xref: /aosp_15_r20/external/coreboot/src/arch/x86/pirq_routing.c (revision b9411a12aaaa7e1e6a6fb7c5e057f44ee179a49c)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 
3 #include <arch/pirq_routing.h>
4 #include <commonlib/helpers.h>
5 #include <console/console.h>
6 #include <device/pci.h>
7 #include <string.h>
8 #include <types.h>
9 
check_pirq_routing_table(struct irq_routing_table * rt)10 static void check_pirq_routing_table(struct irq_routing_table *rt)
11 {
12 	uint8_t *addr = (uint8_t *)rt;
13 	uint8_t sum = 0;
14 	int i;
15 
16 	printk(BIOS_INFO, "Checking Interrupt Routing Table consistency...\n");
17 
18 	if (sizeof(struct irq_routing_table) != rt->size) {
19 		printk(BIOS_WARNING,
20 			"Inconsistent Interrupt Routing Table size (0x%x/0x%x).\n",
21 			(unsigned int)sizeof(struct irq_routing_table),
22 			rt->size);
23 		rt->size = sizeof(struct irq_routing_table);
24 	}
25 
26 	for (i = 0; i < rt->size; i++)
27 		sum += addr[i];
28 
29 	printk(BIOS_DEBUG, "%s(): Interrupt Routing Table located at %p.\n",
30 		     __func__, addr);
31 
32 	sum = rt->checksum - sum;
33 
34 	if (sum != rt->checksum) {
35 		printk(BIOS_WARNING,
36 			"Interrupt Routing Table checksum is: 0x%02x but should be: 0x%02x.\n",
37 			rt->checksum, sum);
38 		rt->checksum = sum;
39 	}
40 
41 	if (rt->signature != PIRQ_SIGNATURE || rt->version != PIRQ_VERSION ||
42 	    rt->size % 16) {
43 		printk(BIOS_WARNING, "Interrupt Routing Table not valid.\n");
44 		return;
45 	}
46 
47 	sum = 0;
48 	for (i = 0; i < rt->size; i++)
49 		sum += addr[i];
50 
51 	/* We're manually fixing the checksum above. This warning can probably
52 	 * never happen because if the target location is read-only this
53 	 * function would have bailed out earlier.
54 	 */
55 	if (sum) {
56 		printk(BIOS_WARNING, "Checksum error in Interrupt Routing Table "
57 				"could not be fixed.\n");
58 	}
59 
60 	printk(BIOS_INFO, "done.\n");
61 }
62 
verify_copy_pirq_routing_table(unsigned long addr,const struct irq_routing_table * routing_table)63 static enum cb_err verify_copy_pirq_routing_table(unsigned long addr,
64 	const struct irq_routing_table *routing_table)
65 {
66 	int i;
67 	uint8_t *rt_orig, *rt_curr;
68 
69 	rt_curr = (uint8_t *)addr;
70 	rt_orig = (uint8_t *)routing_table;
71 	printk(BIOS_INFO,
72 		"Verifying copy of Interrupt Routing Table at 0x%08lx... ",
73 		addr);
74 	for (i = 0; i < routing_table->size; i++) {
75 		if (*(rt_curr + i) != *(rt_orig + i)) {
76 			printk(BIOS_INFO, "failed\n");
77 			return CB_ERR;
78 		}
79 	}
80 	printk(BIOS_INFO, "done\n");
81 
82 	check_pirq_routing_table((struct irq_routing_table *)addr);
83 
84 	return CB_SUCCESS;
85 }
86 
pirq_get_next_free_irq(u8 * pirq,u16 bitmap)87 static u8 pirq_get_next_free_irq(u8 *pirq, u16 bitmap)
88 {
89 	int i, link;
90 	u8 irq = 0;
91 	for (i = 2; i <= 15; i++) {
92 		/* Can we assign this IRQ ? */
93 		if (!((bitmap >> i) & 1))
94 			continue;
