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 */
25static 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->fsl_mc.msi_index + (dev->icid * 10000));
33}
34
35static 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
46static 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
60static void __fsl_mc_msi_write_msg(struct fsl_mc_device *mc_bus_dev,
61				   struct fsl_mc_device_irq *mc_dev_irq)
62{
63	int error;
64	struct fsl_mc_device *owner_mc_dev = mc_dev_irq->mc_dev;
65	struct msi_desc *msi_desc = mc_dev_irq->msi_desc;
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 */
118static 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->fsl_mc.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);
133}
134
135static 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 * @np:		Optional device-tree 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 */
161struct 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
174	domain = msi_create_irq_domain(fwnode, info, parent);
175	if (domain)
176		irq_domain_update_bus_token(domain, DOMAIN_BUS_FSL_MC_MSI);
177
178	return domain;
179}
180
181struct irq_domain *fsl_mc_find_msi_domain(struct device *dev)
182{
183	struct device *root_dprc_dev;
184	struct device *bus_dev;
185	struct irq_domain *msi_domain;
186	struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
187
188	fsl_mc_get_root_dprc(dev, &root_dprc_dev);
189	bus_dev = root_dprc_dev->parent;
190
191	if (bus_dev->of_node) {
192		msi_domain = of_msi_map_get_device_domain(dev,
193						  mc_dev->icid,
194						  DOMAIN_BUS_FSL_MC_MSI);
195
196		/*
197		 * if the msi-map property is missing assume that all the
198		 * child containers inherit the domain from the parent
199		 */
200		if (!msi_domain)
201
202			msi_domain = of_msi_get_domain(bus_dev,
203						bus_dev->of_node,
204						DOMAIN_BUS_FSL_MC_MSI);
205	} else {
206		msi_domain = iort_get_device_domain(dev, mc_dev->icid,
207						    DOMAIN_BUS_FSL_MC_MSI);
208	}
209
210	return msi_domain;
211}
212
213static void fsl_mc_msi_free_descs(struct device *dev)
214{
215	struct msi_desc *desc, *tmp;
216
217	list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) {
218		list_del(&desc->list);
219		free_msi_entry(desc);
220	}
221}
222
223static int fsl_mc_msi_alloc_descs(struct device *dev, unsigned int irq_count)
224
225{
226	unsigned int i;
227	int error;
228	struct msi_desc *msi_desc;
229
230	for (i = 0; i < irq_count; i++) {
231		msi_desc = alloc_msi_entry(dev, 1, NULL);
232		if (!msi_desc) {
233			dev_err(dev, "Failed to allocate msi entry\n");
234			error = -ENOMEM;
235			goto cleanup_msi_descs;
236		}
237
238		msi_desc->fsl_mc.msi_index = i;
239		INIT_LIST_HEAD(&msi_desc->list);
240		list_add_tail(&msi_desc->list, dev_to_msi_list(dev));
241	}
242
243	return 0;
244
245cleanup_msi_descs:
246	fsl_mc_msi_free_descs(dev);
247	return error;
248}
249
250int fsl_mc_msi_domain_alloc_irqs(struct device *dev,
251				 unsigned int irq_count)
252{
253	struct irq_domain *msi_domain;
254	int error;
255
256	if (!list_empty(dev_to_msi_list(dev)))
257		return -EINVAL;
258
259	error = fsl_mc_msi_alloc_descs(dev, irq_count);
260	if (error < 0)
261		return error;
262
263	msi_domain = dev_get_msi_domain(dev);
264	if (!msi_domain) {
265		error = -EINVAL;
266		goto cleanup_msi_descs;
267	}
268
269	/*
270	 * NOTE: Calling this function will trigger the invocation of the
271	 * its_fsl_mc_msi_prepare() callback
272	 */
273	error = msi_domain_alloc_irqs(msi_domain, dev, irq_count);
274
275	if (error) {
276		dev_err(dev, "Failed to allocate IRQs\n");
277		goto cleanup_msi_descs;
278	}
279
280	return 0;
281
282cleanup_msi_descs:
283	fsl_mc_msi_free_descs(dev);
284	return error;
285}
286
287void fsl_mc_msi_domain_free_irqs(struct device *dev)
288{
289	struct irq_domain *msi_domain;
290
291	msi_domain = dev_get_msi_domain(dev);
292	if (!msi_domain)
293		return;
294
295	msi_domain_free_irqs(msi_domain, dev);
296
297	if (list_empty(dev_to_msi_list(dev)))
298		return;
299
300	fsl_mc_msi_free_descs(dev);
301}
302