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