Re: [PATCH v4 15/15] fwctl/cxl: Add documentation to FWCTL CXL

[Dan Williams <dan.j.williams@intel.com>]

Dave Jiang wrote:
> Add policy and operational documentation for FWCTL CXL.
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
[..]
> +Code example of a Get Feature
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +.. code-block:: c
> +
> +        static int cxl_fwctl_rpc_get_test_feature(int fd, struct test_feature *feat_ctx,
> +                                                  const uint32_t expected_data)
> +        {
> +                struct cxl_mbox_get_feat_in feat_in __attribute__((aligned(16))) = {0};
> +                struct fwctl_rpc_cxl in __attribute__((aligned(16))) = {0};
> +                struct fwctl_rpc_cxl_out *out;
> +                struct fwctl_rpc rpc = {0};
> +                size_t out_size;
> +                uint32_t val;
> +                void *data;
> +                int rc;
> +
> +                uuid_copy(feat_in.uuid, feat_ctx->uuid);
> +                feat_in.count = feat_ctx->get_size;
> +
> +                out_size = sizeof(*out) + feat_in.count;
> +                out = aligned_alloc(16, out_size);
> +                if (!out)
> +                        return -ENOMEM;
> +
> +                memset(out, 0, out_size);
> +                data = out->payload;
> +
> +                in.opcode = CXL_MBOX_OPCODE_GET_FEATURE;

Oh, this went a bit further than I expected, but I think its fine to not
have fwctl command ids to wrap the Feature opcodes.

You can add:

Reviewed-by: Dan Williams <dan.j.williams@intel.com>

...and if we ever decide to expand the operations that fwctl supports
just need to be careful about aliasing.