1 // SPDX-License-Identifier: GPL-2.0-only
3 * Support PCI IO workaround
5 * Copyright (C) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org>
7 * (C) Copyright 2007-2008 TOSHIBA CORPORATION
11 #include <linux/kernel.h>
12 #include <linux/sched/mm.h> /* for init_mm */
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>
22 #define IOWA_MAX_BUS 8
24 static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
25 static unsigned int iowa_bus_count;
27 static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
31 unsigned long vstart, vend;
33 for (i = 0; i < iowa_bus_count; i++) {
34 struct iowa_bus *bus = &iowa_busses[i];
35 struct pci_controller *phb = bus->phb;
38 vstart = (unsigned long)phb->io_base_virt;
39 vend = vstart + phb->pci_io_size - 1;
40 if ((vaddr >= vstart) && (vaddr <= vend))
45 for (j = 0; j < 3; j++) {
46 res = &phb->mem_resources[j];
47 if (paddr >= res->start && paddr <= res->end)
55 #ifdef CONFIG_PPC_INDIRECT_MMIO
56 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
58 unsigned hugepage_shift;
62 token = PCI_GET_ADDR_TOKEN(addr);
64 if (token && token <= iowa_bus_count)
65 bus = &iowa_busses[token - 1];
67 unsigned long vaddr, paddr;
70 vaddr = (unsigned long)PCI_FIX_ADDR(addr);
71 if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
74 * We won't find huge pages here (iomem). Also can't hit
75 * a page table free due to init_mm
77 ptep = find_init_mm_pte(vaddr, &hugepage_shift);
81 WARN_ON(hugepage_shift);
82 paddr = pte_pfn(*ptep) << PAGE_SHIFT;
84 bus = iowa_pci_find(vaddr, paddr);
92 #else /* CONFIG_PPC_INDIRECT_MMIO */
93 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
97 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
99 #ifdef CONFIG_PPC_INDIRECT_PIO
100 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
102 unsigned long vaddr = (unsigned long)pci_io_base + port;
103 return iowa_pci_find(vaddr, 0);
106 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
112 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa) \
113 static ret iowa_##name at \
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; \
122 #define DEF_PCI_AC_NORET(name, at, al, space, aa) \
123 static void iowa_##name at \
125 struct iowa_bus *bus; \
126 bus = iowa_##space##_find_bus(aa); \
127 if (bus && bus->ops && bus->ops->name) { \
134 #include <asm/io-defs.h>
136 #undef DEF_PCI_AC_RET
137 #undef DEF_PCI_AC_NORET
139 static const struct ppc_pci_io iowa_pci_io = {
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,
144 #include <asm/io-defs.h>
146 #undef DEF_PCI_AC_RET
147 #undef DEF_PCI_AC_NORET
151 #ifdef CONFIG_PPC_INDIRECT_MMIO
152 void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
153 pgprot_t prot, void *caller)
155 struct iowa_bus *bus;
156 void __iomem *res = __ioremap_caller(addr, size, prot, caller);
159 bus = iowa_pci_find(0, (unsigned long)addr);
161 busno = bus - iowa_busses;
162 PCI_SET_ADDR_TOKEN(res, busno + 1);
166 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
168 bool io_workaround_inited;
170 /* Enable IO workaround */
171 static void io_workaround_init(void)
173 if (io_workaround_inited)
175 ppc_pci_io = iowa_pci_io;
176 io_workaround_inited = true;
179 /* Register new bus to support workaround */
180 void iowa_register_bus(struct pci_controller *phb, struct ppc_pci_io *ops,
181 int (*initfunc)(struct iowa_bus *, void *), void *data)
183 struct iowa_bus *bus;
184 struct device_node *np = phb->dn;
186 io_workaround_init();
188 if (iowa_bus_count >= IOWA_MAX_BUS) {
189 pr_err("IOWA:Too many pci bridges, "
190 "workarounds disabled for %pOF\n", np);
194 bus = &iowa_busses[iowa_bus_count];
200 if ((*initfunc)(bus, data))
205 pr_debug("IOWA:[%d]Add bus, %pOF.\n", iowa_bus_count-1, np);