Re: [Qemu-devel] [PATCH v3 26/32] nvdimm: save arg3 for NVDIMM device _DSM method

["Michael S. Tsirkin" <mst@redhat.com>]

On Sun, Oct 11, 2015 at 11:52:58AM +0800, Xiao Guangrong wrote:
> Check if the input Arg3 is valid then store it into dsm_in if needed
> 
> We only do the save on NVDIMM device since we are not going to support any
> function on root device
> 
> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
> ---
>  hw/mem/nvdimm/acpi.c | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/mem/nvdimm/acpi.c b/hw/mem/nvdimm/acpi.c
> index d9fa0fd..3b9399c 100644
> --- a/hw/mem/nvdimm/acpi.c
> +++ b/hw/mem/nvdimm/acpi.c
> @@ -442,7 +442,7 @@ static void build_nvdimm_devices(NVDIMMState *state, GSList *device_list,
>          int slot = object_property_get_int(OBJECT(nvdimm), DIMM_SLOT_PROP,
>                                             NULL);
>          uint32_t handle = nvdimm_slot_to_handle(slot);
> -        Aml *dev, *method;
> +        Aml *dev, *method, *ifctx;
>  
>          dev = aml_device("NV%02X", slot);
>          aml_append(dev, aml_name_decl("_ADR", aml_int(handle)));
> @@ -452,6 +452,24 @@ static void build_nvdimm_devices(NVDIMMState *state, GSList *device_list,
>          method = aml_method("_DSM", 4);
>          {
>              SAVE_ARG012_HANDLE_LOCK(method, aml_int(handle));
> +
> +            /* Arg3 is passed as Package and it has one element? */
> +            ifctx = aml_if(aml_and(aml_equal(aml_object_type(aml_arg(3)),
> +                                             aml_int(4)),
> +                                   aml_equal(aml_sizeof(aml_arg(3)),

aml_arg(3) is used many times below.
Pls give it a name that makes sense (not arg3! what is it for?)

> +                                             aml_int(1))));

Pls document AML constants used.
Like this:

            ifctx = aml_if(aml_and(aml_equal(aml_object_type(aml_arg(3)),
                                             aml_int(4 /* 4 - Package */) ),
                                   aml_equal(aml_sizeof(aml_arg(3)),
                                             aml_int(1))));

> +            {
> +                /* Local0 = Index(Arg3, 0) */
> +                aml_append(ifctx, aml_store(aml_index(aml_arg(3), aml_int(0)),
> +                                            aml_local(0)));
> +                /* Local3 = DeRefOf(Local0) */
> +                aml_append(ifctx, aml_store(aml_derefof(aml_local(0)),
> +                                            aml_local(3)));
> +                /* ARG3 = Local3 */
> +                aml_append(ifctx, aml_store(aml_local(3), aml_name("ARG3")));

This isn't a good way to comment things: you are
just adding ASL before the equivalent C.
Pls document what's going on.




> +            }
> +            aml_append(method, ifctx);
> +
>              NOTIFY_AND_RETURN_UNLOCK(method);
>          }
>          aml_append(dev, method);
> @@ -534,6 +552,7 @@ static void nvdimm_build_acpi_devices(NVDIMMState *state, GSList *device_list,
>      method = aml_method("_DSM", 4);
>      {
>          SAVE_ARG012_HANDLE_LOCK(method, aml_int(0));
> +        /* no command we support on ROOT device has Arg3. */
>          NOTIFY_AND_RETURN_UNLOCK(method);
>      }
>      aml_append(dev, method);
> -- 
> 1.8.3.1