pci-legacy.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *
  4 * Copyright (C) 2003, 04, 11 Ralf Baechle (ralf@linux-mips.org)
  5 * Copyright (C) 2011 Wind River Systems,
  6 *   written by Ralf Baechle (ralf@linux-mips.org)
  7 */
  8#include <linux/bug.h>
  9#include <linux/kernel.h>
 10#include <linux/mm.h>
 11#include <linux/memblock.h>
 12#include <linux/export.h>
 13#include <linux/init.h>
 14#include <linux/types.h>
 15#include <linux/pci.h>
 16#include <linux/of_address.h>
 17
 18#include <asm/cpu-info.h>
 19
 20/*
 21 * If PCI_PROBE_ONLY in pci_flags is set, we don't change any PCI resource
 22 * assignments.
 23 */
 24
 25/*
 26 * The PCI controller list.
 27 */
 28static LIST_HEAD(controllers);
 29
 30static int pci_initialized;
 31
 32unsigned long pci_address_to_pio(phys_addr_t address)
 33{
 34	if (address > IO_SPACE_LIMIT)
 35		return (unsigned long)-1;
 36
 37	return (unsigned long) address;
 38}
 39
 40/*
 41 * We need to avoid collisions with `mirrored' VGA ports
 42 * and other strange ISA hardware, so we always want the
 43 * addresses to be allocated in the 0x000-0x0ff region
 44 * modulo 0x400.
 45 *
 46 * Why? Because some silly external IO cards only decode
 47 * the low 10 bits of the IO address. The 0x00-0xff region
 48 * is reserved for motherboard devices that decode all 16
 49 * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
 50 * but we want to try to avoid allocating at 0x2900-0x2bff
 51 * which might have be mirrored at 0x0100-0x03ff..
 52 */
 53resource_size_t
 54pcibios_align_resource(void *data, const struct resource *res,
 55		       resource_size_t size, resource_size_t align)
 56{
 57	struct pci_dev *dev = data;
 58	struct pci_controller *hose = dev->sysdata;
 59	resource_size_t start = res->start;
 60
 61	if (res->flags & IORESOURCE_IO) {
 62		/* Make sure we start at our min on all hoses */
 63		if (start < PCIBIOS_MIN_IO + hose->io_resource->start)
 64			start = PCIBIOS_MIN_IO + hose->io_resource->start;
 65
 66		/*
 67		 * Put everything into 0x00-0xff region modulo 0x400
 68		 */
 69		if (start & 0x300)
 70			start = (start + 0x3ff) & ~0x3ff;
 71	} else if (res->flags & IORESOURCE_MEM) {
 72		/* Make sure we start at our min on all hoses */
 73		if (start < PCIBIOS_MIN_MEM + hose->mem_resource->start)
 74			start = PCIBIOS_MIN_MEM + hose->mem_resource->start;
 75	}
 76
 77	return start;
 78}
 79
 80static void pcibios_scanbus(struct pci_controller *hose)
 81{
 82	static int next_busno;
 83	static int need_domain_info;
 84	LIST_HEAD(resources);
 85	struct pci_bus *bus;
 86	struct pci_host_bridge *bridge;
 87	int ret;
 88
 89	bridge = pci_alloc_host_bridge(0);
 90	if (!bridge)
 91		return;
 92
 93	if (hose->get_busno && pci_has_flag(PCI_PROBE_ONLY))
 94		next_busno = (*hose->get_busno)();
 95
 96	pci_add_resource_offset(&resources,
 97				hose->mem_resource, hose->mem_offset);
 98	pci_add_resource_offset(&resources,
 99				hose->io_resource, hose->io_offset);
100	list_splice_init(&resources, &bridge->windows);
101	bridge->dev.parent = NULL;
102	bridge->sysdata = hose;
103	bridge->busnr = next_busno;
104	bridge->ops = hose->pci_ops;
105	bridge->swizzle_irq = pci_common_swizzle;
106	bridge->map_irq = pcibios_map_irq;
107	ret = pci_scan_root_bus_bridge(bridge);
108	if (ret) {
109		pci_free_host_bridge(bridge);
110		return;
111	}
112
113	hose->bus = bus = bridge->bus;
114
115	need_domain_info = need_domain_info || pci_domain_nr(bus);
116	set_pci_need_domain_info(hose, need_domain_info);
117
118	next_busno = bus->busn_res.end + 1;
119	/* Don't allow 8-bit bus number overflow inside the hose -
120	   reserve some space for bridges. */
121	if (next_busno > 224) {
122		next_busno = 0;
123		need_domain_info = 1;
124	}
125
126	/*
127	 * We insert PCI resources into the iomem_resource and
128	 * ioport_resource trees in either pci_bus_claim_resources()
129	 * or pci_bus_assign_resources().
