1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Common pmac/prep/chrp pci routines. -- Cort
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/pci.h>
8 #include <linux/delay.h>
9 #include <linux/string.h>
10 #include <linux/init.h>
11 #include <linux/capability.h>
12 #include <linux/sched.h>
13 #include <linux/errno.h>
14 #include <linux/memblock.h>
15 #include <linux/syscalls.h>
16 #include <linux/irq.h>
17 #include <linux/list.h>
18 #include <linux/of.h>
19 #include <linux/slab.h>
20 #include <linux/export.h>
21 
22 #include <asm/processor.h>
23 #include <asm/io.h>
24 #include <asm/prom.h>
25 #include <asm/sections.h>
26 #include <asm/pci-bridge.h>
27 #include <asm/ppc-pci.h>
28 #include <asm/byteorder.h>
29 #include <linux/uaccess.h>
30 #include <asm/machdep.h>
31 
32 #undef DEBUG
33 
34 unsigned long isa_io_base     = 0;
35 unsigned long pci_dram_offset = 0;
36 int pcibios_assign_bus_offset = 1;
37 EXPORT_SYMBOL(isa_io_base);
38 EXPORT_SYMBOL(pci_dram_offset);
39 
40 void pcibios_make_OF_bus_map(void);
41 
42 static void fixup_cpc710_pci64(struct pci_dev* dev);
43 static u8* pci_to_OF_bus_map;
44 
45 /* By default, we don't re-assign bus numbers. We do this only on
46  * some pmacs
47  */
48 static int pci_assign_all_buses;
49 
50 static int pci_bus_count;
51 
52 /* This will remain NULL for now, until isa-bridge.c is made common
53  * to both 32-bit and 64-bit.
54  */
55 struct pci_dev *isa_bridge_pcidev;
56 EXPORT_SYMBOL_GPL(isa_bridge_pcidev);
57 
58 static void
fixup_cpc710_pci64(struct pci_dev * dev)59 fixup_cpc710_pci64(struct pci_dev* dev)
60 {
61 	/* Hide the PCI64 BARs from the kernel as their content doesn't
62 	 * fit well in the resource management
63 	 */
64 	dev->resource[0].start = dev->resource[0].end = 0;
65 	dev->resource[0].flags = 0;
66 	dev->resource[1].start = dev->resource[1].end = 0;
67 	dev->resource[1].flags = 0;
68 }
69 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_IBM,	PCI_DEVICE_ID_IBM_CPC710_PCI64,	fixup_cpc710_pci64);
70 
71 /*
72  * Functions below are used on OpenFirmware machines.
73  */
74 static void
make_one_node_map(struct device_node * node,u8 pci_bus)75 make_one_node_map(struct device_node* node, u8 pci_bus)
76 {
77 	const int *bus_range;
78 	int len;
79 
80 	if (pci_bus >= pci_bus_count)
81 		return;
82 	bus_range = of_get_property(node, "bus-range", &len);
83 	if (bus_range == NULL || len < 2 * sizeof(int)) {
84 		printk(KERN_WARNING "Can't get bus-range for %pOF, "
85 		       "assuming it starts at 0\n", node);
86 		pci_to_OF_bus_map[pci_bus] = 0;
87 	} else
88 		pci_to_OF_bus_map[pci_bus] = bus_range[0];
89 
90 	for_each_child_of_node(node, node) {
91 		struct pci_dev* dev;
92 		const unsigned int *class_code, *reg;
93 
94 		class_code = of_get_property(node, "class-code", NULL);
95 		if (!class_code || ((*class_code >> 8) != PCI_CLASS_BRIDGE_PCI &&
96 			(*class_code >> 8) != PCI_CLASS_BRIDGE_CARDBUS))
97 			continue;
98 		reg = of_get_property(node, "reg", NULL);
99 		if (!reg)
100 			continue;
101 		dev = pci_get_domain_bus_and_slot(0, pci_bus,
102 						  ((reg[0] >> 8) & 0xff));
103 		if (!dev || !dev->subordinate) {
104 			pci_dev_put(dev);
105 			continue;
106 		}
107 		make_one_node_map(node, dev->subordinate->number);
108 		pci_dev_put(dev);
109 	}
110 }
111 
112 void
pcibios_make_OF_bus_map(void)113 pcibios_make_OF_bus_map(void)
114 {
115 	int i;
116 	struct pci_controller *hose, *tmp;
117 	struct property *map_prop;
118 	struct device_node *dn;
119 
120 	pci_to_OF_bus_map = kmalloc(pci_bus_count, GFP_KERNEL);
121 	if (!pci_to_OF_bus_map) {
122 		printk(KERN_ERR "Can't allocate OF bus map !\n");
123 		return;
124 	}
125 
126 	/* We fill the bus map with invalid values, that helps
127 	 * debugging.
