1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright 2016-17 IBM Corp.
4 */
5
6 #define pr_fmt(fmt) "vas: " fmt
7
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/export.h>
11 #include <linux/types.h>
12 #include <linux/slab.h>
13 #include <linux/platform_device.h>
14 #include <linux/of_platform.h>
15 #include <linux/of_address.h>
16 #include <linux/of.h>
17 #include <linux/irqdomain.h>
18 #include <linux/interrupt.h>
19 #include <asm/prom.h>
20 #include <asm/xive.h>
21
22 #include "vas.h"
23
24 DEFINE_MUTEX(vas_mutex);
25 static LIST_HEAD(vas_instances);
26
27 static DEFINE_PER_CPU(int, cpu_vas_id);
28
vas_irq_fault_window_setup(struct vas_instance * vinst)29 static int vas_irq_fault_window_setup(struct vas_instance *vinst)
30 {
31 int rc = 0;
32
33 rc = request_threaded_irq(vinst->virq, vas_fault_handler,
34 vas_fault_thread_fn, 0, vinst->name, vinst);
35
36 if (rc) {
37 pr_err("VAS[%d]: Request IRQ(%d) failed with %d\n",
38 vinst->vas_id, vinst->virq, rc);
39 goto out;
40 }
41
42 rc = vas_setup_fault_window(vinst);
43 if (rc)
44 free_irq(vinst->virq, vinst);
45
46 out:
47 return rc;
48 }
49
init_vas_instance(struct platform_device * pdev)50 static int init_vas_instance(struct platform_device *pdev)
51 {
52 struct device_node *dn = pdev->dev.of_node;
53 struct vas_instance *vinst;
54 struct xive_irq_data *xd;
55 uint32_t chipid, hwirq;
56 struct resource *res;
57 int rc, cpu, vasid;
58
59 rc = of_property_read_u32(dn, "ibm,vas-id", &vasid);
60 if (rc) {
61 pr_err("No ibm,vas-id property for %s?\n", pdev->name);
62 return -ENODEV;
63 }
64
65 rc = of_property_read_u32(dn, "ibm,chip-id", &chipid);
66 if (rc) {
67 pr_err("No ibm,chip-id property for %s?\n", pdev->name);
68 return -ENODEV;
69 }
70
71 if (pdev->num_resources != 4) {
72 pr_err("Unexpected DT configuration for [%s, %d]\n",
73 pdev->name, vasid);
74 return -ENODEV;
75 }
76
77 vinst = kzalloc(sizeof(*vinst), GFP_KERNEL);
78 if (!vinst)
79 return -ENOMEM;
80
81 vinst->name = kasprintf(GFP_KERNEL, "vas-%d", vasid);
82 if (!vinst->name) {
83 kfree(vinst);
84 return -ENOMEM;
85 }
86
87 INIT_LIST_HEAD(&vinst->node);
88 ida_init(&vinst->ida);
89 mutex_init(&vinst->mutex);
90 vinst->vas_id = vasid;
91 vinst->pdev = pdev;
92
93 res = &pdev->resource[0];
94 vinst->hvwc_bar_start = res->start;
95
96 res = &pdev->resource[1];
97 vinst->uwc_bar_start = res->start;
98
99 res = &pdev->resource[2];
100 vinst->paste_base_addr = res->start;
101
102 res = &pdev->resource[3];
103 if (res->end > 62) {
104 pr_err("Bad 'paste_win_id_shift' in DT, %llx\n", res->end);
105 goto free_vinst;
106 }
107
108 vinst->paste_win_id_shift = 63 - res->end;
109
110 hwirq = xive_native_alloc_irq_on_chip(chipid);
111 if (!hwirq) {
112 pr_err("Inst%d: Unable to allocate global irq for chip %d\n",
113 vinst->vas_id, chipid);
114 return -ENOENT;
115 }
116
117 vinst->virq = irq_create_mapping(NULL, hwirq);
118 if (!vinst->virq) {
119 pr_err("Inst%d: Unable to map global irq %d\n",
120 vinst->vas_id, hwirq);
121 return -EINVAL;
122 }
123
124 xd = irq_get_handler_data(vinst->virq);
125 if (!xd) {
126 pr_err("Inst%d: Invalid virq %d\n",
127 vinst->vas_id, vinst->virq);
128 return -EINVAL;
129 }
130
131 vinst->irq_port = xd->trig_page;
132 pr_devel("Initialized instance [%s, %d] paste_base 0x%llx paste_win_id_shift 0x%llx IRQ %d Port 0x%llx\n",
133 pdev->name, vasid, vinst->paste_base_addr,
134 vinst->paste_win_id_shift, vinst->virq,
135 vinst->irq_port);
136
137 for_each_possible_cpu(cpu) {
138 if (cpu_to_chip_id(cpu) == of_get_ibm_chip_id(dn))
139 per_cpu(cpu_vas_id, cpu) = vasid;
140 }
141
142 mutex_lock(&vas_mutex);
143 list_add(&vinst->node, &vas_instances);
144 mutex_unlock(&vas_mutex);
145
146 spin_lock_init(&vinst->fault_lock);
147 /*
148 * IRQ and fault handling setup is needed only for user space
149 * send windows.
