1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Code borrowed from powerpc/kernel/pci-common.c
  4 *
  5 * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
  6 * Copyright (C) 2014 ARM Ltd.
  7 */
  8
  9#include <linux/acpi.h>
 10#include <linux/init.h>
 11#include <linux/io.h>
 12#include <linux/kernel.h>
 13#include <linux/mm.h>
 14#include <linux/of_pci.h>
 15#include <linux/of_platform.h>
 16#include <linux/pci.h>
 17#include <linux/pci-acpi.h>
 18#include <linux/pci-ecam.h>
 19#include <linux/slab.h>
 20
 21#ifdef CONFIG_ACPI
 22/*
 23 * Try to assign the IRQ number when probing a new device
 24 */
 25int pcibios_alloc_irq(struct pci_dev *dev)
 26{
 27	if (!acpi_disabled)
 28		acpi_pci_irq_enable(dev);
 29
 30	return 0;
 31}
 32#endif
 33
 34/*
 35 * raw_pci_read/write - Platform-specific PCI config space access.
 36 */
 37int raw_pci_read(unsigned int domain, unsigned int bus,
 38		  unsigned int devfn, int reg, int len, u32 *val)
 39{
 40	struct pci_bus *b = pci_find_bus(domain, bus);
 41
 42	if (!b)
 43		return PCIBIOS_DEVICE_NOT_FOUND;
 44	return b->ops->read(b, devfn, reg, len, val);
 45}
 46
 47int raw_pci_write(unsigned int domain, unsigned int bus,
 48		unsigned int devfn, int reg, int len, u32 val)
 49{
 50	struct pci_bus *b = pci_find_bus(domain, bus);
 51
 52	if (!b)
 53		return PCIBIOS_DEVICE_NOT_FOUND;
 54	return b->ops->write(b, devfn, reg, len, val);
 55}
 56
 57#ifdef CONFIG_NUMA
 58
 59int pcibus_to_node(struct pci_bus *bus)
 60{
 61	return dev_to_node(&bus->dev);
 62}
 63EXPORT_SYMBOL(pcibus_to_node);
 64
 65#endif
 66
 67#ifdef CONFIG_ACPI
 68
 69struct acpi_pci_generic_root_info {
 70	struct acpi_pci_root_info	common;
 71	struct pci_config_window	*cfg;	/* config space mapping */
 72};
 73
 74int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
 75{
 76	struct pci_config_window *cfg = bus->sysdata;
 77	struct acpi_device *adev = to_acpi_device(cfg->parent);
 78	struct acpi_pci_root *root = acpi_driver_data(adev);
 79
 80	return root->segment;
 81}
 82
 83int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
 84{
 85	if (!acpi_disabled) {
 86		struct pci_config_window *cfg = bridge->bus->sysdata;
 87		struct acpi_device *adev = to_acpi_device(cfg->parent);
 88		struct device *bus_dev = &bridge->bus->dev;
 89
 90		ACPI_COMPANION_SET(&bridge->dev, adev);
 91		set_dev_node(bus_dev, acpi_get_node(acpi_device_handle(adev)));
 92	}
 93
 94	return 0;
 95}
 96
 97static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci)
 98{
 99	struct resource_entry *entry, *tmp;
100	int status;
101
102	status = acpi_pci_probe_root_resources(ci);
103	resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
104		if (!(entry->res->flags & IORESOURCE_WINDOW))
105			resource_list_destroy_entry(entry);
106	}
107	return status;
108}
109
110/*
111 * Lookup the bus range for the domain in MCFG, and set up config space
112 * mapping.
113 */
114static struct pci_config_window *
115pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
116{
117	struct device *dev = &root->device->dev;
118	struct resource *bus_res = &root->secondary;
119	u16 seg = root->segment;
120	const struct pci_ecam_ops *ecam_ops;
121	struct resource cfgres;
122	struct acpi_device *adev;
123	struct pci_config_window *cfg;
124	int ret;
125
126	ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops);
127	if (ret) {
128		dev_err(dev, "%04x:%pR ECAM region not found\n", seg, bus_res);
129		return NULL;
130	}
131
132	adev = acpi_resource_consumer(&cfgres);
133	if (adev)
134		dev_info(dev, "ECAM area %pR reserved by %s\n", &cfgres,
135			 dev_name(&adev->dev));
136	else
137		dev_warn(dev, FW_BUG "ECAM area %pR not reserved in ACPI namespace\n",
138			 &cfgres);
139
140	cfg = pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
141	if (IS_ERR(cfg)) {
142		dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res,
143			PTR_ERR(cfg));
144		return NULL;
145	}
146
147	return cfg;
148}
149
150/* release_info: free resources allocated by init_info */
151static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
152{
153	struct acpi_pci_generic_root_info *ri;
154
155	ri = container_of(ci, struct acpi_pci_generic_root_info, common);
156	pci_ecam_free(ri->cfg);
157	kfree(ci->ops);
158	kfree(ri);
159}
160
161/* Interface called from ACPI code to setup PCI host controller */
162struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
163{
164	struct acpi_pci_generic_root_info *ri;
165	struct pci_bus *bus, *child;
166	struct acpi_pci_root_ops *root_ops;
167	struct pci_host_bridge *host;
168
169	ri = kzalloc(sizeof(*ri), GFP_KERNEL);
170	if (!ri)
171		return NULL;
172
173	root_ops = kzalloc(sizeof(*root_ops), GFP_KERNEL);
174	if (!root_ops) {
175		kfree(ri);
176		return NULL;
177	}
178
179	ri->cfg = pci_acpi_setup_ecam_mapping(root);
180	if (!ri->cfg) {
181		kfree(ri);
182		kfree(root_ops);
183		return NULL;
184	}
185
186	root_ops->release_info = pci_acpi_generic_release_info;
187	root_ops->prepare_resources = pci_acpi_root_prepare_resources;
188	root_ops->pci_ops = (struct pci_ops *)&ri->cfg->ops->pci_ops;
189	bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
190	if (!bus)
191		return NULL;
192
193	/* If we must preserve the resource configuration, claim now */
194	host = pci_find_host_bridge(bus);
195	if (host->preserve_config)
196		pci_bus_claim_resources(bus);
197
198	/*
199	 * Assign whatever was left unassigned. If we didn't claim above,
200	 * this will reassign everything.
201	 */
202	pci_assign_unassigned_root_bus_resources(bus);
203
204	list_for_each_entry(child, &bus->children, node)
205		pcie_bus_configure_settings(child);
206
207	return bus;
208}
209
210void pcibios_add_bus(struct pci_bus *bus)
211{
212	acpi_pci_add_bus(bus);
213}
214
215void pcibios_remove_bus(struct pci_bus *bus)
216{
217	acpi_pci_remove_bus(bus);
218}
219
220#endif