cxl: Use fixed width predefined types in data structure.

This patch fixes a regression introduced by commit b810253bd934 ("cxl:
Add mechanism for delivering AFU driver specific events").

It changes the type u8 to __u8 in the uapi header cxl.h, because the
former is a kernel internal type, and may not be defined in userland
build environments, in particular when cross-compiling libcxl on x86_64
linux machines (RHEL6.7 and Ubuntu 16.04).

This patch also changes the size of the field data_size, and makes it
constant, to support 32-bit userland applications running on big-endian
ppc64 kernels transparently.

mpe: This is an ABI change, however the ABI was only added during the
4.8 merge window so has never been part of a released kernel - therefore
we give ourselves permission to change it.

Fixes: b810253bd934 ("cxl: Add mechanism for delivering AFU driver specific events")
Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/uapi/misc/cxl.h b/include/uapi/misc/cxl.h
index cbae529b7ce0..180d526a55c3 100644
--- a/include/uapi/misc/cxl.h
+++ b/include/uapi/misc/cxl.h
@@ -136,8 +136,8 @@ struct cxl_event_afu_driver_reserved {
          *
          * Of course the contents will be ABI, but that's up the AFU driver.
          */
-        size_t data_size;
-        u8 data[];
+        __u32 data_size;
+        __u8 data[];
 };
 
 struct cxl_event {