130	 */
131	if (pci_has_flag(PCI_PROBE_ONLY)) {
132		pci_bus_claim_resources(bus);
133	} else {
134		struct pci_bus *child;
135
136		pci_bus_size_bridges(bus);
137		pci_bus_assign_resources(bus);
138		list_for_each_entry(child, &bus->children, node)
139			pcie_bus_configure_settings(child);
140	}
141	pci_bus_add_devices(bus);
142}
143
144#ifdef CONFIG_OF
145void pci_load_of_ranges(struct pci_controller *hose, struct device_node *node)
146{
147	struct of_pci_range range;
148	struct of_pci_range_parser parser;
149
150	hose->of_node = node;
151
152	if (of_pci_range_parser_init(&parser, node))
153		return;
154
155	for_each_of_pci_range(&parser, &range) {
156		struct resource *res = NULL;
157
158		switch (range.flags & IORESOURCE_TYPE_BITS) {
159		case IORESOURCE_IO:
160			hose->io_map_base =
161				(unsigned long)ioremap(range.cpu_addr,
162						       range.size);
163			res = hose->io_resource;
164			break;
165		case IORESOURCE_MEM:
166			res = hose->mem_resource;
167			break;
168		}
169		if (res != NULL) {
170			res->name = node->full_name;
171			res->flags = range.flags;
172			res->start = range.cpu_addr;
173			res->end = range.cpu_addr + range.size - 1;
174			res->parent = res->child = res->sibling = NULL;
175		}
176	}
177}
178
179struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus)
180{
181	struct pci_controller *hose = bus->sysdata;
182
183	return of_node_get(hose->of_node);
184}
185#endif
186
187static DEFINE_MUTEX(pci_scan_mutex);
188
189void register_pci_controller(struct pci_controller *hose)
190{
191	struct resource *parent;
192
193	parent = hose->mem_resource->parent;
194	if (!parent)
195		parent = &iomem_resource;
196
197	if (request_resource(parent, hose->mem_resource) < 0)
198		goto out;
199
200	parent = hose->io_resource->parent;
201	if (!parent)
202		parent = &ioport_resource;
203
204	if (request_resource(parent, hose->io_resource) < 0) {
205		release_resource(hose->mem_resource);
206		goto out;
207	}
208
209	INIT_LIST_HEAD(&hose->list);
210	list_add_tail(&hose->list, &controllers);
211
212	/*
213	 * Do not panic here but later - this might happen before console init.
214	 */
215	if (!hose->io_map_base) {
216		printk(KERN_WARNING
217		       "registering PCI controller with io_map_base unset\n");
218	}
219
220	/*
221	 * Scan the bus if it is register after the PCI subsystem
222	 * initialization.
223	 */
224	if (pci_initialized) {
225		mutex_lock(&pci_scan_mutex);
226		pcibios_scanbus(hose);
227		mutex_unlock(&pci_scan_mutex);
228	}
229
230	return;
231
232out:
233	printk(KERN_WARNING
234	       "Skipping PCI bus scan due to resource conflict\n");
235}
236
237static int __init pcibios_init(void)
238{
239	struct pci_controller *hose;
240
241	/* Scan all of the recorded PCI controllers.  */
242	list_for_each_entry(hose, &controllers, list)
243		pcibios_scanbus(hose);
244
245	pci_initialized = 1;
246
247	return 0;
248}
249
250subsys_initcall(pcibios_init);
251
252int pcibios_enable_device(struct pci_dev *dev, int mask)
253{
254	int err;
255
256	err = pci_enable_resources(dev, mask);
257	if (err < 0)
258		return err;
259
260	return pcibios_plat_dev_init(dev);
261}
262
263void pcibios_fixup_bus(struct pci_bus *bus)
264{
265	struct pci_dev *dev = bus->self;
266
267	if (pci_has_flag(PCI_PROBE_ONLY) && dev &&
268	    (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
269		pci_read_bridge_bases(bus);
270	}
271}
272
273char * (*pcibios_plat_setup)(char *str) __initdata;
274
275char *__init pcibios_setup(char *str)
276{
277	if (pcibios_plat_setup)
278		return pcibios_plat_setup(str);
279	return str;
280}