In order to properly re-initialize the VMD domain during repetitive driver
attachment or reboot tests, ensure that the VMD root ports are re-initialized
to a blank state that can be re-enumerated appropriately by the PCI core.
This is performed by re-initializing all of the bridge windows to ensure
that PCI core enumeration does not detect potentially invalid bridge windows
and misinterpret them as firmware-assigned windows, when they simply may be
invalid bridge window information from a previous boot.
Signed-off-by: Nirmal Patel <nirmal.patel@xxxxxxxxxxxxxxx>
Reviewed-by: Jon Derrick <jonathan.derrick@xxxxxxxxx>
---
drivers/pci/controller/vmd.c | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 6e1c60048774..e52bdb95218e 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -651,6 +651,39 @@ static int vmd_alloc_irqs(struct vmd_dev *vmd)
return 0;
}
+
+static void vmd_domain_reset_windows(struct vmd_dev *vmd)
+{
+ u8 hdr_type;
+ char __iomem *addr;
+ int dev_seq;
+ u8 functions;
+ u8 fn_seq;
+ int max_devs = resource_size(&vmd->resources[0]) * 32;
+
+ for (dev_seq = 0; dev_seq < max_devs; dev_seq++) {
+ addr = VMD_DEVICE_BASE(vmd, dev_seq) + PCI_VENDOR_ID;
+ if (readw(addr) != PCI_VENDOR_ID_INTEL)
+ continue;
+
+ addr = VMD_DEVICE_BASE(vmd, dev_seq) + PCI_HEADER_TYPE;
+ hdr_type = readb(addr) & PCI_HEADER_TYPE_MASK;
+ if (hdr_type != PCI_HEADER_TYPE_BRIDGE)
+ continue;
+
+ functions = !!(hdr_type & 0x80) ? 8 : 1;
+ for (fn_seq = 0; fn_seq < functions; fn_seq++)
+ {
+ addr = VMD_FUNCTION_BASE(vmd, dev_seq, fn_seq) + PCI_VENDOR_ID;
+ if (readw(addr) != PCI_VENDOR_ID_INTEL)
+ continue;
+
+ memset_io((VMD_FUNCTION_BASE(vmd, dev_seq, fn_seq) + PCI_IO_BASE),
+ 0, PCI_ROM_ADDRESS1 - PCI_IO_BASE);
+ }
+ }
+}
+
static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
{
struct pci_sysdata *sd = &vmd->sysdata;
@@ -741,6 +774,8 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
.parent = res,
};
+ vmd_domain_reset_windows(vmd);
+
sd->vmd_dev = vmd->dev;
sd->domain = vmd_find_free_domain();
if (sd->domain < 0)
--
2.27.0
