xref: /linux/arch/mips/loongson64/smp.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2010, 2011, 2012, Lemote, Inc.
4  * Author: Chen Huacai, chenhc@lemote.com
5  */
6 
7 #include <irq.h>
8 #include <linux/init.h>
9 #include <linux/cpu.h>
10 #include <linux/sched.h>
11 #include <linux/sched/hotplug.h>
12 #include <linux/sched/task_stack.h>
13 #include <linux/smp.h>
14 #include <linux/cpufreq.h>
15 #include <linux/kexec.h>
16 #include <asm/processor.h>
17 #include <asm/smp.h>
18 #include <asm/time.h>
19 #include <asm/tlbflush.h>
20 #include <asm/cacheflush.h>
21 #include <loongson.h>
22 #include <loongson_regs.h>
23 #include <workarounds.h>
24 
25 #include "smp.h"
26 
27 DEFINE_PER_CPU(int, cpu_state);
28 
29 #define LS_IPI_IRQ (MIPS_CPU_IRQ_BASE + 6)
30 
31 static void __iomem *ipi_set0_regs[16];
32 static void __iomem *ipi_clear0_regs[16];
33 static void __iomem *ipi_status0_regs[16];
34 static void __iomem *ipi_en0_regs[16];
35 static void __iomem *ipi_mailbox_buf[16];
36 
37 static u32 (*ipi_read_clear)(int cpu);
38 static void (*ipi_write_action)(int cpu, u32 action);
39 static void (*ipi_write_enable)(int cpu);
40 static void (*ipi_clear_buf)(int cpu);
41 static void (*ipi_write_buf)(int cpu, struct task_struct *idle);
42 
43 /* send mail via Mail_Send register for 3A4000+ CPU */
44 static void csr_mail_send(uint64_t data, int cpu, int mailbox)
45 {
46 	uint64_t val;
47 
48 	/* send high 32 bits */
49 	val = CSR_MAIL_SEND_BLOCK;
50 	val |= (CSR_MAIL_SEND_BOX_HIGH(mailbox) << CSR_MAIL_SEND_BOX_SHIFT);
51 	val |= (cpu << CSR_MAIL_SEND_CPU_SHIFT);
52 	val |= (data & CSR_MAIL_SEND_H32_MASK);
53 	csr_writeq(val, LOONGSON_CSR_MAIL_SEND);
54 
55 	/* send low 32 bits */
56 	val = CSR_MAIL_SEND_BLOCK;
57 	val |= (CSR_MAIL_SEND_BOX_LOW(mailbox) << CSR_MAIL_SEND_BOX_SHIFT);
58 	val |= (cpu << CSR_MAIL_SEND_CPU_SHIFT);
59 	val |= (data << CSR_MAIL_SEND_BUF_SHIFT);
60 	csr_writeq(val, LOONGSON_CSR_MAIL_SEND);
61 };
62 
63 static u32 csr_ipi_read_clear(int cpu)
64 {
65 	u32 action;
66 
67 	/* Load the ipi register to figure out what we're supposed to do */
68 	action = csr_readl(LOONGSON_CSR_IPI_STATUS);
69 	/* Clear the ipi register to clear the interrupt */
70 	csr_writel(action, LOONGSON_CSR_IPI_CLEAR);
71 
72 	return action;
73 }
74 
75 static void csr_ipi_write_action(int cpu, u32 action)
76 {
77 	unsigned int irq = 0;
78 
79 	while ((irq = ffs(action))) {
80 		uint32_t val = CSR_IPI_SEND_BLOCK;
81 		val |= (irq - 1);
82 		val |= (cpu << CSR_IPI_SEND_CPU_SHIFT);
83 		csr_writel(val, LOONGSON_CSR_IPI_SEND);
84 		action &= ~BIT(irq - 1);
85 	}
86 }
87 
88 static void csr_ipi_write_enable(int cpu)
89 {
90 	csr_writel(0xffffffff, LOONGSON_CSR_IPI_EN);
91 }
92 
93 static void csr_ipi_clear_buf(int cpu)
94 {
95 	csr_writeq(0, LOONGSON_CSR_MAIL_BUF0);
96 }
97 
98 static void csr_ipi_write_buf(int cpu, struct task_struct *idle)
99 {
100 	unsigned long startargs[4];
101 
102 	/* startargs[] are initial PC, SP and GP for secondary CPU */
103 	startargs[0] = (unsigned long)&smp_bootstrap;
104 	startargs[1] = (unsigned long)__KSTK_TOS(idle);
105 	startargs[2] = (unsigned long)task_thread_info(idle);
106 	startargs[3] = 0;
107 
108 	pr_debug("CPU#%d, func_pc=%lx, sp=%lx, gp=%lx\n",
109 		cpu, startargs[0], startargs[1], startargs[2]);
110 
111 	csr_mail_send(startargs[3], cpu_logical_map(cpu), 3);
112 	csr_mail_send(startargs[2], cpu_logical_map(cpu), 2);
113 	csr_mail_send(startargs[1], cpu_logical_map(cpu), 1);
114 	csr_mail_send(startargs[0], cpu_logical_map(cpu), 0);
115 }
116 
117 static u32 legacy_ipi_read_clear(int cpu)
118 {
119 	u32 action;
120 
121 	/* Load the ipi register to figure out what we're supposed to do */
122 	action = readl_relaxed(ipi_status0_regs[cpu_logical_map(cpu)]);
123 	/* Clear the ipi register to clear the interrupt */
124 	writel_relaxed(action, ipi_clear0_regs[cpu_logical_map(cpu)]);
125 	nudge_writes();
126 
127 	return action;
128 }
129 
130 static void legacy_ipi_write_action(int cpu, u32 action)
131 {
132 	writel_relaxed((u32)action, ipi_set0_regs[cpu]);
133 	nudge_writes();
134 }
135 
136 static void legacy_ipi_write_enable(int cpu)
