PCI: epf-mhi: Simulate async read/write using iATU

Even though iATU only supports synchronous read/write, the MHI stack may
call async read/write callbacks without knowing the limitations of the
controller driver. So in order to maintain compatibility, let's simulate
async read/write operation with iATU by invoking the completion callback
after memcpy.
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

drivers/pci/endpoint/functions/pci-epf-mhi.c

@@ -234,6 +234,9 @@ static int pci_epf_mhi_iatu_read(struct mhi_ep_cntrl *mhi_cntrl,
 
 	mutex_unlock(&epf_mhi->lock);
 
+	if (buf_info->cb)
+		buf_info->cb(buf_info);
+
 	return 0;
 }
 
@@ -262,6 +265,9 @@ static int pci_epf_mhi_iatu_write(struct mhi_ep_cntrl *mhi_cntrl,
 
 	mutex_unlock(&epf_mhi->lock);
 
+	if (buf_info->cb)
+		buf_info->cb(buf_info);
+
 	return 0;
 }