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 
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
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 */
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
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
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
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 */
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 */
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