1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Support PCI IO workaround
4 *
5 * Copyright (C) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org>
6 * IBM, Corp.
7 * (C) Copyright 2007-2008 TOSHIBA CORPORATION
8 */
9 #undef DEBUG
10
11 #include <linux/kernel.h>
12 #include <linux/sched/mm.h> /* for init_mm */
13 #include <linux/pgtable.h>
14
15 #include <asm/io.h>
16 #include <asm/machdep.h>
17 #include <asm/ppc-pci.h>
18 #include <asm/io-workarounds.h>
19 #include <asm/pte-walk.h>
20
21
22 #define IOWA_MAX_BUS 8
23
24 static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
25 static unsigned int iowa_bus_count;
26
iowa_pci_find(unsigned long vaddr,unsigned long paddr)27 static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
28 {
29 int i, j;
30 struct resource *res;
31 unsigned long vstart, vend;
32
33 for (i = 0; i < iowa_bus_count; i++) {
34 struct iowa_bus *bus = &iowa_busses[i];
35 struct pci_controller *phb = bus->phb;
36
37 if (vaddr) {
38 vstart = (unsigned long)phb->io_base_virt;
39 vend = vstart + phb->pci_io_size - 1;
40 if ((vaddr >= vstart) && (vaddr <= vend))
41 return bus;
42 }
43
44 if (paddr)
45 for (j = 0; j < 3; j++) {
46 res = &phb->mem_resources[j];
47 if (paddr >= res->start && paddr <= res->end)
48 return bus;
49 }
50 }
51
52 return NULL;
53 }
54
55 #ifdef CONFIG_PPC_INDIRECT_MMIO
iowa_mem_find_bus(const PCI_IO_ADDR addr)56 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
57 {
58 struct iowa_bus *bus;
59 int token;
60
61 token = PCI_GET_ADDR_TOKEN(addr);
62
63 if (token && token <= iowa_bus_count)
64 bus = &iowa_busses[token - 1];
65 else {
66 unsigned long vaddr, paddr;
67
68 vaddr = (unsigned long)PCI_FIX_ADDR(addr);
69 if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
70 return NULL;
71
72 paddr = ppc_find_vmap_phys(vaddr);
73
74 bus = iowa_pci_find(vaddr, paddr);
75
76 if (bus == NULL)
77 return NULL;
78 }
79
80 return bus;
81 }
82 #else /* CONFIG_PPC_INDIRECT_MMIO */
iowa_mem_find_bus(const PCI_IO_ADDR addr)83 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
84 {
85 return NULL;
86 }
87 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
88
89 #ifdef CONFIG_PPC_INDIRECT_PIO
iowa_pio_find_bus(unsigned long port)90 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
91 {
92 unsigned long vaddr = (unsigned long)pci_io_base + port;
93 return iowa_pci_find(vaddr, 0);
94 }
95 #else
iowa_pio_find_bus(unsigned long port)96 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
97 {
98 return NULL;
99 }
100 #endif
101
102 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa) \
103 static ret iowa_##name at \
104 { \
105 struct iowa_bus *bus; \
106 bus = iowa_##space##_find_bus(aa); \
107 if (bus && bus->ops && bus->ops->name) \
108 return bus->ops->name al; \
109 return __do_##name al; \
110 }
111
112 #define DEF_PCI_AC_NORET(name, at, al, space, aa) \
113 static void iowa_##name at \
114 { \
115 struct iowa_bus *bus; \
116 bus = iowa_##space##_find_bus(aa); \
117 if (bus && bus->ops && bus->ops->name) { \
118 bus->ops->name al; \
119 return; \
120 } \
121 __do_##name al; \
122 }
123
124 #include <asm/io-defs.h>
125
126 #undef DEF_PCI_AC_RET
127 #undef DEF_PCI_AC_NORET
128
129 static const struct ppc_pci_io iowa_pci_io = {
130
131 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa) .name = iowa_##name,
132 #define DEF_PCI_AC_NORET(name, at, al, space, aa) .name = iowa_##name,
133
134 #include <asm/io-defs.h>
135
136 #undef DEF_PCI_AC_RET
137 #undef DEF_PCI_AC_NORET
138
139 };
140
141 #ifdef CONFIG_PPC_INDIRECT_MMIO
iowa_ioremap(phys_addr_t addr,unsigned long size,pgprot_t prot,void * caller)142 void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
143 pgprot_t prot, void *caller)
144 {
145 struct iowa_bus *bus;
146 void __iomem *res = __ioremap_caller(addr, size, prot, caller);
147 int busno;
148
149 bus = iowa_pci_find(0, (unsigned long)addr);
150 if (bus != NULL) {
151 busno = bus - iowa_busses;
152 PCI_SET_ADDR_TOKEN(res, busno + 1);
153 }
154 return res;
155 }
156 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
157
158 bool io_workaround_inited;
159
160 /* Enable IO workaround */
io_workaround_init(void)161 static void io_workaround_init(void)
162 {
163 if (io_workaround_inited)
164 return;
165 ppc_pci_io = iowa_pci_io;
166 io_workaround_inited = true;
167 }
168
169 /* Register new bus to support workaround */
iowa_register_bus(struct pci_controller * phb,struct ppc_pci_io * ops,int (* initfunc)(struct iowa_bus *,void *),void * data)170 void iowa_register_bus(struct pci_controller *phb, struct ppc_pci_io *ops,
171 int (*initfunc)(struct iowa_bus *, void *), void *data)
172 {
173 struct iowa_bus *bus;
174 struct device_node *np = phb->dn;
175
176 io_workaround_init();
177
178 if (iowa_bus_count >= IOWA_MAX_BUS) {
179 pr_err("IOWA:Too many pci bridges, "
180 "workarounds disabled for %pOF\n", np);
181 return;
182 }
183
184 bus = &iowa_busses[iowa_bus_count];
185 bus->phb = phb;
186 bus->ops = ops;
187 bus->private = data;
188
189 if (initfunc)
190 if ((*initfunc)(bus, data))
191 return;
192
193 iowa_bus_count++;
194
195 pr_debug("IOWA:[%d]Add bus, %pOF.\n", iowa_bus_count-1, np);
196 }
197
198