xref: /openbmc/linux/kernel/irq/msi.c (revision c819e2cf)
1 /*
2  * linux/kernel/irq/msi.c
3  *
4  * Copyright (C) 2014 Intel Corp.
5  * Author: Jiang Liu <jiang.liu@linux.intel.com>
6  *
7  * This file is licensed under GPLv2.
8  *
9  * This file contains common code to support Message Signalled Interrupt for
10  * PCI compatible and non PCI compatible devices.
11  */
12 #include <linux/types.h>
13 #include <linux/device.h>
14 #include <linux/irq.h>
15 #include <linux/irqdomain.h>
16 #include <linux/msi.h>
17 
18 /* Temparory solution for building, will be removed later */
19 #include <linux/pci.h>
20 
21 void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
22 {
23 	*msg = entry->msg;
24 }
25 
26 void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
27 {
28 	struct msi_desc *entry = irq_get_msi_desc(irq);
29 
30 	__get_cached_msi_msg(entry, msg);
31 }
32 EXPORT_SYMBOL_GPL(get_cached_msi_msg);
33 
34 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
35 static inline void irq_chip_write_msi_msg(struct irq_data *data,
36 					  struct msi_msg *msg)
37 {
38 	data->chip->irq_write_msi_msg(data, msg);
39 }
40 
41 /**
42  * msi_domain_set_affinity - Generic affinity setter function for MSI domains
43  * @irq_data:	The irq data associated to the interrupt
44  * @mask:	The affinity mask to set
45  * @force:	Flag to enforce setting (disable online checks)
46  *
47  * Intended to be used by MSI interrupt controllers which are
48  * implemented with hierarchical domains.
49  */
50 int msi_domain_set_affinity(struct irq_data *irq_data,
51 			    const struct cpumask *mask, bool force)
52 {
53 	struct irq_data *parent = irq_data->parent_data;
54 	struct msi_msg msg;
55 	int ret;
56 
57 	ret = parent->chip->irq_set_affinity(parent, mask, force);
58 	if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) {
59 		BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg));
60 		irq_chip_write_msi_msg(irq_data, &msg);
61 	}
62 
63 	return ret;
64 }
65 
66 static void msi_domain_activate(struct irq_domain *domain,
67 				struct irq_data *irq_data)
68 {
69 	struct msi_msg msg;
70 
71 	BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg));
72 	irq_chip_write_msi_msg(irq_data, &msg);
73 }
74 
75 static void msi_domain_deactivate(struct irq_domain *domain,
76 				  struct irq_data *irq_data)
77 {
78 	struct msi_msg msg;
79 
80 	memset(&msg, 0, sizeof(msg));
81 	irq_chip_write_msi_msg(irq_data, &msg);
82 }
83 
84 static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
85 			    unsigned int nr_irqs, void *arg)
86 {
87 	struct msi_domain_info *info = domain->host_data;
88 	struct msi_domain_ops *ops = info->ops;
89 	irq_hw_number_t hwirq = ops->get_hwirq(info, arg);
90 	int i, ret;
91 
92 	if (irq_find_mapping(domain, hwirq) > 0)
93 		return -EEXIST;
94 
95 	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
96 	if (ret < 0)
97 		return ret;
98 
99 	for (i = 0; i < nr_irqs; i++) {
100 		ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg);
101 		if (ret < 0) {
102 			if (ops->msi_free) {
103 				for (i--; i > 0; i--)
104 					ops->msi_free(domain, info, virq + i);
105 			}
106 			irq_domain_free_irqs_top(domain, virq, nr_irqs);
107 			return ret;
108 		}
109 	}
110 
111 	return 0;
112 }
113 
114 static void msi_domain_free(struct irq_domain *domain, unsigned int virq,
115 			    unsigned int nr_irqs)
116 {
117 	struct msi_domain_info *info = domain->host_data;
118 	int i;
119 
120 	if (info->ops->msi_free) {
121 		for (i = 0; i < nr_irqs; i++)
122 			info->ops->msi_free(domain, info, virq + i);
123 	}
124 	irq_domain_free_irqs_top(domain, virq, nr_irqs);
125 }
126 
127 static struct irq_domain_ops msi_domain_ops = {
128 	.alloc		= msi_domain_alloc,
129 	.free		= msi_domain_free,
130 	.activate	= msi_domain_activate,
131 	.deactivate	= msi_domain_deactivate,
132 };
133 
134 #ifdef GENERIC_MSI_DOMAIN_OPS
135 static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info,
136 						msi_alloc_info_t *arg)
137 {
138 	return arg->hwirq;
139 }
140 
141 static int msi_domain_ops_prepare(struct irq_domain *domain, struct device *dev,
142 				  int nvec, msi_alloc_info_t *arg)
143 {
144 	memset(arg, 0, sizeof(*arg));
145 	return 0;
146 }
147 
148 static void msi_domain_ops_set_desc(msi_alloc_info_t *arg,
149 				    struct msi_desc *desc)
150 {
151 	arg->desc = desc;
152 }
153 #else
154 #define msi_domain_ops_get_hwirq	NULL
155 #define msi_domain_ops_prepare		NULL
156 #define msi_domain_ops_set_desc		NULL
157 #endif /* !GENERIC_MSI_DOMAIN_OPS */
158 
159 static int msi_domain_ops_init(struct irq_domain *domain,
160 			       struct msi_domain_info *info,
161 			       unsigned int virq, irq_hw_number_t hwirq,
162 			       msi_alloc_info_t *arg)
163 {
164 	irq_domain_set_hwirq_and_chip(domain, virq, hwirq, info->chip,
165 				      info->chip_data);
166 	if (info->handler && info->handler_name) {
167 		__irq_set_handler(virq, info->handler, 0, info->handler_name);
