xref: /linux/drivers/irqchip/irq-riscv-aplic-main.c (revision 9270102a00aabbe4d1bbb6890d514b01f1c42989)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2021 Western Digital Corporation or its affiliates.
4  * Copyright (C) 2022 Ventana Micro Systems Inc.
5  */
6 
7 #include <linux/acpi.h>
8 #include <linux/bitfield.h>
9 #include <linux/irqchip/riscv-aplic.h>
10 #include <linux/irqchip/riscv-imsic.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/of_irq.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm_domain.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/printk.h>
18 #include <linux/syscore_ops.h>
19 
20 #include "irq-riscv-aplic-main.h"
21 
22 static LIST_HEAD(aplics);
23 
24 static void aplic_restore_states(struct aplic_priv *priv)
25 {
26 	struct aplic_saved_regs *saved_regs = &priv->saved_hw_regs;
27 	struct aplic_src_ctrl *srcs;
28 	void __iomem *regs;
29 	u32 nr_irqs, i;
30 
31 	regs = priv->regs;
32 	writel(saved_regs->domaincfg, regs + APLIC_DOMAINCFG);
33 #ifdef CONFIG_RISCV_M_MODE
34 	writel(saved_regs->msiaddr, regs + APLIC_xMSICFGADDR);
35 	writel(saved_regs->msiaddrh, regs + APLIC_xMSICFGADDRH);
36 #endif
37 	/*
38 	 * The sourcecfg[i] has to be restored prior to the target[i], interrupt-pending and
39 	 * interrupt-enable bits. The AIA specification states that "Whenever interrupt source i is
40 	 * inactive in an interrupt domain, the corresponding interrupt-pending and interrupt-enable
41 	 * bits within the domain are read-only zeros, and register target[i] is also read-only
42 	 * zero."
43 	 */
44 	nr_irqs = priv->nr_irqs;
45 	for (i = 0; i < nr_irqs; i++) {
46 		srcs = &priv->saved_hw_regs.srcs[i];
47 		writel(srcs->sourcecfg, regs + APLIC_SOURCECFG_BASE + i * sizeof(u32));
48 		writel(srcs->target, regs + APLIC_TARGET_BASE + i * sizeof(u32));
49 	}
50 
51 	for (i = 0; i <= nr_irqs; i += 32) {
52 		srcs = &priv->saved_hw_regs.srcs[i];
53 		writel(-1U, regs + APLIC_CLRIE_BASE + (i / 32) * sizeof(u32));
54 		writel(srcs->ie, regs + APLIC_SETIE_BASE + (i / 32) * sizeof(u32));
55 
56 		/* Re-trigger the interrupts if it forwards interrupts to target harts by MSIs */
57 		if (!priv->nr_idcs)
58 			writel(readl(regs + APLIC_CLRIP_BASE + (i / 32) * sizeof(u32)),
59 			       regs + APLIC_SETIP_BASE + (i / 32) * sizeof(u32));
60 	}
61 
62 	if (priv->nr_idcs)
63 		aplic_direct_restore_states(priv);
64 }
65 
66 static void aplic_save_states(struct aplic_priv *priv)
67 {
68 	struct aplic_src_ctrl *srcs;
69 	void __iomem *regs;
70 	u32 i, nr_irqs;
71 
72 	regs = priv->regs;
73 	nr_irqs = priv->nr_irqs;
74 	/* The valid interrupt source IDs range from 1 to N, where N is priv->nr_irqs */
75 	for (i = 0; i < nr_irqs; i++) {
76 		srcs = &priv->saved_hw_regs.srcs[i];
77 		srcs->target = readl(regs + APLIC_TARGET_BASE + i * sizeof(u32));
78 
79 		if (i % 32)
80 			continue;
81 
82 		srcs->ie = readl(regs + APLIC_SETIE_BASE + (i / 32) * sizeof(u32));
83 	}
84 
85 	/* Save the nr_irqs bit if needed */
86 	if (!(nr_irqs % 32)) {
87 		srcs = &priv->saved_hw_regs.srcs[nr_irqs];
