arch/x86/lib/pirq_routing.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
   4  *
   5  * Part of this file is ported from coreboot src/arch/x86/boot/pirq_routing.c
   6  */
   7
   8 #include <common.h>
   9 #include <pci.h>
  10 #include <asm/pci.h>
  11 #include <asm/pirq_routing.h>
  12
  13 DECLARE_GLOBAL_DATA_PTR;
  14
  15 static u8 pirq_get_next_free_irq(struct udevice *dev, u8 *pirq, u16 bitmap,
  16                                  bool irq_already_routed[])
  17 {
  18         int i, link;
  19         u8 irq = 0;
  20
  21         /* IRQ sharing starts from IRQ#3 */
  22         for (i = 3; i < 16; i++) {
  23                 /* Can we assign this IRQ? */
  24                 if (!((bitmap >> i) & 1))
  25                         continue;
  26
  27                 /* We can, now let's assume we can use this IRQ */
  28                 irq = i;
  29
  30                 /* Have we already routed it? */
  31                 if (irq_already_routed[irq])
  32                         continue;
  33
  34                 for (link = 0; link < CONFIG_MAX_PIRQ_LINKS; link++) {
  35                         if (pirq_check_irq_routed(dev, link, irq)) {
  36                                 irq_already_routed[irq] = true;
  37                                 break;
  38                         }
  39                 }
  40
  41                 /* If it's not yet routed, use it */
  42                 if (!irq_already_routed[irq]) {
  43                         irq_already_routed[irq] = true;
  44                         break;
  45                 }
  46
  47                 /* But if it was already routed, try the next one */
  48         }
  49
  50         /* Now we get our IRQ */
  51         return irq;
  52 }
  53
  54 void pirq_route_irqs(struct udevice *dev, struct irq_info *irq, int num)
  55 {
  56         unsigned char irq_slot[MAX_INTX_ENTRIES];
  57         unsigned char pirq[CONFIG_MAX_PIRQ_LINKS];
  58         bool irq_already_routed[16];
  59         int i, intx;
  60
  61         memset(pirq, 0, CONFIG_MAX_PIRQ_LINKS);
  62         memset(irq_already_routed, '\0', sizeof(irq_already_routed));
  63
  64         /* Set PCI IRQs */
  65         for (i = 0; i < num; i++) {
  66                 debug("PIRQ Entry %d Dev: %d.%x.%d\n", i,
  67                       irq->bus, irq->devfn >> 3, irq->devfn & 7);
  68
  69                 for (intx = 0; intx < MAX_INTX_ENTRIES; intx++) {
  70                         int link = irq->irq[intx].link;
  71                         int bitmap = irq->irq[intx].bitmap;
  72                         int irq = 0;
  73
  74                         debug("INT%c link: %x bitmap: %x ",
  75                               'A' + intx, link, bitmap);
  76
  77                         if (!bitmap || !link) {
  78                                 debug("not routed\n");
  79                                 irq_slot[intx] = irq;
  80                                 continue;
  81                         }
  82
  83                         /* translate link value to link number */
  84                         link = pirq_translate_link(dev, link);
  85
  86                         /* yet not routed */
  87                         if (!pirq[link]) {
  88                                 irq = pirq_get_next_free_irq(dev, pirq, bitmap,
  89                                                 irq_already_routed);
  90                                 pirq[link] = irq;
  91                         } else {
  92                                 irq = pirq[link];
  93                         }
  94
  95                         debug("IRQ: %d\n", irq);
  96                         irq_slot[intx] = irq;
  97
  98                         /* Assign IRQ in the interrupt router */
  99                         pirq_assign_irq(dev, link, irq);
 100                 }
 101
 102                 /* Bus, device, slots IRQs for {A,B,C,D} */
 103                 pci_assign_irqs(irq->bus, irq->devfn >> 3, irq_slot);
 104
 105                 irq++;
 106         }
 107
 108         for (i = 0; i < CONFIG_MAX_PIRQ_LINKS; i++)
 109                 debug("PIRQ%c: %d\n", 'A' + i, pirq[i]);
 110 }
 111
 112 u32 copy_pirq_routing_table(u32 addr, struct irq_routing_table *rt)
 113 {
 114         struct irq_routing_table *rom_rt;
 115
 116         /* Align the table to be 16 byte aligned */
 117         addr = ALIGN(addr, 16);
 118
 119         debug("Copying Interrupt Routing Table to 0x%x\n", addr);
 120         memcpy((void *)(uintptr_t)addr, rt, rt->size);
 121
 122         /*
 123          * We do the sanity check here against the copied table after memcpy,
 124          * as something might go wrong after the memcpy, which is normally
 125          * due to the F segment decode is not turned on to systeam RAM.
 126          */
 127         rom_rt = (struct irq_routing_table *)(uintptr_t)addr;
 128         if (rom_rt->signature != PIRQ_SIGNATURE ||
 129             rom_rt->version != PIRQ_VERSION || rom_rt->size % 16) {
 130                 printf("Interrupt Routing Table not valid\n");
 131                 return addr;
 132         }
 133
 134         return addr + rt->size;
 135 }
 136
 137 ulong write_pirq_routing_table(ulong addr)
 138 {
 139         if (!gd->arch.pirq_routing_table)
 140                 return addr;
 141
 142         return copy_pirq_routing_table(addr, gd->arch.pirq_routing_table);
 143 }