Re: [PATCH v3 4/7] acpi, nfit: Use bus_dsm_mask for passthru

[Jerry Hoemann]

On Thu, Jun 29, 2017 at 02:55:55PM -0700, Dan Williams wrote:
> On Thu, Jun 29, 2017 at 2:47 PM, Jerry Hoemann <jerry.hoemann@xxxxxxx> wrote:
> > On Thu, Jun 29, 2017 at 02:35:14PM -0700, Dan Williams wrote:
> >> On Thu, Jun 29, 2017 at 9:56 AM, Jerry Hoemann <jerry.hoemann@xxxxxxx> wrote:
> >> > Populate bus_dsm_mask and use it to filter dsm calls that user can
> >> > make through the pass thru interface.
> >> >
> >> > Signed-off-by: Jerry Hoemann <jerry.hoemann@xxxxxxx>
> >> > ---
> >> >  drivers/acpi/nfit/core.c | 5 +++++
> >> >  1 file changed, 5 insertions(+)
> >> >
> >> > diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
> >> > index b46fca2..971002b 100644
> >> > --- a/drivers/acpi/nfit/core.c
> >> > +++ b/drivers/acpi/nfit/core.c
> >> > @@ -253,6 +253,8 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
> >> >                 cmd_name = nvdimm_bus_cmd_name(cmd);
> >> >                 cmd_mask = nd_desc->cmd_mask;
> >> >                 dsm_mask = cmd_mask;
> >> > +               if (cmd == ND_CMD_CALL)
> >> > +                       dsm_mask = nd_desc->bus_dsm_mask;
> >> >                 desc = nd_cmd_bus_desc(cmd);
> >> >                 uuid = to_nfit_uuid(NFIT_DEV_BUS);
> >> >                 handle = adev->handle;
> >> > @@ -1624,6 +1626,9 @@ static void acpi_nfit_init_dsms(struct acpi_nfit_desc *acpi_desc)
> >> >                 if (acpi_check_dsm(adev->handle, uuid, 1, 1ULL << i))
> >> >                         set_bit(i, &nd_desc->cmd_mask);
> >> >         set_bit(ND_CMD_CALL, &nd_desc->cmd_mask);
> >> > +       for (i = 0; i < ND_CMD_CALL; i++)
> >> > +               if (acpi_check_dsm(adev->handle, uuid, 1, 1ULL << i))
> >> > +                       set_bit(i, &nd_desc->bus_dsm_mask);
> >> >  }
> >>
> >> This loop checks for function 6 which is specified as reserved. Lets
> >> explicitly test for the known good function numbers with something
> >> like this:
> >>
> >> /* this should be private in drivers/acpi/nfit/nfit.h */
> >> enum nfit_aux_cmds {
> >>         NFIT_CMD_TRANSLATE_SPA = 5,
> >>         NFIT_CMD_ARS_INJECT_SET = 7,
> >>         NFIT_CMD_ARS_INJECT_CLEAR = 8,
> >>         NFIT_CMD_ARS_INJECT_GET = 9,
> >> };
> >>
> >> bus_dsm_mask =
> >>         (1 << ND_CMD_ARS_CAP) |
> >>         (1 << ND_CMD_ARS_START) |
> >>         (1 << ND_CMD_ARS_STATUS) |
> >>         (1 << ND_CMD_CLEAR_ERROR) |
> >>         (1 << NFIT_CMD_TRANSLATE_SPA) |
> >>         (1 << NFIT_CMD_ARS_INJECT_SET) |
> >>         (1 << NFIT_CMD_ARS_INJECT_CLEAR) |
> >>         (1 << NFIT_CMD_ARS_INJECT_GET);
> >>
> >> for_each_set_bit(i, &bus_dsm_mask...
> >
> >
> >   I added the for_each_set_bit check in patch 7 of the series.
> 
> True, but in a patch series we shouldn't introduce a bug in one patch
> and fix it later in the same series. Also, if patch7 goes away we
> would need to fold that enabling in here.
> 

A bug?   What bad thing happens?


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Jerry Hoemann                  Software Engineer   Hewlett Packard Enterprise
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