88 		srcs->ie = readl(regs + APLIC_SETIE_BASE + (nr_irqs / 32) * sizeof(u32));
89 	}
90 }
91 
92 static int aplic_syscore_suspend(void *data)
93 {
94 	struct aplic_priv *priv;
95 
96 	list_for_each_entry(priv, &aplics, head)
97 		aplic_save_states(priv);
98 
99 	return 0;
100 }
101 
102 static void aplic_syscore_resume(void *data)
103 {
104 	struct aplic_priv *priv;
105 
106 	list_for_each_entry(priv, &aplics, head)
107 		aplic_restore_states(priv);
108 }
109 
110 static struct syscore_ops aplic_syscore_ops = {
111 	.suspend = aplic_syscore_suspend,
112 	.resume = aplic_syscore_resume,
113 };
114 
115 static struct syscore aplic_syscore = {
116 	.ops = &aplic_syscore_ops,
117 };
118 
119 static bool aplic_syscore_registered __ro_after_init;
120 
121 static void aplic_syscore_init(void)
122 {
123 	if (!aplic_syscore_registered) {
124 		register_syscore(&aplic_syscore);
125 		aplic_syscore_registered = true;
126 	}
127 }
128 
129 static int aplic_pm_notifier(struct notifier_block *nb, unsigned long action, void *data)
130 {
131 	struct aplic_priv *priv = container_of(nb, struct aplic_priv, genpd_nb);
132 
133 	switch (action) {
134 	case GENPD_NOTIFY_PRE_OFF:
135 		aplic_save_states(priv);
136 		break;
137 	case GENPD_NOTIFY_ON:
138 		aplic_restore_states(priv);
139 		break;
140 	default:
141 		break;
142 	}
143 
144 	return 0;
145 }
146 
147 static void aplic_pm_remove(void *data)
148 {
149 	struct aplic_priv *priv = data;
150 	struct device *dev = priv->dev;
151 
152 	list_del(&priv->head);
153 	if (dev->pm_domain)
154 		dev_pm_genpd_remove_notifier(dev);
155 }
156 
157 static int aplic_pm_add(struct device *dev, struct aplic_priv *priv)
158 {
159 	struct aplic_src_ctrl *srcs;
160 	int ret;
161 
162 	srcs = devm_kzalloc(dev, (priv->nr_irqs + 1) * sizeof(*srcs), GFP_KERNEL);
163 	if (!srcs)
164 		return -ENOMEM;
165 
166 	priv->saved_hw_regs.srcs = srcs;
167 	list_add(&priv->head, &aplics);
168 	if (dev->pm_domain) {
169 		priv->genpd_nb.notifier_call = aplic_pm_notifier;
170 		ret = dev_pm_genpd_add_notifier(dev, &priv->genpd_nb);
171 		if (ret)
172 			goto remove_head;
173 
174 		ret = devm_pm_runtime_enable(dev);
175 		if (ret)
176 			goto remove_notifier;
177 	}
178 
179 	return devm_add_action_or_reset(dev, aplic_pm_remove, priv);
180 
181 remove_notifier:
182 	dev_pm_genpd_remove_notifier(dev);
183 remove_head:
184 	list_del(&priv->head);
185 	return ret;
186 }
187 
188 void aplic_irq_unmask(struct irq_data *d)
189 {
190 	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
191 
192 	writel(d->hwirq, priv->regs + APLIC_SETIENUM);
193 }
194 
195 void aplic_irq_mask(struct irq_data *d)
196 {
197 	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
198 
199 	writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
200 }
201 
202 int aplic_irq_set_type(struct irq_data *d, unsigned int type)
203 {
204 	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
205 	void __iomem *sourcecfg;
206 	u32 val = 0;
207 
208 	switch (type) {
209 	case IRQ_TYPE_NONE:
