1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Freescale SCFG MSI(-X) support
4 *
5 * Copyright (C) 2016 Freescale Semiconductor.
6 *
7 * Author: Minghuan Lian <Minghuan.Lian@nxp.com>
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/msi.h>
13 #include <linux/interrupt.h>
14 #include <linux/iommu.h>
15 #include <linux/irq.h>
16 #include <linux/irqchip/chained_irq.h>
17 #include <linux/irqdomain.h>
18 #include <linux/of_irq.h>
19 #include <linux/of_pci.h>
20 #include <linux/platform_device.h>
21 #include <linux/property.h>
22 #include <linux/spinlock.h>
23
24 #define MSI_IRQS_PER_MSIR 32
25 #define MSI_MSIR_OFFSET 4
26
27 #define MSI_LS1043V1_1_IRQS_PER_MSIR 8
28 #define MSI_LS1043V1_1_MSIR_OFFSET 0x10
29
30 struct ls_scfg_msi_cfg {
31 u32 ibs_shift; /* Shift of interrupt bit select */
32 u32 msir_irqs; /* The irq number per MSIR */
33 u32 msir_base; /* The base address of MSIR */
34 };
35
36 struct ls_scfg_msir {
37 struct ls_scfg_msi *msi_data;
38 unsigned int index;
39 unsigned int gic_irq;
40 unsigned int bit_start;
41 unsigned int bit_end;
42 unsigned int srs; /* Shared interrupt register select */
43 void __iomem *reg;
44 };
45
46 struct ls_scfg_msi {
47 spinlock_t lock;
48 struct platform_device *pdev;
49 struct irq_domain *parent;
50 struct irq_domain *msi_domain;
51 void __iomem *regs;
52 phys_addr_t msiir_addr;
53 struct ls_scfg_msi_cfg *cfg;
54 u32 msir_num;
55 struct ls_scfg_msir *msir;
56 u32 irqs_num;
57 unsigned long *used;
58 };
59
60 static struct irq_chip ls_scfg_msi_irq_chip = {
61 .name = "MSI",
62 .irq_mask = pci_msi_mask_irq,
63 .irq_unmask = pci_msi_unmask_irq,
64 };
65
66 static struct msi_domain_info ls_scfg_msi_domain_info = {
67 .flags = (MSI_FLAG_USE_DEF_DOM_OPS |
68 MSI_FLAG_USE_DEF_CHIP_OPS |
69 MSI_FLAG_PCI_MSIX),
70 .chip = &ls_scfg_msi_irq_chip,
71 };
72
73 static int msi_affinity_flag = 1;
74
early_parse_ls_scfg_msi(char * p)75 static int __init early_parse_ls_scfg_msi(char *p)
76 {
77 if (p && strncmp(p, "no-affinity", 11) == 0)
78 msi_affinity_flag = 0;
79 else
80 msi_affinity_flag = 1;
81
82 return 0;
83 }
84 early_param("lsmsi", early_parse_ls_scfg_msi);
85
ls_scfg_msi_compose_msg(struct irq_data * data,struct msi_msg * msg)86 static void ls_scfg_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
87 {
88 struct ls_scfg_msi *msi_data = irq_data_get_irq_chip_data(data);
89
90 msg->address_hi = upper_32_bits(msi_data->msiir_addr);
91 msg->address_lo = lower_32_bits(msi_data->msiir_addr);
92 msg->data = data->hwirq;
93
94 if (msi_affinity_flag) {
95 const struct cpumask *mask;
96
97 mask = irq_data_get_effective_affinity_mask(data);
98 msg->data |= cpumask_first(mask);
99 }
100
101 iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), msg);
102 }
103
ls_scfg_msi_set_affinity(struct irq_data * irq_data,const struct cpumask * mask,bool force)104 static int ls_scfg_msi_set_affinity(struct irq_data *irq_data,
105 const struct cpumask *mask, bool force)
106 {
107 struct ls_scfg_msi *msi_data = irq_data_get_irq_chip_data(irq_data);
108 u32 cpu;
109
110 if (!msi_affinity_flag)
111 return -EINVAL;
112
113 if (!force)
