xref: /openbmc/linux/arch/mips/loongson64/smp.c (revision f125e2d4)
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 <linux/init.h>
8 #include <linux/cpu.h>
9 #include <linux/sched.h>
10 #include <linux/sched/hotplug.h>
11 #include <linux/sched/task_stack.h>
12 #include <linux/smp.h>
13 #include <linux/cpufreq.h>
14 #include <linux/kexec.h>
15 #include <asm/processor.h>
16 #include <asm/time.h>
17 #include <asm/clock.h>
18 #include <asm/tlbflush.h>
19 #include <asm/cacheflush.h>
20 #include <loongson.h>
21 #include <loongson_regs.h>
22 #include <workarounds.h>
23 
24 #include "smp.h"
25 
26 DEFINE_PER_CPU(int, cpu_state);
27 
28 static void *ipi_set0_regs[16];
29 static void *ipi_clear0_regs[16];
30 static void *ipi_status0_regs[16];
31 static void *ipi_en0_regs[16];
32 static void *ipi_mailbox_buf[16];
33 static uint32_t core0_c0count[NR_CPUS];
34 
35 /* read a 32bit value from ipi register */
36 #define loongson3_ipi_read32(addr) readl(addr)
37 /* read a 64bit value from ipi register */
38 #define loongson3_ipi_read64(addr) readq(addr)
39 /* write a 32bit value to ipi register */
40 #define loongson3_ipi_write32(action, addr)	\
41 	do {					\
42 		writel(action, addr);		\
43 		__wbflush();			\
44 	} while (0)
45 /* write a 64bit value to ipi register */
46 #define loongson3_ipi_write64(action, addr)	\
47 	do {					\
48 		writeq(action, addr);		\
49 		__wbflush();			\
50 	} while (0)
51 
52 u32 (*ipi_read_clear)(int cpu);
53 void (*ipi_write_action)(int cpu, u32 action);
54 
55 static u32 csr_ipi_read_clear(int cpu)
56 {
57 	u32 action;
58 
59 	/* Load the ipi register to figure out what we're supposed to do */
60 	action = csr_readl(LOONGSON_CSR_IPI_STATUS);
61 	/* Clear the ipi register to clear the interrupt */
62 	csr_writel(action, LOONGSON_CSR_IPI_CLEAR);
63 
64 	return action;
65 }
66 
67 static void csr_ipi_write_action(int cpu, u32 action)
68 {
69 	unsigned int irq = 0;
70 
71 	while ((irq = ffs(action))) {
72 		uint32_t val = CSR_IPI_SEND_BLOCK;
73 		val |= (irq - 1);
74 		val |= (cpu << CSR_IPI_SEND_CPU_SHIFT);
75 		csr_writel(val, LOONGSON_CSR_IPI_SEND);
76 		action &= ~BIT(irq - 1);
77 	}
78 }
79 
80 static u32 legacy_ipi_read_clear(int cpu)
81 {
82 	u32 action;
83 
84 	/* Load the ipi register to figure out what we're supposed to do */
85 	action = loongson3_ipi_read32(ipi_status0_regs[cpu_logical_map(cpu)]);
86 	/* Clear the ipi register to clear the interrupt */
87 	loongson3_ipi_write32(action, ipi_clear0_regs[cpu_logical_map(cpu)]);
88 
89 	return action;
90 }
91 
92 static void legacy_ipi_write_action(int cpu, u32 action)
93 {
94 	loongson3_ipi_write32((u32)action, ipi_set0_regs[cpu]);
95 }
96 
97 static void csr_ipi_probe(void)
98 {
99 	if (cpu_has_csr() && csr_readl(LOONGSON_CSR_FEATURES) & LOONGSON_CSRF_IPI) {
100 		ipi_read_clear = csr_ipi_read_clear;
101 		ipi_write_action = csr_ipi_write_action;
102 	} else {
103 		ipi_read_clear = legacy_ipi_read_clear;
104 		ipi_write_action = legacy_ipi_write_action;
105 	}
106 }
107 
108 static void ipi_set0_regs_init(void)
109 {
110 	ipi_set0_regs[0] = (void *)
111 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + SET0);
112 	ipi_set0_regs[1] = (void *)
113 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + SET0);
114 	ipi_set0_regs[2] = (void *)
115 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + SET0);
116 	ipi_set0_regs[3] = (void *)
117 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + SET0);
118 	ipi_set0_regs[4] = (void *)
119 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + SET0);
120 	ipi_set0_regs[5] = (void *)
121 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + SET0);
122 	ipi_set0_regs[6] = (void *)
123 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + SET0);
124 	ipi_set0_regs[7] = (void *)
125 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + SET0);
126 	ipi_set0_regs[8] = (void *)
127 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + SET0);
128 	ipi_set0_regs[9] = (void *)
129 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + SET0);
130 	ipi_set0_regs[10] = (void *)