210 		val = APLIC_SOURCECFG_SM_INACTIVE;
211 		break;
212 	case IRQ_TYPE_LEVEL_LOW:
213 		val = APLIC_SOURCECFG_SM_LEVEL_LOW;
214 		break;
215 	case IRQ_TYPE_LEVEL_HIGH:
216 		val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
217 		break;
218 	case IRQ_TYPE_EDGE_FALLING:
219 		val = APLIC_SOURCECFG_SM_EDGE_FALL;
220 		break;
221 	case IRQ_TYPE_EDGE_RISING:
222 		val = APLIC_SOURCECFG_SM_EDGE_RISE;
223 		break;
224 	default:
225 		return -EINVAL;
226 	}
227 
228 	sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
229 	sourcecfg += (d->hwirq - 1) * sizeof(u32);
230 	writel(val, sourcecfg);
231 
232 	priv->saved_hw_regs.srcs[d->hwirq - 1].sourcecfg = val;
233 
234 	return 0;
235 }
236 
237 int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
238 			      unsigned long *hwirq, unsigned int *type)
239 {
240 	if (WARN_ON(fwspec->param_count < 2))
241 		return -EINVAL;
242 	if (WARN_ON(!fwspec->param[0]))
243 		return -EINVAL;
244 
245 	/* For DT, gsi_base is always zero. */
246 	*hwirq = fwspec->param[0] - gsi_base;
247 	*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
248 
249 	WARN_ON(*type == IRQ_TYPE_NONE);
250 
251 	return 0;
252 }
253 
254 void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
255 {
256 	struct aplic_saved_regs *saved_regs = &priv->saved_hw_regs;
257 	u32 val;
258 #ifdef CONFIG_RISCV_M_MODE
259 	u32 valh;
260 
261 	if (msi_mode) {
262 		val = lower_32_bits(priv->msicfg.base_ppn);
263 		valh = FIELD_PREP(APLIC_xMSICFGADDRH_BAPPN, upper_32_bits(priv->msicfg.base_ppn));
264 		valh |= FIELD_PREP(APLIC_xMSICFGADDRH_LHXW, priv->msicfg.lhxw);
265 		valh |= FIELD_PREP(APLIC_xMSICFGADDRH_HHXW, priv->msicfg.hhxw);
266 		valh |= FIELD_PREP(APLIC_xMSICFGADDRH_LHXS, priv->msicfg.lhxs);
267 		valh |= FIELD_PREP(APLIC_xMSICFGADDRH_HHXS, priv->msicfg.hhxs);
268 		writel(val, priv->regs + APLIC_xMSICFGADDR);
269 		writel(valh, priv->regs + APLIC_xMSICFGADDRH);
270 		saved_regs->msiaddr = val;
271 		saved_regs->msiaddrh = valh;
272 	}
273 #endif
274 
275 	/* Setup APLIC domaincfg register */
276 	val = readl(priv->regs + APLIC_DOMAINCFG);
277 	val |= APLIC_DOMAINCFG_IE;
278 	if (msi_mode)
279 		val |= APLIC_DOMAINCFG_DM;
280 	writel(val, priv->regs + APLIC_DOMAINCFG);
281 	if (readl(priv->regs + APLIC_DOMAINCFG) != val)
282 		dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n", val);
283 
284 	saved_regs->domaincfg = val;
285 }
286 
287 static void aplic_init_hw_irqs(struct aplic_priv *priv)
288 {
289 	int i;
290 
291 	/* Disable all interrupts */
292 	for (i = 0; i <= priv->nr_irqs; i += 32)
293 		writel(-1U, priv->regs + APLIC_CLRIE_BASE + (i / 32) * sizeof(u32));
294 
295 	/* Set interrupt type and default priority for all interrupts */
296 	for (i = 1; i <= priv->nr_irqs; i++) {
297 		writel(0, priv->regs + APLIC_SOURCECFG_BASE + (i - 1) * sizeof(u32));
298 		writel(APLIC_DEFAULT_PRIORITY,
299 		       priv->regs + APLIC_TARGET_BASE + (i - 1) * sizeof(u32));
300 	}
301 
302 	/* Clear APLIC domaincfg */
303 	writel(0, priv->regs + APLIC_DOMAINCFG);