114 cpu = cpumask_any_and(mask, cpu_online_mask);
115 else
116 cpu = cpumask_first(mask);
117
118 if (cpu >= msi_data->msir_num)
119 return -EINVAL;
120
121 if (msi_data->msir[cpu].gic_irq <= 0) {
122 pr_warn("cannot bind the irq to cpu%d\n", cpu);
123 return -EINVAL;
124 }
125
126 irq_data_update_effective_affinity(irq_data, cpumask_of(cpu));
127
128 return IRQ_SET_MASK_OK;
129 }
130
131 static struct irq_chip ls_scfg_msi_parent_chip = {
132 .name = "SCFG",
133 .irq_compose_msi_msg = ls_scfg_msi_compose_msg,
134 .irq_set_affinity = ls_scfg_msi_set_affinity,
135 };
136
ls_scfg_msi_domain_irq_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * args)137 static int ls_scfg_msi_domain_irq_alloc(struct irq_domain *domain,
138 unsigned int virq,
139 unsigned int nr_irqs,
140 void *args)
141 {
142 msi_alloc_info_t *info = args;
143 struct ls_scfg_msi *msi_data = domain->host_data;
144 int pos, err = 0;
145
146 WARN_ON(nr_irqs != 1);
147
148 spin_lock(&msi_data->lock);
149 pos = find_first_zero_bit(msi_data->used, msi_data->irqs_num);
150 if (pos < msi_data->irqs_num)
151 __set_bit(pos, msi_data->used);
152 else
153 err = -ENOSPC;
154 spin_unlock(&msi_data->lock);
155
156 if (err)
157 return err;
158
159 err = iommu_dma_prepare_msi(info->desc, msi_data->msiir_addr);
160 if (err)
161 return err;
162
163 irq_domain_set_info(domain, virq, pos,
164 &ls_scfg_msi_parent_chip, msi_data,
165 handle_simple_irq, NULL, NULL);
166
167 return 0;
168 }
169
ls_scfg_msi_domain_irq_free(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs)170 static void ls_scfg_msi_domain_irq_free(struct irq_domain *domain,
171 unsigned int virq, unsigned int nr_irqs)
172 {
173 struct irq_data *d = irq_domain_get_irq_data(domain, virq);
174 struct ls_scfg_msi *msi_data = irq_data_get_irq_chip_data(d);
175 int pos;
176
177 pos = d->hwirq;
178 if (pos < 0 || pos >= msi_data->irqs_num) {
179 pr_err("failed to teardown msi. Invalid hwirq %d\n", pos);
180 return;
181 }
182
183 spin_lock(&msi_data->lock);
184 __clear_bit(pos, msi_data->used);
185 spin_unlock(&msi_data->lock);
186 }
187
188 static const struct irq_domain_ops ls_scfg_msi_domain_ops = {
189 .alloc = ls_scfg_msi_domain_irq_alloc,
190 .free = ls_scfg_msi_domain_irq_free,
191 };
192
ls_scfg_msi_irq_handler(struct irq_desc * desc)193 static void ls_scfg_msi_irq_handler(struct irq_desc *desc)
194 {
195 struct ls_scfg_msir *msir = irq_desc_get_handler_data(desc);
196 struct ls_scfg_msi *msi_data = msir->msi_data;
197 unsigned long val;
198 int pos, size, hwirq;
199
200 chained_irq_enter(irq_desc_get_chip(desc), desc);
201
202 val = ioread32be(msir->reg);
203
204 pos = msir->bit_start;
205 size = msir->bit_end + 1;
206
207 for_each_set_bit_from(pos, &val, size) {
208 hwirq = ((msir->bit_end - pos) << msi_data->cfg->ibs_shift) |
209 msir->srs;
210 generic_handle_domain_irq(msi_data->parent, hwirq);
211 }
212
213 chained_irq_exit(irq_desc_get_chip(desc), desc);
214 }
215
ls_scfg_msi_domains_init(struct ls_scfg_msi * msi_data)216 static int ls_scfg_msi_domains_init(struct ls_scfg_msi *msi_data)
217 {
218 /* Initialize MSI domain parent */
219 msi_data->parent = irq_domain_add_linear(NULL,
