The VMD subdevice domain resource requirements may have changed
in-between module loads. Generic PCI resource assignment code may rely
on existing resource configuration rather than the VMD preference of
re-examining the domain. Add a Secondary Bus Reset to the VMD subdevice
domain during driver attachment to clear the PCI config space of the
subdevices.
Signed-off-by: Jon Derrick <jonathan.derrick@xxxxxxxxx>
---
drivers/pci/controller/vmd.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 50b3520d261d..676acff3622f 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -445,6 +445,36 @@ static struct pci_ops vmd_ops = {
.write = vmd_pci_write,
};
+static void vmd_domain_reset_sbr(struct vmd_dev *vmd)
+{
+ char __iomem *base;
+ int rp;
+ u16 ctl;
+
+ /*
+ * Subdevice config space is mapped linearly using 4k config space
+ * increments. Use increments of 0x8000 to locate root ports devices.
+ */
+ for (rp = 0; rp < 4; rp++) {
+ base = vmd->cfgbar + rp * 0x8000;
+ if (readl(base + PCI_COMMAND) == 0xFFFFFFFF)
+ continue;
+
+ /* pci_reset_secondary_bus() */
+ ctl = readw(base + PCI_BRIDGE_CONTROL);
+ ctl |= PCI_BRIDGE_CTL_BUS_RESET;
+ writew(ctl, base + PCI_BRIDGE_CONTROL);
+ readw(base + PCI_BRIDGE_CONTROL);
+ msleep(2);
+
+ ctl &= ~PCI_BRIDGE_CTL_BUS_RESET;
+ writew(ctl, base + PCI_BRIDGE_CONTROL);
+ readw(base + PCI_BRIDGE_CONTROL);
+ }
+
+ ssleep(1);
+}
+
static void vmd_attach_resources(struct vmd_dev *vmd)
{
vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[1];
@@ -784,6 +814,7 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
if (!vmd->cfgbar)
return -ENOMEM;
+ vmd_domain_reset_sbr(dev);
pci_set_master(dev);
if (dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(64)) &&
dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32)))
--
2.18.1
