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
14 #include <asm/io.h>
15 #include <asm/machdep.h>
16 #include <asm/pgtable.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 unsigned hugepage_shift;
59 struct iowa_bus *bus;
60 int token;
61
62 token = PCI_GET_ADDR_TOKEN(addr);
63
64 if (token && token <= iowa_bus_count)
65 bus = &iowa_busses[token - 1];
66 else {
67 unsigned long vaddr, paddr;
68 pte_t *ptep;
69
70 vaddr = (unsigned long)PCI_FIX_ADDR(addr);
71 if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
72 return NULL;
73 /*
74 * We won't find huge pages here (iomem). Also can't hit
75 * a page table free due to init_mm
76 */
77 ptep = find_init_mm_pte(vaddr, &hugepage_shift);
78 if (ptep == NULL)
79 paddr = 0;
80 else {
81 WARN_ON(hugepage_shift);
82 paddr = pte_pfn(*ptep) << PAGE_SHIFT;
83 }
84 bus = iowa_pci_find(vaddr, paddr);
85
86 if (bus == NULL)
87 return NULL;
88 }
89
90 return bus;
91 }
92 #else /* CONFIG_PPC_INDIRECT_MMIO */
iowa_mem_find_bus(const PCI_IO_ADDR addr)93 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
94 {
95 return NULL;
96 }
97 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
98
99 #ifdef CONFIG_PPC_INDIRECT_PIO
iowa_pio_find_bus(unsigned long port)100 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
101 {
102 unsigned long vaddr = (unsigned long)pci_io_base + port;
103 return iowa_pci_find(vaddr, 0);
104 }
105 #else
iowa_pio_find_bus(unsigned long port)106 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
107 {
108 return NULL;
109 }
110 #endif
111
112 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa) \
113 static ret 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 return bus->ops->name al; \
119 return __do_##name al; \
120 }
121
122 #define DEF_PCI_AC_NORET(name, at, al, space, aa) \
123 static void iowa_##name at \
124 { \
125 struct iowa_bus *bus; \
126 bus = iowa_##space##_find_bus(aa); \
127 if (bus && bus->ops && bus->ops->name) { \
128 bus->ops->name al; \
129 return; \
130 } \
131 __do_##name al; \
132 }
133
134 #include <asm/io-defs.h>
135
136 #undef DEF_PCI_AC_RET
137 #undef DEF_PCI_AC_NORET
138
139 static const struct ppc_pci_io iowa_pci_io = {
140
141 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa) .name = iowa_##name,
142 #define DEF_PCI_AC_NORET(name, at, al, space, aa) .name = iowa_##name,
143
144 #include <asm/io-defs.h>
145
146 #undef DEF_PCI_AC_RET
147 #undef DEF_PCI_AC_NORET
148
149 };
150
151 #ifdef CONFIG_PPC_INDIRECT_MMIO
iowa_ioremap(phys_addr_t addr,unsigned long size,pgprot_t prot,void * caller)152 void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
153 pgprot_t prot, void *caller)
154 {
155 struct iowa_bus *bus;
156 void __iomem *res = __ioremap_caller(addr, size, prot, caller);
157 int busno;
158
159 bus = iowa_pci_find(0, (unsigned long)addr);
160 if (bus != NULL) {
161 busno = bus - iowa_busses;
162 PCI_SET_ADDR_TOKEN(res, busno + 1);
163 }
164 return res;
165 }
166 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
167
168 bool io_workaround_inited;
169
170 /* Enable IO workaround */
io_workaround_init(void)171 static void io_workaround_init(void)
172 {
173 if (io_workaround_inited)
174 return;
175 ppc_pci_io = iowa_pci_io;
176 io_workaround_inited = true;
177 }
178
179 /* 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)180 void iowa_register_bus(struct pci_controller *phb, struct ppc_pci_io *ops,
181 int (*initfunc)(struct iowa_bus *, void *), void *data)
182 {
183 struct iowa_bus *bus;
184 struct device_node *np = phb->dn;
185
186 io_workaround_init();
187
188 if (iowa_bus_count >= IOWA_MAX_BUS) {
189 pr_err("IOWA:Too many pci bridges, "
190 "workarounds disabled for %pOF\n", np);
191 return;
192 }
193
194 bus = &iowa_busses[iowa_bus_count];
195 bus->phb = phb;
196 bus->ops = ops;
197 bus->private = data;
198
199 if (initfunc)
200 if ((*initfunc)(bus, data))
201 return;
202
203 iowa_bus_count++;
204
205 pr_debug("IOWA:[%d]Add bus, %pOF.\n", iowa_bus_count-1, np);
206 }
207
208
