		data->unsigned_support = true;
 		/* Create both device nodes so that we can allow both Signed and Unsigned PD */
 		err = fastrpc_device_register(rdev, data, true, domain);