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 #include <linux/acpi_iort.h>
17 
18 #include "fsl-mc-private.h"
19 
20 #ifdef GENERIC_MSI_DOMAIN_OPS
21 /*
22  * Generate a unique ID identifying the interrupt (only used within the MSI
23  * irqdomain.  Combine the icid with the interrupt index.
24  */
fsl_mc_domain_calc_hwirq(struct fsl_mc_device * dev,struct msi_desc * desc)25 static irq_hw_number_t fsl_mc_domain_calc_hwirq(struct fsl_mc_device *dev,
26 						struct msi_desc *desc)
27 {
28 	/*
29 	 * Make the base hwirq value for ICID*10000 so it is readable
30 	 * as a decimal value in /proc/interrupts.
31 	 */
32 	return (irq_hw_number_t)(desc->msi_index + (dev->icid * 10000));
33 }
34 
fsl_mc_msi_set_desc(msi_alloc_info_t * arg,struct msi_desc * desc)35 static void fsl_mc_msi_set_desc(msi_alloc_info_t *arg,
36 				struct msi_desc *desc)
37 {
38 	arg->desc = desc;
39 	arg->hwirq = fsl_mc_domain_calc_hwirq(to_fsl_mc_device(desc->dev),
40 					      desc);
41 }
42 #else
43 #define fsl_mc_msi_set_desc NULL
44 #endif
45 
fsl_mc_msi_update_dom_ops(struct msi_domain_info * info)46 static void fsl_mc_msi_update_dom_ops(struct msi_domain_info *info)
47 {
48 	struct msi_domain_ops *ops = info->ops;
49 
50 	if (!ops)
51 		return;
52 
53 	/*
54 	 * set_desc should not be set by the caller
55 	 */
56 	if (!ops->set_desc)
57 		ops->set_desc = fsl_mc_msi_set_desc;
58 }
59 
__fsl_mc_msi_write_msg(struct fsl_mc_device * mc_bus_dev,struct fsl_mc_device_irq * mc_dev_irq,struct msi_desc * msi_desc)60 static void __fsl_mc_msi_write_msg(struct fsl_mc_device *mc_bus_dev,
61 				   struct fsl_mc_device_irq *mc_dev_irq,
62 				   struct msi_desc *msi_desc)
63 {
64 	int error;
65 	struct fsl_mc_device *owner_mc_dev = mc_dev_irq->mc_dev;
66 	struct dprc_irq_cfg irq_cfg;
67 
68 	/*
69 	 * msi_desc->msg.address is 0x0 when this function is invoked in
70 	 * the free_irq() code path. In this case, for the MC, we don't
71 	 * really need to "unprogram" the MSI, so we just return.
72 	 */
73 	if (msi_desc->msg.address_lo == 0x0 && msi_desc->msg.address_hi == 0x0)
74 		return;
75 
76 	if (!owner_mc_dev)
77 		return;
78 
79 	irq_cfg.paddr = ((u64)msi_desc->msg.address_hi << 32) |
80 			msi_desc->msg.address_lo;
81 	irq_cfg.val = msi_desc->msg.data;
82 	irq_cfg.irq_num = msi_desc->irq;
83 
84 	if (owner_mc_dev == mc_bus_dev) {
85 		/*
86 		 * IRQ is for the mc_bus_dev's DPRC itself
87 		 */
88 		error = dprc_set_irq(mc_bus_dev->mc_io,
89 				     MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI,
90 				     mc_bus_dev->mc_handle,
91 				     mc_dev_irq->dev_irq_index,
92 				     &irq_cfg);
93 		if (error < 0) {
94 			dev_err(&owner_mc_dev->dev,
95 				"dprc_set_irq() failed: %d\n", error);
96 		}
97 	} else {
98 		/*
99 		 * IRQ is for for a child device of mc_bus_dev
100 		 */
101 		error = dprc_set_obj_irq(mc_bus_dev->mc_io,
102 					 MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI,
103 					 mc_bus_dev->mc_handle,
104 					 owner_mc_dev->obj_desc.type,
105 					 owner_mc_dev->obj_desc.id,
106 					 mc_dev_irq->dev_irq_index,
107 					 &irq_cfg);
108 		if (error < 0) {
109 			dev_err(&owner_mc_dev->dev,
110 				"dprc_obj_set_irq() failed: %d\n", error);
111 		}
112 	}
113 }
114 
115 /*
116  * NOTE: This function is invoked with interrupts disabled
117  */
fsl_mc_msi_write_msg(struct irq_data * irq_data,struct msi_msg * msg)118 static void fsl_mc_msi_write_msg(struct irq_data *irq_data,
119 				 struct msi_msg *msg)
120 {
121 	struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
122 	struct fsl_mc_device *mc_bus_dev = to_fsl_mc_device(msi_desc->dev);
123 	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
124 	struct fsl_mc_device_irq *mc_dev_irq =
125 		&mc_bus->irq_resources[msi_desc->msi_index];
126 
127 	msi_desc->msg = *msg;
128 
129 	/*
130 	 * Program the MSI (paddr, value) pair in the device:
131 	 */
132 	__fsl_mc_msi_write_msg(mc_bus_dev, mc_dev_irq, msi_desc);
133 }
134 
fsl_mc_msi_update_chip_ops(struct msi_domain_info * info)135 static void fsl_mc_msi_update_chip_ops(struct msi_domain_info *info)
136 {
137 	struct irq_chip *chip = info->chip;
138 
139 	if (!chip)
140 		return;
141 
142 	/*
143 	 * irq_write_msi_msg should not be set by the caller
144 	 */
145 	if (!chip->irq_write_msi_msg)
146 		chip->irq_write_msi_msg = fsl_mc_msi_write_msg;
147 }
148 
149 /**
150  * fsl_mc_msi_create_irq_domain - Create a fsl-mc MSI interrupt domain
151  * @fwnode:	Optional firmware node of the interrupt controller
152  * @info:	MSI domain info
153  * @parent:	Parent irq domain
154  *
155  * Updates the domain and chip ops and creates a fsl-mc MSI
156  * interrupt domain.
