1 /*
2 * Support PCI IO workaround
3 *
4 * Copyright (C) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org>
5 * IBM, Corp.
6 * (C) Copyright 2007-2008 TOSHIBA CORPORATION
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12 #undef DEBUG
13
14 #include <linux/kernel.h>
15 #include <linux/sched.h> /* for init_mm */
16
17 #include <asm/io.h>
18 #include <asm/machdep.h>
19 #include <asm/pgtable.h>
20 #include <asm/ppc-pci.h>
21 #include <asm/io-workarounds.h>
22
23 #define IOWA_MAX_BUS 8
24
25 static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
26 static unsigned int iowa_bus_count;
27
iowa_pci_find(unsigned long vaddr,unsigned long paddr)28 static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
29 {
30 int i, j;
31 struct resource *res;
32 unsigned long vstart, vend;
33
34 for (i = 0; i < iowa_bus_count; i++) {
35 struct iowa_bus *bus = &iowa_busses[i];
36 struct pci_controller *phb = bus->phb;
37
38 if (vaddr) {
39 vstart = (unsigned long)phb->io_base_virt;
40 vend = vstart + phb->pci_io_size - 1;
41 if ((vaddr >= vstart) && (vaddr <= vend))
42 return bus;
43 }
44
45 if (paddr)
46 for (j = 0; j < 3; j++) {
47 res = &phb->mem_resources[j];
48 if (paddr >= res->start && paddr <= res->end)
49 return bus;
50 }
51 }
52
53 return NULL;
54 }
55
56 #ifdef CONFIG_PPC_INDIRECT_MMIO
iowa_mem_find_bus(const PCI_IO_ADDR addr)57 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
58 {
59 unsigned hugepage_shift;
60 struct iowa_bus *bus;
61 int token;
62
63 token = PCI_GET_ADDR_TOKEN(addr);
64
65 if (token && token <= iowa_bus_count)
66 bus = &iowa_busses[token - 1];
67 else {
68 unsigned long vaddr, paddr;
69 pte_t *ptep;
70
71 vaddr = (unsigned long)PCI_FIX_ADDR(addr);
72 if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
73 return NULL;
74 /*
75 * We won't find huge pages here (iomem). Also can't hit
76 * a page table free due to init_mm
77 */
78 ptep = __find_linux_pte_or_hugepte(init_mm.pgd, vaddr,
79 NULL, &hugepage_shift);
80 if (ptep == NULL)
81 paddr = 0;
82 else {
83 WARN_ON(hugepage_shift);
84 paddr = pte_pfn(*ptep) << PAGE_SHIFT;
85 }
86 bus = iowa_pci_find(vaddr, paddr);
87
88 if (bus == NULL)
89 return NULL;
90 }
91
92 return bus;
93 }
94 #else /* CONFIG_PPC_INDIRECT_MMIO */
iowa_mem_find_bus(const PCI_IO_ADDR addr)95 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
96 {
97 return NULL;
98 }
99 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
100
101 #ifdef CONFIG_PPC_INDIRECT_PIO
iowa_pio_find_bus(unsigned long port)102 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
103 {
104 unsigned long vaddr = (unsigned long)pci_io_base + port;
105 return iowa_pci_find(vaddr, 0);
106 }
107 #else
iowa_pio_find_bus(unsigned long port)108 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
109 {
110 return NULL;
111 }
112 #endif
113
114 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa) \
115 static ret iowa_##name at \
116 { \
117 struct iowa_bus *bus; \
118 bus = iowa_##space##_find_bus(aa); \
119 if (bus && bus->ops && bus->ops->name) \
120 return bus->ops->name al; \
121 return __do_##name al; \
122 }
123
124 #define DEF_PCI_AC_NORET(name, at, al, space, aa) \
125 static void iowa_##name at \
126 { \
127 struct iowa_bus *bus; \
128 bus = iowa_##space##_find_bus(aa); \
129 if (bus && bus->ops && bus->ops->name) { \
130 bus->ops->name al; \
131 return; \
132 } \
133 __do_##name al; \
134 }
135
136 #include <asm/io-defs.h>
137
138 #undef DEF_PCI_AC_RET
139 #undef DEF_PCI_AC_NORET
140
141 static const struct ppc_pci_io iowa_pci_io = {
142
143 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa) .name = iowa_##name,
144 #define DEF_PCI_AC_NORET(name, at, al, space, aa) .name = iowa_##name,
145
146 #include <asm/io-defs.h>
147
148 #undef DEF_PCI_AC_RET
149 #undef DEF_PCI_AC_NORET
150
151 };
152
153 #ifdef CONFIG_PPC_INDIRECT_MMIO
iowa_ioremap(phys_addr_t addr,unsigned long size,unsigned long flags,void * caller)154 static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
155 unsigned long flags, void *caller)
156 {
157 struct iowa_bus *bus;
158 void __iomem *res = __ioremap_caller(addr, size, flags, caller);
159 int busno;
160
161 bus = iowa_pci_find(0, (unsigned long)addr);
162 if (bus != NULL) {
163 busno = bus - iowa_busses;
164 PCI_SET_ADDR_TOKEN(res, busno + 1);
165 }
166 return res;
167 }
168 #else /* CONFIG_PPC_INDIRECT_MMIO */
169 #define iowa_ioremap NULL
170 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
171
172 /* Enable IO workaround */
io_workaround_init(void)173 static void io_workaround_init(void)
174 {
175 static int io_workaround_inited;
176
177 if (io_workaround_inited)
178 return;
179 ppc_pci_io = iowa_pci_io;
180 ppc_md.ioremap = iowa_ioremap;
181 io_workaround_inited = 1;
182 }
183
184 /* 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)185 void iowa_register_bus(struct pci_controller *phb, struct ppc_pci_io *ops,
186 int (*initfunc)(struct iowa_bus *, void *), void *data)
187 {
188 struct iowa_bus *bus;
189 struct device_node *np = phb->dn;
190
191 io_workaround_init();
192
193 if (iowa_bus_count >= IOWA_MAX_BUS) {
194 pr_err("IOWA:Too many pci bridges, "
195 "workarounds disabled for %s\n", np->full_name);
196 return;
197 }
198
199 bus = &iowa_busses[iowa_bus_count];
200 bus->phb = phb;
201 bus->ops = ops;
202 bus->private = data;
203
204 if (initfunc)
205 if ((*initfunc)(bus, data))
206 return;
207
208 iowa_bus_count++;
209
210 pr_debug("IOWA:[%d]Add bus, %s.\n", iowa_bus_count-1, np->full_name);
211 }
212
213