xref: /openbmc/u-boot/arch/x86/lib/pirq_routing.c (revision d66ff4ba)
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 }
134