PCI: vmd: Reset VMD config register between soft reboots

VMD driver can disable or enable MSI remapping by changing
VMCONFIG_MSI_REMAP register. This register needs to be set to the
default value during soft reboots. Drives failed to enumerate
when Windows boots after performing a soft reboot from Linux.
Windows doesn't support MSI remapping disable feature and stale
register value hinders Windows VMD driver initialization process.
Adding vmd_shutdown function to make sure to set the VMCONFIG
register to the default value.

Link: https://lore.kernel.org/r/20230224202811.644370-1-nirmal.patel@linux.intel.com
Fixes: ee81ee84f873 ("PCI: vmd: Disable MSI-X remapping when possible")
Signed-off-by: Nirmal Patel <nirmal.patel@linux.intel.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Jon Derrick <jonathan.derrick@linux.dev>

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 990630ec57c6a5f3825b3998e73cb3edde302626..30ec18283aaf4e5ec360672b986c3070e5a05f40 100644 (file)
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -1036,6 +1036,13 @@ static void vmd_remove(struct pci_dev *dev)
        ida_simple_remove(&vmd_instance_ida, vmd->instance);
 }
 
+static void vmd_shutdown(struct pci_dev *dev)
+{
+        struct vmd_dev *vmd = pci_get_drvdata(dev);
+
+        vmd_remove_irq_domain(vmd);
+}
+
 #ifdef CONFIG_PM_SLEEP
 static int vmd_suspend(struct device *dev)
 {
@@ -1101,6 +1108,7 @@ static struct pci_driver vmd_drv = {
        .id_table       = vmd_ids,
        .probe          = vmd_probe,
        .remove         = vmd_remove,
+       .shutdown       = vmd_shutdown,
        .driver         = {
                .pm     = &vmd_dev_pm_ops,
        },