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 <log.h>
  10 #include <pci.h>
  11 #include <asm/pci.h>
  12 #include <asm/pirq_routing.h>
  13
  14 DECLARE_GLOBAL_DATA_PTR;
  15
  16 static u8 pirq_get_next_free_irq(struct udevice *dev, u8 *pirq, u16 bitmap,
  17                                  bool irq_already_routed[])
  18 {
  19         int i, link;
  20         u8 irq = 0;
  21
  22         /* IRQ sharing starts from IRQ#3 */
  23         for (i = 3; i < 16; i++) {
  24                 /* Can we assign this IRQ? */
  25                 if (!((bitmap >> i) & 1))
  26                         continue;
  27
  28                 /* We can, now let's assume we can use this IRQ */
  29                 irq = i;
  30
  31                 /* Have we already routed it? */
  32                 if (irq_already_routed[irq])
  33                         continue;
  34
  35                 for (link = 0; link < CONFIG_MAX_PIRQ_LINKS; link++) {
  36                         if (pirq_check_irq_routed(dev, link, irq)) {
  37                                 irq_already_routed[irq] = true;
  38                                 break;
  39                         }
  40                 }
  41
  42                 /* If it's not yet routed, use it */
  43                 if (!irq_already_routed[irq]) {
  44                         irq_already_routed[irq] = true;
  45                         break;
  46                 }
  47
  48                 /* But if it was already routed, try the next one */
  49         }
  50
  51         /* Now we get our IRQ */
  52         return irq;
  53 }
  54
  55 void pirq_route_irqs(struct udevice *dev, struct irq_info *irq, int num)
  56 {
  57         unsigned char irq_slot[MAX_INTX_ENTRIES];
  58         unsigned char pirq[CONFIG_MAX_PIRQ_LINKS];
  59         bool irq_already_routed[16];
  60         int i, intx;
  61
  62         memset(pirq, 0, CONFIG_MAX_PIRQ_LINKS);
  63         memset(irq_already_routed, '\0', sizeof(irq_already_routed));
  64
  65         /* Set PCI IRQs */
  66         for (i = 0; i < num; i++) {
  67                 debug("PIRQ Entry %d Dev: %d.%x.%d\n", i,
  68                       irq->bus, irq->devfn >> 3, irq->devfn & 7);
  69
  70                 for (intx = 0; intx < MAX_INTX_ENTRIES; intx++) {
  71                         int link = irq->irq[intx].link;
  72                         int bitmap = irq->irq[intx].bitmap;
  73                         int irq = 0;
  74
  75                         debug("INT%c link: %x bitmap: %x ",
  76                               'A' + intx, link, bitmap);
  77
  78                         if (!bitmap || !link) {
  79                                 debug("not routed\n");
  80                                 irq_slot[intx] = irq;
  81                                 continue;
  82                         }
  83
  84                         /* translate link value to link number */
  85                         link = pirq_translate_link(dev, link);
  86
  87                         /* yet not routed */
  88                         if (!pirq[link]) {
  89                                 irq = pirq_get_next_free_irq(dev, pirq, bitmap,
  90                                                 irq_already_routed);
  91                                 pirq[link] = irq;
  92                         } else {
  93                                 irq = pirq[link];
  94                         }
  95
  96                         debug("IRQ: %d\n", irq);
  97                         irq_slot[intx] = irq;
  98
  99                         /* Assign IRQ in the interrupt router */
 100                         pirq_assign_irq(dev, link, irq);
 101                 }
 102
 103                 /* Bus, device, slots IRQs for {A,B,C,D} */
 104                 pci_assign_irqs(irq->bus, irq->devfn >> 3, irq_slot);
 105
 106                 irq++;
 107         }
 108
 109         for (i = 0; i < CONFIG_MAX_PIRQ_LINKS; i++)
 110                 debug("PIRQ%c: %d\n", 'A' + i, pirq[i]);
 111 }
 112
 113 u32 copy_pirq_routing_table(u32 addr, struct irq_routing_table *rt)
 114 {
 115         struct irq_routing_table *rom_rt;
 116
 117         /* Align the table to be 16 byte aligned */
 118         addr = ALIGN(addr, 16);
 119
 120         debug("Copying Interrupt Routing Table to 0x%x\n", addr);
 121         memcpy((void *)(uintptr_t)addr, rt, rt->size);
 122
 123         /*
 124          * We do the sanity check here against the copied table after memcpy,
 125          * as something might go wrong after the memcpy, which is normally
 126          * due to the F segment decode is not turned on to systeam RAM.
 127          */
 128         rom_rt = (struct irq_routing_table *)(uintptr_t)addr;
 129         if (rom_rt->signature != PIRQ_SIGNATURE ||
 130             rom_rt->version != PIRQ_VERSION || rom_rt->size % 16) {
 131                 printf("Interrupt Routing Table not valid\n");
 132                 return addr;
 133         }
 134
 135         return addr + rt->size;
 136 }
 137
 138 ulong write_pirq_routing_table(ulong addr)
 139 {
 140         if (!gd->arch.pirq_routing_table)
 141                 return addr;
 142
 143         return copy_pirq_routing_table(addr, gd->arch.pirq_routing_table);
 144 }