xref: /openbmc/u-boot/arch/x86/cpu/irq.c (revision ad5b5801)
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 <dm.h>
9 #include <errno.h>
10 #include <fdtdec.h>
11 #include <malloc.h>
12 #include <asm/io.h>
13 #include <asm/irq.h>
14 #include <asm/pci.h>
15 #include <asm/pirq_routing.h>
16 
17 DECLARE_GLOBAL_DATA_PTR;
18 
19 static struct irq_routing_table *pirq_routing_table;
20 
21 bool pirq_check_irq_routed(struct udevice *dev, int link, u8 irq)
22 {
23 	struct irq_router *priv = dev_get_priv(dev);
24 	u8 pirq;
25 	int base = priv->link_base;
26 
27 	if (priv->config == PIRQ_VIA_PCI)
28 		dm_pci_read_config8(dev->parent, LINK_N2V(link, base), &pirq);
29 	else
30 		pirq = readb(priv->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(struct udevice *dev, int link)
42 {
43 	struct irq_router *priv = dev_get_priv(dev);
44 
45 	return LINK_V2N(link, priv->link_base);
46 }
47 
48 void pirq_assign_irq(struct udevice *dev, int link, u8 irq)
49 {
50 	struct irq_router *priv = dev_get_priv(dev);
51 	int base = priv->link_base;
52 
53 	/* IRQ# 0/1/2/8/13 are reserved */
54 	if (irq < 3 || irq == 8 || irq == 13)
55 		return;
56 
57 	if (priv->config == PIRQ_VIA_PCI)
58 		dm_pci_write_config8(dev->parent, LINK_N2V(link, base), irq);
59 	else
60 		writeb(irq, priv->ibase + LINK_N2V(link, base));
61 }
62 
63 static struct irq_info *check_dup_entry(struct irq_info *slot_base,
64 					int entry_num, int bus, int device)
65 {
66 	struct irq_info *slot = slot_base;
67 	int i;
68 
69 	for (i = 0; i < entry_num; i++) {
70 		if (slot->bus == bus && slot->devfn == (device << 3))
71 			break;
72 		slot++;
73 	}
74 
75 	return (i == entry_num) ? NULL : slot;
76 }
77 
78 static inline void fill_irq_info(struct irq_router *priv, struct irq_info *slot,
79 				 int bus, int device, int pin, int pirq)
80 {
81 	slot->bus = bus;
82 	slot->devfn = (device << 3) | 0;
83 	slot->irq[pin - 1].link = LINK_N2V(pirq, priv->link_base);
84 	slot->irq[pin - 1].bitmap = priv->irq_mask;
85 }
86 
87 static int create_pirq_routing_table(struct udevice *dev)
88 {
89 	struct irq_router *priv = dev_get_priv(dev);
90 	const void *blob = gd->fdt_blob;
91 	int node;
92 	int len, count;
93 	const u32 *cell;
94 	struct irq_routing_table *rt;
95 	struct irq_info *slot, *slot_base;
96 	int irq_entries = 0;
97 	int i;
98 	int ret;
99 
100 	node = dev->of_offset;
101 
102 	/* extract the bdf from fdt_pci_addr */
103 	priv->bdf = dm_pci_get_bdf(dev->parent);
104 
105 	ret = fdt_find_string(blob, node, "intel,pirq-config", "pci");
106 	if (!ret) {
107 		priv->config = PIRQ_VIA_PCI;
108 	} else {
109 		ret = fdt_find_string(blob, node, "intel,pirq-config", "ibase");
110 		if (!ret)
111 			priv->config = PIRQ_VIA_IBASE;
112 		else
113 			return -EINVAL;
114 	}
115 
116 	ret = fdtdec_get_int(blob, node, "intel,pirq-link", -1);
117 	if (ret == -1)
118 		return ret;
119 	priv->link_base = ret;
120 
121 	priv->irq_mask = fdtdec_get_int(blob, node,
122 					"intel,pirq-mask", PIRQ_BITMAP);
123 
124 	if (priv->config == PIRQ_VIA_IBASE) {
125 		int ibase_off;
126 
127 		ibase_off = fdtdec_get_int(blob, node, "intel,ibase-offset", 0);
128 		if (!ibase_off)
129 			return -EINVAL;
130 
131 		/*
132 		 * Here we assume that the IBASE register has already been
133 		 * properly configured by U-Boot before.
134 		 *
135 		 * By 'valid' we mean:
136 		 *   1) a valid memory space carved within system memory space
137 		 *      assigned to IBASE register block.
138 		 *   2) memory range decoding is enabled.
139 		 * Hence we don't do any santify test here.