131 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + SET0);
132 	ipi_set0_regs[11] = (void *)
133 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + SET0);
134 	ipi_set0_regs[12] = (void *)
135 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + SET0);
136 	ipi_set0_regs[13] = (void *)
137 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + SET0);
138 	ipi_set0_regs[14] = (void *)
139 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + SET0);
140 	ipi_set0_regs[15] = (void *)
141 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + SET0);
142 }
143 
144 static void ipi_clear0_regs_init(void)
145 {
146 	ipi_clear0_regs[0] = (void *)
147 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + CLEAR0);
148 	ipi_clear0_regs[1] = (void *)
149 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + CLEAR0);
150 	ipi_clear0_regs[2] = (void *)
151 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + CLEAR0);
152 	ipi_clear0_regs[3] = (void *)
153 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + CLEAR0);
154 	ipi_clear0_regs[4] = (void *)
155 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + CLEAR0);
156 	ipi_clear0_regs[5] = (void *)
157 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + CLEAR0);
158 	ipi_clear0_regs[6] = (void *)
159 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + CLEAR0);
160 	ipi_clear0_regs[7] = (void *)
161 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + CLEAR0);
162 	ipi_clear0_regs[8] = (void *)
163 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + CLEAR0);
164 	ipi_clear0_regs[9] = (void *)
165 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + CLEAR0);
166 	ipi_clear0_regs[10] = (void *)
167 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + CLEAR0);
168 	ipi_clear0_regs[11] = (void *)
169 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + CLEAR0);
170 	ipi_clear0_regs[12] = (void *)
171 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + CLEAR0);
172 	ipi_clear0_regs[13] = (void *)
173 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + CLEAR0);
174 	ipi_clear0_regs[14] = (void *)
175 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + CLEAR0);
176 	ipi_clear0_regs[15] = (void *)
177 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + CLEAR0);
178 }
179 
180 static void ipi_status0_regs_init(void)
181 {
182 	ipi_status0_regs[0] = (void *)
183 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + STATUS0);
184 	ipi_status0_regs[1] = (void *)
185 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + STATUS0);
186 	ipi_status0_regs[2] = (void *)
187 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + STATUS0);
188 	ipi_status0_regs[3] = (void *)
189 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + STATUS0);
190 	ipi_status0_regs[4] = (void *)
191 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + STATUS0);
192 	ipi_status0_regs[5] = (void *)
193 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + STATUS0);
194 	ipi_status0_regs[6] = (void *)
195 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + STATUS0);
196 	ipi_status0_regs[7] = (void *)
197 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + STATUS0);
198 	ipi_status0_regs[8] = (void *)
199 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + STATUS0);
200 	ipi_status0_regs[9] = (void *)
201 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + STATUS0);
202 	ipi_status0_regs[10] = (void *)
203 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + STATUS0);
204 	ipi_status0_regs[11] = (void *)
205 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + STATUS0);
206 	ipi_status0_regs[12] = (void *)
207 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + STATUS0);
208 	ipi_status0_regs[13] = (void *)
209 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + STATUS0);
210 	ipi_status0_regs[14] = (void *)
211 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + STATUS0);
212 	ipi_status0_regs[15] = (void *)
213 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + STATUS0);
214 }
215 