137 {
138 	writel_relaxed(0xffffffff, ipi_en0_regs[cpu_logical_map(cpu)]);
139 }
140 
141 static void legacy_ipi_clear_buf(int cpu)
142 {
143 	writeq_relaxed(0, ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x0);
144 }
145 
146 static void legacy_ipi_write_buf(int cpu, struct task_struct *idle)
147 {
148 	unsigned long startargs[4];
149 
150 	/* startargs[] are initial PC, SP and GP for secondary CPU */
151 	startargs[0] = (unsigned long)&smp_bootstrap;
152 	startargs[1] = (unsigned long)__KSTK_TOS(idle);
153 	startargs[2] = (unsigned long)task_thread_info(idle);
154 	startargs[3] = 0;
155 
156 	pr_debug("CPU#%d, func_pc=%lx, sp=%lx, gp=%lx\n",
157 			cpu, startargs[0], startargs[1], startargs[2]);
158 
159 	writeq_relaxed(startargs[3],
160 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x18);
161 	writeq_relaxed(startargs[2],
162 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x10);
163 	writeq_relaxed(startargs[1],
164 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x8);
165 	writeq_relaxed(startargs[0],
166 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x0);
167 	nudge_writes();
168 }
169 
170 static void csr_ipi_probe(void)
171 {
172 	if (cpu_has_csr() && csr_readl(LOONGSON_CSR_FEATURES) & LOONGSON_CSRF_IPI) {
173 		ipi_read_clear = csr_ipi_read_clear;
174 		ipi_write_action = csr_ipi_write_action;
175 		ipi_write_enable = csr_ipi_write_enable;
176 		ipi_clear_buf = csr_ipi_clear_buf;
177 		ipi_write_buf = csr_ipi_write_buf;
178 	} else {
179 		ipi_read_clear = legacy_ipi_read_clear;
180 		ipi_write_action = legacy_ipi_write_action;
181 		ipi_write_enable = legacy_ipi_write_enable;
182 		ipi_clear_buf = legacy_ipi_clear_buf;
183 		ipi_write_buf = legacy_ipi_write_buf;
184 	}
185 }
186 
187 static void ipi_set0_regs_init(void)
188 {
189 	ipi_set0_regs[0] = (void __iomem *)
190 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + SET0);
191 	ipi_set0_regs[1] = (void __iomem *)
192 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + SET0);
193 	ipi_set0_regs[2] = (void __iomem *)
194 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + SET0);
195 	ipi_set0_regs[3] = (void __iomem *)
196 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + SET0);
197 	ipi_set0_regs[4] = (void __iomem *)
198 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + SET0);
199 	ipi_set0_regs[5] = (void __iomem *)
200 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + SET0);
201 	ipi_set0_regs[6] = (void __iomem *)
202 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + SET0);
203 	ipi_set0_regs[7] = (void __iomem *)
204 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + SET0);
205 	ipi_set0_regs[8] = (void __iomem *)
206 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + SET0);
207 	ipi_set0_regs[9] = (void __iomem *)
208 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + SET0);
209 	ipi_set0_regs[10] = (void __iomem *)
210 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + SET0);
211 	ipi_set0_regs[11] = (void __iomem *)
212 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + SET0);
213 	ipi_set0_regs[12] = (void __iomem *)
214 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + SET0);
215 	ipi_set0_regs[13] = (void __iomem *)
216 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + SET0);
217 	ipi_set0_regs[14] = (void __iomem *)
218 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + SET0);
219 	ipi_set0_regs[15] = (void __iomem *)
220 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + SET0);
221 }
222 
223 static void ipi_clear0_regs_init(void)
224 {
225 	ipi_clear0_regs[0] = (void __iomem *)
226 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + CLEAR0);
227 	ipi_clear0_regs[1] = (void __iomem *)
228 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + CLEAR0);
229 	ipi_clear0_regs[2] = (void __iomem *)
230 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + CLEAR0);
231 	ipi_clear0_regs[3] = (void __iomem *)
232 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + CLEAR0);
233 	ipi_clear0_regs[4] = (void __iomem *)
234 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + CLEAR0);
