misc: fastrpc: add ioctl for attaching to sensors pd

Initializing sensors requires attaching to pd 2. Add an ioctl for that.

This corresponds to FASTRPC_INIT_ATTACH_SENSORS in the downstream driver.
Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Link: https://lore.kernel.org/r/20200908131013.19630-4-jonathan@marek.caSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/fastrpc.c

@@ -1281,7 +1281,7 @@ static int fastrpc_dmabuf_alloc(struct fastrpc_user *fl, char __user *argp)
 	return 0;
 }
 
-static int fastrpc_init_attach(struct fastrpc_user *fl)
+static int fastrpc_init_attach(struct fastrpc_user *fl, int pd)
 {
 	struct fastrpc_invoke_args args[1];
 	int tgid = fl->tgid;
@@ -1292,7 +1292,7 @@ static int fastrpc_init_attach(struct fastrpc_user *fl)
 	args[0].fd = -1;
 	args[0].reserved = 0;
 	sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_ATTACH, 1, 0);
-	fl->pd = AUDIO_PD;
+	fl->pd = pd;
 
 	return fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE,
 				       sc, &args[0]);
@@ -1482,7 +1482,10 @@ static long fastrpc_device_ioctl(struct file *file, unsigned int cmd,
 		err = fastrpc_invoke(fl, argp);
 		break;
 	case FASTRPC_IOCTL_INIT_ATTACH:
-		err = fastrpc_init_attach(fl);
+		err = fastrpc_init_attach(fl, AUDIO_PD);
+		break;
+	case FASTRPC_IOCTL_INIT_ATTACH_SNS:
+		err = fastrpc_init_attach(fl, SENSORS_PD);
 		break;
 	case FASTRPC_IOCTL_INIT_CREATE:
 		err = fastrpc_init_create_process(fl, argp);

include/uapi/misc/fastrpc.h

@@ -12,6 +12,7 @@
 #define FASTRPC_IOCTL_INIT_CREATE	_IOWR('R', 5, struct fastrpc_init_create)
 #define FASTRPC_IOCTL_MMAP		_IOWR('R', 6, struct fastrpc_req_mmap)
 #define FASTRPC_IOCTL_MUNMAP		_IOWR('R', 7, struct fastrpc_req_munmap)
+#define FASTRPC_IOCTL_INIT_ATTACH_SNS	_IO('R', 8)
 
 struct fastrpc_invoke_args {
 	__u64 ptr;