216 static void ipi_en0_regs_init(void)
217 {
218 	ipi_en0_regs[0] = (void *)
219 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + EN0);
220 	ipi_en0_regs[1] = (void *)
221 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + EN0);
222 	ipi_en0_regs[2] = (void *)
223 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + EN0);
224 	ipi_en0_regs[3] = (void *)
225 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + EN0);
226 	ipi_en0_regs[4] = (void *)
227 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + EN0);
228 	ipi_en0_regs[5] = (void *)
229 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + EN0);
230 	ipi_en0_regs[6] = (void *)
231 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + EN0);
232 	ipi_en0_regs[7] = (void *)
233 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + EN0);
234 	ipi_en0_regs[8] = (void *)
235 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + EN0);
236 	ipi_en0_regs[9] = (void *)
237 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + EN0);
238 	ipi_en0_regs[10] = (void *)
239 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + EN0);
240 	ipi_en0_regs[11] = (void *)
241 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + EN0);
242 	ipi_en0_regs[12] = (void *)
243 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + EN0);
244 	ipi_en0_regs[13] = (void *)
245 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + EN0);
246 	ipi_en0_regs[14] = (void *)
247 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + EN0);
248 	ipi_en0_regs[15] = (void *)
249 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + EN0);
250 }
251 
252 static void ipi_mailbox_buf_init(void)
253 {
254 	ipi_mailbox_buf[0] = (void *)
255 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + BUF);
256 	ipi_mailbox_buf[1] = (void *)
257 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + BUF);
258 	ipi_mailbox_buf[2] = (void *)
259 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + BUF);
260 	ipi_mailbox_buf[3] = (void *)
261 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + BUF);
262 	ipi_mailbox_buf[4] = (void *)
263 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + BUF);
264 	ipi_mailbox_buf[5] = (void *)
265 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + BUF);
266 	ipi_mailbox_buf[6] = (void *)
267 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + BUF);
268 	ipi_mailbox_buf[7] = (void *)
269 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + BUF);
270 	ipi_mailbox_buf[8] = (void *)
271 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + BUF);
272 	ipi_mailbox_buf[9] = (void *)
273 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + BUF);
274 	ipi_mailbox_buf[10] = (void *)
275 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + BUF);
276 	ipi_mailbox_buf[11] = (void *)
277 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + BUF);
278 	ipi_mailbox_buf[12] = (void *)
279 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + BUF);
280 	ipi_mailbox_buf[13] = (void *)
281 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + BUF);
282 	ipi_mailbox_buf[14] = (void *)
283 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + BUF);
284 	ipi_mailbox_buf[15] = (void *)
285 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + BUF);
286 }
287 
288 /*
289  * Simple enough, just poke the appropriate ipi register
290  */
291 static void loongson3_send_ipi_single(int cpu, unsigned int action)
292 {
293 	ipi_write_action(cpu_logical_map(cpu), (u32)action);
294 }
295 
296 static void
297 loongson3_send_ipi_mask(const struct cpumask *mask, unsigned int action)
298 {
299 	unsigned int i;
300 
301 	for_each_cpu(i, mask)
302 		ipi_write_action(cpu_logical_map(i), (u32)action);
303 }
304 
305 #define IPI_IRQ_OFFSET 6
306 
307 void loongson3_send_irq_by_ipi(int cpu, int irqs)
308 {
309 	ipi_write_action(cpu_logical_map(cpu), irqs << IPI_IRQ_OFFSET);
310 }
311 
312 void loongson3_ipi_interrupt(struct pt_regs *regs)
313 {
314 	int i, cpu = smp_processor_id();
315 	unsigned int action, c0count, irqs;
316 
317 	action = ipi_read_clear(cpu);