235 	ipi_clear0_regs[5] = (void __iomem *)
236 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + CLEAR0);
237 	ipi_clear0_regs[6] = (void __iomem *)
238 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + CLEAR0);
239 	ipi_clear0_regs[7] = (void __iomem *)
240 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + CLEAR0);
241 	ipi_clear0_regs[8] = (void __iomem *)
242 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + CLEAR0);
243 	ipi_clear0_regs[9] = (void __iomem *)
244 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + CLEAR0);
245 	ipi_clear0_regs[10] = (void __iomem *)
246 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + CLEAR0);
247 	ipi_clear0_regs[11] = (void __iomem *)
248 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + CLEAR0);
249 	ipi_clear0_regs[12] = (void __iomem *)
250 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + CLEAR0);
251 	ipi_clear0_regs[13] = (void __iomem *)
252 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + CLEAR0);
253 	ipi_clear0_regs[14] = (void __iomem *)
254 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + CLEAR0);
255 	ipi_clear0_regs[15] = (void __iomem *)
256 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + CLEAR0);
257 }
258 
259 static void ipi_status0_regs_init(void)
260 {
261 	ipi_status0_regs[0] = (void __iomem *)
262 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + STATUS0);
263 	ipi_status0_regs[1] = (void __iomem *)
264 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + STATUS0);
265 	ipi_status0_regs[2] = (void __iomem *)
266 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + STATUS0);
267 	ipi_status0_regs[3] = (void __iomem *)
268 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + STATUS0);
269 	ipi_status0_regs[4] = (void __iomem *)
270 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + STATUS0);
271 	ipi_status0_regs[5] = (void __iomem *)
272 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + STATUS0);
273 	ipi_status0_regs[6] = (void __iomem *)
274 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + STATUS0);
275 	ipi_status0_regs[7] = (void __iomem *)
276 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + STATUS0);
277 	ipi_status0_regs[8] = (void __iomem *)
278 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + STATUS0);
279 	ipi_status0_regs[9] = (void __iomem *)
280 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + STATUS0);
281 	ipi_status0_regs[10] = (void __iomem *)
282 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + STATUS0);
283 	ipi_status0_regs[11] = (void __iomem *)
284 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + STATUS0);
285 	ipi_status0_regs[12] = (void __iomem *)
286 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + STATUS0);
287 	ipi_status0_regs[13] = (void __iomem *)
288 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + STATUS0);
289 	ipi_status0_regs[14] = (void __iomem *)
290 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + STATUS0);
291 	ipi_status0_regs[15] = (void __iomem *)
292 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + STATUS0);
293 }
294 
295 static void ipi_en0_regs_init(void)
296 {
297 	ipi_en0_regs[0] = (void __iomem *)
298 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + EN0);
299 	ipi_en0_regs[1] = (void __iomem *)
300 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + EN0);
301 	ipi_en0_regs[2] = (void __iomem *)
302 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + EN0);
303 	ipi_en0_regs[3] = (void __iomem *)
304 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + EN0);
305 	ipi_en0_regs[4] = (void __iomem *)
306 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + EN0);
307 	ipi_en0_regs[5] = (void __iomem *)
308 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + EN0);
309 	ipi_en0_regs[6] = (void __iomem *)
310 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + EN0);
311 	ipi_en0_regs[7] = (void __iomem *)
312 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + EN0);
313 	ipi_en0_regs[8] = (void __iomem *)
314 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + EN0);
