1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Freescale Management Complex (MC) bus driver MSI support
4  *
5  * Copyright (C) 2015-2016 Freescale Semiconductor, Inc.
6  * Author: German Rivera <German.Rivera@freescale.com>
7  *
8  */
9 
10 #include <linux/of_device.h>
11 #include <linux/of_address.h>
12 #include <linux/of_irq.h>
13 #include <linux/irq.h>
14 #include <linux/irqdomain.h>
15 #include <linux/msi.h>
16 
17 #include "fsl-mc-private.h"
18 
19 #ifdef GENERIC_MSI_DOMAIN_OPS
20 /*
21  * Generate a unique ID identifying the interrupt (only used within the MSI
22  * irqdomain.  Combine the icid with the interrupt index.
23  */
fsl_mc_domain_calc_hwirq(struct fsl_mc_device * dev,struct msi_desc * desc)24 static irq_hw_number_t fsl_mc_domain_calc_hwirq(struct fsl_mc_device *dev,
25 						struct msi_desc *desc)
26 {
27 	/*
28 	 * Make the base hwirq value for ICID*10000 so it is readable
29 	 * as a decimal value in /proc/interrupts.
30 	 */
31 	return (irq_hw_number_t)(desc->fsl_mc.msi_index + (dev->icid * 10000));
32 }
33 
fsl_mc_msi_set_desc(msi_alloc_info_t * arg,struct msi_desc * desc)34 static void fsl_mc_msi_set_desc(msi_alloc_info_t *arg,
35 				struct msi_desc *desc)
36 {
37 	arg->desc = desc;
38 	arg->hwirq = fsl_mc_domain_calc_hwirq(to_fsl_mc_device(desc->dev),
39 					      desc);
40 }
41 #else
42 #define fsl_mc_msi_set_desc NULL
43 #endif
44 
fsl_mc_msi_update_dom_ops(struct msi_domain_info * info)45 static void fsl_mc_msi_update_dom_ops(struct msi_domain_info *info)
46 {
47 	struct msi_domain_ops *ops = info->ops;
48 
49 	if (!ops)
50 		return;
51 
52 	/*
53 	 * set_desc should not be set by the caller
54 	 */
55 	if (!ops->set_desc)
56 		ops->set_desc = fsl_mc_msi_set_desc;
57 }
58 
__fsl_mc_msi_write_msg(struct fsl_mc_device * mc_bus_dev,struct fsl_mc_device_irq * mc_dev_irq)59 static void __fsl_mc_msi_write_msg(struct fsl_mc_device *mc_bus_dev,
60 				   struct fsl_mc_device_irq *mc_dev_irq)
61 {
62 	int error;
63 	struct fsl_mc_device *owner_mc_dev = mc_dev_irq->mc_dev;
64 	struct msi_desc *msi_desc = mc_dev_irq->msi_desc;
65 	struct dprc_irq_cfg irq_cfg;
66 
67 	/*
68 	 * msi_desc->msg.address is 0x0 when this function is invoked in
69 	 * the free_irq() code path. In this case, for the MC, we don't
70 	 * really need to "unprogram" the MSI, so we just return.
71 	 */
72 	if (msi_desc->msg.address_lo == 0x0 && msi_desc->msg.address_hi == 0x0)
73 		return;
74 
75 	if (!owner_mc_dev)
76 		return;
77 
78 	irq_cfg.paddr = ((u64)msi_desc->msg.address_hi << 32) |
79 			msi_desc->msg.address_lo;
80 	irq_cfg.val = msi_desc->msg.data;
81 	irq_cfg.irq_num = msi_desc->irq;
82 
83 	if (owner_mc_dev == mc_bus_dev) {
84 		/*
85 		 * IRQ is for the mc_bus_dev's DPRC itself
86 		 */
87 		error = dprc_set_irq(mc_bus_dev->mc_io,
88 				     MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI,
89 				     mc_bus_dev->mc_handle,
90 				     mc_dev_irq->dev_irq_index,
91 				     &irq_cfg);
92 		if (error < 0) {
93 			dev_err(&owner_mc_dev->dev,
94 				"dprc_set_irq() failed: %d\n", error);
95 		}
96 	} else {
97 		/*
98 		 * IRQ is for for a child device of mc_bus_dev
99 		 */
100 		error = dprc_set_obj_irq(mc_bus_dev->mc_io,
101 					 MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI,
102 					 mc_bus_dev->mc_handle,
103 					 owner_mc_dev->obj_desc.type,
104 					 owner_mc_dev->obj_desc.id,
105 					 mc_dev_irq->dev_irq_index,
106 					 &irq_cfg);
107 		if (error < 0) {
108 			dev_err(&owner_mc_dev->dev,
109 				"dprc_obj_set_irq() failed: %d\n", error);
110 		}
111 	}
112 }
113 
114 /*
115  * NOTE: This function is invoked with interrupts disabled
116  */
fsl_mc_msi_write_msg(struct irq_data * irq_data,struct msi_msg * msg)117 static void fsl_mc_msi_write_msg(struct irq_data *irq_data,
118 				 struct msi_msg *msg)
119 {
120 	struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
121 	struct fsl_mc_device *mc_bus_dev = to_fsl_mc_device(msi_desc->dev);
122 	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
123 	struct fsl_mc_device_irq *mc_dev_irq =
124 		&mc_bus->irq_resources[msi_desc->fsl_mc.msi_index];
125 
126 	msi_desc->msg = *msg;
127 
128 	/*
129 	 * Program the MSI (paddr, value) pair in the device:
130 	 */
131 	__fsl_mc_msi_write_msg(mc_bus_dev, mc_dev_irq);
132 }
133 
fsl_mc_msi_update_chip_ops(struct msi_domain_info * info)134 static void fsl_mc_msi_update_chip_ops(struct msi_domain_info *info)
135 {
136 	struct irq_chip *chip = info->chip;
137 
138 	if (!chip)
139 		return;
140 
141 	/*
142 	 * irq_write_msi_msg should not be set by the caller
143 	 */
144 	if (!chip->irq_write_msi_msg)
145 		chip->irq_write_msi_msg = fsl_mc_msi_write_msg;
146 }
147 
148 /**
149  * fsl_mc_msi_create_irq_domain - Create a fsl-mc MSI interrupt domain
150  * @np:		Optional device-tree node of the interrupt controller
151  * @info:	MSI domain info
152  * @parent:	Parent irq domain
153  *
154  * Updates the domain and chip ops and creates a fsl-mc MSI
155  * interrupt domain.
