xref: /openbmc/linux/arch/mips/loongson64/smp.c (revision fb799447)
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 *ipi_set0_regs[16];
32 static void *ipi_clear0_regs[16];
33 static void *ipi_status0_regs[16];
34 static void *ipi_en0_regs[16];
35 static void *ipi_mailbox_buf[16];
36 static uint32_t core0_c0count[NR_CPUS];
37 
38 /* read a 32bit value from ipi register */
39 #define loongson3_ipi_read32(addr) readl(addr)
40 /* read a 64bit value from ipi register */
41 #define loongson3_ipi_read64(addr) readq(addr)
42 /* write a 32bit value to ipi register */
43 #define loongson3_ipi_write32(action, addr)	\
44 	do {					\
45 		writel(action, addr);		\
46 		__wbflush();			\
47 	} while (0)
48 /* write a 64bit value to ipi register */
49 #define loongson3_ipi_write64(action, addr)	\
50 	do {					\
51 		writeq(action, addr);		\
52 		__wbflush();			\
53 	} while (0)
54 
55 static u32 (*ipi_read_clear)(int cpu);
56 static void (*ipi_write_action)(int cpu, u32 action);
57 static void (*ipi_write_enable)(int cpu);
58 static void (*ipi_clear_buf)(int cpu);
59 static void (*ipi_write_buf)(int cpu, struct task_struct *idle);
60 
61 /* send mail via Mail_Send register for 3A4000+ CPU */
62 static void csr_mail_send(uint64_t data, int cpu, int mailbox)
63 {
64 	uint64_t val;
65 
66 	/* send high 32 bits */
67 	val = CSR_MAIL_SEND_BLOCK;
68 	val |= (CSR_MAIL_SEND_BOX_HIGH(mailbox) << CSR_MAIL_SEND_BOX_SHIFT);
69 	val |= (cpu << CSR_MAIL_SEND_CPU_SHIFT);
70 	val |= (data & CSR_MAIL_SEND_H32_MASK);
71 	csr_writeq(val, LOONGSON_CSR_MAIL_SEND);
72 
73 	/* send low 32 bits */
74 	val = CSR_MAIL_SEND_BLOCK;
75 	val |= (CSR_MAIL_SEND_BOX_LOW(mailbox) << CSR_MAIL_SEND_BOX_SHIFT);
76 	val |= (cpu << CSR_MAIL_SEND_CPU_SHIFT);
77 	val |= (data << CSR_MAIL_SEND_BUF_SHIFT);
78 	csr_writeq(val, LOONGSON_CSR_MAIL_SEND);
79 };
80 
81 static u32 csr_ipi_read_clear(int cpu)
82 {
83 	u32 action;
84 
85 	/* Load the ipi register to figure out what we're supposed to do */
86 	action = csr_readl(LOONGSON_CSR_IPI_STATUS);
87 	/* Clear the ipi register to clear the interrupt */
88 	csr_writel(action, LOONGSON_CSR_IPI_CLEAR);
89 
90 	return action;
91 }
92 
93 static void csr_ipi_write_action(int cpu, u32 action)
94 {
95 	unsigned int irq = 0;
96 
97 	while ((irq = ffs(action))) {
98 		uint32_t val = CSR_IPI_SEND_BLOCK;
99 		val |= (irq - 1);
100 		val |= (cpu << CSR_IPI_SEND_CPU_SHIFT);
101 		csr_writel(val, LOONGSON_CSR_IPI_SEND);
102 		action &= ~BIT(irq - 1);
103 	}
104 }
105 
106 static void csr_ipi_write_enable(int cpu)
107 {
108 	csr_writel(0xffffffff, LOONGSON_CSR_IPI_EN);
109 }
110 
111 static void csr_ipi_clear_buf(int cpu)
112 {
113 	csr_writeq(0, LOONGSON_CSR_MAIL_BUF0);
114 }
115 
116 static void csr_ipi_write_buf(int cpu, struct task_struct *idle)
117 {
118 	unsigned long startargs[4];
119 
120 	/* startargs[] are initial PC, SP and GP for secondary CPU */
121 	startargs[0] = (unsigned long)&smp_bootstrap;
122 	startargs[1] = (unsigned long)__KSTK_TOS(idle);
123 	startargs[2] = (unsigned long)task_thread_info(idle);
124 	startargs[3] = 0;
125 
126 	pr_debug("CPU#%d, func_pc=%lx, sp=%lx, gp=%lx\n",
127 		cpu, startargs[0], startargs[1], startargs[2]);
128 
129 	csr_mail_send(startargs[3], cpu_logical_map(cpu), 3);
130 	csr_mail_send(startargs[2], cpu_logical_map(cpu), 2);
131 	csr_mail_send(startargs[1], cpu_logical_map(cpu), 1);
132 	csr_mail_send(startargs[0], cpu_logical_map(cpu), 0);
133 }
134 
135 static u32 legacy_ipi_read_clear(int cpu)
136 {
137 	u32 action;
138 
139 	/* Load the ipi register to figure out what we're supposed to do */
140 	action = loongson3_ipi_read32(ipi_status0_regs[cpu_logical_map(cpu)]);
141 	/* Clear the ipi register to clear the interrupt */
142 	loongson3_ipi_write32(action, ipi_clear0_regs[cpu_logical_map(cpu)]);
143 
144 	return action;
145 }
146 
147 static void legacy_ipi_write_action(int cpu, u32 action)
148 {
149 	loongson3_ipi_write32((u32)action, ipi_set0_regs[cpu]);
150 }
151 
152 static void legacy_ipi_write_enable(int cpu)
153 {
