xref: /openbmc/linux/arch/powerpc/kernel/pci_64.c (revision 81de3bf3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Port for PPC64 David Engebretsen, IBM Corp.
4  * Contains common pci routines for ppc64 platform, pSeries and iSeries brands.
5  *
6  * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
7  *   Rework, based on alpha PCI code.
8  */
9 
10 #undef DEBUG
11 
12 #include <linux/kernel.h>
13 #include <linux/pci.h>
14 #include <linux/string.h>
15 #include <linux/init.h>
16 #include <linux/export.h>
17 #include <linux/mm.h>
18 #include <linux/list.h>
19 #include <linux/syscalls.h>
20 #include <linux/irq.h>
21 #include <linux/vmalloc.h>
22 
23 #include <asm/processor.h>
24 #include <asm/io.h>
25 #include <asm/prom.h>
26 #include <asm/pci-bridge.h>
27 #include <asm/byteorder.h>
28 #include <asm/machdep.h>
29 #include <asm/ppc-pci.h>
30 
31 /* pci_io_base -- the base address from which io bars are offsets.
32  * This is the lowest I/O base address (so bar values are always positive),
33  * and it *must* be the start of ISA space if an ISA bus exists because
34  * ISA drivers use hard coded offsets.  If no ISA bus exists nothing
35  * is mapped on the first 64K of IO space
36  */
37 unsigned long pci_io_base;
38 EXPORT_SYMBOL(pci_io_base);
39 
40 static int __init pcibios_init(void)
41 {
42 	struct pci_controller *hose, *tmp;
43 
44 	printk(KERN_INFO "PCI: Probing PCI hardware\n");
45 
46 	/* For now, override phys_mem_access_prot. If we need it,g
47 	 * later, we may move that initialization to each ppc_md
48 	 */
49 	ppc_md.phys_mem_access_prot = pci_phys_mem_access_prot;
50 
51 	/* On ppc64, we always enable PCI domains and we keep domain 0
52 	 * backward compatible in /proc for video cards
53 	 */
54 	pci_add_flags(PCI_ENABLE_PROC_DOMAINS | PCI_COMPAT_DOMAIN_0);
55 
56 	/* Scan all of the recorded PCI controllers.  */
57 	list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
58 		pcibios_scan_phb(hose);
59 
60 	/* Call common code to handle resource allocation */
61 	pcibios_resource_survey();
62 
63 	/* Add devices. */
64 	list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
65 		pci_bus_add_devices(hose->bus);
66 
67 	/* Call machine dependent fixup */
68 	if (ppc_md.pcibios_fixup)
69 		ppc_md.pcibios_fixup();
70 
71 	printk(KERN_DEBUG "PCI: Probing PCI hardware done\n");
72 
73 	return 0;
74 }
75 
76 subsys_initcall(pcibios_init);
77 
78 int pcibios_unmap_io_space(struct pci_bus *bus)
79 {
80 	struct pci_controller *hose;
81 
82 	WARN_ON(bus == NULL);
83 
84 	/* If this is not a PHB, we only flush the hash table over
85 	 * the area mapped by this bridge. We don't play with the PTE
86 	 * mappings since we might have to deal with sub-page alignments
87 	 * so flushing the hash table is the only sane way to make sure
88 	 * that no hash entries are covering that removed bridge area
89 	 * while still allowing other busses overlapping those pages
90 	 *
91 	 * Note: If we ever support P2P hotplug on Book3E, we'll have
92 	 * to do an appropriate TLB flush here too
93 	 */
94 	if (bus->self) {
95 #ifdef CONFIG_PPC_BOOK3S_64
96 		struct resource *res = bus->resource[0];
97 #endif
98 
99 		pr_debug("IO unmapping for PCI-PCI bridge %s\n",
100 			 pci_name(bus->self));
101 
102 #ifdef CONFIG_PPC_BOOK3S_64
103 		__flush_hash_table_range(&init_mm, res->start + _IO_BASE,
104 					 res->end + _IO_BASE + 1);
105 #endif
106 		return 0;
107 	}
108 
109 	/* Get the host bridge */
110 	hose = pci_bus_to_host(bus);
111 
112 	/* Check if we have IOs allocated */
113 	if (hose->io_base_alloc == NULL)
114 		return 0;
115 
116 	pr_debug("IO unmapping for PHB %pOF\n", hose->dn);
117 	pr_debug("  alloc=0x%p\n", hose->io_base_alloc);
118 
119 	/* This is a PHB, we fully unmap the IO area */
120 	vunmap(hose->io_base_alloc);
121 
122 	return 0;
123 }
124 EXPORT_SYMBOL_GPL(pcibios_unmap_io_space);
125 
126 static int pcibios_map_phb_io_space(struct pci_controller *hose)
127 {
128 	struct vm_struct *area;
129 	unsigned long phys_page;
130 	unsigned long size_page;
131 	unsigned long io_virt_offset;
132 
133 	phys_page = _ALIGN_DOWN(hose->io_base_phys, PAGE_SIZE);
134 	size_page = _ALIGN_UP(hose->pci_io_size, PAGE_SIZE);
135 
136 	/* Make sure IO area address is clear */
137 	hose->io_base_alloc = NULL;
138 
139 	/* If there's no IO to map on that bus, get away too */
140 	if (hose->pci_io_size == 0 || hose->io_base_phys == 0)
141 		return 0;
142 
143 	/* Let's allocate some IO space for that guy. We don't pass
144 	 * VM_IOREMAP because we don't care about alignment tricks that
145 	 * the core does in that case. Maybe we should due to stupid card
146 	 * with incomplete address decoding but I'd rather not deal with
147 	 * those outside of the reserved 64K legacy region.
