xref: /openbmc/u-boot/arch/x86/cpu/irq.c (revision 00a457b2)
1 /*
2  * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <errno.h>
9 #include <fdtdec.h>
10 #include <malloc.h>
11 #include <asm/io.h>
12 #include <asm/irq.h>
13 #include <asm/pci.h>
14 #include <asm/pirq_routing.h>
15 
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 static struct irq_router irq_router;
19 static struct irq_routing_table *pirq_routing_table;
20 
21 bool pirq_check_irq_routed(int link, u8 irq)
22 {
23 	u8 pirq;
24 	int base = irq_router.link_base;
25 
26 	if (irq_router.config == PIRQ_VIA_PCI)
27 		pirq = x86_pci_read_config8(irq_router.bdf,
28 					    LINK_N2V(link, base));
29 	else
30 		pirq = readb(irq_router.ibase + LINK_N2V(link, base));
31 
32 	pirq &= 0xf;
33 
34 	/* IRQ# 0/1/2/8/13 are reserved */
35 	if (pirq < 3 || pirq == 8 || pirq == 13)
36 		return false;
37 
38 	return pirq == irq ? true : false;
39 }
40 
41 int pirq_translate_link(int link)
42 {
43 	return LINK_V2N(link, irq_router.link_base);
44 }
45 
46 void pirq_assign_irq(int link, u8 irq)
47 {
48 	int base = irq_router.link_base;
49 
50 	/* IRQ# 0/1/2/8/13 are reserved */
51 	if (irq < 3 || irq == 8 || irq == 13)
52 		return;
53 
54 	if (irq_router.config == PIRQ_VIA_PCI)
55 		x86_pci_write_config8(irq_router.bdf,
56 				      LINK_N2V(link, base), irq);
57 	else
58 		writeb(irq, irq_router.ibase + LINK_N2V(link, base));
59 }
60 
61 static struct irq_info *check_dup_entry(struct irq_info *slot_base,
62 					int entry_num, int bus, int device)
63 {
64 	struct irq_info *slot = slot_base;
65 	int i;
66 
67 	for (i = 0; i < entry_num; i++) {
68 		if (slot->bus == bus && slot->devfn == (device << 3))
69 			break;
70 		slot++;
71 	}
72 
73 	return (i == entry_num) ? NULL : slot;
74 }
75 
76 static inline void fill_irq_info(struct irq_info *slot, int bus, int device,
77 				 int pin, int pirq)
78 {
79 	slot->bus = bus;
80 	slot->devfn = (device << 3) | 0;
81 	slot->irq[pin - 1].link = LINK_N2V(pirq, irq_router.link_base);
82 	slot->irq[pin - 1].bitmap = irq_router.irq_mask;
83 }
84 
85 __weak void cpu_irq_init(void)
86 {
87 	return;
88 }
89 
90 static int create_pirq_routing_table(void)
91 {
92 	const void *blob = gd->fdt_blob;
93 	struct fdt_pci_addr addr;
94 	int node;
95 	int len, count;
96 	const u32 *cell;
97 	struct irq_routing_table *rt;
98 	struct irq_info *slot, *slot_base;
99 	int irq_entries = 0;
100 	int i;
101 	int ret;
102 
103 	node = fdtdec_next_compatible(blob, 0, COMPAT_INTEL_IRQ_ROUTER);
104 	if (node < 0) {
105 		debug("%s: Cannot find irq router node\n", __func__);
106 		return -EINVAL;
107 	}
108 
109 	ret = fdtdec_get_pci_addr(blob, node, FDT_PCI_SPACE_CONFIG,
110 				  "reg", &addr);
111 	if (ret)
112 		return ret;
113 
114 	/* extract the bdf from fdt_pci_addr */
115 	irq_router.bdf = addr.phys_hi & 0xffff00;
116 
117 	ret = fdt_find_string(blob, node, "intel,pirq-config", "pci");
118 	if (!ret) {
119 		irq_router.config = PIRQ_VIA_PCI;
120 	} else {
121 		ret = fdt_find_string(blob, node, "intel,pirq-config", "ibase");
122 		if (!ret)
123 			irq_router.config = PIRQ_VIA_IBASE;
124 		else
125 			return -EINVAL;
126 	}
127 
128 	ret = fdtdec_get_int(blob, node, "intel,pirq-link", -1);
129 	if (ret == -1)
130 		return ret;
131 	irq_router.link_base = ret;
132 
133 	irq_router.irq_mask = fdtdec_get_int(blob, node,
134 					     "intel,pirq-mask", PIRQ_BITMAP);
135 
136 	if (irq_router.config == PIRQ_VIA_IBASE) {
137 		int ibase_off;
138 
139 		ibase_off = fdtdec_get_int(blob, node, "intel,ibase-offset", 0);
140 		if (!ibase_off)
141 			return -EINVAL;
142 
143 		/*
144 		 * Here we assume that the IBASE register has already been
145 		 * properly configured by U-Boot before.
