powerpc/kernel/io-workarounds.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Support PCI IO workaround
0004  *
0005  *  Copyright (C) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org>
0006  *             IBM, Corp.
0007  *  (C) Copyright 2007-2008 TOSHIBA CORPORATION
0008  */
0009 #undef DEBUG
0010
0011 #include <linux/kernel.h>
0012 #include <linux/sched/mm.h> /* for init_mm */
0013 #include <linux/pgtable.h>
0014
0015 #include <asm/io.h>
0016 #include <asm/machdep.h>
0017 #include <asm/ppc-pci.h>
0018 #include <asm/io-workarounds.h>
0019 #include <asm/pte-walk.h>
0020
0021
0022 #define IOWA_MAX_BUS    8
0023
0024 static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
0025 static unsigned int iowa_bus_count;
0026
0027 static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
0028 {
0029     int i, j;
0030     struct resource *res;
0031     unsigned long vstart, vend;
0032
0033     for (i = 0; i < iowa_bus_count; i++) {
0034         struct iowa_bus *bus = &iowa_busses[i];
0035         struct pci_controller *phb = bus->phb;
0036
0037         if (vaddr) {
0038             vstart = (unsigned long)phb->io_base_virt;
0039             vend = vstart + phb->pci_io_size - 1;
0040             if ((vaddr >= vstart) && (vaddr <= vend))
0041                 return bus;
0042         }
0043
0044         if (paddr)
0045             for (j = 0; j < 3; j++) {
0046                 res = &phb->mem_resources[j];
0047                 if (paddr >= res->start && paddr <= res->end)
0048                     return bus;
0049             }
0050     }
0051
0052     return NULL;
0053 }
0054
0055 #ifdef CONFIG_PPC_INDIRECT_MMIO
0056 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
0057 {
0058     struct iowa_bus *bus;
0059     int token;
0060
0061     token = PCI_GET_ADDR_TOKEN(addr);
0062
0063     if (token && token <= iowa_bus_count)
0064         bus = &iowa_busses[token - 1];
0065     else {
0066         unsigned long vaddr, paddr;
0067
0068         vaddr = (unsigned long)PCI_FIX_ADDR(addr);
0069         if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
0070             return NULL;
0071
0072         paddr = ppc_find_vmap_phys(vaddr);
0073
0074         bus = iowa_pci_find(vaddr, paddr);
0075
0076         if (bus == NULL)
0077             return NULL;
0078     }
0079
0080     return bus;
0081 }
0082 #else /* CONFIG_PPC_INDIRECT_MMIO */
0083 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
0084 {
0085     return NULL;
0086 }
0087 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
0088
0089 #ifdef CONFIG_PPC_INDIRECT_PIO
0090 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
0091 {
0092     unsigned long vaddr = (unsigned long)pci_io_base + port;
0093     return iowa_pci_find(vaddr, 0);
0094 }
0095 #else
0096 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
0097 {
0098     return NULL;
0099 }
0100 #endif
0101
0102 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)        \
0103 static ret iowa_##name at                   \
0104 {                               \
0105     struct iowa_bus *bus;                   \
0106     bus = iowa_##space##_find_bus(aa);          \
0107     if (bus && bus->ops && bus->ops->name)          \
0108         return bus->ops->name al;           \
0109     return __do_##name al;                  \
0110 }
0111
0112 #define DEF_PCI_AC_NORET(name, at, al, space, aa)       \
0113 static void iowa_##name at                  \
0114 {                               \
0115     struct iowa_bus *bus;                   \
0116     bus = iowa_##space##_find_bus(aa);          \
0117     if (bus && bus->ops && bus->ops->name) {        \
0118         bus->ops->name al;              \
0119         return;                     \
0120     }                           \
0121     __do_##name al;                     \
0122 }
0123
0124 #include <asm/io-defs.h>
0125
0126 #undef DEF_PCI_AC_RET
0127 #undef DEF_PCI_AC_NORET
0128
0129 static const struct ppc_pci_io iowa_pci_io = {
0130
0131 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)    .name = iowa_##name,
0132 #define DEF_PCI_AC_NORET(name, at, al, space, aa)   .name = iowa_##name,
0133
0134 #include <asm/io-defs.h>
0135
0136 #undef DEF_PCI_AC_RET
0137 #undef DEF_PCI_AC_NORET
0138
0139 };
0140
0141 #ifdef CONFIG_PPC_INDIRECT_MMIO
0142 void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
0143                pgprot_t prot, void *caller)
0144 {
0145     struct iowa_bus *bus;
0146     void __iomem *res = __ioremap_caller(addr, size, prot, caller);
0147     int busno;
0148
0149     bus = iowa_pci_find(0, (unsigned long)addr);
0150     if (bus != NULL) {
0151         busno = bus - iowa_busses;
0152         PCI_SET_ADDR_TOKEN(res, busno + 1);
0153     }
0154     return res;
0155 }
0156 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
0157
0158 bool io_workaround_inited;
0159
0160 /* Enable IO workaround */
0161 static void io_workaround_init(void)
0162 {
0163     if (io_workaround_inited)
0164         return;
0165     ppc_pci_io = iowa_pci_io;
0166     io_workaround_inited = true;
0167 }
0168
0169 /* Register new bus to support workaround */
0170 void iowa_register_bus(struct pci_controller *phb, struct ppc_pci_io *ops,
0171                int (*initfunc)(struct iowa_bus *, void *), void *data)
0172 {
0173     struct iowa_bus *bus;
0174     struct device_node *np = phb->dn;
0175
0176     io_workaround_init();
0177
0178     if (iowa_bus_count >= IOWA_MAX_BUS) {
0179         pr_err("IOWA:Too many pci bridges, "
0180                "workarounds disabled for %pOF\n", np);
0181         return;
0182     }
0183
0184     bus = &iowa_busses[iowa_bus_count];
0185     bus->phb = phb;
0186     bus->ops = ops;
0187     bus->private = data;
0188
0189     if (initfunc)
0190         if ((*initfunc)(bus, data))
0191             return;
0192
0193     iowa_bus_count++;
0194
0195     pr_debug("IOWA:[%d]Add bus, %pOF.\n", iowa_bus_count-1, np);
0196 }
0197