From: Pali Rohár <pali@xxxxxxxxxx> commit 12998087d9f48b66965b97412069c7826502cd7e upstream. Some bits in PCI_EXP registers are reserved for non-root ports. Driver pci-bridge-emul.c implements PCIe Root Port device therefore it should not allow setting reserved bits of registers. Properly define non-reserved bits for all PCI_EXP registers. Link: https://lore.kernel.org/r/20211124155944.1290-5-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 | 36 +++++++++++++++++++++++++----------- 1 file changed, 25 insertions(+), 11 deletions(-) --- a/drivers/pci/pci-bridge-emul.c +++ b/drivers/pci/pci-bridge-emul.c @@ -176,41 +176,55 @@ struct pci_bridge_reg_behavior pcie_cap_ [PCI_CAP_LIST_ID / 4] = { /* * Capability ID, Next Capability Pointer and - * Capabilities register are all read-only. + * bits [14:0] of Capabilities register are all read-only. + * Bit 15 of Capabilities register is reserved. */ - .ro = ~0, + .ro = GENMASK(30, 0), }, [PCI_EXP_DEVCAP / 4] = { - .ro = ~0, + /* + * Bits [31:29] and [17:16] are reserved. + * Bits [27:18] are reserved for non-upstream ports. + * Bits 28 and [14:6] are reserved for non-endpoint devices. + * Other bits are read-only. + */ + .ro = BIT(15) | GENMASK(5, 0), }, [PCI_EXP_DEVCTL / 4] = { - /* Device control register is RW */ - .rw = GENMASK(15, 0), + /* + * Device control register is RW, except bit 15 which is + * reserved for non-endpoints or non-PCIe-to-PCI/X bridges. + */ + .rw = GENMASK(14, 0), /* * Device status register has bits 6 and [3:0] W1C, [5:4] RO, - * the rest is reserved + * the rest is reserved. Also bit 6 is reserved for non-upstream + * ports. */ - .w1c = (BIT(6) | GENMASK(3, 0)) << 16, + .w1c = GENMASK(3, 0) << 16, .ro = GENMASK(5, 4) << 16, }, [PCI_EXP_LNKCAP / 4] = { - /* All bits are RO, except bit 23 which is reserved */ - .ro = lower_32_bits(~BIT(23)), + /* + * All bits are RO, except bit 23 which is reserved and + * bit 18 which is reserved for non-upstream ports. + */ + .ro = lower_32_bits(~(BIT(23) | PCI_EXP_LNKCAP_CLKPM)), }, [PCI_EXP_LNKCTL / 4] = { /* * Link control has bits [15:14], [11:3] and [1:0] RW, the - * rest is reserved. + * rest is reserved. Bit 8 is reserved for non-upstream ports. * * Link status has bits [13:0] RO, and bits [15:14] * W1C. */ - .rw = GENMASK(15, 14) | GENMASK(11, 3) | GENMASK(1, 0), + .rw = GENMASK(15, 14) | GENMASK(11, 9) | GENMASK(7, 3) | GENMASK(1, 0), .ro = GENMASK(13, 0) << 16, .w1c = GENMASK(15, 14) << 16, },