220 msi_data->irqs_num,
221 &ls_scfg_msi_domain_ops,
222 msi_data);
223 if (!msi_data->parent) {
224 dev_err(&msi_data->pdev->dev, "failed to create IRQ domain\n");
225 return -ENOMEM;
226 }
227
228 msi_data->msi_domain = pci_msi_create_irq_domain(
229 of_node_to_fwnode(msi_data->pdev->dev.of_node),
230 &ls_scfg_msi_domain_info,
231 msi_data->parent);
232 if (!msi_data->msi_domain) {
233 dev_err(&msi_data->pdev->dev, "failed to create MSI domain\n");
234 irq_domain_remove(msi_data->parent);
235 return -ENOMEM;
236 }
237
238 return 0;
239 }
240
ls_scfg_msi_setup_hwirq(struct ls_scfg_msi * msi_data,int index)241 static int ls_scfg_msi_setup_hwirq(struct ls_scfg_msi *msi_data, int index)
242 {
243 struct ls_scfg_msir *msir;
244 int virq, i, hwirq;
245
246 virq = platform_get_irq(msi_data->pdev, index);
247 if (virq <= 0)
248 return -ENODEV;
249
250 msir = &msi_data->msir[index];
251 msir->index = index;
252 msir->msi_data = msi_data;
253 msir->gic_irq = virq;
254 msir->reg = msi_data->regs + msi_data->cfg->msir_base + 4 * index;
255
256 if (msi_data->cfg->msir_irqs == MSI_LS1043V1_1_IRQS_PER_MSIR) {
257 msir->bit_start = 32 - ((msir->index + 1) *
258 MSI_LS1043V1_1_IRQS_PER_MSIR);
259 msir->bit_end = msir->bit_start +
260 MSI_LS1043V1_1_IRQS_PER_MSIR - 1;
261 } else {
262 msir->bit_start = 0;
263 msir->bit_end = msi_data->cfg->msir_irqs - 1;
264 }
265
266 irq_set_chained_handler_and_data(msir->gic_irq,
267 ls_scfg_msi_irq_handler,
268 msir);
269
270 if (msi_affinity_flag) {
271 /* Associate MSIR interrupt to the cpu */
272 irq_set_affinity(msir->gic_irq, get_cpu_mask(index));
273 msir->srs = 0; /* This value is determined by the CPU */
274 } else
275 msir->srs = index;
276
277 /* Release the hwirqs corresponding to this MSIR */
278 if (!msi_affinity_flag || msir->index == 0) {
279 for (i = 0; i < msi_data->cfg->msir_irqs; i++) {
280 hwirq = i << msi_data->cfg->ibs_shift | msir->index;
281 bitmap_clear(msi_data->used, hwirq, 1);
282 }
283 }
284
285 return 0;
286 }
287
ls_scfg_msi_teardown_hwirq(struct ls_scfg_msir * msir)288 static int ls_scfg_msi_teardown_hwirq(struct ls_scfg_msir *msir)
289 {
290 struct ls_scfg_msi *msi_data = msir->msi_data;
291 int i, hwirq;
292
293 if (msir->gic_irq > 0)
294 irq_set_chained_handler_and_data(msir->gic_irq, NULL, NULL);
295
296 for (i = 0; i < msi_data->cfg->msir_irqs; i++) {
297 hwirq = i << msi_data->cfg->ibs_shift | msir->index;
298 bitmap_set(msi_data->used, hwirq, 1);
299 }
300
301 return 0;
302 }
303
304 static struct ls_scfg_msi_cfg ls1021_msi_cfg = {
305 .ibs_shift = 3,
306 .msir_irqs = MSI_IRQS_PER_MSIR,
307 .msir_base = MSI_MSIR_OFFSET,
308 };
309
310 static struct ls_scfg_msi_cfg ls1046_msi_cfg = {
311 .ibs_shift = 2,
312 .msir_irqs = MSI_IRQS_PER_MSIR,
313 .msir_base = MSI_MSIR_OFFSET,
314 };
315
316 static struct ls_scfg_msi_cfg ls1043_v1_1_msi_cfg = {
317 .ibs_shift = 2,
318 .msir_irqs = MSI_LS1043V1_1_IRQS_PER_MSIR,
319 .msir_base = MSI_LS1043V1_1_MSIR_OFFSET,
320 };
321
322 static const struct of_device_id ls_scfg_msi_id[] = {
323 /* The following two misspelled compatibles are obsolete */
324 { .compatible = "fsl,1s1021a-msi", .data = &ls1021_msi_cfg},