128 	 */
129 	for (i=0; i<pci_bus_count; i++)
130 		pci_to_OF_bus_map[i] = 0xff;
131 
132 	/* For each hose, we begin searching bridges */
133 	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
134 		struct device_node* node = hose->dn;
135 
136 		if (!node)
137 			continue;
138 		make_one_node_map(node, hose->first_busno);
139 	}
140 	dn = of_find_node_by_path("/");
141 	map_prop = of_find_property(dn, "pci-OF-bus-map", NULL);
142 	if (map_prop) {
143 		BUG_ON(pci_bus_count > map_prop->length);
144 		memcpy(map_prop->value, pci_to_OF_bus_map, pci_bus_count);
145 	}
146 	of_node_put(dn);
147 #ifdef DEBUG
148 	printk("PCI->OF bus map:\n");
149 	for (i=0; i<pci_bus_count; i++) {
150 		if (pci_to_OF_bus_map[i] == 0xff)
151 			continue;
152 		printk("%d -> %d\n", i, pci_to_OF_bus_map[i]);
153 	}
154 #endif
155 }
156 
157 
158 /*
159  * Returns the PCI device matching a given OF node
160  */
pci_device_from_OF_node(struct device_node * node,u8 * bus,u8 * devfn)161 int pci_device_from_OF_node(struct device_node *node, u8 *bus, u8 *devfn)
162 {
163 	struct pci_dev *dev = NULL;
164 	const __be32 *reg;
165 	int size;
166 
167 	/* Check if it might have a chance to be a PCI device */
168 	if (!pci_find_hose_for_OF_device(node))
169 		return -ENODEV;
170 
171 	reg = of_get_property(node, "reg", &size);
172 	if (!reg || size < 5 * sizeof(u32))
173 		return -ENODEV;
174 
175 	*bus = (be32_to_cpup(&reg[0]) >> 16) & 0xff;
176 	*devfn = (be32_to_cpup(&reg[0]) >> 8) & 0xff;
177 
178 	/* Ok, here we need some tweak. If we have already renumbered
179 	 * all busses, we can't rely on the OF bus number any more.
180 	 * the pci_to_OF_bus_map is not enough as several PCI busses
181 	 * may match the same OF bus number.