154 	loongson3_ipi_write32(0xffffffff, ipi_en0_regs[cpu_logical_map(cpu)]);
155 }
156 
157 static void legacy_ipi_clear_buf(int cpu)
158 {
159 	loongson3_ipi_write64(0, ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x0);
160 }
161 
162 static void legacy_ipi_write_buf(int cpu, struct task_struct *idle)
163 {
164 	unsigned long startargs[4];
165 
166 	/* startargs[] are initial PC, SP and GP for secondary CPU */
167 	startargs[0] = (unsigned long)&smp_bootstrap;
168 	startargs[1] = (unsigned long)__KSTK_TOS(idle);
169 	startargs[2] = (unsigned long)task_thread_info(idle);
170 	startargs[3] = 0;
171 
172 	pr_debug("CPU#%d, func_pc=%lx, sp=%lx, gp=%lx\n",
173 			cpu, startargs[0], startargs[1], startargs[2]);
174 
175 	loongson3_ipi_write64(startargs[3],
176 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x18);
177 	loongson3_ipi_write64(startargs[2],
178 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x10);
179 	loongson3_ipi_write64(startargs[1],
180 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x8);
181 	loongson3_ipi_write64(startargs[0],
182 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x0);
183 }
184 
185 static void csr_ipi_probe(void)
186 {
187 	if (cpu_has_csr() && csr_readl(LOONGSON_CSR_FEATURES) & LOONGSON_CSRF_IPI) {
188 		ipi_read_clear = csr_ipi_read_clear;
189 		ipi_write_action = csr_ipi_write_action;
190 		ipi_write_enable = csr_ipi_write_enable;
191 		ipi_clear_buf = csr_ipi_clear_buf;
192 		ipi_write_buf = csr_ipi_write_buf;
193 	} else {
194 		ipi_read_clear = legacy_ipi_read_clear;
195 		ipi_write_action = legacy_ipi_write_action;
196 		ipi_write_enable = legacy_ipi_write_enable;
197 		ipi_clear_buf = legacy_ipi_clear_buf;
198 		ipi_write_buf = legacy_ipi_write_buf;
199 	}
200 }
201 
202 static void ipi_set0_regs_init(void)
203 {
204 	ipi_set0_regs[0] = (void *)
205 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + SET0);
206 	ipi_set0_regs[1] = (void *)
207 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + SET0);
208 	ipi_set0_regs[2] = (void *)
209 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + SET0);
210 	ipi_set0_regs[3] = (void *)
211 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + SET0);
212 	ipi_set0_regs[4] = (void *)
213 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + SET0);
214 	ipi_set0_regs[5] = (void *)
215 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + SET0);
216 	ipi_set0_regs[6] = (void *)
217 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + SET0);
218 	ipi_set0_regs[7] = (void *)
219 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + SET0);
220 	ipi_set0_regs[8] = (void *)
221 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + SET0);
222 	ipi_set0_regs[9] = (void *)
223 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + SET0);
224 	ipi_set0_regs[10] = (void *)
225 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + SET0);
226 	ipi_set0_regs[11] = (void *)
227 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + SET0);
228 	ipi_set0_regs[12] = (void *)
229 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + SET0);
230 	ipi_set0_regs[13] = (void *)
231 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + SET0);
232 	ipi_set0_regs[14] = (void *)
233 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + SET0);
234 	ipi_set0_regs[15] = (void *)
235 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + SET0);
236 }
237 
238 static void ipi_clear0_regs_init(void)
239 {
240 	ipi_clear0_regs[0] = (void *)
241 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + CLEAR0);
242 	ipi_clear0_regs[1] = (void *)
243 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + CLEAR0);
244 	ipi_clear0_regs[2] = (void *)
245 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + CLEAR0);
246 	ipi_clear0_regs[3] = (void *)
247 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + CLEAR0);
248 	ipi_clear0_regs[4] = (void *)
249 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + CLEAR0);
250 	ipi_clear0_regs[5] = (void *)
251 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + CLEAR0);
