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
15DECLARE_GLOBAL_DATA_PTR;
16
17static 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
56void 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
114u32 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
139ulong 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