150 */
151 if (vinst->virq) {
152 rc = vas_irq_fault_window_setup(vinst);
153 /*
154 * Fault window is used only for user space send windows.
155 * So if vinst->virq is NULL, tx_win_open returns -ENODEV
156 * for user space.
157 */
158 if (rc)
159 vinst->virq = 0;
160 }
161
162 vas_instance_init_dbgdir(vinst);
163
164 dev_set_drvdata(&pdev->dev, vinst);
165
166 return 0;
167
168 free_vinst:
169 kfree(vinst->name);
170 kfree(vinst);
171 return -ENODEV;
172
173 }
174
175 /*
176 * Although this is read/used multiple times, it is written to only
177 * during initialization.
178 */
find_vas_instance(int vasid)179 struct vas_instance *find_vas_instance(int vasid)
180 {
181 struct list_head *ent;
182 struct vas_instance *vinst;
183
184 mutex_lock(&vas_mutex);
185
186 if (vasid == -1)
187 vasid = per_cpu(cpu_vas_id, smp_processor_id());
188
189 list_for_each(ent, &vas_instances) {
190 vinst = list_entry(ent, struct vas_instance, node);
191 if (vinst->vas_id == vasid) {
192 mutex_unlock(&vas_mutex);
193 return vinst;
194 }
195 }
196 mutex_unlock(&vas_mutex);
197
198 pr_devel("Instance %d not found\n", vasid);
199 return NULL;
200 }
201
chip_to_vas_id(int chipid)202 int chip_to_vas_id(int chipid)
203 {
204 int cpu;
205
206 for_each_possible_cpu(cpu) {
207 if (cpu_to_chip_id(cpu) == chipid)
208 return per_cpu(cpu_vas_id, cpu);
209 }
210 return -1;
211 }
212 EXPORT_SYMBOL(chip_to_vas_id);
213
vas_probe(struct platform_device * pdev)214 static int vas_probe(struct platform_device *pdev)
215 {
216 return init_vas_instance(pdev);
217 }
218
219 static const struct of_device_id powernv_vas_match[] = {
220 { .compatible = "ibm,vas",},
221 {},
222 };
223
224 static struct platform_driver vas_driver = {
225 .driver = {
226 .name = "vas",
227 .of_match_table = powernv_vas_match,
228 },
229 .probe = vas_probe,
230 };
231
vas_init(void)232 static int __init vas_init(void)
233 {
234 int found = 0;
235 struct device_node *dn;
236
237 platform_driver_register(&vas_driver);
238
239 for_each_compatible_node(dn, NULL, "ibm,vas") {
240 of_platform_device_create(dn, NULL, NULL);
241 found++;
242 }
243
244 if (!found) {
245 platform_driver_unregister(&vas_driver);
246 return -ENODEV;
247 }
248
249 pr_devel("Found %d instances\n", found);
250
251 return 0;
252 }
253 device_initcall(vas_init);
254