arch/x86/cpu/irq.c

   1 /*
   2  * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <errno.h>
   9 #include <fdtdec.h>
  10 #include <malloc.h>
  11 #include <asm/io.h>
  12 #include <asm/irq.h>
  13 #include <asm/pci.h>
  14 #include <asm/pirq_routing.h>
  15
  16 DECLARE_GLOBAL_DATA_PTR;
  17
  18 static struct irq_router irq_router;
  19 static struct irq_routing_table *pirq_routing_table;
  20
  21 bool pirq_check_irq_routed(int link, u8 irq)
  22 {
  23         u8 pirq;
  24         int base = irq_router.link_base;
  25
  26         if (irq_router.config == PIRQ_VIA_PCI)
  27                 pirq = x86_pci_read_config8(irq_router.bdf,
  28                                             LINK_N2V(link, base));
  29         else
  30                 pirq = readb(irq_router.ibase + LINK_N2V(link, base));
  31
  32         pirq &= 0xf;
  33
  34         /* IRQ# 0/1/2/8/13 are reserved */
  35         if (pirq < 3 || pirq == 8 || pirq == 13)
  36                 return false;
  37
  38         return pirq == irq ? true : false;
  39 }
  40
  41 int pirq_translate_link(int link)
  42 {
  43         return LINK_V2N(link, irq_router.link_base);
  44 }
  45
  46 void pirq_assign_irq(int link, u8 irq)
  47 {
  48         int base = irq_router.link_base;
  49
  50         /* IRQ# 0/1/2/8/13 are reserved */
  51         if (irq < 3 || irq == 8 || irq == 13)
  52                 return;
  53
  54         if (irq_router.config == PIRQ_VIA_PCI)
  55                 x86_pci_write_config8(irq_router.bdf,
  56                                       LINK_N2V(link, base), irq);
  57         else
  58                 writeb(irq, irq_router.ibase + LINK_N2V(link, base));
  59 }
  60
  61 static struct irq_info *check_dup_entry(struct irq_info *slot_base,
  62                                         int entry_num, int bus, int device)
  63 {
  64         struct irq_info *slot = slot_base;
  65         int i;
  66
  67         for (i = 0; i < entry_num; i++) {
  68                 if (slot->bus == bus && slot->devfn == (device << 3))
  69                         break;
  70                 slot++;
  71         }
  72
  73         return (i == entry_num) ? NULL : slot;
  74 }
  75
  76 static inline void fill_irq_info(struct irq_info *slot, int bus, int device,
  77                                  int pin, int pirq)
  78 {
  79         slot->bus = bus;
  80         slot->devfn = (device << 3) | 0;
  81         slot->irq[pin - 1].link = LINK_N2V(pirq, irq_router.link_base);
  82         slot->irq[pin - 1].bitmap = irq_router.irq_mask;
  83 }
  84
  85 __weak void cpu_irq_init(void)
  86 {
  87         return;
  88 }
  89
  90 static int create_pirq_routing_table(void)
  91 {
  92         const void *blob = gd->fdt_blob;
  93         struct fdt_pci_addr addr;
  94         int node;
  95         int len, count;
  96         const u32 *cell;
  97         struct irq_routing_table *rt;
  98         struct irq_info *slot, *slot_base;
  99         int irq_entries = 0;
 100         int i;
 101         int ret;
 102
 103         node = fdtdec_next_compatible(blob, 0, COMPAT_INTEL_IRQ_ROUTER);
 104         if (node < 0) {
 105                 debug("%s: Cannot find irq router node\n", __func__);
 106                 return -EINVAL;
 107         }
 108
 109         ret = fdtdec_get_pci_addr(blob, node, FDT_PCI_SPACE_CONFIG,
 110                                   "reg", &addr);
 111         if (ret)
 112                 return ret;
 113
 114         /* extract the bdf from fdt_pci_addr */
 115         irq_router.bdf = addr.phys_hi & 0xffff00;
 116
 117         ret = fdt_find_string(blob, node, "intel,pirq-config", "pci");
 118         if (!ret) {
 119                 irq_router.config = PIRQ_VIA_PCI;
 120         } else {
 121                 ret = fdt_find_string(blob, node, "intel,pirq-config", "ibase");
 122                 if (!ret)
 123                         irq_router.config = PIRQ_VIA_IBASE;
 124                 else
 125                         return -EINVAL;
 126         }
 127
 128         ret = fdtdec_get_int(blob, node, "intel,pirq-link", -1);
 129         if (ret == -1)
 130                 return ret;
 131         irq_router.link_base = ret;
 132
 133         irq_router.irq_mask = fdtdec_get_int(blob, node,
 134                                              "intel,pirq-mask", PIRQ_BITMAP);
 135
 136         if (irq_router.config == PIRQ_VIA_IBASE) {
 137                 int ibase_off;
 138
 139                 ibase_off = fdtdec_get_int(blob, node, "intel,ibase-offset", 0);
 140                 if (!ibase_off)
 141                         return -EINVAL;
 142
 143                 /*
 144                  * Here we assume that the IBASE register has already been
 145                  * properly configured by U-Boot before.
