From: Tuan Phan <tuanphan@xxxxxxxxxxxxxxxxxxxxxx> commit 877c1a5f79c6984bbe3f2924234c08e2f4f1acd5 upstream. Ampere Altra SOC supports only 32-bit ECAM reads. Add an MCFG quirk for the platform. Link: https://lore.kernel.org/r/1596751055-12316-1-git-send-email-tuanphan@xxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Tuan Phan <tuanphan@xxxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> [ dannf: backport drops const qualifier from pci_32b_read_ops for consistency with the other quirks that weren't yet constified in v5.4 ] Signed-off-by: dann frazier <dann.frazier@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/acpi/pci_mcfg.c | 20 ++++++++++++++++++++ drivers/pci/ecam.c | 10 ++++++++++ include/linux/pci-ecam.h | 1 + 3 files changed, 31 insertions(+) --- a/drivers/acpi/pci_mcfg.c +++ b/drivers/acpi/pci_mcfg.c @@ -142,6 +142,26 @@ static struct mcfg_fixup mcfg_quirks[] = XGENE_V2_ECAM_MCFG(4, 0), XGENE_V2_ECAM_MCFG(4, 1), XGENE_V2_ECAM_MCFG(4, 2), + +#define ALTRA_ECAM_QUIRK(rev, seg) \ + { "Ampere", "Altra ", rev, seg, MCFG_BUS_ANY, &pci_32b_read_ops } + + ALTRA_ECAM_QUIRK(1, 0), + ALTRA_ECAM_QUIRK(1, 1), + ALTRA_ECAM_QUIRK(1, 2), + ALTRA_ECAM_QUIRK(1, 3), + ALTRA_ECAM_QUIRK(1, 4), + ALTRA_ECAM_QUIRK(1, 5), + ALTRA_ECAM_QUIRK(1, 6), + ALTRA_ECAM_QUIRK(1, 7), + ALTRA_ECAM_QUIRK(1, 8), + ALTRA_ECAM_QUIRK(1, 9), + ALTRA_ECAM_QUIRK(1, 10), + ALTRA_ECAM_QUIRK(1, 11), + ALTRA_ECAM_QUIRK(1, 12), + ALTRA_ECAM_QUIRK(1, 13), + ALTRA_ECAM_QUIRK(1, 14), + ALTRA_ECAM_QUIRK(1, 15), }; static char mcfg_oem_id[ACPI_OEM_ID_SIZE]; --- a/drivers/pci/ecam.c +++ b/drivers/pci/ecam.c @@ -164,4 +164,14 @@ struct pci_ecam_ops pci_32b_ops = { .write = pci_generic_config_write32, } }; + +/* ECAM ops for 32-bit read only (non-compliant) */ +struct pci_ecam_ops pci_32b_read_ops = { + .bus_shift = 20, + .pci_ops = { + .map_bus = pci_ecam_map_bus, + .read = pci_generic_config_read32, + .write = pci_generic_config_write, + } +}; #endif --- a/include/linux/pci-ecam.h +++ b/include/linux/pci-ecam.h @@ -51,6 +51,7 @@ extern struct pci_ecam_ops pci_generic_e #if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) extern struct pci_ecam_ops pci_32b_ops; /* 32-bit accesses only */ +extern struct pci_ecam_ops pci_32b_read_ops; /* 32-bit read only */ extern struct pci_ecam_ops hisi_pcie_ops; /* HiSilicon */ extern struct pci_ecam_ops thunder_pem_ecam_ops; /* Cavium ThunderX 1.x & 2.x */ extern struct pci_ecam_ops pci_thunder_ecam_ops; /* Cavium ThunderX 1.x */
