xref: /openbmc/u-boot/arch/x86/cpu/irq.c (revision 699c4e59)
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 #include <asm/tables.h>
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 static struct irq_routing_table *pirq_routing_table;
21 
22 bool pirq_check_irq_routed(struct udevice *dev, int link, u8 irq)
23 {
24 	struct irq_router *priv = dev_get_priv(dev);
25 	u8 pirq;
26 	int base = priv->link_base;
27 
28 	if (priv->config == PIRQ_VIA_PCI)
29 		dm_pci_read_config8(dev->parent, LINK_N2V(link, base), &pirq);
30 	else
31 		pirq = readb(priv->ibase + LINK_N2V(link, base));
32 
33 	pirq &= 0xf;
34 
35 	/* IRQ# 0/1/2/8/13 are reserved */
36 	if (pirq < 3 || pirq == 8 || pirq == 13)
37 		return false;
38 
39 	return pirq == irq ? true : false;
40 }
41 
42 int pirq_translate_link(struct udevice *dev, int link)
43 {
44 	struct irq_router *priv = dev_get_priv(dev);
45 
46 	return LINK_V2N(link, priv->link_base);
47 }
48 
49 void pirq_assign_irq(struct udevice *dev, int link, u8 irq)
50 {
51 	struct irq_router *priv = dev_get_priv(dev);
52 	int base = priv->link_base;
53 
54 	/* IRQ# 0/1/2/8/13 are reserved */
55 	if (irq < 3 || irq == 8 || irq == 13)
56 		return;
57 
58 	if (priv->config == PIRQ_VIA_PCI)
59 		dm_pci_write_config8(dev->parent, LINK_N2V(link, base), irq);
60 	else
61 		writeb(irq, priv->ibase + LINK_N2V(link, base));
62 }
63 
64 static struct irq_info *check_dup_entry(struct irq_info *slot_base,
65 					int entry_num, int bus, int device)
66 {
67 	struct irq_info *slot = slot_base;
68 	int i;
69 
70 	for (i = 0; i < entry_num; i++) {
71 		if (slot->bus == bus && slot->devfn == (device << 3))
72 			break;
73 		slot++;
74 	}
75 
76 	return (i == entry_num) ? NULL : slot;
77 }
78 
79 static inline void fill_irq_info(struct irq_router *priv, struct irq_info *slot,
80 				 int bus, int device, int pin, int pirq)
81 {
82 	slot->bus = bus;
83 	slot->devfn = (device << 3) | 0;
84 	slot->irq[pin - 1].link = LINK_N2V(pirq, priv->link_base);
85 	slot->irq[pin - 1].bitmap = priv->irq_mask;
86 }
87 
88 static int create_pirq_routing_table(struct udevice *dev)
89 {
90 	struct irq_router *priv = dev_get_priv(dev);
91 	const void *blob = gd->fdt_blob;
92 	int node;
93 	int len, count;
94 	const u32 *cell;
95 	struct irq_routing_table *rt;
96 	struct irq_info *slot, *slot_base;
97 	int irq_entries = 0;
98 	int i;
99 	int ret;
100 
101 	node = dev->of_offset;
102 
103 	/* extract the bdf from fdt_pci_addr */
104 	priv->bdf = dm_pci_get_bdf(dev->parent);
105 
106 	ret = fdt_find_string(blob, node, "intel,pirq-config", "pci");
107 	if (!ret) {
108 		priv->config = PIRQ_VIA_PCI;
109 	} else {
110 		ret = fdt_find_string(blob, node, "intel,pirq-config", "ibase");
111 		if (!ret)
112 			priv->config = PIRQ_VIA_IBASE;
113 		else
114 			return -EINVAL;
115 	}
116 
117 	ret = fdtdec_get_int(blob, node, "intel,pirq-link", -1);
118 	if (ret == -1)
119 		return ret;
120 	priv->link_base = ret;
121 
122 	priv->irq_mask = fdtdec_get_int(blob, node,
123 					"intel,pirq-mask", PIRQ_BITMAP);
124 
125 	if (IS_ENABLED(CONFIG_GENERATE_ACPI_TABLE)) {
126 		/* Reserve IRQ9 for SCI */
127 		priv->irq_mask &= ~(1 << 9);
128 	}
129 
130 	if (priv->config == PIRQ_VIA_IBASE) {
131 		int ibase_off;
132 
133 		ibase_off = fdtdec_get_int(blob, node, "intel,ibase-offset", 0);
134 		if (!ibase_off)
135 			return -EINVAL;
136 
137 		/*
138 		 * Here we assume that the IBASE register has already been
139 		 * properly configured by U-Boot before.
140 		 *
141 		 * By 'valid' we mean:
142 		 *   1) a valid memory space carved within system memory space
143 		 *      assigned to IBASE register block.
144 		 *   2) memory range decoding is enabled.
145 		 * Hence we don't do any santify test here.