325 { .compatible = "fsl,1s1043a-msi", .data = &ls1021_msi_cfg},
326
327 { .compatible = "fsl,ls1012a-msi", .data = &ls1021_msi_cfg },
328 { .compatible = "fsl,ls1021a-msi", .data = &ls1021_msi_cfg },
329 { .compatible = "fsl,ls1043a-msi", .data = &ls1021_msi_cfg },
330 { .compatible = "fsl,ls1043a-v1.1-msi", .data = &ls1043_v1_1_msi_cfg },
331 { .compatible = "fsl,ls1046a-msi", .data = &ls1046_msi_cfg },
332 {},
333 };
334 MODULE_DEVICE_TABLE(of, ls_scfg_msi_id);
335
ls_scfg_msi_probe(struct platform_device * pdev)336 static int ls_scfg_msi_probe(struct platform_device *pdev)
337 {
338 struct ls_scfg_msi *msi_data;
339 struct resource *res;
340 int i, ret;
341
342 msi_data = devm_kzalloc(&pdev->dev, sizeof(*msi_data), GFP_KERNEL);
343 if (!msi_data)
344 return -ENOMEM;
345
346 msi_data->cfg = (struct ls_scfg_msi_cfg *)device_get_match_data(&pdev->dev);
347 if (!msi_data->cfg)
348 return -ENODEV;
349
350 msi_data->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
351 if (IS_ERR(msi_data->regs)) {
352 dev_err(&pdev->dev, "failed to initialize 'regs'\n");
353 return PTR_ERR(msi_data->regs);
354 }
355 msi_data->msiir_addr = res->start;
356
357 msi_data->pdev = pdev;
358 spin_lock_init(&msi_data->lock);
359
360 msi_data->irqs_num = MSI_IRQS_PER_MSIR *
361 (1 << msi_data->cfg->ibs_shift);
362 msi_data->used = devm_bitmap_zalloc(&pdev->dev, msi_data->irqs_num, GFP_KERNEL);
363 if (!msi_data->used)
364 return -ENOMEM;
365 /*
366 * Reserve all the hwirqs
367 * The available hwirqs will be released in ls1_msi_setup_hwirq()
368 */
369 bitmap_set(msi_data->used, 0, msi_data->irqs_num);
370
371 msi_data->msir_num = of_irq_count(pdev->dev.of_node);
372
373 if (msi_affinity_flag) {
374 u32 cpu_num;
375
376 cpu_num = num_possible_cpus();
377 if (msi_data->msir_num >= cpu_num)
378 msi_data->msir_num = cpu_num;
379 else
380 msi_affinity_flag = 0;
381 }
382
383 msi_data->msir = devm_kcalloc(&pdev->dev, msi_data->msir_num,
384 sizeof(*msi_data->msir),
385 GFP_KERNEL);
386 if (!msi_data->msir)
387 return -ENOMEM;
388
389 for (i = 0; i < msi_data->msir_num; i++)
390 ls_scfg_msi_setup_hwirq(msi_data, i);
391
392 ret = ls_scfg_msi_domains_init(msi_data);
393 if (ret)
394 return ret;
395
396 platform_set_drvdata(pdev, msi_data);
397
398 return 0;
399 }
400
ls_scfg_msi_remove(struct platform_device * pdev)401 static void ls_scfg_msi_remove(struct platform_device *pdev)
402 {
403 struct ls_scfg_msi *msi_data = platform_get_drvdata(pdev);
404 int i;
405
406 for (i = 0; i < msi_data->msir_num; i++)
407 ls_scfg_msi_teardown_hwirq(&msi_data->msir[i]);
408
409 irq_domain_remove(msi_data->msi_domain);
410 irq_domain_remove(msi_data->parent);
411
412 platform_set_drvdata(pdev, NULL);
413 }
414
415 static struct platform_driver ls_scfg_msi_driver = {
416 .driver = {
417 .name = "ls-scfg-msi",
418 .of_match_table = ls_scfg_msi_id,
419 },
420 .probe = ls_scfg_msi_probe,
421 .remove = ls_scfg_msi_remove,
422 };
423
424 module_platform_driver(ls_scfg_msi_driver);
425
426 MODULE_AUTHOR("Minghuan Lian <Minghuan.Lian@nxp.com>");
427 MODULE_DESCRIPTION("Freescale Layerscape SCFG MSI controller driver");
428