From: Pali Rohár <pali@xxxxxxxxxx> commit 7b067ac63a5730d2fae18399fed7e45f23d36912 upstream. Some bits in PCI config space are reserved when device is PCIe. Properly define behavior of PCI registers for PCIe emulated bridge and ensure that it would not be possible change these reserved bits. Link: https://lore.kernel.org/r/20211124155944.1290-3-pali@xxxxxxxxxx Fixes: 23a5fba4d941 ("PCI: Introduce PCI bridge emulated config space common logic") Signed-off-by: Pali Rohár <pali@xxxxxxxxxx> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pci/pci-bridge-emul.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) --- a/drivers/pci/pci-bridge-emul.c +++ b/drivers/pci/pci-bridge-emul.c @@ -295,6 +295,27 @@ int pci_bridge_emul_init(struct pci_brid kfree(bridge->pci_regs_behavior); return -ENOMEM; } + /* These bits are applicable only for PCI and reserved on PCIe */ + bridge->pci_regs_behavior[PCI_CACHE_LINE_SIZE / 4].ro &= + ~GENMASK(15, 8); + bridge->pci_regs_behavior[PCI_COMMAND / 4].ro &= + ~((PCI_COMMAND_SPECIAL | PCI_COMMAND_INVALIDATE | + PCI_COMMAND_VGA_PALETTE | PCI_COMMAND_WAIT | + PCI_COMMAND_FAST_BACK) | + (PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK | + PCI_STATUS_DEVSEL_MASK) << 16); + bridge->pci_regs_behavior[PCI_PRIMARY_BUS / 4].ro &= + ~GENMASK(31, 24); + bridge->pci_regs_behavior[PCI_IO_BASE / 4].ro &= + ~((PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK | + PCI_STATUS_DEVSEL_MASK) << 16); + bridge->pci_regs_behavior[PCI_INTERRUPT_LINE / 4].rw &= + ~((PCI_BRIDGE_CTL_MASTER_ABORT | + BIT(8) | BIT(9) | BIT(11)) << 16); + bridge->pci_regs_behavior[PCI_INTERRUPT_LINE / 4].ro &= + ~((PCI_BRIDGE_CTL_FAST_BACK) << 16); + bridge->pci_regs_behavior[PCI_INTERRUPT_LINE / 4].w1c &= + ~(BIT(10) << 16); } if (flags & PCI_BRIDGE_EMUL_NO_PREFETCHABLE_BAR) {
