xref: /openbmc/u-boot/arch/x86/lib/pirq_routing.c (revision ee7bb5be)
1 /*
2  * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
3  *
4  * Part of this file is ported from coreboot src/arch/x86/boot/pirq_routing.c
5  *
6  * SPDX-License-Identifier:	GPL-2.0+
7  */
8 
9 #include <common.h>
10 #include <pci.h>
11 #include <asm/pci.h>
12 #include <asm/pirq_routing.h>
13 #include <asm/tables.h>
14 
15 static bool irq_already_routed[16];
16 
17 static u8 pirq_get_next_free_irq(struct udevice *dev, u8 *pirq, u16 bitmap)
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 	int i, intx;
60 
61 	memset(pirq, 0, CONFIG_MAX_PIRQ_LINKS);
62 
63 	/* Set PCI IRQs */
64 	for (i = 0; i < num; i++) {
65 		debug("PIRQ Entry %d Dev: %d.%x.%d\n", i,
66 		      irq->bus, irq->devfn >> 3, irq->devfn & 7);
67 
68 		for (intx = 0; intx < MAX_INTX_ENTRIES; intx++) {
69 			int link = irq->irq[intx].link;
70 			int bitmap = irq->irq[intx].bitmap;
71 			int irq = 0;
72 
73 			debug("INT%c link: %x bitmap: %x ",
74 			      'A' + intx, link, bitmap);
75 
76 			if (!bitmap || !link) {
77 				debug("not routed\n");
78 				irq_slot[intx] = irq;
79 				continue;
80 			}
81 
82 			/* translate link value to link number */
83 			link = pirq_translate_link(dev, link);
84 
85 			/* yet not routed */
86 			if (!pirq[link]) {
87 				irq = pirq_get_next_free_irq(dev, pirq, bitmap);
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 	/* Fix up the table checksum */
115 	rt->checksum = table_compute_checksum(rt, rt->size);
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 *)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 *)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