diff options
Diffstat (limited to 'drivers/acpi/pci_mcfg.c')
| -rw-r--r-- | drivers/acpi/pci_mcfg.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c new file mode 100644 index 000000000000..f3d4570a4f9c --- /dev/null +++ b/drivers/acpi/pci_mcfg.c @@ -0,0 +1,126 @@ +/* + * Copyright (C) 2016 Broadcom + * Author: Jayachandran C <jchandra@broadcom.com> + * Copyright (C) 2016 Semihalf + * Author: Tomasz Nowicki <tn@semihalf.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation (the "GPL"). + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License version 2 (GPLv2) for more details. + * + * You should have received a copy of the GNU General Public License + * version 2 (GPLv2) along with this source code. + */ + +#define pr_fmt(fmt) "ACPI: " fmt + +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/pci-acpi.h> +#include <linux/pci-ecam.h> + +/* Root pointer to the mapped MCFG table */ +static struct acpi_table_mcfg *mcfg_table; +static int mcfg_entries; + +extern struct pci_cfg_fixup __start_acpi_mcfg_fixups[]; +extern struct pci_cfg_fixup __end_acpi_mcfg_fixups[]; + +struct pci_ecam_ops *pci_mcfg_get_ops(struct acpi_pci_root *root) +{ + int bus_num = root->secondary.start; + int domain = root->segment; + struct pci_cfg_fixup *f; + + if (!mcfg_table) + return &pci_generic_ecam_ops; + + /* + * Match against platform specific quirks and return corresponding + * CAM ops. + * + * First match against PCI topology <domain:bus> then use OEM ID and + * OEM revision from MCFG table standard header. + */ + for (f = __start_acpi_mcfg_fixups; f < __end_acpi_mcfg_fixups; f++) { + if ((f->domain == domain || f->domain == PCI_MCFG_DOMAIN_ANY) && + (f->bus_num == bus_num || f->bus_num == PCI_MCFG_BUS_ANY) && + (!strncmp(f->oem_id, mcfg_table->header.oem_id, + ACPI_OEM_ID_SIZE)) && + (f->oem_revision == mcfg_table->header.oem_revision)) + return f->ops; + } + /* No quirks, use ECAM */ + return &pci_generic_ecam_ops; +} + +int pci_mcfg_lookup(struct acpi_pci_root *root) +{ + struct acpi_mcfg_allocation *mptr, *entry = NULL; + struct resource *bus_res = &root->secondary; + int i; + + if (mcfg_table) { + mptr = (struct acpi_mcfg_allocation *) &mcfg_table[1]; + for (i = 0; i < mcfg_entries && !entry; i++, mptr++) + if (mptr->pci_segment == root->segment && + mptr->start_bus_number == bus_res->start) + entry = mptr; + } + + /* not found, use _CBA if available, else error */ + if (!entry) { + if (root->mcfg_addr) + return root->mcfg_addr; + pr_err("%04x:%pR MCFG lookup failed\n", root->segment, bus_res); + return -ENOENT; + } else if (root->mcfg_addr && entry->address != root->mcfg_addr) { + pr_warn("%04x:%pR CBA %pa != MCFG %lx, using CBA\n", + root->segment, bus_res, &root->mcfg_addr, + (unsigned long)entry->address); + return 0; + } + + /* found matching entry, bus range check */ + if (entry->end_bus_number != bus_res->end) { + resource_size_t bus_end = min_t(resource_size_t, + entry->end_bus_number, bus_res->end); + pr_warn("%04x:%pR bus end mismatch, using %02lx\n", + root->segment, bus_res, (unsigned long)bus_end); + bus_res->end = bus_end; + } + + if (!root->mcfg_addr) + root->mcfg_addr = entry->address; + return 0; +} + +static __init int pci_mcfg_parse(struct acpi_table_header *header) +{ + if (header->length < sizeof(struct acpi_table_mcfg)) + return -EINVAL; + + mcfg_entries = (header->length - sizeof(struct acpi_table_mcfg)) / + sizeof(struct acpi_mcfg_allocation); + if (mcfg_entries == 0) { + pr_err("MCFG has no entries\n"); + return -EINVAL; + } + + mcfg_table = (struct acpi_table_mcfg *)header; + pr_info("MCFG table detected, %d entries\n", mcfg_entries); + return 0; +} + +/* Interface called by ACPI - parse and save MCFG table */ +void __init pci_mmcfg_late_init(void) +{ + int err = acpi_table_parse(ACPI_SIG_MCFG, pci_mcfg_parse); + if (err) + pr_err("Failed to parse MCFG (%d)\n", err); +} |