252 	ipi_clear0_regs[6] = (void *)
253 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + CLEAR0);
254 	ipi_clear0_regs[7] = (void *)
255 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + CLEAR0);
256 	ipi_clear0_regs[8] = (void *)
257 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + CLEAR0);
258 	ipi_clear0_regs[9] = (void *)
259 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + CLEAR0);
260 	ipi_clear0_regs[10] = (void *)
261 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + CLEAR0);
262 	ipi_clear0_regs[11] = (void *)
263 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + CLEAR0);
264 	ipi_clear0_regs[12] = (void *)
265 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + CLEAR0);
266 	ipi_clear0_regs[13] = (void *)
267 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + CLEAR0);
268 	ipi_clear0_regs[14] = (void *)
269 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + CLEAR0);
270 	ipi_clear0_regs[15] = (void *)
271 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + CLEAR0);
272 }
273 
274 static void ipi_status0_regs_init(void)
275 {
276 	ipi_status0_regs[0] = (void *)
277 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + STATUS0);
278 	ipi_status0_regs[1] = (void *)
279 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + STATUS0);
280 	ipi_status0_regs[2] = (void *)
281 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + STATUS0);
282 	ipi_status0_regs[3] = (void *)
283 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + STATUS0);
284 	ipi_status0_regs[4] = (void *)
285 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + STATUS0);
286 	ipi_status0_regs[5] = (void *)
287 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + STATUS0);
288 	ipi_status0_regs[6] = (void *)
289 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + STATUS0);
290 	ipi_status0_regs[7] = (void *)
291 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + STATUS0);
292 	ipi_status0_regs[8] = (void *)
293 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + STATUS0);
294 	ipi_status0_regs[9] = (void *)
295 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + STATUS0);
296 	ipi_status0_regs[10] = (void *)
297 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + STATUS0);
298 	ipi_status0_regs[11] = (void *)
299 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + STATUS0);
300 	ipi_status0_regs[12] = (void *)
301 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + STATUS0);
302 	ipi_status0_regs[13] = (void *)
303 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + STATUS0);
304 	ipi_status0_regs[14] = (void *)
305 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + STATUS0);
306 	ipi_status0_regs[15] = (void *)
307 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + STATUS0);
308 }
309 
310 static void ipi_en0_regs_init(void)
311 {
312 	ipi_en0_regs[0] = (void *)
313 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + EN0);
314 	ipi_en0_regs[1] = (void *)
315 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + EN0);
316 	ipi_en0_regs[2] = (void *)
317 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + EN0);
318 	ipi_en0_regs[3] = (void *)
319 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + EN0);
320 	ipi_en0_regs[4] = (void *)
321 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + EN0);
322 	ipi_en0_regs[5] = (void *)
323 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + EN0);
324 	ipi_en0_regs[6] = (void *)
325 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + EN0);
326 	ipi_en0_regs[7] = (void *)
327 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + EN0);
328 	ipi_en0_regs[8] = (void *)
329 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + EN0);
330 	ipi_en0_regs[9] = (void *)
331 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + EN0);
332 	ipi_en0_regs[10] = (void *)
333 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + EN0);
334 	ipi_en0_regs[11] = (void *)
335 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + EN0);
336 	ipi_en0_regs[12] = (void *)
