xref: /openbmc/linux/arch/powerpc/kernel/pci_64.c (revision 4b4f3acc)
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 		pci_bus_add_devices(hose->bus);
60 	}
61 
62 	/* Call common code to handle resource allocation */
63 	pcibios_resource_survey();
64 
65 	printk(KERN_DEBUG "PCI: Probing PCI hardware done\n");
66 
67 	return 0;
68 }
69 
70 subsys_initcall(pcibios_init);
71 
72 int pcibios_unmap_io_space(struct pci_bus *bus)
73 {
74 	struct pci_controller *hose;
75 
76 	WARN_ON(bus == NULL);
77 
78 	/* If this is not a PHB, we only flush the hash table over
79 	 * the area mapped by this bridge. We don't play with the PTE
80 	 * mappings since we might have to deal with sub-page alignments
81 	 * so flushing the hash table is the only sane way to make sure
82 	 * that no hash entries are covering that removed bridge area
83 	 * while still allowing other busses overlapping those pages
84 	 *
85 	 * Note: If we ever support P2P hotplug on Book3E, we'll have
86 	 * to do an appropriate TLB flush here too
87 	 */
88 	if (bus->self) {
89 #ifdef CONFIG_PPC_BOOK3S_64
90 		struct resource *res = bus->resource[0];
91 #endif
92 
93 		pr_debug("IO unmapping for PCI-PCI bridge %s\n",
94 			 pci_name(bus->self));
95 
96 #ifdef CONFIG_PPC_BOOK3S_64
97 		__flush_hash_table_range(&init_mm, res->start + _IO_BASE,
98 					 res->end + _IO_BASE + 1);
99 #endif
100 		return 0;
101 	}
102 
103 	/* Get the host bridge */
104 	hose = pci_bus_to_host(bus);
105 
106 	/* Check if we have IOs allocated */
107 	if (hose->io_base_alloc == NULL)
108 		return 0;
109 
110 	pr_debug("IO unmapping for PHB %pOF\n", hose->dn);
111 	pr_debug("  alloc=0x%p\n", hose->io_base_alloc);
112 
113 	/* This is a PHB, we fully unmap the IO area */
114 	vunmap(hose->io_base_alloc);
115 
116 	return 0;
117 }
118 EXPORT_SYMBOL_GPL(pcibios_unmap_io_space);
119 
120 static int pcibios_map_phb_io_space(struct pci_controller *hose)
121 {
122 	struct vm_struct *area;
123 	unsigned long phys_page;
124 	unsigned long size_page;
125 	unsigned long io_virt_offset;
126 
127 	phys_page = _ALIGN_DOWN(hose->io_base_phys, PAGE_SIZE);
128 	size_page = _ALIGN_UP(hose->pci_io_size, PAGE_SIZE);
129 
130 	/* Make sure IO area address is clear */
131 	hose->io_base_alloc = NULL;
132 
133 	/* If there's no IO to map on that bus, get away too */
134 	if (hose->pci_io_size == 0 || hose->io_base_phys == 0)
135 		return 0;
136 
137 	/* Let's allocate some IO space for that guy. We don't pass
138 	 * VM_IOREMAP because we don't care about alignment tricks that
139 	 * the core does in that case. Maybe we should due to stupid card
140 	 * with incomplete address decoding but I'd rather not deal with
141 	 * those outside of the reserved 64K legacy region.
