Add a generic ACPI based PCI host controller, and provide config option ACPI_PCI_HOST_GENERIC to enable it.
The implementation selects PCI_MMCONFIG and implements function pci_mmcfg_late_init() to parse MCFG table and save its entries. PCI_GENERIC_ECAM is also selected and pci/ecam.c functions are used to map the config space of the PCI controller.
acpi_pci_root_ops is setup so that init_info looks up the saved MCFG entries and sets up the config space mapping. release_info deletes the mapping and frees the memory. Generic PCI functions are used for accessing config space.
Signed-off-by: Jayachandran C jchandra@broadcom.com --- drivers/acpi/Kconfig | 9 ++ drivers/acpi/Makefile | 1 + drivers/acpi/pci_gen_host.c | 247 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 257 insertions(+) create mode 100644 drivers/acpi/pci_gen_host.c
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 82b96ee..f178f2e 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -343,6 +343,15 @@ config ACPI_PCI_SLOT i.e., segment/bus/device/function tuples, with physical slots in the system. If you are unsure, say N.
+config ACPI_PCI_HOST_GENERIC + bool "Generic ACPI based PCI controller" + depends on ARM64 + select PCI_MMCONFIG + select PCI_GENERIC_ECAM + help + Say Y if you want the generic ACPI based PCI controller + implementation. + config X86_PM_TIMER bool "Power Management Timer Support" if EXPERT depends on X86 diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index cb648a4..ceab5b0 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -65,6 +65,7 @@ obj-$(CONFIG_ACPI_BUTTON) += button.o obj-$(CONFIG_ACPI_FAN) += fan.o obj-$(CONFIG_ACPI_VIDEO) += video.o obj-$(CONFIG_ACPI_PCI_SLOT) += pci_slot.o +obj-$(CONFIG_ACPI_PCI_HOST_GENERIC) += pci_gen_host.o obj-$(CONFIG_ACPI_PROCESSOR) += processor.o obj-$(CONFIG_ACPI) += container.o obj-$(CONFIG_ACPI_THERMAL) += thermal.o diff --git a/drivers/acpi/pci_gen_host.c b/drivers/acpi/pci_gen_host.c new file mode 100644 index 0000000..a43f2cee --- /dev/null +++ b/drivers/acpi/pci_gen_host.c @@ -0,0 +1,247 @@ +/* + * Copyright 2016 Broadcom + * + * 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. + */ +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/pci-acpi.h> +#include <linux/sfi_acpi.h> +#include <linux/slab.h> + +#define PREFIX "ACPI: " + +/* + * Structure to hold entries from the MCFG table, these need to be + * mapped until a pci host bridge claims them for raw_pci_read/write + * to work + */ +struct mcfg_entry { + phys_addr_t addr; + u16 segment; + u8 bus_start; + u8 bus_end; +}; + +/* + * Global to save mcfg entries + */ +static struct { + struct mcfg_entry *cfg; + int size; +} mcfgsav; + +/* List of all ACPI PCI roots, needed for raw operations */ +static struct list_head gen_acpi_pci_roots; + +/* lock for global table AND list above */ +static struct mutex gen_acpi_pci_lock; + +/* ACPI info for generic ACPI PCI controller */ +struct acpi_pci_generic_root_info { + struct acpi_pci_root_info common; + struct pci_config_window *cfg; /* config space mapping */ + struct list_head node; /* node in acpi_pci_roots */ +}; + +/* Call generic map_bus after getting cfg pointer */ +static void __iomem *gen_acpi_map_cfg_bus(struct pci_bus *bus, + unsigned int devfn, int where) +{ + struct acpi_pci_generic_root_info *ri = bus->sysdata; + + return pci_generic_map_bus(ri->cfg, bus->number, devfn, where); +} + +static struct pci_ops acpi_pci_ops = { + .map_bus = gen_acpi_map_cfg_bus, + .read = pci_generic_config_read, + .write = pci_generic_config_write, +}; + +/* find the entry in mcfgsav.cfg which contains range bus_start..bus_end */ +static int mcfg_lookup(u16 seg, u8 bus_start, u8 bus_end) +{ + struct mcfg_entry *e; + int i; + + for (i = 0, e = mcfgsav.cfg; i < mcfgsav.size; i++, e++) { + if (seg != e->segment) + continue; + if (bus_start >= e->bus_start && bus_start <= e->bus_end) + return (bus_end <= e->bus_end) ? i : -EINVAL; + else if (bus_end >= e->bus_start && bus_end <= e->bus_end) + return -EINVAL; + } + return -ENOENT; +} + +/* + * init_info - lookup the bus range for the domain in MCFG, and set up + * config space mapping. + */ +static int pci_acpi_generic_init_info(struct acpi_pci_root_info *ci) +{ + struct acpi_pci_generic_root_info *ri; + struct acpi_pci_root *root = ci->root; + u16 seg = root->segment; + u8 bus_start = root->secondary.start; + u8 bus_end = root->secondary.end; + phys_addr_t addr = root->mcfg_addr; + struct mcfg_entry *e; + int ret; + + ri = container_of(ci, struct acpi_pci_generic_root_info, common); + + mutex_lock(&gen_acpi_pci_lock); + ret = mcfg_lookup(seg, bus_start, bus_end); + switch (ret) { + case -ENOENT: + if (addr != 0) /* use address from _CBA */ + break; + pr_err("%04x:%02x-%02x mcfg lookup failed\n", seg, + bus_start, bus_end); + goto err_out; + case -EINVAL: + pr_err("%04x:%02x-%02x bus range error\n", seg, bus_start, + bus_end); + goto err_out; + default: + e = &mcfgsav.cfg[ret]; + if (addr == 0) + addr = e->addr; + if (bus_start != e->bus_start) { + pr_err("%04x:%02x-%02x bus range mismatch %02x\n", + seg, bus_start, bus_end, e->bus_start); + goto err_out; + } + if (addr != e->addr) { + pr_warn("%04x:%02x-%02x addr mismatch, ignoring MCFG\n", + seg, bus_start, bus_end); + } else if (bus_end != e->bus_end) { + pr_warn("%04x:%02x-%02x bus end mismatch %02x\n", + seg, bus_start, bus_end, e->bus_end); + bus_end = min(bus_end, e->bus_end); + } + break; + } + + ri->cfg = pci_generic_map_config(addr, bus_start, bus_end, 20, 12); + if (IS_ERR(ri->cfg)) { + ret = PTR_ERR(ri->cfg); + pr_err("%04x:%02x-%02x error %d mapping CFG\n", seg, bus_start, + bus_end, ret); + goto err_out; + } + list_add_tail(&ri->node, &gen_acpi_pci_roots); +err_out: + mutex_unlock(&gen_acpi_pci_lock); + return ret; +} + +/* release_info: free resrouces allocated by init_info */ +static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci) +{ + struct acpi_pci_generic_root_info *ri; + + ri = container_of(ci, struct acpi_pci_generic_root_info, common); + + mutex_lock(&gen_acpi_pci_lock); + list_del(&ri->node); + pci_generic_unmap_config(ri->cfg); + mutex_unlock(&gen_acpi_pci_lock); + + kfree(ri); +} + +static struct acpi_pci_root_ops acpi_pci_root_ops = { + .pci_ops = &acpi_pci_ops, + .init_info = pci_acpi_generic_init_info, + .release_info = pci_acpi_generic_release_info, +}; + +/* Interface called from ACPI code to setup PCI host controller */ +struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) +{ + int node = acpi_get_node(root->device->handle); + struct acpi_pci_generic_root_info *ri; + struct pci_bus *bus, *child; + + ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node); + if (!ri) + return NULL; + + bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common, ri); + if (!bus) + return NULL; + + pci_bus_size_bridges(bus); + pci_bus_assign_resources(bus); + + list_for_each_entry(child, &bus->children, node) + pcie_bus_configure_settings(child); + + return bus; +} + +/* handle MCFG table entries */ +static __init int handle_mcfg(struct acpi_table_header *header) +{ + struct acpi_table_mcfg *mcfg; + struct acpi_mcfg_allocation *mptr; + struct mcfg_entry *e, *arr; + int i, n; + + if (!header) + return -EINVAL; + + mcfg = (struct acpi_table_mcfg *)header; + mptr = (struct acpi_mcfg_allocation *) &mcfg[1]; + n = (header->length - sizeof(*mcfg)) / sizeof(*mptr); + if (n <= 0 || n > 255) { + pr_err(PREFIX " MCFG has incorrect entries (%d).\n", n); + return -EINVAL; + } + + arr = kcalloc(n, sizeof(*arr), GFP_KERNEL); + if (!arr) + return -ENOMEM; + + for (i = 0, e = arr; i < n; i++, mptr++, e++) { + e->segment = mptr->pci_segment; + e->addr = mptr->address; + e->bus_start = mptr->start_bus_number; + e->bus_end = mptr->end_bus_number; + } + + mcfgsav.cfg = arr; + mcfgsav.size = n; + return 0; +} + +/* Interface called by ACPI - parse and save MCFG table */ +void __init pci_mmcfg_late_init(void) +{ + int err; + + mutex_init(&gen_acpi_pci_lock); + INIT_LIST_HEAD(&gen_acpi_pci_roots); + err = acpi_sfi_table_parse(ACPI_SIG_MCFG, handle_mcfg); + if (err) { + pr_err(PREFIX " Failed to parse MCFG (%d)\n", err); + mcfgsav.size = 0; + } else { + pr_info(PREFIX " MCFG table at %p, %d entries.\n", + mcfgsav.cfg, mcfgsav.size); + } +}