337 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + EN0);
338 	ipi_en0_regs[13] = (void *)
339 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + EN0);
340 	ipi_en0_regs[14] = (void *)
341 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + EN0);
342 	ipi_en0_regs[15] = (void *)
343 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + EN0);
344 }
345 
346 static void ipi_mailbox_buf_init(void)
347 {
348 	ipi_mailbox_buf[0] = (void *)
349 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + BUF);
350 	ipi_mailbox_buf[1] = (void *)
351 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + BUF);
352 	ipi_mailbox_buf[2] = (void *)
353 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + BUF);
354 	ipi_mailbox_buf[3] = (void *)
355 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + BUF);
356 	ipi_mailbox_buf[4] = (void *)
357 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + BUF);
358 	ipi_mailbox_buf[5] = (void *)
359 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + BUF);
360 	ipi_mailbox_buf[6] = (void *)
361 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + BUF);
362 	ipi_mailbox_buf[7] = (void *)
363 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + BUF);
364 	ipi_mailbox_buf[8] = (void *)
365 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + BUF);
366 	ipi_mailbox_buf[9] = (void *)
367 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + BUF);
368 	ipi_mailbox_buf[10] = (void *)
369 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + BUF);
370 	ipi_mailbox_buf[11] = (void *)
371 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + BUF);
372 	ipi_mailbox_buf[12] = (void *)
373 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + BUF);
374 	ipi_mailbox_buf[13] = (void *)
375 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + BUF);
376 	ipi_mailbox_buf[14] = (void *)
377 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + BUF);
378 	ipi_mailbox_buf[15] = (void *)
379 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + BUF);
380 }
381 
382 /*
383  * Simple enough, just poke the appropriate ipi register
384  */
385 static void loongson3_send_ipi_single(int cpu, unsigned int action)
386 {
387 	ipi_write_action(cpu_logical_map(cpu), (u32)action);
388 }
389 
390 static void
391 loongson3_send_ipi_mask(const struct cpumask *mask, unsigned int action)
392 {
393 	unsigned int i;
394 
395 	for_each_cpu(i, mask)
396 		ipi_write_action(cpu_logical_map(i), (u32)action);
397 }
398 
399 
400 static irqreturn_t loongson3_ipi_interrupt(int irq, void *dev_id)
401 {
402 	int i, cpu = smp_processor_id();
403 	unsigned int action, c0count;
404 
405 	action = ipi_read_clear(cpu);
406 
407 	if (action & SMP_RESCHEDULE_YOURSELF)
408 		scheduler_ipi();
409 
410 	if (action & SMP_CALL_FUNCTION) {
411 		irq_enter();
412 		generic_smp_call_function_interrupt();
413 		irq_exit();
414 	}
415 
416 	if (action & SMP_ASK_C0COUNT) {
417 		BUG_ON(cpu != 0);
418 		c0count = read_c0_count();
419 		c0count = c0count ? c0count : 1;
420 		for (i = 1; i < nr_cpu_ids; i++)
421 			core0_c0count[i] = c0count;
422 		__wbflush(); /* Let others see the result ASAP */
423 	}
424 
425 	return IRQ_HANDLED;
426 }
427 
428 #define MAX_LOOPS 800
429 /*
430  * SMP init and finish on secondary CPUs
431  */
432 static void loongson3_init_secondary(void)
433 {
434 	int i;
435 	uint32_t initcount;
436 	unsigned int cpu = smp_processor_id();
437 	unsigned int imask = STATUSF_IP7 | STATUSF_IP6 |
438 			     STATUSF_IP3 | STATUSF_IP2;
439 
440 	/* Set interrupt mask, but don't enable */
441 	change_c0_status(ST0_IM, imask);
442 	ipi_write_enable(cpu);
443 
444 	per_cpu(cpu_state, cpu) = CPU_ONLINE;
445 	cpu_set_core(&cpu_data[cpu],
446 		     cpu_logical_map(cpu) % loongson_sysconf.cores_per_package);
447 	cpu_data[cpu].package =
448 		cpu_logical_map(cpu) / loongson_sysconf.cores_per_package;
449 
450 	i = 0;
451 	core0_c0count[cpu] = 0;
452 	loongson3_send_ipi_single(0, SMP_ASK_C0COUNT);
453 	while (!core0_c0count[cpu]) {
454 		i++;
455 		cpu_relax();
456 	}
457 
458 	if (i > MAX_LOOPS)
459 		i = MAX_LOOPS;
