Re: [PATCH v2 2/7] drivers/soc: Add Aspeed XDMA Engine Driver

From: Eddie James
Date: Fri May 24 2019 - 12:12:07 EST



On 5/21/19 7:02 AM, Arnd Bergmann wrote:
On Mon, May 20, 2019 at 10:19 PM Eddie James <eajames@xxxxxxxxxxxxx> wrote:
diff --git a/include/uapi/linux/aspeed-xdma.h b/include/uapi/linux/aspeed-xdma.h
new file mode 100644
index 0000000..2a4bd13
--- /dev/null
+++ b/include/uapi/linux/aspeed-xdma.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/* Copyright IBM Corp 2019 */
+
+#ifndef _UAPI_LINUX_ASPEED_XDMA_H_
+#define _UAPI_LINUX_ASPEED_XDMA_H_
+
+#include <linux/types.h>
+
+/*
+ * aspeed_xdma_op
+ *
+ * upstream: boolean indicating the direction of the DMA operation; upstream
+ * means a transfer from the BMC to the host
+ *
+ * host_addr: the DMA address on the host side, typically configured by PCI
+ * subsystem
+ *
+ * len: the size of the transfer in bytes; it should be a multiple of 16 bytes
+ */
+struct aspeed_xdma_op {
+ __u32 upstream;
+ __u64 host_addr;
+ __u32 len;
+};
+
+#endif /* _UAPI_LINUX_ASPEED_XDMA_H_ */
If this is a user space interface, please remove the holes in the
data structure.


Surely it's 4-byte aligned and there won't be holes??



I don't see how this is actually used in this patch, maybe you meant
the definition to be part of another patch?


The structure is used in this patch as an argument to aspeed_xdma_start().


Thanks,

Eddie



Arnd