Merge tag 'iio-fixes-for-5.12a' of https://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-microblaze.git] / arch / powerpc / platforms / powernv / vas.c
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
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
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  */
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
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
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
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);