304 }
305 
306 #ifdef CONFIG_ACPI
307 static const struct acpi_device_id aplic_acpi_match[] = {
308 	{ "RSCV0002", 0 },
309 	{}
310 };
311 MODULE_DEVICE_TABLE(acpi, aplic_acpi_match);
312 
313 #endif
314 
315 int aplic_setup_priv(struct aplic_priv *priv, struct device *dev, void __iomem *regs)
316 {
317 	struct device_node *np = to_of_node(dev->fwnode);
318 	struct of_phandle_args parent;
319 	int rc;
320 
321 	/* Save device pointer and register base */
322 	priv->dev = dev;
323 	priv->regs = regs;
324 
325 	if (np) {
326 		/* Find out number of interrupt sources */
327 		rc = of_property_read_u32(np, "riscv,num-sources", &priv->nr_irqs);
328 		if (rc) {
329 			dev_err(dev, "failed to get number of interrupt sources\n");
330 			return rc;
331 		}
332 
333 		/*
334 		 * Find out number of IDCs based on parent interrupts
335 		 *
336 		 * If "msi-parent" property is present then we ignore the
337 		 * APLIC IDCs which forces the APLIC driver to use MSI mode.
338 		 */
339 		if (!of_property_present(np, "msi-parent")) {
340 			while (!of_irq_parse_one(np, priv->nr_idcs, &parent))
341 				priv->nr_idcs++;
342 		}
343 	} else {
344 		rc = riscv_acpi_get_gsi_info(dev->fwnode, &priv->gsi_base, &priv->acpi_aplic_id,
345 					     &priv->nr_irqs, &priv->nr_idcs);
346 		if (rc) {
347 			dev_err(dev, "failed to find GSI mapping\n");
348 			return rc;
349 		}
350 	}
351 
352 	/* Setup initial state APLIC interrupts */
353 	aplic_init_hw_irqs(priv);
354 
355 	return aplic_pm_add(dev, priv);
356 }
357 
358 static int aplic_probe(struct platform_device *pdev)
359 {
360 	struct device *dev = &pdev->dev;
361 	bool msi_mode = false;
362 	void __iomem *regs;
363 	int rc;
364 
365 	/* Map the MMIO registers */
366 	regs = devm_platform_ioremap_resource(pdev, 0);
367 	if (IS_ERR(regs)) {
368 		dev_err(dev, "failed map MMIO registers\n");
369 		return PTR_ERR(regs);
370 	}
371 
372 	/*
373 	 * If msi-parent property is present then setup APLIC MSI
374 	 * mode otherwise setup APLIC direct mode.
375 	 */
376 	if (is_of_node(dev->fwnode))
377 		msi_mode = of_property_present(to_of_node(dev->fwnode), "msi-parent");
378 	else
379 		msi_mode = imsic_acpi_get_fwnode(NULL) ? 1 : 0;
380 
381 	if (msi_mode)
382 		rc = aplic_msi_setup(dev, regs);
383 	else
384 		rc = aplic_direct_setup(dev, regs);
385 
386 	if (rc) {
387 		dev_err_probe(dev, rc, "failed to setup APLIC in %s mode\n",
388 			      msi_mode ? "MSI" : "direct");
389 		return rc;
390 	}
391 
392 	aplic_syscore_init();
393 
394 #ifdef CONFIG_ACPI
395 	if (!acpi_disabled)
396 		acpi_dev_clear_dependencies(ACPI_COMPANION(dev));
397 #endif
398 
399 	return 0;
400 }
401 
402 static const struct of_device_id aplic_match[] = {
403 	{ .compatible = "riscv,aplic" },
404 	{}
405 };
406 
407 static struct platform_driver aplic_driver = {
408 	.driver = {
409 		.name		= "riscv-aplic",
410 		.of_match_table	= aplic_match,
411 		.acpi_match_table = ACPI_PTR(aplic_acpi_match),
412 	},
413 	.probe = aplic_probe,
414 };
415 builtin_platform_driver(aplic_driver);
416