460 	if (cpu_data[cpu].package)
461 		initcount = core0_c0count[cpu] + i;
462 	else /* Local access is faster for loops */
463 		initcount = core0_c0count[cpu] + i/2;
464 
465 	write_c0_count(initcount);
466 }
467 
468 static void loongson3_smp_finish(void)
469 {
470 	int cpu = smp_processor_id();
471 
472 	write_c0_compare(read_c0_count() + mips_hpt_frequency/HZ);
473 	local_irq_enable();
474 	ipi_clear_buf(cpu);
475 
476 	pr_info("CPU#%d finished, CP0_ST=%x\n",
477 			smp_processor_id(), read_c0_status());
478 }
479 
480 static void __init loongson3_smp_setup(void)
481 {
482 	int i = 0, num = 0; /* i: physical id, num: logical id */
483 
484 	init_cpu_possible(cpu_none_mask);
485 
486 	/* For unified kernel, NR_CPUS is the maximum possible value,
487 	 * loongson_sysconf.nr_cpus is the really present value
488 	 */
489 	while (i < loongson_sysconf.nr_cpus) {
490 		if (loongson_sysconf.reserved_cpus_mask & (1<<i)) {
491 			/* Reserved physical CPU cores */
492 			__cpu_number_map[i] = -1;
493 		} else {
494 			__cpu_number_map[i] = num;
495 			__cpu_logical_map[num] = i;
496 			set_cpu_possible(num, true);
497 			/* Loongson processors are always grouped by 4 */
498 			cpu_set_cluster(&cpu_data[num], i / 4);
499 			num++;
500 		}
501 		i++;
502 	}
503 	pr_info("Detected %i available CPU(s)\n", num);
504 
505 	while (num < loongson_sysconf.nr_cpus) {
506 		__cpu_logical_map[num] = -1;
507 		num++;
508 	}
509 
510 	csr_ipi_probe();
511 	ipi_set0_regs_init();
512 	ipi_clear0_regs_init();
513 	ipi_status0_regs_init();
514 	ipi_en0_regs_init();
515 	ipi_mailbox_buf_init();
516 	ipi_write_enable(0);
517 
518 	cpu_set_core(&cpu_data[0],
519 		     cpu_logical_map(0) % loongson_sysconf.cores_per_package);
520 	cpu_data[0].package = cpu_logical_map(0) / loongson_sysconf.cores_per_package;
521 }
522 
523 static void __init loongson3_prepare_cpus(unsigned int max_cpus)
524 {
525 	if (request_irq(LS_IPI_IRQ, loongson3_ipi_interrupt,
526 			IRQF_PERCPU | IRQF_NO_SUSPEND, "SMP_IPI", NULL))
527 		pr_err("Failed to request IPI IRQ\n");
528 	init_cpu_present(cpu_possible_mask);
529 	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
530 }
531 
532 /*
533  * Setup the PC, SP, and GP of a secondary processor and start it runing!
534  */
535 static int loongson3_boot_secondary(int cpu, struct task_struct *idle)
536 {
537 	pr_info("Booting CPU#%d...\n", cpu);
538 
539 	ipi_write_buf(cpu, idle);
540 
541 	return 0;
542 }
543 
544 #ifdef CONFIG_HOTPLUG_CPU
545 
546 static int loongson3_cpu_disable(void)
547 {
548 	unsigned long flags;
549 	unsigned int cpu = smp_processor_id();
550 
551 	set_cpu_online(cpu, false);
552 	calculate_cpu_foreign_map();
553 	local_irq_save(flags);
554 	clear_c0_status(ST0_IM);
555 	local_irq_restore(flags);
556 	local_flush_tlb_all();
557 
558 	return 0;
559 }
560 
561 
562 static void loongson3_cpu_die(unsigned int cpu)
563 {
564 	while (per_cpu(cpu_state, cpu) != CPU_DEAD)
565 		cpu_relax();
566 
567 	mb();
568 }
569 
570 /* To shutdown a core in Loongson 3, the target core should go to CKSEG1 and
571  * flush all L1 entries at first. Then, another core (usually Core 0) can
572  * safely disable the clock of the target core. loongson3_play_dead() is
573  * called via CKSEG1 (uncached and unmmaped)
574  */
575 static void loongson3_type1_play_dead(int *state_addr)
576 {
577 	register int val;
578 	register long cpuid, core, node, count;
579 	register void *addr, *base, *initfunc;
580 
581 	__asm__ __volatile__(
582 		"   .set push                     \n"
583 		"   .set noreorder                \n"
584 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
585 		"1: cache 0, 0(%[addr])           \n" /* flush L1 ICache */
586 		"   cache 0, 1(%[addr])           \n"
587 		"   cache 0, 2(%[addr])           \n"
588 		"   cache 0, 3(%[addr])           \n"
589 		"   cache 1, 0(%[addr])           \n" /* flush L1 DCache */
590 		"   cache 1, 1(%[addr])           \n"
591 		"   cache 1, 2(%[addr])           \n"
592 		"   cache 1, 3(%[addr])           \n"
593 		"   addiu %[sets], %[sets], -1    \n"