315 	ipi_en0_regs[9] = (void __iomem *)
316 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + EN0);
317 	ipi_en0_regs[10] = (void __iomem *)
318 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + EN0);
319 	ipi_en0_regs[11] = (void __iomem *)
320 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + EN0);
321 	ipi_en0_regs[12] = (void __iomem *)
322 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + EN0);
323 	ipi_en0_regs[13] = (void __iomem *)
324 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + EN0);
325 	ipi_en0_regs[14] = (void __iomem *)
326 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + EN0);
327 	ipi_en0_regs[15] = (void __iomem *)
328 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + EN0);
329 }
330 
331 static void ipi_mailbox_buf_init(void)
332 {
333 	ipi_mailbox_buf[0] = (void __iomem *)
334 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + BUF);
335 	ipi_mailbox_buf[1] = (void __iomem *)
336 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + BUF);
337 	ipi_mailbox_buf[2] = (void __iomem *)
338 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + BUF);
339 	ipi_mailbox_buf[3] = (void __iomem *)
340 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + BUF);
341 	ipi_mailbox_buf[4] = (void __iomem *)
342 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + BUF);
343 	ipi_mailbox_buf[5] = (void __iomem *)
344 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + BUF);
345 	ipi_mailbox_buf[6] = (void __iomem *)
346 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + BUF);
347 	ipi_mailbox_buf[7] = (void __iomem *)
348 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + BUF);
349 	ipi_mailbox_buf[8] = (void __iomem *)
350 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + BUF);
351 	ipi_mailbox_buf[9] = (void __iomem *)
352 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + BUF);
353 	ipi_mailbox_buf[10] = (void __iomem *)
354 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + BUF);
355 	ipi_mailbox_buf[11] = (void __iomem *)
356 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + BUF);
357 	ipi_mailbox_buf[12] = (void __iomem *)
358 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + BUF);
359 	ipi_mailbox_buf[13] = (void __iomem *)
360 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + BUF);
361 	ipi_mailbox_buf[14] = (void __iomem *)
362 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + BUF);
363 	ipi_mailbox_buf[15] = (void __iomem *)
364 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + BUF);
365 }
366 
367 /*
368  * Simple enough, just poke the appropriate ipi register
369  */
370 static void loongson3_send_ipi_single(int cpu, unsigned int action)
371 {
372 	ipi_write_action(cpu_logical_map(cpu), (u32)action);
373 }
374 
375 static void
376 loongson3_send_ipi_mask(const struct cpumask *mask, unsigned int action)
377 {
378 	unsigned int i;
379 
380 	for_each_cpu(i, mask)
381 		ipi_write_action(cpu_logical_map(i), (u32)action);
382 }
383 
384 static irqreturn_t loongson3_ipi_interrupt(int irq, void *dev_id)
385 {
386 	int cpu = smp_processor_id();
387 	unsigned int action;
388 
389 	action = ipi_read_clear(cpu);
390 
391 	if (action & SMP_RESCHEDULE_YOURSELF)
392 		scheduler_ipi();
393 
394 	if (action & SMP_CALL_FUNCTION) {
395 		irq_enter();
396 		generic_smp_call_function_interrupt();
397 		irq_exit();
398 	}
399 
400 	return IRQ_HANDLED;
401 }
402 
403 /*
404  * SMP init and finish on secondary CPUs
405  */
406 static void loongson3_init_secondary(void)
407 {
408 	unsigned int cpu = smp_processor_id();
409 	unsigned int imask = STATUSF_IP7 | STATUSF_IP6 |
410 			     STATUSF_IP3 | STATUSF_IP2;
411 
412 	/* Set interrupt mask, but don't enable */
413 	change_c0_status(ST0_IM, imask);
414 	ipi_write_enable(cpu);
415 
416 	per_cpu(cpu_state, cpu) = CPU_ONLINE;
417 	cpu_set_core(&cpu_data[cpu],
418 		     cpu_logical_map(cpu) % loongson_sysconf.cores_per_package);
419 	cpu_data[cpu].package =
420 		cpu_logical_map(cpu) / loongson_sysconf.cores_per_package;
421 }
422 
423 static void loongson3_smp_finish(void)
424 {
425 	int cpu = smp_processor_id();
426 
