This source file includes following definitions.
- plic_toggle
- plic_irq_toggle
- plic_irq_unmask
- plic_irq_mask
- plic_set_affinity
- plic_irq_eoi
- plic_irqdomain_map
- plic_handle_irq
- plic_find_hart_id
- plic_init
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5
6 #define pr_fmt(fmt) "plic: " fmt
7 #include <linux/interrupt.h>
8 #include <linux/io.h>
9 #include <linux/irq.h>
10 #include <linux/irqchip.h>
11 #include <linux/irqdomain.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/of_irq.h>
16 #include <linux/platform_device.h>
17 #include <linux/spinlock.h>
18 #include <asm/smp.h>
19
20
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22
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27
28
29
30
31 #define MAX_DEVICES 1024
32 #define MAX_CONTEXTS 15872
33
34
35
36
37
38 #define PRIORITY_BASE 0
39 #define PRIORITY_PER_ID 4
40
41
42
43
44
45 #define ENABLE_BASE 0x2000
46 #define ENABLE_PER_HART 0x80
47
48
49
50
51
52
53 #define CONTEXT_BASE 0x200000
54 #define CONTEXT_PER_HART 0x1000
55 #define CONTEXT_THRESHOLD 0x00
56 #define CONTEXT_CLAIM 0x04
57
58 static void __iomem *plic_regs;
59
60 struct plic_handler {
61 bool present;
62 void __iomem *hart_base;
63
64
65
66
67 raw_spinlock_t enable_lock;
68 void __iomem *enable_base;
69 };
70 static DEFINE_PER_CPU(struct plic_handler, plic_handlers);
71
72 static inline void plic_toggle(struct plic_handler *handler,
73 int hwirq, int enable)
74 {
75 u32 __iomem *reg = handler->enable_base + (hwirq / 32) * sizeof(u32);
76 u32 hwirq_mask = 1 << (hwirq % 32);
77
78 raw_spin_lock(&handler->enable_lock);
79 if (enable)
80 writel(readl(reg) | hwirq_mask, reg);
81 else
82 writel(readl(reg) & ~hwirq_mask, reg);
83 raw_spin_unlock(&handler->enable_lock);
84 }
85
86 static inline void plic_irq_toggle(const struct cpumask *mask,
87 int hwirq, int enable)
88 {
89 int cpu;
90
91 writel(enable, plic_regs + PRIORITY_BASE + hwirq * PRIORITY_PER_ID);
92 for_each_cpu(cpu, mask) {
93 struct plic_handler *handler = per_cpu_ptr(&plic_handlers, cpu);
94
95 if (handler->present)
96 plic_toggle(handler, hwirq, enable);
97 }
98 }
99
100 static void plic_irq_unmask(struct irq_data *d)
101 {
102 unsigned int cpu = cpumask_any_and(irq_data_get_affinity_mask(d),
103 cpu_online_mask);
104 if (WARN_ON_ONCE(cpu >= nr_cpu_ids))
105 return;
106 plic_irq_toggle(cpumask_of(cpu), d->hwirq, 1);
107 }
108
109 static void plic_irq_mask(struct irq_data *d)
110 {
111 plic_irq_toggle(cpu_possible_mask, d->hwirq, 0);
112 }
113
114 #ifdef CONFIG_SMP
115 static int plic_set_affinity(struct irq_data *d,
116 const struct cpumask *mask_val, bool force)
117 {
118 unsigned int cpu;
119
120 if (force)
121 cpu = cpumask_first(mask_val);
122 else
123 cpu = cpumask_any_and(mask_val, cpu_online_mask);
124
125 if (cpu >= nr_cpu_ids)
126 return -EINVAL;
127
128 plic_irq_toggle(cpu_possible_mask, d->hwirq, 0);
129 plic_irq_toggle(cpumask_of(cpu), d->hwirq, 1);
130
131 irq_data_update_effective_affinity(d, cpumask_of(cpu));
132
133 return IRQ_SET_MASK_OK_DONE;
134 }
135 #endif
136
137 static void plic_irq_eoi(struct irq_data *d)
138 {
139 struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
140
141 writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM);
142 }
143
144 static struct irq_chip plic_chip = {
145 .name = "SiFive PLIC",
146 .irq_mask = plic_irq_mask,
147 .irq_unmask = plic_irq_unmask,
148 .irq_eoi = plic_irq_eoi,
149 #ifdef CONFIG_SMP
150 .irq_set_affinity = plic_set_affinity,
151 #endif
152 };
153
154 static int plic_irqdomain_map(struct irq_domain *d, unsigned int irq,
155 irq_hw_number_t hwirq)
156 {