594 		"   bnez  %[sets], 1b             \n"
595 		"   addiu %[addr], %[addr], 0x20  \n"
596 		"   li    %[val], 0x7             \n" /* *state_addr = CPU_DEAD; */
597 		"   sw    %[val], (%[state_addr]) \n"
598 		"   sync                          \n"
599 		"   cache 21, (%[state_addr])     \n" /* flush entry of *state_addr */
600 		"   .set pop                      \n"
601 		: [addr] "=&r" (addr), [val] "=&r" (val)
602 		: [state_addr] "r" (state_addr),
603 		  [sets] "r" (cpu_data[smp_processor_id()].dcache.sets));
604 
605 	__asm__ __volatile__(
606 		"   .set push                         \n"
607 		"   .set noreorder                    \n"
608 		"   .set mips64                       \n"
609 		"   mfc0  %[cpuid], $15, 1            \n"
610 		"   andi  %[cpuid], 0x3ff             \n"
611 		"   dli   %[base], 0x900000003ff01000 \n"
612 		"   andi  %[core], %[cpuid], 0x3      \n"
613 		"   sll   %[core], 8                  \n" /* get core id */
614 		"   or    %[base], %[base], %[core]   \n"
615 		"   andi  %[node], %[cpuid], 0xc      \n"
616 		"   dsll  %[node], 42                 \n" /* get node id */
617 		"   or    %[base], %[base], %[node]   \n"
618 		"1: li    %[count], 0x100             \n" /* wait for init loop */
619 		"2: bnez  %[count], 2b                \n" /* limit mailbox access */
620 		"   addiu %[count], -1                \n"
621 		"   ld    %[initfunc], 0x20(%[base])  \n" /* get PC via mailbox */
622 		"   beqz  %[initfunc], 1b             \n"
623 		"   nop                               \n"
624 		"   ld    $sp, 0x28(%[base])          \n" /* get SP via mailbox */
625 		"   ld    $gp, 0x30(%[base])          \n" /* get GP via mailbox */
626 		"   ld    $a1, 0x38(%[base])          \n"
627 		"   jr    %[initfunc]                 \n" /* jump to initial PC */
628 		"   nop                               \n"
629 		"   .set pop                          \n"
630 		: [core] "=&r" (core), [node] "=&r" (node),
631 		  [base] "=&r" (base), [cpuid] "=&r" (cpuid),
632 		  [count] "=&r" (count), [initfunc] "=&r" (initfunc)
633 		: /* No Input */
634 		: "a1");
635 }
636 
637 static void loongson3_type2_play_dead(int *state_addr)
638 {
639 	register int val;
640 	register long cpuid, core, node, count;
641 	register void *addr, *base, *initfunc;
642 
643 	__asm__ __volatile__(
644 		"   .set push                     \n"
645 		"   .set noreorder                \n"
646 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
647 		"1: cache 0, 0(%[addr])           \n" /* flush L1 ICache */
648 		"   cache 0, 1(%[addr])           \n"
649 		"   cache 0, 2(%[addr])           \n"
650 		"   cache 0, 3(%[addr])           \n"
651 		"   cache 1, 0(%[addr])           \n" /* flush L1 DCache */
652 		"   cache 1, 1(%[addr])           \n"
653 		"   cache 1, 2(%[addr])           \n"
654 		"   cache 1, 3(%[addr])           \n"
655 		"   addiu %[sets], %[sets], -1    \n"
656 		"   bnez  %[sets], 1b             \n"
657 		"   addiu %[addr], %[addr], 0x20  \n"
658 		"   li    %[val], 0x7             \n" /* *state_addr = CPU_DEAD; */
659 		"   sw    %[val], (%[state_addr]) \n"
660 		"   sync                          \n"
661 		"   cache 21, (%[state_addr])     \n" /* flush entry of *state_addr */
662 		"   .set pop                      \n"
663 		: [addr] "=&r" (addr), [val] "=&r" (val)
664 		: [state_addr] "r" (state_addr),
665 		  [sets] "r" (cpu_data[smp_processor_id()].dcache.sets));
666 
667 	__asm__ __volatile__(
668 		"   .set push                         \n"
669 		"   .set noreorder                    \n"
670 		"   .set mips64                       \n"
671 		"   mfc0  %[cpuid], $15, 1            \n"
672 		"   andi  %[cpuid], 0x3ff             \n"
673 		"   dli   %[base], 0x900000003ff01000 \n"
674 		"   andi  %[core], %[cpuid], 0x3      \n"
675 		"   sll   %[core], 8                  \n" /* get core id */
676 		"   or    %[base], %[base], %[core]   \n"
677 		"   andi  %[node], %[cpuid], 0xc      \n"
678 		"   dsll  %[node], 42                 \n" /* get node id */