182 	 */
183 	if (!pci_to_OF_bus_map)
184 		return 0;
185 
186 	for_each_pci_dev(dev)
187 		if (pci_to_OF_bus_map[dev->bus->number] == *bus &&
188 				dev->devfn == *devfn) {
189 			*bus = dev->bus->number;
190 			pci_dev_put(dev);
191 			return 0;
192 		}
193 
194 	return -ENODEV;
195 }
196 EXPORT_SYMBOL(pci_device_from_OF_node);
197 
198 /* We create the "pci-OF-bus-map" property now so it appears in the
199  * /proc device tree
200  */
201 void __init
pci_create_OF_bus_map(void)202 pci_create_OF_bus_map(void)
203 {
204 	struct property* of_prop;
205 	struct device_node *dn;
206 
207 	of_prop = memblock_alloc(sizeof(struct property) + 256,
208 				 SMP_CACHE_BYTES);
209 	if (!of_prop)
210 		panic("%s: Failed to allocate %zu bytes\n", __func__,
211 		      sizeof(struct property) + 256);
212 	dn = of_find_node_by_path("/");
213 	if (dn) {
214 		memset(of_prop, -1, sizeof(struct property) + 256);
215 		of_prop->name = "pci-OF-bus-map";
216 		of_prop->length = 256;
217 		of_prop->value = &of_prop[1];
218 		of_add_property(dn, of_prop);
219 		of_node_put(dn);
220 	}
221 }
222 
pcibios_setup_phb_io_space(struct pci_controller * hose)223 void pcibios_setup_phb_io_space(struct pci_controller *hose)
224 {
225 	unsigned long io_offset;
226 	struct resource *res = &hose->io_resource;
227 
228 	/* Fixup IO space offset */
229 	io_offset = pcibios_io_space_offset(hose);
230 	res->start += io_offset;
231 	res->end += io_offset;
232 }
233 
pcibios_init(void)234 static int __init pcibios_init(void)
235 {
236 	struct pci_controller *hose, *tmp;
237 	int next_busno = 0;
238 
239 	printk(KERN_INFO "PCI: Probing PCI hardware\n");
240 
241 	if (pci_has_flag(PCI_REASSIGN_ALL_BUS))
242 		pci_assign_all_buses = 1;
243 
244 	/* Scan all of the recorded PCI controllers.  */
245 	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
246 		if (pci_assign_all_buses)
247 			hose->first_busno = next_busno;
248 		hose->last_busno = 0xff;
249 		pcibios_scan_phb(hose);
250 		pci_bus_add_devices(hose->bus);
251 		if (pci_assign_all_buses || next_busno <= hose->last_busno)
252 			next_busno = hose->last_busno + pcibios_assign_bus_offset;
253 	}
254 	pci_bus_count = next_busno;
255 
256 	/* OpenFirmware based machines need a map of OF bus
257 	 * numbers vs. kernel bus numbers since we may have to
258 	 * remap them.
259 	 */
260 	if (pci_assign_all_buses)
261 		pcibios_make_OF_bus_map();
262 
263 	/* Call common code to handle resource allocation */
264 	pcibios_resource_survey();
265 
266 	/* Call machine dependent fixup */
267 	if (ppc_md.pcibios_fixup)
268 		ppc_md.pcibios_fixup();
269 
270 	/* Call machine dependent post-init code */
271 	if (ppc_md.pcibios_after_init)
272 		ppc_md.pcibios_after_init();
273 
274 	return 0;
275 }
276 
277 subsys_initcall(pcibios_init);
278 
279 static struct pci_controller*
pci_bus_to_hose(int bus)280 pci_bus_to_hose(int bus)
281 {
282 	struct pci_controller *hose, *tmp;
283 
284 	list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
285 		if (bus >= hose->first_busno && bus <= hose->last_busno)
286 			return hose;
287 	return NULL;
288 }
289 
290 /* Provide information on locations of various I/O regions in physical
291  * memory.  Do this on a per-card basis so that we choose the right
292  * root bridge.
293  * Note that the returned IO or memory base is a physical address
294  */
295 
SYSCALL_DEFINE3(pciconfig_iobase,long,which,unsigned long,bus,unsigned long,devfn)296 SYSCALL_DEFINE3(pciconfig_iobase, long, which,
297 		unsigned long, bus, unsigned long, devfn)
298 {
299 	struct pci_controller* hose;
300 	long result = -EOPNOTSUPP;
301 
302 	hose = pci_bus_to_hose(bus);
303 	if (!hose)
304 		return -ENODEV;
305 
306 	switch (which) {
307 	case IOBASE_BRIDGE_NUMBER:
308 		return (long)hose->first_busno;
309 	case IOBASE_MEMORY:
310 		return (long)hose->mem_offset[0];
311 	case IOBASE_IO:
312 		return (long)hose->io_base_phys;
313 	case IOBASE_ISA_IO:
314 		return (long)isa_io_base;
315 	case IOBASE_ISA_MEM:
316 		return (long)isa_mem_base;
317 	}
318 
319 	return result;
320 }
321