* [PATCH] PCI: Workaround for NTB BAR size issue
@ 2013-05-06 18:03 Jon Mason
2013-05-08 22:51 ` Bjorn Helgaas
0 siblings, 1 reply; 3+ messages in thread
From: Jon Mason @ 2013-05-06 18:03 UTC (permalink / raw)
To: Bjorn Helgaas; +Cc: linux-pci
Certain NTB devices have a hardware errata where, regardless of
pre-configured value, reading the BAR size returns 4096. To work around
this issue, add a PCI quirk to read the appropriate values from an
alternative register in PCI config space and move the resource endpoints
to the appropriate location.
Signed-off-by: Jon Mason <jon.mason@intel.com>
---
drivers/pci/quirks.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 7d68aee..a57a93b 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2865,6 +2865,30 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65f9, quirk_intel_mc_errata);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65fa, quirk_intel_mc_errata);
+/* Ivytown NTB BAR sizes are misreported by the hardware due to an errata. To
+ * work around this, query the size it should be configured to by the device and
+ * modify the resource end to correspond to this new size.
+ */
+static void quirk_intel_ntb(struct pci_dev *dev)
+{
+ int rc;
+ u8 val;
+
+ rc = pci_read_config_byte(dev, 0x00D0, &val);
+ if (rc)
+ return;
+
+ dev->resource[2].end = dev->resource[2].start + ((u64) 1 << val) - 1;
+
+ rc = pci_read_config_byte(dev, 0x00D1, &val);
+ if (rc)
+ return;
+
+ dev->resource[4].end = dev->resource[4].start + ((u64) 1 << val) - 1;
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0e08, quirk_intel_ntb);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0e0d, quirk_intel_ntb);
+
static ktime_t fixup_debug_start(struct pci_dev *dev,
void (*fn)(struct pci_dev *dev))
{
--
1.7.9.5
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] PCI: Workaround for NTB BAR size issue
2013-05-06 18:03 [PATCH] PCI: Workaround for NTB BAR size issue Jon Mason
@ 2013-05-08 22:51 ` Bjorn Helgaas
2013-05-09 21:52 ` Jon Mason
0 siblings, 1 reply; 3+ messages in thread
From: Bjorn Helgaas @ 2013-05-08 22:51 UTC (permalink / raw)
To: Jon Mason; +Cc: linux-pci@vger.kernel.org
On Mon, May 6, 2013 at 11:03 AM, Jon Mason <jon.mason@intel.com> wrote:
> Certain NTB devices have a hardware errata where, regardless of
> pre-configured value, reading the BAR size returns 4096. To work around
> this issue, add a PCI quirk to read the appropriate values from an
> alternative register in PCI config space and move the resource endpoints
> to the appropriate location.
Is there a documentation pointer we could add to the changelog?
I applied this to my pci/misc branch. As soon as v3.10-rc1 is out,
I'll rebase to that and incorporate it into -next.
> Signed-off-by: Jon Mason <jon.mason@intel.com>
> ---
> drivers/pci/quirks.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 7d68aee..a57a93b 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -2865,6 +2865,30 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65f9, quirk_intel_mc_errata);
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65fa, quirk_intel_mc_errata);
>
>
> +/* Ivytown NTB BAR sizes are misreported by the hardware due to an errata. To
> + * work around this, query the size it should be configured to by the device and
> + * modify the resource end to correspond to this new size.
> + */
> +static void quirk_intel_ntb(struct pci_dev *dev)
> +{
> + int rc;
> + u8 val;
> +
> + rc = pci_read_config_byte(dev, 0x00D0, &val);
> + if (rc)
> + return;
> +
> + dev->resource[2].end = dev->resource[2].start + ((u64) 1 << val) - 1;
> +
> + rc = pci_read_config_byte(dev, 0x00D1, &val);
> + if (rc)
> + return;
> +
> + dev->resource[4].end = dev->resource[4].start + ((u64) 1 << val) - 1;
> +}
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0e08, quirk_intel_ntb);
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0e0d, quirk_intel_ntb);
> +
> static ktime_t fixup_debug_start(struct pci_dev *dev,
> void (*fn)(struct pci_dev *dev))
> {
> --
> 1.7.9.5
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] PCI: Workaround for NTB BAR size issue
2013-05-08 22:51 ` Bjorn Helgaas
@ 2013-05-09 21:52 ` Jon Mason
0 siblings, 0 replies; 3+ messages in thread
From: Jon Mason @ 2013-05-09 21:52 UTC (permalink / raw)
To: Bjorn Helgaas; +Cc: linux-pci@vger.kernel.org
On Wed, May 08, 2013 at 03:51:56PM -0700, Bjorn Helgaas wrote:
> On Mon, May 6, 2013 at 11:03 AM, Jon Mason <jon.mason@intel.com> wrote:
> > Certain NTB devices have a hardware errata where, regardless of
> > pre-configured value, reading the BAR size returns 4096. To work around
> > this issue, add a PCI quirk to read the appropriate values from an
> > alternative register in PCI config space and move the resource endpoints
> > to the appropriate location.
>
> Is there a documentation pointer we could add to the changelog?
Processor not released yet, but the errata won't be fixed :(
> I applied this to my pci/misc branch. As soon as v3.10-rc1 is out,
> I'll rebase to that and incorporate it into -next.
Great!
Thanks,
Jon
>
> > Signed-off-by: Jon Mason <jon.mason@intel.com>
> > ---
> > drivers/pci/quirks.c | 24 ++++++++++++++++++++++++
> > 1 file changed, 24 insertions(+)
> >
> > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> > index 7d68aee..a57a93b 100644
> > --- a/drivers/pci/quirks.c
> > +++ b/drivers/pci/quirks.c
> > @@ -2865,6 +2865,30 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65f9, quirk_intel_mc_errata);
> > DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65fa, quirk_intel_mc_errata);
> >
> >
> > +/* Ivytown NTB BAR sizes are misreported by the hardware due to an errata. To
> > + * work around this, query the size it should be configured to by the device and
> > + * modify the resource end to correspond to this new size.
> > + */
> > +static void quirk_intel_ntb(struct pci_dev *dev)
> > +{
> > + int rc;
> > + u8 val;
> > +
> > + rc = pci_read_config_byte(dev, 0x00D0, &val);
> > + if (rc)
> > + return;
> > +
> > + dev->resource[2].end = dev->resource[2].start + ((u64) 1 << val) - 1;
> > +
> > + rc = pci_read_config_byte(dev, 0x00D1, &val);
> > + if (rc)
> > + return;
> > +
> > + dev->resource[4].end = dev->resource[4].start + ((u64) 1 << val) - 1;
> > +}
> > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0e08, quirk_intel_ntb);
> > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0e0d, quirk_intel_ntb);
> > +
> > static ktime_t fixup_debug_start(struct pci_dev *dev,
> > void (*fn)(struct pci_dev *dev))
> > {
> > --
> > 1.7.9.5
> >
^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-05-06 18:03 [PATCH] PCI: Workaround for NTB BAR size issue Jon Mason
2013-05-08 22:51 ` Bjorn Helgaas
2013-05-09 21:52 ` Jon Mason
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