427 	write_c0_compare(read_c0_count() + mips_hpt_frequency/HZ);
428 	local_irq_enable();
429 	ipi_clear_buf(cpu);
430 
431 	pr_info("CPU#%d finished, CP0_ST=%x\n",
432 			smp_processor_id(), read_c0_status());
433 }
434 
435 static void __init loongson3_smp_setup(void)
436 {
437 	int i = 0, num = 0; /* i: physical id, num: logical id */
438 	int max_cpus = 0;
439 
440 	init_cpu_possible(cpu_none_mask);
441 
442 	for (i = 0; i < ARRAY_SIZE(smp_group); i++) {
443 		if (!smp_group[i])
444 			break;
445 		max_cpus += loongson_sysconf.cores_per_node;
446 	}
447 
448 	if (max_cpus < loongson_sysconf.nr_cpus) {
449 		pr_err("SMP Groups are less than the number of CPUs\n");
450 		loongson_sysconf.nr_cpus = max_cpus ? max_cpus : 1;
451 	}
452 
453 	/* For unified kernel, NR_CPUS is the maximum possible value,
454 	 * loongson_sysconf.nr_cpus is the really present value
455 	 */
456 	i = 0;
457 	while (i < loongson_sysconf.nr_cpus) {
458 		if (loongson_sysconf.reserved_cpus_mask & (1<<i)) {
459 			/* Reserved physical CPU cores */
460 			__cpu_number_map[i] = -1;
461 		} else {
462 			__cpu_number_map[i] = num;
463 			__cpu_logical_map[num] = i;
464 			set_cpu_possible(num, true);
465 			/* Loongson processors are always grouped by 4 */
466 			cpu_set_cluster(&cpu_data[num], i / 4);
467 			num++;
468 		}
469 		i++;
470 	}
471 	pr_info("Detected %i available CPU(s)\n", num);
472 
473 	while (num < loongson_sysconf.nr_cpus) {
474 		__cpu_logical_map[num] = -1;
475 		num++;
476 	}
477 	csr_ipi_probe();
478 	ipi_set0_regs_init();
479 	ipi_clear0_regs_init();
480 	ipi_status0_regs_init();
481 	ipi_en0_regs_init();
482 	ipi_mailbox_buf_init();
483 	if (smp_group[0])
484 		ipi_write_enable(0);
485 
486 	cpu_set_core(&cpu_data[0],
487 		     cpu_logical_map(0) % loongson_sysconf.cores_per_package);
488 	cpu_data[0].package = cpu_logical_map(0) / loongson_sysconf.cores_per_package;
489 }
490 
491 static void __init loongson3_prepare_cpus(unsigned int max_cpus)
492 {
493 	if (request_irq(LS_IPI_IRQ, loongson3_ipi_interrupt,
494 			IRQF_PERCPU | IRQF_NO_SUSPEND, "SMP_IPI", NULL))
495 		pr_err("Failed to request IPI IRQ\n");
496 	init_cpu_present(cpu_possible_mask);
497 	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
498 }
499 
500 /*
501  * Setup the PC, SP, and GP of a secondary processor and start it running!
502  */
503 static int loongson3_boot_secondary(int cpu, struct task_struct *idle)
504 {
505 	pr_info("Booting CPU#%d...\n", cpu);
506 
507 	ipi_write_buf(cpu, idle);
508 
509 	return 0;
510 }
511 
512 #ifdef CONFIG_HOTPLUG_CPU
513 
514 static int loongson3_cpu_disable(void)
515 {
516 	unsigned long flags;
517 	unsigned int cpu = smp_processor_id();
518 
519 	set_cpu_online(cpu, false);
520 	calculate_cpu_foreign_map();
521 	local_irq_save(flags);
522 	clear_c0_status(ST0_IM);
523 	local_irq_restore(flags);
524 	local_flush_tlb_all();
525 
526 	return 0;
527 }
528 
529 
530 static void loongson3_cpu_die(unsigned int cpu)
531 {
532 	while (per_cpu(cpu_state, cpu) != CPU_DEAD)
533 		cpu_relax();
534 
535 	mb();
536 }
537 
538 /* To shutdown a core in Loongson 3, the target core should go to CKSEG1 and
539  * flush all L1 entries at first. Then, another core (usually Core 0) can
540  * safely disable the clock of the target core. loongson3_play_dead() is
541  * called via CKSEG1 (uncached and unmmaped)
542  */
543 static void loongson3_type1_play_dead(int *state_addr)
544 {
545 	register int val;
546 	register long cpuid, core, node, count;
547 	register void *addr, *base, *initfunc;
548 
549 	__asm__ __volatile__(
550 		"   .set push                     \n"
551 		"   .set noreorder                \n"
552 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
553 		"1: cache 0, 0(%[addr])           \n" /* flush L1 ICache */
554 		"   cache 0, 1(%[addr])           \n"
555 		"   cache 0, 2(%[addr])           \n"
556 		"   cache 0, 3(%[addr])           \n"
557 		"   cache 1, 0(%[addr])           \n" /* flush L1 DCache */
558 		"   cache 1, 1(%[addr])           \n"
559 		"   cache 1, 2(%[addr])           \n"
560 		"   cache 1, 3(%[addr])           \n"
561 		"   addiu %[sets], %[sets], -1    \n"
