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 <log.h>
10 #include <pci.h>
11 #include <asm/global_data.h>
12 #include <asm/pci.h>
13 #include <asm/pirq_routing.h>
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
pirq_get_next_free_irq(struct udevice * dev,u8 * pirq,u16 bitmap,bool irq_already_routed[])17 static u8 pirq_get_next_free_irq(struct udevice *dev, u8 *pirq, u16 bitmap,
18 				 bool irq_already_routed[])
19 {
20 	int i, link;
21 	u8 irq = 0;
22 
23 	/* IRQ sharing starts from IRQ#3 */
24 	for (i = 3; i < 16; i++) {
25 		/* Can we assign this IRQ? */
26 		if (!((bitmap >> i) & 1))
27 			continue;
28 
29 		/* We can, now let's assume we can use this IRQ */
30 		irq = i;
31 
32 		/* Have we already routed it? */
33 		if (irq_already_routed[irq])
34 			continue;
35 
36 		for (link = 0; link < CONFIG_MAX_PIRQ_LINKS; link++) {
37 			if (pirq_check_irq_routed(dev, link, irq)) {
38 				irq_already_routed[irq] = true;
39 				break;
40 			}
41 		}
42 
43 		/* If it's not yet routed, use it */
44 		if (!irq_already_routed[irq]) {
45 			irq_already_routed[irq] = true;
46 			break;
47 		}
48 
49 		/* But if it was already routed, try the next one */
50 	}
51 
52 	/* Now we get our IRQ */
53 	return irq;
54 }
55 
pirq_route_irqs(struct udevice * dev,struct irq_info * irq,int num)56 void pirq_route_irqs(struct udevice *dev, struct irq_info *irq, int num)
57 {
58 	unsigned char irq_slot[MAX_INTX_ENTRIES];
59 	unsigned char pirq[CONFIG_MAX_PIRQ_LINKS];
60 	bool irq_already_routed[16];
61 	int i, intx;
62 
63 	memset(pirq, 0, CONFIG_MAX_PIRQ_LINKS);
64 	memset(irq_already_routed, '\0', sizeof(irq_already_routed));
65 
66 	/* Set PCI IRQs */
67 	for (i = 0; i < num; i++) {
68 		debug("PIRQ Entry %d Dev: %d.%x.%d\n", i,
69 		      irq->bus, irq->devfn >> 3, irq->devfn & 7);
70 
71 		for (intx = 0; intx < MAX_INTX_ENTRIES; intx++) {
72 			int link = irq->irq[intx].link;
73 			int bitmap = irq->irq[intx].bitmap;
74 			int irq = 0;
75 
76 			debug("INT%c link: %x bitmap: %x ",
77 			      'A' + intx, link, bitmap);
78 
79 			if (!bitmap || !link) {
80 				debug("not routed\n");
81 				irq_slot[intx] = irq;
82 				continue;
83 			}
84 
85 			/* translate link value to link number */
86 			link = pirq_translate_link(dev, link);
87 
88 			/* yet not routed */
89 			if (!pirq[link]) {
90 				irq = pirq_get_next_free_irq(dev, pirq, bitmap,
91 						irq_already_routed);
92 				pirq[link] = irq;
93 			} else {
94 				irq = pirq[link];
95 			}
96 
97 			debug("IRQ: %d\n", irq);
98 			irq_slot[intx] = irq;
99 
100 			/* Assign IRQ in the interrupt router */
101 			pirq_assign_irq(dev, link, irq);
102 		}
103 
104 		/* Bus, device, slots IRQs for {A,B,C,D} */
105 		pci_assign_irqs(irq->bus, irq->devfn >> 3, irq_slot);
106 
107 		irq++;
108 	}
109 
110 	for (i = 0; i < CONFIG_MAX_PIRQ_LINKS; i++)
111 		debug("PIRQ%c: %d\n", 'A' + i, pirq[i]);
112 }
113 
copy_pirq_routing_table(u32 addr,struct irq_routing_table * rt)114 u32 copy_pirq_routing_table(u32 addr, struct irq_routing_table *rt)
115 {
116 	struct irq_routing_table *rom_rt;
117 
118 	/* Align the table to be 16 byte aligned */
119 	addr = ALIGN(addr, 16);
120 
121 	debug("Copying Interrupt Routing Table to 0x%x\n", addr);
122 	memcpy((void *)(uintptr_t)addr, rt, rt->size);
123 
124 	/*
125 	 * We do the sanity check here against the copied table after memcpy,
126 	 * as something might go wrong after the memcpy, which is normally
127 	 * due to the F segment decode is not turned on to systeam RAM.
128 	 */
129 	rom_rt = (struct irq_routing_table *)(uintptr_t)addr;
130 	if (rom_rt->signature != PIRQ_SIGNATURE ||
131 	    rom_rt->version != PIRQ_VERSION || rom_rt->size % 16) {
132 		printf("Interrupt Routing Table not valid\n");
133 		return addr;
134 	}
135 
136 	return addr + rt->size;
137 }
138 
write_pirq_routing_table(ulong addr)139 ulong write_pirq_routing_table(ulong addr)
140 {
141 	if (!gd->arch.pirq_routing_table)
142 		return addr;
143 
144 	return copy_pirq_routing_table(addr, gd->arch.pirq_routing_table);
145 }
146