142 	 */
143 	area = __get_vm_area(size_page, 0, PHB_IO_BASE, PHB_IO_END);
144 	if (area == NULL)
145 		return -ENOMEM;
146 	hose->io_base_alloc = area->addr;
147 	hose->io_base_virt = (void __iomem *)(area->addr +
148 					      hose->io_base_phys - phys_page);
149 
150 	pr_debug("IO mapping for PHB %pOF\n", hose->dn);
151 	pr_debug("  phys=0x%016llx, virt=0x%p (alloc=0x%p)\n",
152 		 hose->io_base_phys, hose->io_base_virt, hose->io_base_alloc);
153 	pr_debug("  size=0x%016llx (alloc=0x%016lx)\n",
154 		 hose->pci_io_size, size_page);
155 
156 	/* Establish the mapping */
157 	if (__ioremap_at(phys_page, area->addr, size_page,
158 			 pgprot_noncached(PAGE_KERNEL)) == NULL)
159 		return -ENOMEM;
160 
161 	/* Fixup hose IO resource */
162 	io_virt_offset = pcibios_io_space_offset(hose);
163 	hose->io_resource.start += io_virt_offset;
164 	hose->io_resource.end += io_virt_offset;
165 
166 	pr_debug("  hose->io_resource=%pR\n", &hose->io_resource);
167 
168 	return 0;
169 }
170 
171 int pcibios_map_io_space(struct pci_bus *bus)
172 {
173 	WARN_ON(bus == NULL);
174 
175 	/* If this not a PHB, nothing to do, page tables still exist and
176 	 * thus HPTEs will be faulted in when needed
177 	 */
178 	if (bus->self) {
179 		pr_debug("IO mapping for PCI-PCI bridge %s\n",
180 			 pci_name(bus->self));
181 		pr_debug("  virt=0x%016llx...0x%016llx\n",
182 			 bus->resource[0]->start + _IO_BASE,
183 			 bus->resource[0]->end + _IO_BASE);
184 		return 0;
185 	}
186 
187 	return pcibios_map_phb_io_space(pci_bus_to_host(bus));
188 }
189 EXPORT_SYMBOL_GPL(pcibios_map_io_space);
190 
191 void pcibios_setup_phb_io_space(struct pci_controller *hose)
192 {
193 	pcibios_map_phb_io_space(hose);
194 }
195 
196 #define IOBASE_BRIDGE_NUMBER	0
197 #define IOBASE_MEMORY		1
198 #define IOBASE_IO		2
199 #define IOBASE_ISA_IO		3
200 #define IOBASE_ISA_MEM		4
201 
202 SYSCALL_DEFINE3(pciconfig_iobase, long, which, unsigned long, in_bus,
203 			  unsigned long, in_devfn)
204 {
205 	struct pci_controller* hose;
206 	struct pci_bus *tmp_bus, *bus = NULL;
207 	struct device_node *hose_node;
208 
209 	/* Argh ! Please forgive me for that hack, but that's the
210 	 * simplest way to get existing XFree to not lockup on some
211 	 * G5 machines... So when something asks for bus 0 io base
212 	 * (bus 0 is HT root), we return the AGP one instead.
213 	 */
214 	if (in_bus == 0 && of_machine_is_compatible("MacRISC4")) {
215 		struct device_node *agp;
216 
217 		agp = of_find_compatible_node(NULL, NULL, "u3-agp");
218 		if (agp)
219 			in_bus = 0xf0;
220 		of_node_put(agp);
221 	}
222 
223 	/* That syscall isn't quite compatible with PCI domains, but it's
224 	 * used on pre-domains setup. We return the first match
225 	 */
226 
227 	list_for_each_entry(tmp_bus, &pci_root_buses, node) {
228 		if (in_bus >= tmp_bus->number &&
229 		    in_bus <= tmp_bus->busn_res.end) {
230 			bus = tmp_bus;
231 			break;
232 		}
233 	}
234 	if (bus == NULL || bus->dev.of_node == NULL)
235 		return -ENODEV;
236 
237 	hose_node = bus->dev.of_node;
238 	hose = PCI_DN(hose_node)->phb;
239 
240 	switch (which) {
241 	case IOBASE_BRIDGE_NUMBER:
242 		return (long)hose->first_busno;
243 	case IOBASE_MEMORY:
244 		return (long)hose->mem_offset[0];
245 	case IOBASE_IO:
246 		return (long)hose->io_base_phys;
247 	case IOBASE_ISA_IO:
248 		return (long)isa_io_base;
249 	case IOBASE_ISA_MEM:
250 		return -EINVAL;
251 	}
252 
253 	return -EOPNOTSUPP;
254 }
255 
256 #ifdef CONFIG_NUMA
257 int pcibus_to_node(struct pci_bus *bus)
258 {
259 	struct pci_controller *phb = pci_bus_to_host(bus);
260 	return phb->node;
261 }
262 EXPORT_SYMBOL(pcibus_to_node);
263 #endif
264