562 		"   bnez  %[sets], 1b             \n"
563 		"   addiu %[addr], %[addr], 0x20  \n"
564 		"   li    %[val], 0x7             \n" /* *state_addr = CPU_DEAD; */
565 		"   sw    %[val], (%[state_addr]) \n"
566 		"   sync                          \n"
567 		"   cache 21, (%[state_addr])     \n" /* flush entry of *state_addr */
568 		"   .set pop                      \n"
569 		: [addr] "=&r" (addr), [val] "=&r" (val)
570 		: [state_addr] "r" (state_addr),
571 		  [sets] "r" (cpu_data[smp_processor_id()].dcache.sets));
572 
573 	__asm__ __volatile__(
574 		"   .set push                         \n"
575 		"   .set noreorder                    \n"
576 		"   .set mips64                       \n"
577 		"   mfc0  %[cpuid], $15, 1            \n"
578 		"   andi  %[cpuid], 0x3ff             \n"
579 		"   dli   %[base], 0x900000003ff01000 \n"
580 		"   andi  %[core], %[cpuid], 0x3      \n"
581 		"   sll   %[core], 8                  \n" /* get core id */
582 		"   or    %[base], %[base], %[core]   \n"
583 		"   andi  %[node], %[cpuid], 0xc      \n"
584 		"   dsll  %[node], 42                 \n" /* get node id */
585 		"   or    %[base], %[base], %[node]   \n"
586 		"1: li    %[count], 0x100             \n" /* wait for init loop */
587 		"2: bnez  %[count], 2b                \n" /* limit mailbox access */
588 		"   addiu %[count], -1                \n"
589 		"   ld    %[initfunc], 0x20(%[base])  \n" /* get PC via mailbox */
590 		"   beqz  %[initfunc], 1b             \n"
591 		"   nop                               \n"
592 		"   ld    $sp, 0x28(%[base])          \n" /* get SP via mailbox */
593 		"   ld    $gp, 0x30(%[base])          \n" /* get GP via mailbox */
594 		"   ld    $a1, 0x38(%[base])          \n"
595 		"   jr    %[initfunc]                 \n" /* jump to initial PC */
596 		"   nop                               \n"
597 		"   .set pop                          \n"
598 		: [core] "=&r" (core), [node] "=&r" (node),
599 		  [base] "=&r" (base), [cpuid] "=&r" (cpuid),
600 		  [count] "=&r" (count), [initfunc] "=&r" (initfunc)
601 		: /* No Input */
602 		: "a1");
603 }
604 
605 static void loongson3_type2_play_dead(int *state_addr)
606 {
607 	register int val;
608 	register long cpuid, core, node, count;
609 	register void *addr, *base, *initfunc;
610 
611 	__asm__ __volatile__(
612 		"   .set push                     \n"
613 		"   .set noreorder                \n"
614 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
615 		"1: cache 0, 0(%[addr])           \n" /* flush L1 ICache */
616 		"   cache 0, 1(%[addr])           \n"
617 		"   cache 0, 2(%[addr])           \n"
618 		"   cache 0, 3(%[addr])           \n"
619 		"   cache 1, 0(%[addr])           \n" /* flush L1 DCache */
620 		"   cache 1, 1(%[addr])           \n"
621 		"   cache 1, 2(%[addr])           \n"
622 		"   cache 1, 3(%[addr])           \n"
623 		"   addiu %[sets], %[sets], -1    \n"
624 		"   bnez  %[sets], 1b             \n"
625 		"   addiu %[addr], %[addr], 0x20  \n"
626 		"   li    %[val], 0x7             \n" /* *state_addr = CPU_DEAD; */
627 		"   sw    %[val], (%[state_addr]) \n"
628 		"   sync                          \n"
629 		"   cache 21, (%[state_addr])     \n" /* flush entry of *state_addr */
630 		"   .set pop                      \n"
631 		: [addr] "=&r" (addr), [val] "=&r" (val)
632 		: [state_addr] "r" (state_addr),
633 		  [sets] "r" (cpu_data[smp_processor_id()].dcache.sets));
634 
635 	__asm__ __volatile__(
636 		"   .set push                         \n"
637 		"   .set noreorder                    \n"
638 		"   .set mips64                       \n"
639 		"   mfc0  %[cpuid], $15, 1            \n"
640 		"   andi  %[cpuid], 0x3ff             \n"
641 		"   dli   %[base], 0x900000003ff01000 \n"
642 		"   andi  %[core], %[cpuid], 0x3      \n"
643 		"   sll   %[core], 8                  \n" /* get core id */
644 		"   or    %[base], %[base], %[core]   \n"
645 		"   andi  %[node], %[cpuid], 0xc      \n"
646 		"   dsll  %[node], 42                 \n" /* get node id */
647 		"   or    %[base], %[base], %[node]   \n"
648 		"   dsrl  %[node], 30                 \n" /* 15:14 */