679 		"   or    %[base], %[base], %[node]   \n"
680 		"   dsrl  %[node], 30                 \n" /* 15:14 */
681 		"   or    %[base], %[base], %[node]   \n"
682 		"1: li    %[count], 0x100             \n" /* wait for init loop */
683 		"2: bnez  %[count], 2b                \n" /* limit mailbox access */
684 		"   addiu %[count], -1                \n"
685 		"   ld    %[initfunc], 0x20(%[base])  \n" /* get PC via mailbox */
686 		"   beqz  %[initfunc], 1b             \n"
687 		"   nop                               \n"
688 		"   ld    $sp, 0x28(%[base])          \n" /* get SP via mailbox */
689 		"   ld    $gp, 0x30(%[base])          \n" /* get GP via mailbox */
690 		"   ld    $a1, 0x38(%[base])          \n"
691 		"   jr    %[initfunc]                 \n" /* jump to initial PC */
692 		"   nop                               \n"
693 		"   .set pop                          \n"
694 		: [core] "=&r" (core), [node] "=&r" (node),
695 		  [base] "=&r" (base), [cpuid] "=&r" (cpuid),
696 		  [count] "=&r" (count), [initfunc] "=&r" (initfunc)
697 		: /* No Input */
698 		: "a1");
699 }
700 
701 static void loongson3_type3_play_dead(int *state_addr)
702 {
703 	register int val;
704 	register long cpuid, core, node, count;
705 	register void *addr, *base, *initfunc;
706 
707 	__asm__ __volatile__(
708 		"   .set push                     \n"
709 		"   .set noreorder                \n"
710 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
711 		"1: cache 0, 0(%[addr])           \n" /* flush L1 ICache */
712 		"   cache 0, 1(%[addr])           \n"
713 		"   cache 0, 2(%[addr])           \n"
714 		"   cache 0, 3(%[addr])           \n"
715 		"   cache 1, 0(%[addr])           \n" /* flush L1 DCache */
716 		"   cache 1, 1(%[addr])           \n"
717 		"   cache 1, 2(%[addr])           \n"
718 		"   cache 1, 3(%[addr])           \n"
719 		"   addiu %[sets], %[sets], -1    \n"
720 		"   bnez  %[sets], 1b             \n"
721 		"   addiu %[addr], %[addr], 0x40  \n"
722 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
723 		"2: cache 2, 0(%[addr])           \n" /* flush L1 VCache */
724 		"   cache 2, 1(%[addr])           \n"
725 		"   cache 2, 2(%[addr])           \n"
726 		"   cache 2, 3(%[addr])           \n"
727 		"   cache 2, 4(%[addr])           \n"
728 		"   cache 2, 5(%[addr])           \n"
729 		"   cache 2, 6(%[addr])           \n"
730 		"   cache 2, 7(%[addr])           \n"
731 		"   cache 2, 8(%[addr])           \n"
732 		"   cache 2, 9(%[addr])           \n"
733 		"   cache 2, 10(%[addr])          \n"
734 		"   cache 2, 11(%[addr])          \n"
735 		"   cache 2, 12(%[addr])          \n"
736 		"   cache 2, 13(%[addr])          \n"
737 		"   cache 2, 14(%[addr])          \n"
738 		"   cache 2, 15(%[addr])          \n"
739 		"   addiu %[vsets], %[vsets], -1  \n"
740 		"   bnez  %[vsets], 2b            \n"
741 		"   addiu %[addr], %[addr], 0x40  \n"
742 		"   li    %[val], 0x7             \n" /* *state_addr = CPU_DEAD; */
743 		"   sw    %[val], (%[state_addr]) \n"
744 		"   sync                          \n"
745 		"   cache 21, (%[state_addr])     \n" /* flush entry of *state_addr */
746 		"   .set pop                      \n"
747 		: [addr] "=&r" (addr), [val] "=&r" (val)
748 		: [state_addr] "r" (state_addr),
749 		  [sets] "r" (cpu_data[smp_processor_id()].dcache.sets),
750 		  [vsets] "r" (cpu_data[smp_processor_id()].vcache.sets));
751 
752 	__asm__ __volatile__(
753 		"   .set push                         \n"
754 		"   .set noreorder                    \n"
755 		"   .set mips64                       \n"
756 		"   mfc0  %[cpuid], $15, 1            \n"
757 		"   andi  %[cpuid], 0x3ff             \n"
758 		"   dli   %[base], 0x900000003ff01000 \n"
759 		"   andi  %[core], %[cpuid], 0x3      \n"
760 		"   sll   %[core], 8                  \n" /* get core id */
761 		"   or    %[base], %[base], %[core]   \n"
762 		"   andi  %[node], %[cpuid], 0xc      \n"
763 		"   dsll  %[node], 42                 \n" /* get node id */
764 		"   or    %[base], %[base], %[node]   \n"
765 		"1: li    %[count], 0x100             \n" /* wait for init loop */