146 		 *
147 		 * By 'valid' we mean:
148 		 *   1) a valid memory space carved within system memory space
149 		 *      assigned to IBASE register block.
150 		 *   2) memory range decoding is enabled.
151 		 * Hence we don't do any santify test here.
152 		 */
153 		irq_router.ibase = x86_pci_read_config32(irq_router.bdf,
154 							 ibase_off);
155 		irq_router.ibase &= ~0xf;
156 	}
157 
158 	cell = fdt_getprop(blob, node, "intel,pirq-routing", &len);
159 	if (!cell || len % sizeof(struct pirq_routing))
160 		return -EINVAL;
161 	count = len / sizeof(struct pirq_routing);
162 
163 	rt = calloc(1, sizeof(struct irq_routing_table));
164 	if (!rt)
165 		return -ENOMEM;
166 
167 	/* Populate the PIRQ table fields */
168 	rt->signature = PIRQ_SIGNATURE;
169 	rt->version = PIRQ_VERSION;
170 	rt->rtr_bus = PCI_BUS(irq_router.bdf);
171 	rt->rtr_devfn = (PCI_DEV(irq_router.bdf) << 3) |
172 			PCI_FUNC(irq_router.bdf);
173 	rt->rtr_vendor = PCI_VENDOR_ID_INTEL;
174 	rt->rtr_device = PCI_DEVICE_ID_INTEL_ICH7_31;
175 
176 	slot_base = rt->slots;
177 
178 	/* Now fill in the irq_info entries in the PIRQ table */
179 	for (i = 0; i < count;
180 	     i++, cell += sizeof(struct pirq_routing) / sizeof(u32)) {
181 		struct pirq_routing pr;
182 
183 		pr.bdf = fdt_addr_to_cpu(cell[0]);
184 		pr.pin = fdt_addr_to_cpu(cell[1]);
185 		pr.pirq = fdt_addr_to_cpu(cell[2]);
186 
187 		debug("irq_info %d: b.d.f %x.%x.%x INT%c PIRQ%c\n",
188 		      i, PCI_BUS(pr.bdf), PCI_DEV(pr.bdf),
189 		      PCI_FUNC(pr.bdf), 'A' + pr.pin - 1,
190 		      'A' + pr.pirq);
191 
192 		slot = check_dup_entry(slot_base, irq_entries,
193 				       PCI_BUS(pr.bdf), PCI_DEV(pr.bdf));
194 		if (slot) {
195 			debug("found entry for bus %d device %d, ",
196 			      PCI_BUS(pr.bdf), PCI_DEV(pr.bdf));
197 
198 			if (slot->irq[pr.pin - 1].link) {
199 				debug("skipping\n");
200 
201 				/*
202 				 * Sanity test on the routed PIRQ pin
203 				 *
204 				 * If they don't match, show a warning to tell
205 				 * there might be something wrong with the PIRQ
206 				 * routing information in the device tree.
207 				 */
208 				if (slot->irq[pr.pin - 1].link !=
209 					LINK_N2V(pr.pirq, irq_router.link_base))
210 					debug("WARNING: Inconsistent PIRQ routing information\n");
211 				continue;
212 			}
213 		} else {
214 			slot = slot_base + irq_entries++;
215 		}
216 		debug("writing INT%c\n", 'A' + pr.pin - 1);
217 		fill_irq_info(slot, PCI_BUS(pr.bdf), PCI_DEV(pr.bdf), pr.pin,
218 			      pr.pirq);
219 	}
220 
221 	rt->size = irq_entries * sizeof(struct irq_info) + 32;
222 
223 	pirq_routing_table = rt;
224 
225 	return 0;
226 }
227 
228 int pirq_init(void)
229 {
230 	int ret;
231 
232 	cpu_irq_init();
233 
234 	ret = create_pirq_routing_table();
235 	if (ret) {
236 		debug("Failed to create pirq routing table\n");
237 		return ret;
238 	}
239 	/* Route PIRQ */
240 	pirq_route_irqs(pirq_routing_table->slots,
241 			get_irq_slot_count(pirq_routing_table));
242 
243 	return 0;
244 }
245 
246 u32 write_pirq_routing_table(u32 addr)
247 {
248 	if (!pirq_routing_table)
249 		return addr;
250 
251 	return copy_pirq_routing_table(addr, pirq_routing_table);
252 }
253