Home | History | Annotate | Download | only in lib 
      1 // SPDX-License-Identifier: GPL-2.0+
      2 /*
      3  * Copyright (C) 2015, Bin Meng <bmeng.cn (at) 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 }
    134