VMD BUS1 rootbus primary number is 0x80 and pci_scan_bridge_extend()
detects that primary bus number doesn't match the bus it's sitting on.
As a result primary rootbus number is deconfigured in the first pass
of pci_scan_bridge() to be re-assigned to 0x0 in the second pass.
To avoid bus number reconfiguration, BUS1 number has to be the same
as BUS1 primary number.
Suggested-by: Nirmal Patel <nirmal.patel@xxxxxxxxxxxxxxx>
Reviewed-by: Mariusz Tkaczyk <mariusz.tkaczyk@xxxxxxxxxxxxxxx>
Signed-off-by: Szymon Durawa <szymon.durawa@xxxxxxxxxxxxxxx>
---
drivers/pci/controller/vmd.c | 30 ++++++++++++++++++++++++++++--
1 file changed, 28 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 6cd14c28fd4e..3b74cb8dd023 100755
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -421,8 +421,22 @@ static void vmd_remove_irq_domain(struct vmd_dev *vmd)
static void __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
unsigned int devfn, int reg, int len)
{
- unsigned int busnr_ecam = bus->number - vmd->busn_start[VMD_BUS_0];
- u32 offset = PCIE_ECAM_OFFSET(busnr_ecam, devfn, reg);
+ unsigned char bus_number;
+ unsigned int busnr_ecam;
+ u32 offset;
+
+ /*
+ * VMD workaraund: for BUS1, bus->number is set to VMD_PRIMARY_BUS1
+ * (see comment under vmd_create_bus() for BUS1) but original value
+ * is 225 which is stored in vmd->busn_start[VMD_BUS_1].
+ */
+ if (vmd->bus1_rootbus && bus->number == VMD_PRIMARY_BUS1)
+ bus_number = vmd->busn_start[VMD_BUS_1];
+ else
+ bus_number = bus->number;
+
+ busnr_ecam = bus_number - vmd->busn_start[VMD_BUS_0];
+ offset = PCIE_ECAM_OFFSET(busnr_ecam, devfn, reg);
if (offset + len >= resource_size(&vmd->dev->resource[VMD_CFGBAR]))
return NULL;
@@ -1170,6 +1184,18 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
*/
vmd->bus[VMD_BUS_1]->primary = VMD_PRIMARY_BUS1;
+ /*
+ * This is a workaround for pci_scan_bridge_extend() code.
+ * It detects that non-zero (0x80) primary bus number doesn't
+ * match the bus it's sitting on. As a result rootbus number is
+ * deconfigured in the first pass of pci_scan_bridge() to be
+ * re-assigned to 0x0 in the second pass.
+ * Update vmd->bus[VMD_BUS_1]->number and
+ * vmd->bus[VMD_BUS_1]->primary to the same value, which
+ * bypasses bus number reconfiguration.
+ */
+ vmd->bus[VMD_BUS_1]->number = VMD_PRIMARY_BUS1;
+
WARN(sysfs_create_link(&vmd->dev->dev.kobj,
&vmd->bus[VMD_BUS_1]->dev.kobj,
"domain1"),
--
2.39.3