 146                  *
 147                  * By 'valid' we mean:
 148                  *   1) a valid memory space carved within system memory space
 149                  *      assigned to IBASE register block.
 150                  *   2) memory range decoding is enabled.
 151                  * Hence we don't do any santify test here.
 152                  */
 153                 irq_router.ibase = x86_pci_read_config32(irq_router.bdf,
 154                                                          ibase_off);
 155                 irq_router.ibase &= ~0xf;
 156         }
 157
 158         cell = fdt_getprop(blob, node, "intel,pirq-routing", &len);
 159         if (!cell || len % sizeof(struct pirq_routing))
 160                 return -EINVAL;
 161         count = len / sizeof(struct pirq_routing);
 162
 163         rt = calloc(1, sizeof(struct irq_routing_table));
 164         if (!rt)
 165                 return -ENOMEM;
 166
 167         /* Populate the PIRQ table fields */
 168         rt->signature = PIRQ_SIGNATURE;
 169         rt->version = PIRQ_VERSION;
 170         rt->rtr_bus = PCI_BUS(irq_router.bdf);
 171         rt->rtr_devfn = (PCI_DEV(irq_router.bdf) << 3) |
 172                         PCI_FUNC(irq_router.bdf);
 173         rt->rtr_vendor = PCI_VENDOR_ID_INTEL;
 174         rt->rtr_device = PCI_DEVICE_ID_INTEL_ICH7_31;
 175
 176         slot_base = rt->slots;
 177
 178         /* Now fill in the irq_info entries in the PIRQ table */
 179         for (i = 0; i < count;
 180              i++, cell += sizeof(struct pirq_routing) / sizeof(u32)) {
 181                 struct pirq_routing pr;
 182
 183                 pr.bdf = fdt_addr_to_cpu(cell[0]);
 184                 pr.pin = fdt_addr_to_cpu(cell[1]);
 185                 pr.pirq = fdt_addr_to_cpu(cell[2]);
 186
 187                 debug("irq_info %d: b.d.f %x.%x.%x INT%c PIRQ%c\n",
 188                       i, PCI_BUS(pr.bdf), PCI_DEV(pr.bdf),
 189                       PCI_FUNC(pr.bdf), 'A' + pr.pin - 1,
 190                       'A' + pr.pirq);
 191
 192                 slot = check_dup_entry(slot_base, irq_entries,
 193                                        PCI_BUS(pr.bdf), PCI_DEV(pr.bdf));
 194                 if (slot) {
 195                         debug("found entry for bus %d device %d, ",
 196                               PCI_BUS(pr.bdf), PCI_DEV(pr.bdf));
 197
 198                         if (slot->irq[pr.pin - 1].link) {
 199                                 debug("skipping\n");
 200
 201                                 /*
 202                                  * Sanity test on the routed PIRQ pin
 203                                  *
 204                                  * If they don't match, show a warning to tell
 205                                  * there might be something wrong with the PIRQ
 206                                  * routing information in the device tree.
 207                                  */
 208                                 if (slot->irq[pr.pin - 1].link !=
 209                                         LINK_N2V(pr.pirq, irq_router.link_base))
 210                                         debug("WARNING: Inconsistent PIRQ routing information\n");
 211                                 continue;
 212                         }
 213                 } else {
 214                         slot = slot_base + irq_entries++;
 215                 }
 216                 debug("writing INT%c\n", 'A' + pr.pin - 1);
 217                 fill_irq_info(slot, PCI_BUS(pr.bdf), PCI_DEV(pr.bdf), pr.pin,
 218                               pr.pirq);
 219         }
 220
 221         rt->size = irq_entries * sizeof(struct irq_info) + 32;
 222
 223         pirq_routing_table = rt;
 224
 225         return 0;
 226 }
 227
 228 int pirq_init(void)
 229 {
 230         int ret;
 231
 232         cpu_irq_init();
 233
 234         ret = create_pirq_routing_table();
 235         if (ret) {
 236                 debug("Failed to create pirq routing table\n");
 237                 return ret;
 238         }
 239         /* Route PIRQ */
 240         pirq_route_irqs(pirq_routing_table->slots,
 241                         get_irq_slot_count(pirq_routing_table));
 242
 243         return 0;
 244 }
 245
 246 u32 write_pirq_routing_table(u32 addr)
 247 {
 248         if (!pirq_routing_table)
 249                 return addr;
 250
 251         return copy_pirq_routing_table(addr, pirq_routing_table);
 252 }