On Fri, Aug 28, 2015 at 03:39:43PM +0100, Lorenzo Pieralisi wrote: > Hi Dennis, > > You should CC linux-...@vger.kernel.org and the PCI subsystem > maintainer next time. > >
Good reminder! Thanks, mate ;-) > On Fri, Aug 28, 2015 at 01:49:23PM +0100, Dennis Chen wrote: > > This patch will fall back to ACPI MCFG table if _CBA method fails > > to get the configuration base address of ECAM. Firmware on ARM > > platform uses MCFG table instead of _CBA method. This is needed > > to scan the PCIe root complex for ARM SoC. > > Code to enumerate PCI with ACPI on ARM64 is under review: > > https://lkml.org/lkml/2015/6/8/443 > Oops,seems I am late, just go through the code to scan the root: https://lkml.org/lkml/2015/5/26/215 a little bit complicated, to be honest. Maybe I can have some input then. > Having said that, I do not think this patch will be needed, > you can't add code in the kernel because it may be needed in > the future, I do not see how it can be possibly useful at present > on ARM64 unless you pulled some patch dependencies; if that's the > case you should have listed them. > > This patch can't be review standalone since it has no use in > the current kernel (at least for ARM64, it should be tested > on x86 though). I do have a patch set to enumerate all the downstream devices of the PCIe root bridge. With this patch, I can focus on the enabling/fixing of the drivers of those devices. As you can imagine, the patch have some redundant codes with PCI/ACPI codes now under x86 directory. It's reasonable to move those arch-agnostic codes to a common place. I am OK to keep them pending as private as a test code base for me As for this patch, it's used to get the ecam address from MCFG instead of _CBA which x86 is using, see acpi_pci_root_get_mcfg_addr() code. So, it's for ARM64 and can be tested with uefi definitely. I'm missing some context here? > Thanks, > Lorenzo > > > Signed-off-by: Dennis Chen <dennis.c...@arm.com> > > --- > > drivers/pci/pci-acpi.c | 102 > > ++++++++++++++++++++++++++++++++++++++++++++++--- > > 1 file changed, 97 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c > > index 314a625..211b9d9 100644 > > --- a/drivers/pci/pci-acpi.c > > +++ b/drivers/pci/pci-acpi.c > > @@ -27,18 +27,110 @@ const u8 pci_acpi_dsm_uuid[] = { > > 0x91, 0x17, 0xea, 0x4d, 0x19, 0xc3, 0x43, 0x4d > > }; > > > > +static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg) > > +{ > > + if (mcfg->header.revision != 1) { > > + pr_err("invalid header revision:%d in ACPI MCFG table\n", > > + mcfg->header.revision); > > + return -EINVAL; > > + } > > + > > + return 0; > > +} > > + > > +static phys_addr_t __init acpi_get_mcfg_cba(u16 segment, u8 bus) > > +{ > > + struct acpi_table_header *table = NULL; > > + acpi_size tbl_size; > > + struct acpi_table_mcfg *mcfg = NULL; > > + struct acpi_mcfg_allocation *cfg_table, *cfg; > > + acpi_status status; > > + phys_addr_t cba = 0; > > + unsigned long i; > > + int entries; > > + > > + if (acpi_disabled) > > + return 0; > > + > > + status = acpi_get_table_with_size(ACPI_SIG_MCFG, 0, &table, &tbl_size); > > + if (ACPI_FAILURE(status)) { > > + const char *msg = acpi_format_exception(status); > > + > > + pr_err("Failed to get MCFG table, %s\n", msg); > > + return 0; > > + } > > + > > + if (table) > > + mcfg = (struct acpi_table_mcfg *)table; > > + > > + entries = 0; > > + i = table->length - sizeof(struct acpi_table_mcfg); > > + while (i >= sizeof(struct acpi_mcfg_allocation)) { > > + entries++; > > + i -= sizeof(struct acpi_mcfg_allocation); > > + } > > + if (entries == 0) { > > + pr_err("ACPI MCFG table has no entries\n"); > > + goto out; > > + } > > + > > + cfg_table = (struct acpi_mcfg_allocation *) &mcfg[1]; > > + for (i = 0; i < entries; i++) { > > + cfg = &cfg_table[i]; > > + if (acpi_mcfg_check_entry(mcfg)) > > + goto out; > > + > > + if (cfg->pci_segment == segment && > > + cfg->start_bus_number <= bus && > > + bus <= cfg->end_bus_number) { > > + cba = (phys_addr_t)cfg->address; > > + goto out; > > + } > > + } > > +out: > > + /* > > + * acpi_get_table_with_size() creates MCFG table mapping that > > + * should be released after parsing and before resuming boot > > + */ > > + early_acpi_os_unmap_memory(table, tbl_size); > > + return cba; > > +} > > + > > phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle) > > { > > acpi_status status = AE_NOT_EXIST; > > - unsigned long long mcfg_addr; > > + unsigned long long mcfg_addr, mcfg_seg, mcfg_bus; > > + u16 seg; > > + u8 bus; > > + > > + if (!handle) > > + return 0; > > > > - if (handle) > > - status = acpi_evaluate_integer(handle, METHOD_NAME__CBA, > > + status = acpi_evaluate_integer(handle, METHOD_NAME__CBA, > > NULL, &mcfg_addr); > > + if (ACPI_SUCCESS(status)) > > + return (phys_addr_t)mcfg_addr; > > + > > + pr_info("ACPI: Falling back to acpi mcfg table\n"); > > + > > + /* > > + * Fall back to MCFG table if _CBA failed: > > + * get the mcfg_addr via ACPI MCFG table. PCI Firmware v3.2 spec: 4.1.2 > > + */ > > + status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, > > + NULL, &mcfg_seg); > > if (ACPI_FAILURE(status)) > > - return 0; > > + mcfg_seg = 0; > > + > > + status = acpi_evaluate_integer(handle, METHOD_NAME__BBN, > > + NULL, &mcfg_bus); > > + if (ACPI_FAILURE(status)) > > + mcfg_bus = 0; > > + > > + seg = mcfg_seg & 0xFFFF; > > + bus = mcfg_bus & 0xFF; > > > > - return (phys_addr_t)mcfg_addr; > > + return acpi_get_mcfg_cba(seg, bus); > > } > > > > static acpi_status decode_type0_hpx_record(union acpi_object *record, > > -- > > 1.9.1 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majord...@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > > > Regards, Dennis -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