140 		 */
141 		dm_pci_read_config32(dev->parent, ibase_off, &priv->ibase);
142 		priv->ibase &= ~0xf;
143 	}
144 
145 	cell = fdt_getprop(blob, node, "intel,pirq-routing", &len);
146 	if (!cell || len % sizeof(struct pirq_routing))
147 		return -EINVAL;
148 	count = len / sizeof(struct pirq_routing);
149 
150 	rt = calloc(1, sizeof(struct irq_routing_table));
151 	if (!rt)
152 		return -ENOMEM;
153 
154 	/* Populate the PIRQ table fields */
155 	rt->signature = PIRQ_SIGNATURE;
156 	rt->version = PIRQ_VERSION;
157 	rt->rtr_bus = PCI_BUS(priv->bdf);
158 	rt->rtr_devfn = (PCI_DEV(priv->bdf) << 3) | PCI_FUNC(priv->bdf);
159 	rt->rtr_vendor = PCI_VENDOR_ID_INTEL;
160 	rt->rtr_device = PCI_DEVICE_ID_INTEL_ICH7_31;
161 
162 	slot_base = rt->slots;
163 
164 	/* Now fill in the irq_info entries in the PIRQ table */
165 	for (i = 0; i < count;
166 	     i++, cell += sizeof(struct pirq_routing) / sizeof(u32)) {
167 		struct pirq_routing pr;
168 
169 		pr.bdf = fdt_addr_to_cpu(cell[0]);
170 		pr.pin = fdt_addr_to_cpu(cell[1]);
171 		pr.pirq = fdt_addr_to_cpu(cell[2]);
172 
173 		debug("irq_info %d: b.d.f %x.%x.%x INT%c PIRQ%c\n",
174 		      i, PCI_BUS(pr.bdf), PCI_DEV(pr.bdf),
175 		      PCI_FUNC(pr.bdf), 'A' + pr.pin - 1,
176 		      'A' + pr.pirq);
177 
178 		slot = check_dup_entry(slot_base, irq_entries,
179 				       PCI_BUS(pr.bdf), PCI_DEV(pr.bdf));
180 		if (slot) {
181 			debug("found entry for bus %d device %d, ",
182 			      PCI_BUS(pr.bdf), PCI_DEV(pr.bdf));
183 
184 			if (slot->irq[pr.pin - 1].link) {
185 				debug("skipping\n");
186 
187 				/*
188 				 * Sanity test on the routed PIRQ pin
189 				 *
190 				 * If they don't match, show a warning to tell
191 				 * there might be something wrong with the PIRQ
192 				 * routing information in the device tree.
193 				 */
194 				if (slot->irq[pr.pin - 1].link !=
195 					LINK_N2V(pr.pirq, priv->link_base))
196 					debug("WARNING: Inconsistent PIRQ routing information\n");
197 				continue;
198 			}
199 		} else {
200 			slot = slot_base + irq_entries++;
201 		}
202 		debug("writing INT%c\n", 'A' + pr.pin - 1);
203 		fill_irq_info(priv, slot, PCI_BUS(pr.bdf), PCI_DEV(pr.bdf),
204 			      pr.pin, pr.pirq);
205 	}
206 
207 	rt->size = irq_entries * sizeof(struct irq_info) + 32;
208 
209 	pirq_routing_table = rt;
210 
211 	return 0;
212 }
213 
214 int irq_router_common_init(struct udevice *dev)
215 {
216 	int ret;
217 
218 	ret = create_pirq_routing_table(dev);
219 	if (ret) {
220 		debug("Failed to create pirq routing table\n");
221 		return ret;
222 	}
223 	/* Route PIRQ */
224 	pirq_route_irqs(dev, pirq_routing_table->slots,
225 			get_irq_slot_count(pirq_routing_table));
226 
227 	return 0;
228 }
229 
230 int irq_router_probe(struct udevice *dev)
231 {
232 	return irq_router_common_init(dev);
233 }
234 
235 u32 write_pirq_routing_table(u32 addr)
236 {
237 	if (!pirq_routing_table)
238 		return addr;
239 
240 	return copy_pirq_routing_table(addr, pirq_routing_table);
241 }
242 
243 static const struct udevice_id irq_router_ids[] = {
244 	{ .compatible = "intel,irq-router" },
245 	{ }
246 };
247 
248 U_BOOT_DRIVER(irq_router_drv) = {
249 	.name		= "intel_irq",
250 	.id		= UCLASS_IRQ,
251 	.of_match	= irq_router_ids,
252 	.probe		= irq_router_probe,
253 	.priv_auto_alloc_size = sizeof(struct irq_router),
254 };
255 
256 UCLASS_DRIVER(irq) = {
257 	.id		= UCLASS_IRQ,
258 	.name		= "irq",
259 };
260