Re: [PATCH 2/2] ACPI: Ignore Consumer/Producer for QWord/DWord/Word Address Space

From: Lorenzo Pieralisi
Date: Wed Nov 30 2016 - 11:23:36 EST


On Wed, Nov 30, 2016 at 09:56:17AM -0600, Bjorn Helgaas wrote:
> On Wed, Nov 30, 2016 at 12:04:25PM +0000, Lorenzo Pieralisi wrote:
> > On Tue, Nov 29, 2016 at 12:43:34PM -0600, Bjorn Helgaas wrote:
> > > Per ACPI spec r6.0, sec 6.4.3.5.1, 2, 3, Bit [0] of General Flags (the
> > > Consumer/Producer bit) should be ignored for QWord/DWord/Word Address Space
> > > descriptors. The Consumer/Producer bit is defined only for the Extended
> > > Address Space descriptor.
> > >
> > > Ignore Consumer/Producer except for Extended Address Space descriptors.
> > >
> > > Note that for QWord/DWord/Word descriptors, we previously applied the
> > > translation offset (_TRA) only when the Consumer/Producer bit was set.
> >
> > "..Consumer/Producer bit was clear" ? If that bit was set:
> >
> > struct acpi_resource_address->producer_consumer == ACPI_CONSUMER
> >
> > and we are not applying the _TRA offset in that case, right ?
>
> Right, of course. How about this instead?
>
> Note that for QWord/DWord/Word descriptors, we previously applied the
> translation offset (_TRA) only for Producers, i.e., when the Consumer/
> Producer bit was clear. This patch changes that: for those descriptors,
> we ignore Consumer/Producer and always apply the translation offset.

Yes that's a perfect description, thanks a lot !

Lorenzo

> > > This patch changes that: for those descriptors, we ignore Consumer/Producer
> > > and always apply the translation offset.
> > >
> > > Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> > > ---
> > > drivers/acpi/resource.c | 16 +++++++++++-----
> > > 1 file changed, 11 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> > > index 2732d39e..b45cd8f 100644
> > > --- a/drivers/acpi/resource.c
> > > +++ b/drivers/acpi/resource.c
> > > @@ -261,11 +261,16 @@ bool acpi_dev_resource_address_space(struct acpi_resource *ares,
> > > * primary side. Non-bridge devices must list 0 for all Address
> > > * Translation offset bits.
> > > */
> > > - if (addr->producer_consumer == ACPI_PRODUCER)
> > > + if (ares->type == ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64) {
> > > + if (addr->producer_consumer == ACPI_PRODUCER)
> > > + offset = attr->translation_offset;
> > > + else if (attr->translation_offset)
> > > + pr_debug("ACPI: translation_offset(%lld) is invalid for non-bridge device.\n",
> > > + attr->translation_offset);
> > > + } else {
> > > offset = attr->translation_offset;
> > > - else if (attr->translation_offset)
> > > - pr_debug("ACPI: translation_offset(%lld) is invalid for non-bridge device.\n",
> > > - attr->translation_offset);
> > > + }
> > > +
> > > start = attr->minimum + offset;
> > > end = attr->maximum + offset;
> > >
> > > @@ -294,7 +299,8 @@ bool acpi_dev_resource_address_space(struct acpi_resource *ares,
> > > return false;
> > > }
> > >
> > > - if (addr->producer_consumer == ACPI_PRODUCER)
> > > + if (ares->type == ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64 &&
> > > + addr->producer_consumer == ACPI_PRODUCER)
> > > res->flags |= IORESOURCE_WINDOW;
> > >
> > > if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
> > >
> > > --
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