95 		/* We can, Now let's assume we can use this IRQ */
96 		irq = i;
97 		/* And assume we have not yet routed it */
98 		int already_routed = 0;
99 		/* Have we already routed it ? */
100 		for (link = 0; link < CONFIG_MAX_PIRQ_LINKS; link++) {
101 			if (pirq[link] == irq) {
102 				already_routed = 1;
103 				break;
104 			}
105 		}
106 		/* If it's not yet routed, use it */
107 		if (!already_routed)
108 			break;
109 	}
110 	/* Now we got our IRQ */
111 	return irq;
112 }
113 
pirq_route_irqs(unsigned long addr)114 static void pirq_route_irqs(unsigned long addr)
115 {
116 	int i, intx, num_entries;
117 	unsigned char irq_slot[MAX_INTX_ENTRIES];
118 	unsigned char pirq[CONFIG_MAX_PIRQ_LINKS];
119 	struct irq_routing_table *pirq_tbl;
120 
121 	memset(pirq, 0, CONFIG_MAX_PIRQ_LINKS);
122 
123 	pirq_tbl = (struct irq_routing_table *)(addr);
124 	num_entries = (pirq_tbl->size - 32) / 16;
125 
126 	/* Set PCI IRQs. */
127 	for (i = 0; i < num_entries; i++) {
128 		u8 bus = pirq_tbl->slots[i].bus;
129 		u8 devfn = pirq_tbl->slots[i].devfn;
130 
131 		printk(BIOS_DEBUG, "PIRQ Entry %d Dev/Fn: %X Slot: %d\n", i,
132 			devfn >> 3, pirq_tbl->slots[i].slot);
133 
134 		for (intx = 0; intx < MAX_INTX_ENTRIES; intx++) {
135 			int link = pirq_tbl->slots[i].irq[intx].link;
136 			int bitmap = pirq_tbl->slots[i].irq[intx].bitmap;
137 			int irq = 0;
138 
139 			printk(BIOS_DEBUG, "INT: %c link: %x bitmap: %x  ",
140 				'A' + intx, link, bitmap);
141 
142 			if (!bitmap || !link || link > CONFIG_MAX_PIRQ_LINKS) {
143 				printk(BIOS_DEBUG, "not routed\n");
144 				irq_slot[intx] = irq;
145 				continue;
146 			}
147 
148 			/* yet not routed */
149 			if (!pirq[link - 1]) {
150 				irq = pirq_get_next_free_irq(pirq, bitmap);
151 				if (irq)
152 					pirq[link - 1] = irq;
153 			} else
154 				irq = pirq[link - 1];
155 
156 			printk(BIOS_DEBUG, "IRQ: %d\n", irq);
157 			irq_slot[intx] = irq;
158 		}
159 
160 		/* Bus, device, slots IRQs for {A,B,C,D}. */
161 		pci_assign_irqs(pcidev_path_on_bus(bus, devfn), irq_slot);
162 	}
163 
164 	for (i = 0; i < CONFIG_MAX_PIRQ_LINKS; i++)
165 		printk(BIOS_DEBUG, "PIRQ%c: %d\n", i + 'A', pirq[i]);
166 
167 	pirq_assign_irqs(pirq);
168 }
169 
copy_pirq_routing_table(unsigned long addr,const struct irq_routing_table * routing_table)170 unsigned long copy_pirq_routing_table(unsigned long addr,
171 	const struct irq_routing_table *routing_table)
172 {
173 	/* Align the table to be 16 byte aligned. */
174 	addr = ALIGN_UP(addr, 16);
175 
176 	/* This table must be between 0xf0000 & 0x100000 */
177 	printk(BIOS_INFO, "Copying Interrupt Routing Table to 0x%08lx... ",
178 		addr);
179 	memcpy((void *)addr, routing_table, routing_table->size);
180 	printk(BIOS_INFO, "done.\n");
181 	if (CONFIG(DEBUG_PIRQ))
182 		verify_copy_pirq_routing_table(addr, routing_table);
183 	if (CONFIG(PIRQ_ROUTE))
184 		pirq_route_irqs(addr);
185 
186 	return addr + routing_table->size;
187 }
188