168 		if (info->handler_data)
169 			irq_set_handler_data(virq, info->handler_data);
170 	}
171 	return 0;
172 }
173 
174 static int msi_domain_ops_check(struct irq_domain *domain,
175 				struct msi_domain_info *info,
176 				struct device *dev)
177 {
178 	return 0;
179 }
180 
181 static struct msi_domain_ops msi_domain_ops_default = {
182 	.get_hwirq	= msi_domain_ops_get_hwirq,
183 	.msi_init	= msi_domain_ops_init,
184 	.msi_check	= msi_domain_ops_check,
185 	.msi_prepare	= msi_domain_ops_prepare,
186 	.set_desc	= msi_domain_ops_set_desc,
187 };
188 
189 static void msi_domain_update_dom_ops(struct msi_domain_info *info)
190 {
191 	struct msi_domain_ops *ops = info->ops;
192 
193 	if (ops == NULL) {
194 		info->ops = &msi_domain_ops_default;
195 		return;
196 	}
197 
198 	if (ops->get_hwirq == NULL)
199 		ops->get_hwirq = msi_domain_ops_default.get_hwirq;
200 	if (ops->msi_init == NULL)
201 		ops->msi_init = msi_domain_ops_default.msi_init;
202 	if (ops->msi_check == NULL)
203 		ops->msi_check = msi_domain_ops_default.msi_check;
204 	if (ops->msi_prepare == NULL)
205 		ops->msi_prepare = msi_domain_ops_default.msi_prepare;
206 	if (ops->set_desc == NULL)
207 		ops->set_desc = msi_domain_ops_default.set_desc;
208 }
209 
210 static void msi_domain_update_chip_ops(struct msi_domain_info *info)
211 {
212 	struct irq_chip *chip = info->chip;
213 
214 	BUG_ON(!chip);
215 	if (!chip->irq_mask)
216 		chip->irq_mask = pci_msi_mask_irq;
217 	if (!chip->irq_unmask)
218 		chip->irq_unmask = pci_msi_unmask_irq;
219 	if (!chip->irq_set_affinity)
220 		chip->irq_set_affinity = msi_domain_set_affinity;
221 }
222 
223 /**
224  * msi_create_irq_domain - Create a MSI interrupt domain
225  * @of_node:	Optional device-tree node of the interrupt controller
226  * @info:	MSI domain info
227  * @parent:	Parent irq domain
228  */
229 struct irq_domain *msi_create_irq_domain(struct device_node *node,
230 					 struct msi_domain_info *info,
231 					 struct irq_domain *parent)
232 {
233 	if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
234 		msi_domain_update_dom_ops(info);
235 	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
236 		msi_domain_update_chip_ops(info);
237 
238 	return irq_domain_add_hierarchy(parent, 0, 0, node, &msi_domain_ops,
239 					info);
240 }
241 
242 /**
243  * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain
244  * @domain:	The domain to allocate from
245  * @dev:	Pointer to device struct of the device for which the interrupts
246  *		are allocated
247  * @nvec:	The number of interrupts to allocate
248  *
249  * Returns 0 on success or an error code.
250  */
251 int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
252 			  int nvec)
253 {
254 	struct msi_domain_info *info = domain->host_data;
255 	struct msi_domain_ops *ops = info->ops;
256 	msi_alloc_info_t arg;
257 	struct msi_desc *desc;
258 	int i, ret, virq = -1;
259 
260 	ret = ops->msi_check(domain, info, dev);
261 	if (ret == 0)
262 		ret = ops->msi_prepare(domain, dev, nvec, &arg);
263 	if (ret)
264 		return ret;
265 
266 	for_each_msi_entry(desc, dev) {
267 		ops->set_desc(&arg, desc);
268 		if (info->flags & MSI_FLAG_IDENTITY_MAP)
269 			virq = (int)ops->get_hwirq(info, &arg);
270 		else
271 			virq = -1;
272 
273 		virq = __irq_domain_alloc_irqs(domain, virq, desc->nvec_used,
274 					       dev_to_node(dev), &arg, false);
275 		if (virq < 0) {
276 			ret = -ENOSPC;
277 			if (ops->handle_error)
278 				ret = ops->handle_error(domain, desc, ret);
279 			if (ops->msi_finish)
280 				ops->msi_finish(&arg, ret);
281 			return ret;
282 		}
283 
284 		for (i = 0; i < desc->nvec_used; i++)
285 			irq_set_msi_desc_off(virq, i, desc);
286 	}
287 
288 	if (ops->msi_finish)
289 		ops->msi_finish(&arg, 0);
290 
291 	for_each_msi_entry(desc, dev) {
292 		if (desc->nvec_used == 1)
293 			dev_dbg(dev, "irq %d for MSI\n", virq);
294 		else
295 			dev_dbg(dev, "irq [%d-%d] for MSI\n",
296 				virq, virq + desc->nvec_used - 1);
297 	}
298 
299 	return 0;
300 }
301 
302 /**
303  * msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated tp @dev
304  * @domain:	The domain to managing the interrupts
305  * @dev:	Pointer to device struct of the device for which the interrupts
306  *		are free
307  */
308 void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
309 {
310 	struct msi_desc *desc;
311 
312 	for_each_msi_entry(desc, dev) {
313 		irq_domain_free_irqs(desc->irq, desc->nvec_used);
314 		desc->irq = 0;
315 	}
316 }
317 
318 /**
319  * msi_get_domain_info - Get the MSI interrupt domain info for @domain
320  * @domain:	The interrupt domain to retrieve data from
321  *
322  * Returns the pointer to the msi_domain_info stored in
323  * @domain->host_data.
324  */
325 struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
326 {
327 	return (struct msi_domain_info *)domain->host_data;
328 }
329 
330 #endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */
331