misc: fastrpc: Add fastrpc_remote_heap_alloc

Split fastrpc_buf_alloc in such a way it allows allocation of remote
heap too and add fastrpc_remote_heap_alloc to do so.

Co-developed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20221125071405.148786-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: abelvesa

drivers/misc/fastrpc.c

@@ -369,7 +369,7 @@ static void fastrpc_buf_free(struct fastrpc_buf *buf)
 	kfree(buf);
 }
 
-static int fastrpc_buf_alloc(struct fastrpc_user *fl, struct device *dev,
+static int __fastrpc_buf_alloc(struct fastrpc_user *fl, struct device *dev,
 			     u64 size, struct fastrpc_buf **obuf)
 {
 	struct fastrpc_buf *buf;
@@ -397,14 +397,37 @@ static int fastrpc_buf_alloc(struct fastrpc_user *fl, struct device *dev,
 		return -ENOMEM;
 	}
 
+	*obuf = buf;
+
+	return 0;
+}
+
+static int fastrpc_buf_alloc(struct fastrpc_user *fl, struct device *dev,
+			     u64 size, struct fastrpc_buf **obuf)
+{
+	int ret;
+	struct fastrpc_buf *buf;
+
+	ret = __fastrpc_buf_alloc(fl, dev, size, obuf);
+	if (ret)
+		return ret;
+
+	buf = *obuf;
+
 	if (fl->sctx && fl->sctx->sid)
 		buf->phys += ((u64)fl->sctx->sid << 32);
 
-	*obuf = buf;
-
 	return 0;
 }
 
+static int fastrpc_remote_heap_alloc(struct fastrpc_user *fl, struct device *dev,
+				     u64 size, struct fastrpc_buf **obuf)
+{
+	struct device *rdev = &fl->cctx->rpdev->dev;
+
+	return  __fastrpc_buf_alloc(fl, rdev, size, obuf);
+}
+
 static void fastrpc_channel_ctx_free(struct kref *ref)
 {
 	struct fastrpc_channel_ctx *cctx;