148 	 */
149 	area = __get_vm_area(size_page, 0, PHB_IO_BASE, PHB_IO_END);
150 	if (area == NULL)
151 		return -ENOMEM;
152 	hose->io_base_alloc = area->addr;
153 	hose->io_base_virt = (void __iomem *)(area->addr +
154 					      hose->io_base_phys - phys_page);
155 
156 	pr_debug("IO mapping for PHB %pOF\n", hose->dn);
157 	pr_debug("  phys=0x%016llx, virt=0x%p (alloc=0x%p)\n",
158 		 hose->io_base_phys, hose->io_base_virt, hose->io_base_alloc);
159 	pr_debug("  size=0x%016llx (alloc=0x%016lx)\n",
160 		 hose->pci_io_size, size_page);
161 
162 	/* Establish the mapping */
163 	if (__ioremap_at(phys_page, area->addr, size_page,
164 			 pgprot_noncached(PAGE_KERNEL)) == NULL)
165 		return -ENOMEM;
166 
167 	/* Fixup hose IO resource */
168 	io_virt_offset = pcibios_io_space_offset(hose);
169 	hose->io_resource.start += io_virt_offset;
170 	hose->io_resource.end += io_virt_offset;
171 
172 	pr_debug("  hose->io_resource=%pR\n", &hose->io_resource);
173 
174 	return 0;
175 }
176 
177 int pcibios_map_io_space(struct pci_bus *bus)
178 {
179 	WARN_ON(bus == NULL);
180 
181 	/* If this not a PHB, nothing to do, page tables still exist and
182 	 * thus HPTEs will be faulted in when needed
183 	 */
184 	if (bus->self) {
185 		pr_debug("IO mapping for PCI-PCI bridge %s\n",
186 			 pci_name(bus->self));
187 		pr_debug("  virt=0x%016llx...0x%016llx\n",
188 			 bus->resource[0]->start + _IO_BASE,
189 			 bus->resource[0]->end + _IO_BASE);
190 		return 0;
191 	}
192 
193 	return pcibios_map_phb_io_space(pci_bus_to_host(bus));
194 }
195 EXPORT_SYMBOL_GPL(pcibios_map_io_space);
196 
197 void pcibios_setup_phb_io_space(struct pci_controller *hose)
198 {
199 	pcibios_map_phb_io_space(hose);
200 }
201 
202 #define IOBASE_BRIDGE_NUMBER	0
203 #define IOBASE_MEMORY		1
204 #define IOBASE_IO		2
205 #define IOBASE_ISA_IO		3
206 #define IOBASE_ISA_MEM		4
207 
208 SYSCALL_DEFINE3(pciconfig_iobase, long, which, unsigned long, in_bus,
209 			  unsigned long, in_devfn)
210 {
211 	struct pci_controller* hose;
212 	struct pci_bus *tmp_bus, *bus = NULL;
213 	struct device_node *hose_node;
214 
215 	/* Argh ! Please forgive me for that hack, but that's the
216 	 * simplest way to get existing XFree to not lockup on some
217 	 * G5 machines... So when something asks for bus 0 io base
218 	 * (bus 0 is HT root), we return the AGP one instead.
219 	 */
220 	if (in_bus == 0 && of_machine_is_compatible("MacRISC4")) {
221 		struct device_node *agp;
222 
223 		agp = of_find_compatible_node(NULL, NULL, "u3-agp");
224 		if (agp)
225 			in_bus = 0xf0;
226 		of_node_put(agp);
227 	}
228 
229 	/* That syscall isn't quite compatible with PCI domains, but it's
230 	 * used on pre-domains setup. We return the first match
231 	 */
232 
233 	list_for_each_entry(tmp_bus, &pci_root_buses, node) {
234 		if (in_bus >= tmp_bus->number &&
235 		    in_bus <= tmp_bus->busn_res.end) {
236 			bus = tmp_bus;
237 			break;
238 		}
239 	}
240 	if (bus == NULL || bus->dev.of_node == NULL)
241 		return -ENODEV;
242 
243 	hose_node = bus->dev.of_node;
244 	hose = PCI_DN(hose_node)->phb;
245 
246 	switch (which) {
247 	case IOBASE_BRIDGE_NUMBER:
248 		return (long)hose->first_busno;
249 	case IOBASE_MEMORY:
250 		return (long)hose->mem_offset[0];
251 	case IOBASE_IO:
252 		return (long)hose->io_base_phys;
253 	case IOBASE_ISA_IO:
254 		return (long)isa_io_base;
255 	case IOBASE_ISA_MEM:
256 		return -EINVAL;
257 	}
258 
259 	return -EOPNOTSUPP;
260 }
261 
262 #ifdef CONFIG_NUMA
263 int pcibus_to_node(struct pci_bus *bus)
264 {
265 	struct pci_controller *phb = pci_bus_to_host(bus);
266 	return phb->node;
267 }
268 EXPORT_SYMBOL(pcibus_to_node);
269 #endif
270