157 irq_set_chip_and_handler(irq, &plic_chip, handle_fasteoi_irq);
158 irq_set_chip_data(irq, NULL);
159 irq_set_noprobe(irq);
160 return 0;
161 }
162
163 static const struct irq_domain_ops plic_irqdomain_ops = {
164 .map = plic_irqdomain_map,
165 .xlate = irq_domain_xlate_onecell,
166 };
167
168 static struct irq_domain *plic_irqdomain;
169
170
171
172
173
174
175
176 static void plic_handle_irq(struct pt_regs *regs)
177 {
178 struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
179 void __iomem *claim = handler->hart_base + CONTEXT_CLAIM;
180 irq_hw_number_t hwirq;
181
182 WARN_ON_ONCE(!handler->present);
183
184 csr_clear(sie, SIE_SEIE);
185 while ((hwirq = readl(claim))) {
186 int irq = irq_find_mapping(plic_irqdomain, hwirq);
187
188 if (unlikely(irq <= 0))
189 pr_warn_ratelimited("can't find mapping for hwirq %lu\n",
190 hwirq);
191 else
192 generic_handle_irq(irq);
193 }
194 csr_set(sie, SIE_SEIE);
195 }
196
197
198
199
200
201 static int plic_find_hart_id(struct device_node *node)
202 {
203 for (; node; node = node->parent) {
204 if (of_device_is_compatible(node, "riscv"))
205 return riscv_of_processor_hartid(node);
206 }
207
208 return -1;
209 }
210
211 static int __init plic_init(struct device_node *node,
212 struct device_node *parent)
213 {
214 int error = 0, nr_contexts, nr_handlers = 0, i;
215 u32 nr_irqs;
216
217 if (plic_regs) {
218 pr_warn("PLIC already present.\n");
219 return -ENXIO;
220 }
221
222 plic_regs = of_iomap(node, 0);
223 if (WARN_ON(!plic_regs))
224 return -EIO;
225
226 error = -EINVAL;
227 of_property_read_u32(node, "riscv,ndev", &nr_irqs);
228 if (WARN_ON(!nr_irqs))
229 goto out_iounmap;
230
231 nr_contexts = of_irq_count(node);
232 if (WARN_ON(!nr_contexts))
233 goto out_iounmap;
234 if (WARN_ON(nr_contexts < num_possible_cpus()))
235 goto out_iounmap;
236
237 error = -ENOMEM;
238 plic_irqdomain = irq_domain_add_linear(node, nr_irqs + 1,
239 &plic_irqdomain_ops, NULL);
240 if (WARN_ON(!plic_irqdomain))
241 goto out_iounmap;
242
243 for (i = 0; i < nr_contexts; i++) {
244 struct of_phandle_args parent;
245 struct plic_handler *handler;
246 irq_hw_number_t hwirq;
247 int cpu, hartid;
248 u32 threshold = 0;
249
250 if (of_irq_parse_one(node, i, &parent)) {
251 pr_err("failed to parse parent for context %d.\n", i);
252 continue;
253 }
254
255
256 if (parent.args[0] != IRQ_S_EXT)
257 continue;
258
259 hartid = plic_find_hart_id(parent.np);
260 if (hartid < 0) {
261 pr_warn("failed to parse hart ID for context %d.\n", i);
262 continue;
263 }
264
265 cpu = riscv_hartid_to_cpuid(hartid);
266 if (cpu < 0) {
267 pr_warn("Invalid cpuid for context %d\n", i);
268 continue;
269 }
270
271
272
273
274
275
276 handler = per_cpu_ptr(&plic_handlers, cpu);
277 if (handler->present) {
278 pr_warn("handler already present for context %d.\n", i);
279 threshold = 0xffffffff;
280 goto done;
281 }
282
283 handler->present = true;
284 handler->hart_base =
285 plic_regs + CONTEXT_BASE + i * CONTEXT_PER_HART;
286 raw_spin_lock_init(&handler->enable_lock);
287 handler->enable_base =
288 plic_regs + ENABLE_BASE + i * ENABLE_PER_HART;
289
290 done:
291
292 writel(threshold, handler->hart_base + CONTEXT_THRESHOLD);
293 for (hwirq = 1; hwirq <= nr_irqs; hwirq++)
294 plic_toggle(handler, hwirq, 0);
295 nr_handlers++;
296 }
297
298 pr_info("mapped %d interrupts with %d handlers for %d contexts.\n",
299 nr_irqs, nr_handlers, nr_contexts);
300 set_handle_irq(plic_handle_irq);
301 return 0;
302
303 out_iounmap:
304 iounmap(plic_regs);
305 return error;
306 }
307
308 IRQCHIP_DECLARE(sifive_plic, "sifive,plic-1.0.0", plic_init);
309 IRQCHIP_DECLARE(riscv_plic0, "riscv,plic0", plic_init);