xref: /openbmc/u-boot/arch/x86/lib/pirq_routing.c (revision 6e87ae1c)
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 
14 static u8 pirq_get_next_free_irq(struct udevice *dev, u8 *pirq, u16 bitmap,
15 				 bool irq_already_routed[])
16 {
17 	int i, link;
18 	u8 irq = 0;
19 
20 	/* IRQ sharing starts from IRQ#3 */
21 	for (i = 3; i < 16; i++) {
22 		/* Can we assign this IRQ? */
23 		if (!((bitmap >> i) & 1))
24 			continue;
25 
26 		/* We can, now let's assume we can use this IRQ */
27 		irq = i;
28 
29 		/* Have we already routed it? */
30 		if (irq_already_routed[irq])
31 			continue;
32 
33 		for (link = 0; link < CONFIG_MAX_PIRQ_LINKS; link++) {
34 			if (pirq_check_irq_routed(dev, link, irq)) {
35 				irq_already_routed[irq] = true;
36 				break;
37 			}
38 		}
39 
40 		/* If it's not yet routed, use it */
41 		if (!irq_already_routed[irq]) {
42 			irq_already_routed[irq] = true;
43 			break;
44 		}
45 
46 		/* But if it was already routed, try the next one */
47 	}
48 
49 	/* Now we get our IRQ */
50 	return irq;
51 }
52 
53 void pirq_route_irqs(struct udevice *dev, struct irq_info *irq, int num)
54 {
55 	unsigned char irq_slot[MAX_INTX_ENTRIES];
56 	unsigned char pirq[CONFIG_MAX_PIRQ_LINKS];
57 	bool irq_already_routed[16];
58 	int i, intx;
59 
60 	memset(pirq, 0, CONFIG_MAX_PIRQ_LINKS);
61 	memset(irq_already_routed, '\0', sizeof(irq_already_routed));
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 						irq_already_routed);
89 				pirq[link] = irq;
90 			} else {
91 				irq = pirq[link];
92 			}
93 
94 			debug("IRQ: %d\n", irq);
95 			irq_slot[intx] = irq;
96 
97 			/* Assign IRQ in the interrupt router */
98 			pirq_assign_irq(dev, link, irq);
99 		}
100 
101 		/* Bus, device, slots IRQs for {A,B,C,D} */
102 		pci_assign_irqs(irq->bus, irq->devfn >> 3, irq_slot);
103 
104 		irq++;
105 	}
106 
107 	for (i = 0; i < CONFIG_MAX_PIRQ_LINKS; i++)
108 		debug("PIRQ%c: %d\n", 'A' + i, pirq[i]);
109 }
110 
111 u32 copy_pirq_routing_table(u32 addr, struct irq_routing_table *rt)
112 {
113 	struct irq_routing_table *rom_rt;
114 
115 	/* Align the table to be 16 byte aligned */
116 	addr = ALIGN(addr, 16);
117 
118 	debug("Copying Interrupt Routing Table to 0x%x\n", addr);
119 	memcpy((void *)(uintptr_t)addr, rt, rt->size);
120 
121 	/*
122 	 * We do the sanity check here against the copied table after memcpy,
123 	 * as something might go wrong after the memcpy, which is normally
124 	 * due to the F segment decode is not turned on to systeam RAM.
125 	 */
126 	rom_rt = (struct irq_routing_table *)(uintptr_t)addr;
127 	if (rom_rt->signature != PIRQ_SIGNATURE ||
128 	    rom_rt->version != PIRQ_VERSION || rom_rt->size % 16) {
129 		printf("Interrupt Routing Table not valid\n");
130 		return addr;
131 	}
132 
133 	return addr + rt->size;
134 }
135