156  *
157  * Returns:
158  * A domain pointer or NULL in case of failure.
159  */
fsl_mc_msi_create_irq_domain(struct fwnode_handle * fwnode,struct msi_domain_info * info,struct irq_domain * parent)160 struct irq_domain *fsl_mc_msi_create_irq_domain(struct fwnode_handle *fwnode,
161 						struct msi_domain_info *info,
162 						struct irq_domain *parent)
163 {
164 	struct irq_domain *domain;
165 
166 	if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE)))
167 		info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
168 	if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
169 		fsl_mc_msi_update_dom_ops(info);
170 	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
171 		fsl_mc_msi_update_chip_ops(info);
172 
173 	domain = msi_create_irq_domain(fwnode, info, parent);
174 	if (domain)
175 		irq_domain_update_bus_token(domain, DOMAIN_BUS_FSL_MC_MSI);
176 
177 	return domain;
178 }
179 
fsl_mc_find_msi_domain(struct device * mc_platform_dev,struct irq_domain ** mc_msi_domain)180 int fsl_mc_find_msi_domain(struct device *mc_platform_dev,
181 			   struct irq_domain **mc_msi_domain)
182 {
183 	struct irq_domain *msi_domain;
184 	struct device_node *mc_of_node = mc_platform_dev->of_node;
185 
186 	msi_domain = of_msi_get_domain(mc_platform_dev, mc_of_node,
187 				       DOMAIN_BUS_FSL_MC_MSI);
188 	if (!msi_domain) {
189 		pr_err("Unable to find fsl-mc MSI domain for %pOF\n",
190 		       mc_of_node);
191 
192 		return -ENOENT;
193 	}
194 
195 	*mc_msi_domain = msi_domain;
196 	return 0;
197 }
198 
fsl_mc_msi_free_descs(struct device * dev)199 static void fsl_mc_msi_free_descs(struct device *dev)
200 {
201 	struct msi_desc *desc, *tmp;
202 
203 	list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) {
204 		list_del(&desc->list);
205 		free_msi_entry(desc);
206 	}
207 }
208 
fsl_mc_msi_alloc_descs(struct device * dev,unsigned int irq_count)209 static int fsl_mc_msi_alloc_descs(struct device *dev, unsigned int irq_count)
210 
211 {
212 	unsigned int i;
213 	int error;
214 	struct msi_desc *msi_desc;
215 
216 	for (i = 0; i < irq_count; i++) {
217 		msi_desc = alloc_msi_entry(dev, 1, NULL);
218 		if (!msi_desc) {
219 			dev_err(dev, "Failed to allocate msi entry\n");
220 			error = -ENOMEM;
221 			goto cleanup_msi_descs;
222 		}
223 
224 		msi_desc->fsl_mc.msi_index = i;
225 		INIT_LIST_HEAD(&msi_desc->list);
226 		list_add_tail(&msi_desc->list, dev_to_msi_list(dev));
227 	}
228 
229 	return 0;
230 
231 cleanup_msi_descs:
232 	fsl_mc_msi_free_descs(dev);
233 	return error;
234 }
235 
fsl_mc_msi_domain_alloc_irqs(struct device * dev,unsigned int irq_count)236 int fsl_mc_msi_domain_alloc_irqs(struct device *dev,
237 				 unsigned int irq_count)
238 {
239 	struct irq_domain *msi_domain;
240 	int error;
241 
242 	if (!list_empty(dev_to_msi_list(dev)))
243 		return -EINVAL;
244 
245 	error = fsl_mc_msi_alloc_descs(dev, irq_count);
246 	if (error < 0)
247 		return error;
248 
249 	msi_domain = dev_get_msi_domain(dev);
250 	if (!msi_domain) {
251 		error = -EINVAL;
252 		goto cleanup_msi_descs;
253 	}
254 
255 	/*
256 	 * NOTE: Calling this function will trigger the invocation of the
257 	 * its_fsl_mc_msi_prepare() callback
258 	 */
259 	error = msi_domain_alloc_irqs(msi_domain, dev, irq_count);
260 
261 	if (error) {
262 		dev_err(dev, "Failed to allocate IRQs\n");
263 		goto cleanup_msi_descs;
264 	}
265 
266 	return 0;
267 
268 cleanup_msi_descs:
269 	fsl_mc_msi_free_descs(dev);
270 	return error;
271 }
272 
fsl_mc_msi_domain_free_irqs(struct device * dev)273 void fsl_mc_msi_domain_free_irqs(struct device *dev)
274 {
275 	struct irq_domain *msi_domain;
276 
277 	msi_domain = dev_get_msi_domain(dev);
278 	if (!msi_domain)
279 		return;
280 
281 	msi_domain_free_irqs(msi_domain, dev);
282 
283 	if (list_empty(dev_to_msi_list(dev)))
284 		return;
285 
286 	fsl_mc_msi_free_descs(dev);
287 }
288