146 		 */
147 		dm_pci_read_config32(dev->parent, ibase_off, &priv->ibase);
148 		priv->ibase &= ~0xf;
149 	}
150 
151 	priv->actl_8bit = fdtdec_get_bool(blob, node, "intel,actl-8bit");
152 	priv->actl_addr = fdtdec_get_int(blob, node, "intel,actl-addr", 0);
153 
154 	cell = fdt_getprop(blob, node, "intel,pirq-routing", &len);
155 	if (!cell || len % sizeof(struct pirq_routing))
156 		return -EINVAL;
157 	count = len / sizeof(struct pirq_routing);
158 
159 	rt = calloc(1, sizeof(struct irq_routing_table));
160 	if (!rt)
161 		return -ENOMEM;
162 
163 	/* Populate the PIRQ table fields */
164 	rt->signature = PIRQ_SIGNATURE;
165 	rt->version = PIRQ_VERSION;
166 	rt->rtr_bus = PCI_BUS(priv->bdf);
167 	rt->rtr_devfn = (PCI_DEV(priv->bdf) << 3) | PCI_FUNC(priv->bdf);
168 	rt->rtr_vendor = PCI_VENDOR_ID_INTEL;
169 	rt->rtr_device = PCI_DEVICE_ID_INTEL_ICH7_31;
170 
171 	slot_base = rt->slots;
172 
173 	/* Now fill in the irq_info entries in the PIRQ table */
174 	for (i = 0; i < count;
175 	     i++, cell += sizeof(struct pirq_routing) / sizeof(u32)) {
176 		struct pirq_routing pr;
177 
178 		pr.bdf = fdt_addr_to_cpu(cell[0]);
179 		pr.pin = fdt_addr_to_cpu(cell[1]);
180 		pr.pirq = fdt_addr_to_cpu(cell[2]);
181 
182 		debug("irq_info %d: b.d.f %x.%x.%x INT%c PIRQ%c\n",
183 		      i, PCI_BUS(pr.bdf), PCI_DEV(pr.bdf),
184 		      PCI_FUNC(pr.bdf), 'A' + pr.pin - 1,
185 		      'A' + pr.pirq);
186 
187 		slot = check_dup_entry(slot_base, irq_entries,
188 				       PCI_BUS(pr.bdf), PCI_DEV(pr.bdf));
189 		if (slot) {
190 			debug("found entry for bus %d device %d, ",
191 			      PCI_BUS(pr.bdf), PCI_DEV(pr.bdf));
192 
193 			if (slot->irq[pr.pin - 1].link) {
194 				debug("skipping\n");
195 
196 				/*
197 				 * Sanity test on the routed PIRQ pin
198 				 *
199 				 * If they don't match, show a warning to tell
200 				 * there might be something wrong with the PIRQ
201 				 * routing information in the device tree.
202 				 */
203 				if (slot->irq[pr.pin - 1].link !=
204 					LINK_N2V(pr.pirq, priv->link_base))
205 					debug("WARNING: Inconsistent PIRQ routing information\n");
206 				continue;
207 			}
208 		} else {
209 			slot = slot_base + irq_entries++;
210 		}
211 		debug("writing INT%c\n", 'A' + pr.pin - 1);
212 		fill_irq_info(priv, slot, PCI_BUS(pr.bdf), PCI_DEV(pr.bdf),
213 			      pr.pin, pr.pirq);
214 	}
215 
216 	rt->size = irq_entries * sizeof(struct irq_info) + 32;
217 
218 	/* Fix up the table checksum */
219 	rt->checksum = table_compute_checksum(rt, rt->size);
220 
221 	pirq_routing_table = rt;
222 
223 	return 0;
224 }
225 
226 static void irq_enable_sci(struct udevice *dev)
227 {
228 	struct irq_router *priv = dev_get_priv(dev);
229 
230 	if (priv->actl_8bit) {
231 		/* Bit7 must be turned on to enable ACPI */
232 		dm_pci_write_config8(dev->parent, priv->actl_addr, 0x80);
233 	} else {
234 		/* Write 0 to enable SCI on IRQ9 */
235 		if (priv->config == PIRQ_VIA_PCI)
236 			dm_pci_write_config32(dev->parent, priv->actl_addr, 0);
237 		else
238 			writel(0, priv->ibase + priv->actl_addr);
239 	}
240 }
241 
242 int irq_router_common_init(struct udevice *dev)
243 {
244 	int ret;
245 
246 	ret = create_pirq_routing_table(dev);
247 	if (ret) {
248 		debug("Failed to create pirq routing table\n");
249 		return ret;
250 	}
251 	/* Route PIRQ */
252 	pirq_route_irqs(dev, pirq_routing_table->slots,
253 			get_irq_slot_count(pirq_routing_table));
254 
255 	if (IS_ENABLED(CONFIG_GENERATE_ACPI_TABLE))
256 		irq_enable_sci(dev);
257 
258 	return 0;
259 }
260 
261 int irq_router_probe(struct udevice *dev)
262 {
263 	return irq_router_common_init(dev);
264 }
265 
266 u32 write_pirq_routing_table(u32 addr)
267 {
268 	if (!pirq_routing_table)
269 		return addr;
270 
271 	return copy_pirq_routing_table(addr, pirq_routing_table);
272 }
273 
274 static const struct udevice_id irq_router_ids[] = {
275 	{ .compatible = "intel,irq-router" },
276 	{ }
277 };
278 
279 U_BOOT_DRIVER(irq_router_drv) = {
280 	.name		= "intel_irq",
281 	.id		= UCLASS_IRQ,
282 	.of_match	= irq_router_ids,
283 	.probe		= irq_router_probe,
284 	.priv_auto_alloc_size = sizeof(struct irq_router),
285 };
286 
287 UCLASS_DRIVER(irq) = {
288 	.id		= UCLASS_IRQ,
289 	.name		= "irq",
290 };
291