On Tue, 16 Feb 2021 20:09:53 -0800 Ben Widawsky <ben.widawsky@xxxxxxxxx> wrote: > Add a straightforward IOCTL that provides a mechanism for userspace to > query the supported memory device commands. CXL commands as they appear > to userspace are described as part of the UAPI kerneldoc. The command > list returned via this IOCTL will contain the full set of commands that > the driver supports, however, some of those commands may not be > available for use by userspace. > > Memory device commands first appear in the CXL 2.0 specification. They > are submitted through a mailbox mechanism specified in the CXL 2.0 > specification. > > The send command allows userspace to issue mailbox commands directly to > the hardware. The list of available commands to send are the output of > the query command. The driver verifies basic properties of the command > and possibly inspect the input (or output) payload to determine whether > or not the command is allowed (or might taint the kernel). > > Reported-by: kernel test robot <lkp@xxxxxxxxx> # bug in earlier revision > Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> > Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Ben Widawsky <ben.widawsky@xxxxxxxxx> > Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx> (v2) Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