766 		"2: bnez  %[count], 2b                \n" /* limit mailbox access */
767 		"   addiu %[count], -1                \n"
768 		"   lw    %[initfunc], 0x20(%[base])  \n" /* check lower 32-bit as jump indicator */
769 		"   beqz  %[initfunc], 1b             \n"
770 		"   nop                               \n"
771 		"   ld    %[initfunc], 0x20(%[base])  \n" /* get PC (whole 64-bit) via mailbox */
772 		"   ld    $sp, 0x28(%[base])          \n" /* get SP via mailbox */
773 		"   ld    $gp, 0x30(%[base])          \n" /* get GP via mailbox */
774 		"   ld    $a1, 0x38(%[base])          \n"
775 		"   jr    %[initfunc]                 \n" /* jump to initial PC */
776 		"   nop                               \n"
777 		"   .set pop                          \n"
778 		: [core] "=&r" (core), [node] "=&r" (node),
779 		  [base] "=&r" (base), [cpuid] "=&r" (cpuid),
780 		  [count] "=&r" (count), [initfunc] "=&r" (initfunc)
781 		: /* No Input */
782 		: "a1");
783 }
784 
785 void play_dead(void)
786 {
787 	int prid_imp, prid_rev, *state_addr;
788 	unsigned int cpu = smp_processor_id();
789 	void (*play_dead_at_ckseg1)(int *);
790 
791 	idle_task_exit();
792 
793 	prid_imp = read_c0_prid() & PRID_IMP_MASK;
794 	prid_rev = read_c0_prid() & PRID_REV_MASK;
795 
796 	if (prid_imp == PRID_IMP_LOONGSON_64G) {
797 		play_dead_at_ckseg1 =
798 			(void *)CKSEG1ADDR((unsigned long)loongson3_type3_play_dead);
799 		goto out;
800 	}
801 
802 	switch (prid_rev) {
803 	case PRID_REV_LOONGSON3A_R1:
804 	default:
805 		play_dead_at_ckseg1 =
806 			(void *)CKSEG1ADDR((unsigned long)loongson3_type1_play_dead);
807 		break;
808 	case PRID_REV_LOONGSON3B_R1:
809 	case PRID_REV_LOONGSON3B_R2:
810 		play_dead_at_ckseg1 =
811 			(void *)CKSEG1ADDR((unsigned long)loongson3_type2_play_dead);
812 		break;
813 	case PRID_REV_LOONGSON3A_R2_0:
814 	case PRID_REV_LOONGSON3A_R2_1:
815 	case PRID_REV_LOONGSON3A_R3_0:
816 	case PRID_REV_LOONGSON3A_R3_1:
817 		play_dead_at_ckseg1 =
818 			(void *)CKSEG1ADDR((unsigned long)loongson3_type3_play_dead);
819 		break;
820 	}
821 
822 out:
823 	state_addr = &per_cpu(cpu_state, cpu);
824 	mb();
825 	play_dead_at_ckseg1(state_addr);
826 	BUG();
827 }
828 
829 static int loongson3_disable_clock(unsigned int cpu)
830 {
831 	uint64_t core_id = cpu_core(&cpu_data[cpu]);
832 	uint64_t package_id = cpu_data[cpu].package;
833 
834 	if ((read_c0_prid() & PRID_REV_MASK) == PRID_REV_LOONGSON3A_R1) {
835 		LOONGSON_CHIPCFG(package_id) &= ~(1 << (12 + core_id));
836 	} else {
837 		if (!(loongson_sysconf.workarounds & WORKAROUND_CPUHOTPLUG))
838 			LOONGSON_FREQCTRL(package_id) &= ~(1 << (core_id * 4 + 3));
839 	}
840 	return 0;
841 }
842 
843 static int loongson3_enable_clock(unsigned int cpu)
844 {
845 	uint64_t core_id = cpu_core(&cpu_data[cpu]);
846 	uint64_t package_id = cpu_data[cpu].package;
847 
848 	if ((read_c0_prid() & PRID_REV_MASK) == PRID_REV_LOONGSON3A_R1) {
849 		LOONGSON_CHIPCFG(package_id) |= 1 << (12 + core_id);
850 	} else {
851 		if (!(loongson_sysconf.workarounds & WORKAROUND_CPUHOTPLUG))
852 			LOONGSON_FREQCTRL(package_id) |= 1 << (core_id * 4 + 3);
853 	}
854 	return 0;
855 }
856 
857 static int register_loongson3_notifier(void)
858 {
859 	return cpuhp_setup_state_nocalls(CPUHP_MIPS_SOC_PREPARE,
860 					 "mips/loongson:prepare",
861 					 loongson3_enable_clock,
862 					 loongson3_disable_clock);
863 }
864 early_initcall(register_loongson3_notifier);
865 
866 #endif
867 
868 const struct plat_smp_ops loongson3_smp_ops = {
869 	.send_ipi_single = loongson3_send_ipi_single,
870 	.send_ipi_mask = loongson3_send_ipi_mask,
871 	.init_secondary = loongson3_init_secondary,
872 	.smp_finish = loongson3_smp_finish,
873 	.boot_secondary = loongson3_boot_secondary,
874 	.smp_setup = loongson3_smp_setup,
875 	.prepare_cpus = loongson3_prepare_cpus,
876 #ifdef CONFIG_HOTPLUG_CPU
877 	.cpu_disable = loongson3_cpu_disable,
878 	.cpu_die = loongson3_cpu_die,
879 #endif
880 #ifdef CONFIG_KEXEC
881 	.kexec_nonboot_cpu = kexec_nonboot_cpu_jump,
882 #endif
883 };
884