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/global_data.h>
  12 #include <asm/pci.h>
  13 #include <asm/pirq_routing.h>
  14
  15 DECLARE_GLOBAL_DATA_PTR;
  16
  17 static u8 pirq_get_next_free_irq(struct udevice *dev, u8 *pirq, u16 bitmap,
  18                                  bool irq_already_routed[])
  19 {
  20         int i, link;
  21         u8 irq = 0;
  22
  23         /* IRQ sharing starts from IRQ#3 */
  24         for (i = 3; i < 16; i++) {
  25                 /* Can we assign this IRQ? */
  26                 if (!((bitmap >> i) & 1))
  27                         continue;
  28
  29                 /* We can, now let's assume we can use this IRQ */
  30                 irq = i;
  31
  32                 /* Have we already routed it? */
  33                 if (irq_already_routed[irq])
  34                         continue;
  35
  36                 for (link = 0; link < CONFIG_MAX_PIRQ_LINKS; link++) {
  37                         if (pirq_check_irq_routed(dev, link, irq)) {
  38                                 irq_already_routed[irq] = true;
  39                                 break;
  40                         }
  41                 }
  42
  43                 /* If it's not yet routed, use it */
  44                 if (!irq_already_routed[irq]) {
  45                         irq_already_routed[irq] = true;
  46                         break;
  47                 }
  48
  49                 /* But if it was already routed, try the next one */
  50         }
  51
  52         /* Now we get our IRQ */
  53         return irq;
  54 }
  55
  56 void pirq_route_irqs(struct udevice *dev, struct irq_info *irq, int num)
  57 {
  58         unsigned char irq_slot[MAX_INTX_ENTRIES];
  59         unsigned char pirq[CONFIG_MAX_PIRQ_LINKS];
  60         bool irq_already_routed[16];
  61         int i, intx;
  62
  63         memset(pirq, 0, CONFIG_MAX_PIRQ_LINKS);
  64         memset(irq_already_routed, '\0', sizeof(irq_already_routed));
  65
  66         /* Set PCI IRQs */
  67         for (i = 0; i < num; i++) {
  68                 debug("PIRQ Entry %d Dev: %d.%x.%d\n", i,
  69                       irq->bus, irq->devfn >> 3, irq->devfn & 7);
  70
  71                 for (intx = 0; intx < MAX_INTX_ENTRIES; intx++) {
  72                         int link = irq->irq[intx].link;
  73                         int bitmap = irq->irq[intx].bitmap;
  74                         int irq = 0;
  75
  76                         debug("INT%c link: %x bitmap: %x ",
  77                               'A' + intx, link, bitmap);
  78
  79                         if (!bitmap || !link) {
  80                                 debug("not routed\n");
  81                                 irq_slot[intx] = irq;
  82                                 continue;
  83                         }
  84
  85                         /* translate link value to link number */
  86                         link = pirq_translate_link(dev, link);
  87
  88                         /* yet not routed */
  89                         if (!pirq[link]) {
  90                                 irq = pirq_get_next_free_irq(dev, pirq, bitmap,
  91                                                 irq_already_routed);
  92                                 pirq[link] = irq;
  93                         } else {
  94                                 irq = pirq[link];
  95                         }
  96
  97                         debug("IRQ: %d\n", irq);
  98                         irq_slot[intx] = irq;
  99
 100                         /* Assign IRQ in the interrupt router */
 101                         pirq_assign_irq(dev, link, irq);
 102                 }
 103
 104                 /* Bus, device, slots IRQs for {A,B,C,D} */
 105                 pci_assign_irqs(irq->bus, irq->devfn >> 3, irq_slot);
 106
 107                 irq++;
 108         }
 109
 110         for (i = 0; i < CONFIG_MAX_PIRQ_LINKS; i++)
 111                 debug("PIRQ%c: %d\n", 'A' + i, pirq[i]);
 112 }
 113
 114 u32 copy_pirq_routing_table(u32 addr, struct irq_routing_table *rt)
 115 {
 116         struct irq_routing_table *rom_rt;
 117
 118         /* Align the table to be 16 byte aligned */
 119         addr = ALIGN(addr, 16);
 120
 121         debug("Copying Interrupt Routing Table to 0x%x\n", addr);
 122         memcpy((void *)(uintptr_t)addr, rt, rt->size);
 123
 124         /*
 125          * We do the sanity check here against the copied table after memcpy,
 126          * as something might go wrong after the memcpy, which is normally
 127          * due to the F segment decode is not turned on to systeam RAM.
 128          */
 129         rom_rt = (struct irq_routing_table *)(uintptr_t)addr;
 130         if (rom_rt->signature != PIRQ_SIGNATURE ||
 131             rom_rt->version != PIRQ_VERSION || rom_rt->size % 16) {
 132                 printf("Interrupt Routing Table not valid\n");
 133                 return addr;
 134         }
 135
 136         return addr + rt->size;
 137 }
 138
 139 ulong write_pirq_routing_table(ulong addr)
 140 {
 141         if (!gd->arch.pirq_routing_table)
 142                 return addr;
 143
 144         return copy_pirq_routing_table(addr, gd->arch.pirq_routing_table);
 145 }