649 		"   or    %[base], %[base], %[node]   \n"
650 		"1: li    %[count], 0x100             \n" /* wait for init loop */
651 		"2: bnez  %[count], 2b                \n" /* limit mailbox access */
652 		"   addiu %[count], -1                \n"
653 		"   ld    %[initfunc], 0x20(%[base])  \n" /* get PC via mailbox */
654 		"   beqz  %[initfunc], 1b             \n"
655 		"   nop                               \n"
656 		"   ld    $sp, 0x28(%[base])          \n" /* get SP via mailbox */
657 		"   ld    $gp, 0x30(%[base])          \n" /* get GP via mailbox */
658 		"   ld    $a1, 0x38(%[base])          \n"
659 		"   jr    %[initfunc]                 \n" /* jump to initial PC */
660 		"   nop                               \n"
661 		"   .set pop                          \n"
662 		: [core] "=&r" (core), [node] "=&r" (node),
663 		  [base] "=&r" (base), [cpuid] "=&r" (cpuid),
664 		  [count] "=&r" (count), [initfunc] "=&r" (initfunc)
665 		: /* No Input */
666 		: "a1");
667 }
668 
669 static void loongson3_type3_play_dead(int *state_addr)
670 {
671 	register int val;
672 	register long cpuid, core, node, count;
673 	register void *addr, *base, *initfunc;
674 
675 	__asm__ __volatile__(
676 		"   .set push                     \n"
677 		"   .set noreorder                \n"
678 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
679 		"1: cache 0, 0(%[addr])           \n" /* flush L1 ICache */
680 		"   cache 0, 1(%[addr])           \n"
681 		"   cache 0, 2(%[addr])           \n"
682 		"   cache 0, 3(%[addr])           \n"
683 		"   cache 1, 0(%[addr])           \n" /* flush L1 DCache */
684 		"   cache 1, 1(%[addr])           \n"
685 		"   cache 1, 2(%[addr])           \n"
686 		"   cache 1, 3(%[addr])           \n"
687 		"   addiu %[sets], %[sets], -1    \n"
688 		"   bnez  %[sets], 1b             \n"
689 		"   addiu %[addr], %[addr], 0x40  \n"
690 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
691 		"2: cache 2, 0(%[addr])           \n" /* flush L1 VCache */
692 		"   cache 2, 1(%[addr])           \n"
693 		"   cache 2, 2(%[addr])           \n"
694 		"   cache 2, 3(%[addr])           \n"
695 		"   cache 2, 4(%[addr])           \n"
696 		"   cache 2, 5(%[addr])           \n"
697 		"   cache 2, 6(%[addr])           \n"
698 		"   cache 2, 7(%[addr])           \n"
699 		"   cache 2, 8(%[addr])           \n"
700 		"   cache 2, 9(%[addr])           \n"
701 		"   cache 2, 10(%[addr])          \n"
702 		"   cache 2, 11(%[addr])          \n"
703 		"   cache 2, 12(%[addr])          \n"
704 		"   cache 2, 13(%[addr])          \n"
705 		"   cache 2, 14(%[addr])          \n"
706 		"   cache 2, 15(%[addr])          \n"
707 		"   addiu %[vsets], %[vsets], -1  \n"
708 		"   bnez  %[vsets], 2b            \n"
709 		"   addiu %[addr], %[addr], 0x40  \n"
710 		"   li    %[val], 0x7             \n" /* *state_addr = CPU_DEAD; */
711 		"   sw    %[val], (%[state_addr]) \n"
712 		"   sync                          \n"
713 		"   cache 21, (%[state_addr])     \n" /* flush entry of *state_addr */
714 		"   .set pop                      \n"
715 		: [addr] "=&r" (addr), [val] "=&r" (val)
716 		: [state_addr] "r" (state_addr),
717 		  [sets] "r" (cpu_data[smp_processor_id()].dcache.sets),
718 		  [vsets] "r" (cpu_data[smp_processor_id()].vcache.sets));
719 
720 	__asm__ __volatile__(
721 		"   .set push                         \n"
722 		"   .set noreorder                    \n"
723 		"   .set mips64                       \n"
724 		"   mfc0  %[cpuid], $15, 1            \n"
725 		"   andi  %[cpuid], 0x3ff             \n"
726 		"   dli   %[base], 0x900000003ff01000 \n"
727 		"   andi  %[core], %[cpuid], 0x3      \n"
728 		"   sll   %[core], 8                  \n" /* get core id */
729 		"   or    %[base], %[base], %[core]   \n"
730 		"   andi  %[node], %[cpuid], 0xc      \n"
731 		"   dsll  %[node], 42                 \n" /* get node id */
732 		"   or    %[base], %[base], %[node]   \n"
733 		"1: li    %[count], 0x100             \n" /* wait for init loop */
734 		"2: bnez  %[count], 2b                \n" /* limit mailbox access */
735 		"   addiu %[count], -1                \n"