157  *
158  * Returns:
159  * A domain pointer or NULL in case of failure.
160  */
fsl_mc_msi_create_irq_domain(struct fwnode_handle * fwnode,struct msi_domain_info * info,struct irq_domain * parent)161 struct irq_domain *fsl_mc_msi_create_irq_domain(struct fwnode_handle *fwnode,
162 						struct msi_domain_info *info,
163 						struct irq_domain *parent)
164 {
165 	struct irq_domain *domain;
166 
167 	if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE)))
168 		info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
169 	if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
170 		fsl_mc_msi_update_dom_ops(info);
171 	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
172 		fsl_mc_msi_update_chip_ops(info);
173 	info->flags |= MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS | MSI_FLAG_FREE_MSI_DESCS;
174 
175 	domain = msi_create_irq_domain(fwnode, info, parent);
176 	if (domain)
177 		irq_domain_update_bus_token(domain, DOMAIN_BUS_FSL_MC_MSI);
178 
179 	return domain;
180 }
181 
fsl_mc_find_msi_domain(struct device * dev)182 struct irq_domain *fsl_mc_find_msi_domain(struct device *dev)
183 {
184 	struct device *root_dprc_dev;
185 	struct device *bus_dev;
186 	struct irq_domain *msi_domain;
187 	struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
188 
189 	fsl_mc_get_root_dprc(dev, &root_dprc_dev);
190 	bus_dev = root_dprc_dev->parent;
191 
192 	if (bus_dev->of_node) {
193 		msi_domain = of_msi_map_get_device_domain(dev,
194 						  mc_dev->icid,
195 						  DOMAIN_BUS_FSL_MC_MSI);
196 
197 		/*
198 		 * if the msi-map property is missing assume that all the
199 		 * child containers inherit the domain from the parent
200 		 */
201 		if (!msi_domain)
202 
203 			msi_domain = of_msi_get_domain(bus_dev,
204 						bus_dev->of_node,
205 						DOMAIN_BUS_FSL_MC_MSI);
206 	} else {
207 		msi_domain = iort_get_device_domain(dev, mc_dev->icid,
208 						    DOMAIN_BUS_FSL_MC_MSI);
209 	}
210 
211 	return msi_domain;
212 }
213 
fsl_mc_msi_domain_alloc_irqs(struct device * dev,unsigned int irq_count)214 int fsl_mc_msi_domain_alloc_irqs(struct device *dev,  unsigned int irq_count)
215 {
216 	struct irq_domain *msi_domain;
217 	int error;
218 
219 	msi_domain = dev_get_msi_domain(dev);
220 	if (!msi_domain)
221 		return -EINVAL;
222 
223 	error = msi_setup_device_data(dev);
224 	if (error)
225 		return error;
226 
227 	msi_lock_descs(dev);
228 	if (msi_first_desc(dev, MSI_DESC_ALL))
229 		error = -EINVAL;
230 	msi_unlock_descs(dev);
231 	if (error)
232 		return error;
233 
234 	/*
235 	 * NOTE: Calling this function will trigger the invocation of the
236 	 * its_fsl_mc_msi_prepare() callback
237 	 */
238 	error = msi_domain_alloc_irqs(msi_domain, dev, irq_count);
239 
240 	if (error)
241 		dev_err(dev, "Failed to allocate IRQs\n");
242 	return error;
243 }
244 
fsl_mc_msi_domain_free_irqs(struct device * dev)245 void fsl_mc_msi_domain_free_irqs(struct device *dev)
246 {
247 	struct irq_domain *msi_domain;
248 
249 	msi_domain = dev_get_msi_domain(dev);
250 	if (!msi_domain)
251 		return;
252 
253 	msi_domain_free_irqs(msi_domain, dev);
254 }
255