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@xxxxxxxxx>
---
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
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