736 		"   lw    %[initfunc], 0x20(%[base])  \n" /* check lower 32-bit as jump indicator */
737 		"   beqz  %[initfunc], 1b             \n"
738 		"   nop                               \n"
739 		"   ld    %[initfunc], 0x20(%[base])  \n" /* get PC (whole 64-bit) via mailbox */
740 		"   ld    $sp, 0x28(%[base])          \n" /* get SP via mailbox */
741 		"   ld    $gp, 0x30(%[base])          \n" /* get GP via mailbox */
742 		"   ld    $a1, 0x38(%[base])          \n"
743 		"   jr    %[initfunc]                 \n" /* jump to initial PC */
744 		"   nop                               \n"
745 		"   .set pop                          \n"
746 		: [core] "=&r" (core), [node] "=&r" (node),
747 		  [base] "=&r" (base), [cpuid] "=&r" (cpuid),
748 		  [count] "=&r" (count), [initfunc] "=&r" (initfunc)
749 		: /* No Input */
750 		: "a1");
751 }
752 
753 void play_dead(void)
754 {
755 	int prid_imp, prid_rev, *state_addr;
756 	unsigned int cpu = smp_processor_id();
757 	void (*play_dead_at_ckseg1)(int *);
758 
759 	idle_task_exit();
760 	cpuhp_ap_report_dead();
761 
762 	prid_imp = read_c0_prid() & PRID_IMP_MASK;
763 	prid_rev = read_c0_prid() & PRID_REV_MASK;
764 
765 	if (prid_imp == PRID_IMP_LOONGSON_64G) {
766 		play_dead_at_ckseg1 =
767 			(void *)CKSEG1ADDR((unsigned long)loongson3_type3_play_dead);
768 		goto out;
769 	}
770 
771 	switch (prid_rev) {
772 	case PRID_REV_LOONGSON3A_R1:
773 	default:
774 		play_dead_at_ckseg1 =
775 			(void *)CKSEG1ADDR((unsigned long)loongson3_type1_play_dead);
776 		break;
777 	case PRID_REV_LOONGSON3B_R1:
778 	case PRID_REV_LOONGSON3B_R2:
779 		play_dead_at_ckseg1 =
780 			(void *)CKSEG1ADDR((unsigned long)loongson3_type2_play_dead);
781 		break;
782 	case PRID_REV_LOONGSON3A_R2_0:
783 	case PRID_REV_LOONGSON3A_R2_1:
784 	case PRID_REV_LOONGSON3A_R3_0:
785 	case PRID_REV_LOONGSON3A_R3_1:
786 		play_dead_at_ckseg1 =
787 			(void *)CKSEG1ADDR((unsigned long)loongson3_type3_play_dead);
788 		break;
789 	}
790 
791 out:
792 	state_addr = &per_cpu(cpu_state, cpu);
793 	mb();
794 	play_dead_at_ckseg1(state_addr);
795 	BUG();
796 }
797 
798 static int loongson3_disable_clock(unsigned int cpu)
799 {
800 	uint64_t core_id = cpu_core(&cpu_data[cpu]);
801 	uint64_t package_id = cpu_data[cpu].package;
802 
803 	if (!loongson_chipcfg[package_id] || !loongson_freqctrl[package_id])
804 		return 0;
805 
806 	if ((read_c0_prid() & PRID_REV_MASK) == PRID_REV_LOONGSON3A_R1) {
807 		LOONGSON_CHIPCFG(package_id) &= ~(1 << (12 + core_id));
808 	} else {
809 		if (!(loongson_sysconf.workarounds & WORKAROUND_CPUHOTPLUG))
810 			LOONGSON_FREQCTRL(package_id) &= ~(1 << (core_id * 4 + 3));
811 	}
812 	return 0;
813 }
814 
815 static int loongson3_enable_clock(unsigned int cpu)
816 {
817 	uint64_t core_id = cpu_core(&cpu_data[cpu]);
818 	uint64_t package_id = cpu_data[cpu].package;
819 
820 	if (!loongson_chipcfg[package_id] || !loongson_freqctrl[package_id])
821 		return 0;
822 
823 	if ((read_c0_prid() & PRID_REV_MASK) == PRID_REV_LOONGSON3A_R1) {
824 		LOONGSON_CHIPCFG(package_id) |= 1 << (12 + core_id);
825 	} else {
826 		if (!(loongson_sysconf.workarounds & WORKAROUND_CPUHOTPLUG))
827 			LOONGSON_FREQCTRL(package_id) |= 1 << (core_id * 4 + 3);
828 	}
829 	return 0;
830 }
831 
832 static int register_loongson3_notifier(void)
833 {
834 	return cpuhp_setup_state_nocalls(CPUHP_MIPS_SOC_PREPARE,
835 					 "mips/loongson:prepare",
836 					 loongson3_enable_clock,
837 					 loongson3_disable_clock);
838 }
839 early_initcall(register_loongson3_notifier);
840 
841 #endif
842 
843 const struct plat_smp_ops loongson3_smp_ops = {
844 	.send_ipi_single = loongson3_send_ipi_single,
845 	.send_ipi_mask = loongson3_send_ipi_mask,
846 	.init_secondary = loongson3_init_secondary,
847 	.smp_finish = loongson3_smp_finish,
848 	.boot_secondary = loongson3_boot_secondary,
849 	.smp_setup = loongson3_smp_setup,
850 	.prepare_cpus = loongson3_prepare_cpus,
851 #ifdef CONFIG_HOTPLUG_CPU
852 	.cpu_disable = loongson3_cpu_disable,
853 	.cpu_die = loongson3_cpu_die,
854 #endif
855 #ifdef CONFIG_KEXEC_CORE
856 	.kexec_nonboot_cpu = kexec_nonboot_cpu_jump,
857 #endif
858 };
859