xref: /openbmc/u-boot/arch/x86/lib/pirq_routing.c (revision 1d2c0506)
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 bool irq_already_routed[16];
15 
16 static u8 pirq_get_next_free_irq(struct udevice *dev, u8 *pirq, u16 bitmap)
17 {
18 	int i, link;
19 	u8 irq = 0;
20 
21 	/* IRQ sharing starts from IRQ#3 */
22 	for (i = 3; i < 16; i++) {
23 		/* Can we assign this IRQ? */
24 		if (!((bitmap >> i) & 1))
25 			continue;
26 
27 		/* We can, now let's assume we can use this IRQ */
28 		irq = i;
29 
30 		/* Have we already routed it? */
31 		if (irq_already_routed[irq])
32 			continue;
33 
34 		for (link = 0; link < CONFIG_MAX_PIRQ_LINKS; link++) {
35 			if (pirq_check_irq_routed(dev, link, irq)) {
36 				irq_already_routed[irq] = true;
37 				break;
38 			}
39 		}
40 
41 		/* If it's not yet routed, use it */
42 		if (!irq_already_routed[irq]) {
43 			irq_already_routed[irq] = true;
44 			break;
45 		}
46 
47 		/* But if it was already routed, try the next one */
48 	}
49 
50 	/* Now we get our IRQ */
51 	return irq;
52 }
53 
54 void pirq_route_irqs(struct udevice *dev, struct irq_info *irq, int num)
55 {
56 	unsigned char irq_slot[MAX_INTX_ENTRIES];
57 	unsigned char pirq[CONFIG_MAX_PIRQ_LINKS];
58 	int i, intx;
59 
60 	memset(pirq, 0, CONFIG_MAX_PIRQ_LINKS);
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 				pirq[link] = irq;
88 			} else {
89 				irq = pirq[link];
90 			}
91 
92 			debug("IRQ: %d\n", irq);
93 			irq_slot[intx] = irq;
94 
95 			/* Assign IRQ in the interrupt router */
96 			pirq_assign_irq(dev, link, irq);
97 		}
98 
99 		/* Bus, device, slots IRQs for {A,B,C,D} */
100 		pci_assign_irqs(irq->bus, irq->devfn >> 3, irq_slot);
101 
102 		irq++;
103 	}
104 
105 	for (i = 0; i < CONFIG_MAX_PIRQ_LINKS; i++)
106 		debug("PIRQ%c: %d\n", 'A' + i, pirq[i]);
107 }
108 
109 u32 copy_pirq_routing_table(u32 addr, struct irq_routing_table *rt)
110 {
111 	struct irq_routing_table *rom_rt;
112 
113 	/* Align the table to be 16 byte aligned */
114 	addr = ALIGN(addr, 16);
115 
116 	debug("Copying Interrupt Routing Table to 0x%x\n", addr);
117 	memcpy((void *)addr, rt, rt->size);
118 
119 	/*
120 	 * We do the sanity check here against the copied table after memcpy,
121 	 * as something might go wrong after the memcpy, which is normally
122 	 * due to the F segment decode is not turned on to systeam RAM.
123 	 */
124 	rom_rt = (struct irq_routing_table *)addr;
125 	if (rom_rt->signature != PIRQ_SIGNATURE ||
126 	    rom_rt->version != PIRQ_VERSION || rom_rt->size % 16) {
127 		printf("Interrupt Routing Table not valid\n");
128 		return addr;
129 	}
130 
131 	return addr + rt->size;
132 }
133