10:05 p.m.
On Tue, Apr 12, 2016 at 2:41 PM, Jerry Hoemann <jerry.hoemann(a)hpe.com> wrote:
On Mon, Apr 11, 2016 at 05:30:25PM -0700, Dan Williams wrote:
> On Mon, Apr 11, 2016 at 4:58 PM, Jerry Hoemann <jerry.hoemann(a)hpe.com> wrote:
> > On Mon, Apr 11, 2016 at 02:43:39PM -0700, Dan Williams wrote:
> >> On Mon, Mar 21, 2016 at 12:37 PM, Jerry Hoemann
<jerry.hoemann(a)hpe.com> wrote:
> >> > NVDIMM DSMs whose functions map to the Intel Example DSM, can
> >> > be called with the ND_IOCTL_.* ioctl interface. Those that
> >> > don't map, can only be called with the pass thru command.
> >> >
> >> > Save this indication in struct nvdimm to be passed to
> >> > the sysfs interface.
> >> >
> >>
> >> I'm having trouble understanding the intent of cmd_ioctl. I don't
> >> want a flag for "supports Intel Example DSM", I want a mask of ND
> >> commands the bus provider knows how to handle in its ->ndctl() entry
> >> point for the given dimm. The bus provider is free to provide a
> >> translation of ND command to the bus specific command. It's just an
> >> arbitrary coincidence that the current list of ND commands matches the
> >> Intel ACPI _DSM command format.
> >
> > This is my extension of your earlier RFC patch, so I may
> > have misunderstood your original intent.
> >
> > The commands_show functions prints the listing of commands for that device.
> > There is one version for root, and one version for non-root.
> >
> > For root commands, both dsm spec match on names and semantics, so no
> > code works for both nvdimms types.
> >
> > But for non-root commands the names/semantics don't match. So, this
> > is an attempt to show that on an NVDIMM-N, only the pass thru command
> > is supported.
>
> Ah, ok. Rather than telling the core about a dsm_mask and a cmd_ioctl
> at nvdimm_create() time, it should just be passing the mask of generic
> ND commands that the dimm supports. For NVDIMM-N that mask will just
> be (1 << 10) it's up to the nfit driver to manage any ND command to
> ACPI _DSM command number translation.
dsm_mask is used in both acpi_nfit_ctl and __nd_ioctl to filter calls
the functions might make. I think dsm_mask and cmd_ioctl need to be
kept separate, or drop use of filtering by dsm_mask in these two
functions.
Or another way of controlling what commands_show produces?
I was thinking that the dsm_mask cease being a pointer in struct
nvdimm and instead be a cmd_mask (of ND function numbers). struct
nfit_mem would maintain the dsm_mask. acpi_nfit_ctl is charged with
translating from the nd command to the acpi dsm. This "just works"
for the existing sysfs interface, and we can export the dsm_mask in
the nfit-specific attributes of the nme device.