318 	irqs = action >> IPI_IRQ_OFFSET;
319 
320 	if (action & SMP_RESCHEDULE_YOURSELF)
321 		scheduler_ipi();
322 
323 	if (action & SMP_CALL_FUNCTION) {
324 		irq_enter();
325 		generic_smp_call_function_interrupt();
326 		irq_exit();
327 	}
328 
329 	if (action & SMP_ASK_C0COUNT) {
330 		BUG_ON(cpu != 0);
331 		c0count = read_c0_count();
332 		c0count = c0count ? c0count : 1;
333 		for (i = 1; i < nr_cpu_ids; i++)
334 			core0_c0count[i] = c0count;
335 		__wbflush(); /* Let others see the result ASAP */
336 	}
337 
338 	if (irqs) {
339 		int irq;
340 		while ((irq = ffs(irqs))) {
341 			do_IRQ(irq-1);
342 			irqs &= ~(1<<(irq-1));
343 		}
344 	}
345 }
346 
347 #define MAX_LOOPS 800
348 /*
349  * SMP init and finish on secondary CPUs
350  */
351 static void loongson3_init_secondary(void)
352 {
353 	int i;
354 	uint32_t initcount;
355 	unsigned int cpu = smp_processor_id();
356 	unsigned int imask = STATUSF_IP7 | STATUSF_IP6 |
357 			     STATUSF_IP3 | STATUSF_IP2;
358 
359 	/* Set interrupt mask, but don't enable */
360 	change_c0_status(ST0_IM, imask);
361 
362 	for (i = 0; i < num_possible_cpus(); i++)
363 		loongson3_ipi_write32(0xffffffff, ipi_en0_regs[cpu_logical_map(i)]);
364 
365 	per_cpu(cpu_state, cpu) = CPU_ONLINE;
366 	cpu_set_core(&cpu_data[cpu],
367 		     cpu_logical_map(cpu) % loongson_sysconf.cores_per_package);
368 	cpu_data[cpu].package =
369 		cpu_logical_map(cpu) / loongson_sysconf.cores_per_package;
370 
371 	i = 0;
372 	core0_c0count[cpu] = 0;
373 	loongson3_send_ipi_single(0, SMP_ASK_C0COUNT);
374 	while (!core0_c0count[cpu]) {
375 		i++;
376 		cpu_relax();
377 	}
378 
379 	if (i > MAX_LOOPS)
380 		i = MAX_LOOPS;
381 	if (cpu_data[cpu].package)
382 		initcount = core0_c0count[cpu] + i;
383 	else /* Local access is faster for loops */
384 		initcount = core0_c0count[cpu] + i/2;
385 
386 	write_c0_count(initcount);
387 }
388 
389 static void loongson3_smp_finish(void)
390 {
391 	int cpu = smp_processor_id();
392 
393 	write_c0_compare(read_c0_count() + mips_hpt_frequency/HZ);
394 	local_irq_enable();
395 	loongson3_ipi_write64(0,
396 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x0);
397 	pr_info("CPU#%d finished, CP0_ST=%x\n",
398 			smp_processor_id(), read_c0_status());
399 }
400 
401 static void __init loongson3_smp_setup(void)
402 {
403 	int i = 0, num = 0; /* i: physical id, num: logical id */
404 
405 	init_cpu_possible(cpu_none_mask);
406 
407 	/* For unified kernel, NR_CPUS is the maximum possible value,
408 	 * loongson_sysconf.nr_cpus is the really present value */
409 	while (i < loongson_sysconf.nr_cpus) {
410 		if (loongson_sysconf.reserved_cpus_mask & (1<<i)) {
411 			/* Reserved physical CPU cores */
412 			__cpu_number_map[i] = -1;
413 		} else {
414 			__cpu_number_map[i] = num;
415 			__cpu_logical_map[num] = i;
416 			set_cpu_possible(num, true);
417 			num++;
418 		}
419 		i++;
420 	}
421 	pr_info("Detected %i available CPU(s)\n", num);
422 
423 	while (num < loongson_sysconf.nr_cpus) {
424 		__cpu_logical_map[num] = -1;
425 		num++;
426 	}
427 
428 	csr_ipi_probe();
429 	ipi_set0_regs_init();
430 	ipi_clear0_regs_init();
431 	ipi_status0_regs_init();
432 	ipi_en0_regs_init();
433 	ipi_mailbox_buf_init();
434 	cpu_set_core(&cpu_data[0],
435 		     cpu_logical_map(0) % loongson_sysconf.cores_per_package);
436 	cpu_data[0].package = cpu_logical_map(0) / loongson_sysconf.cores_per_package;
437 }
438 
439 static void __init loongson3_prepare_cpus(unsigned int max_cpus)
440 {
441 	init_cpu_present(cpu_possible_mask);
442 	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
443 }
444 
445 /*
446  * Setup the PC, SP, and GP of a secondary processor and start it runing!
447  */
448 static int loongson3_boot_secondary(int cpu, struct task_struct *idle)
449 {
450 	unsigned long startargs[4];
451 
452 	pr_info("Booting CPU#%d...\n", cpu);
453 
454 	/* startargs[] are initial PC, SP and GP for secondary CPU */
455 	startargs[0] = (unsigned long)&smp_bootstrap;
456 	startargs[1] = (unsigned long)__KSTK_TOS(idle);
457 	startargs[2] = (unsigned long)task_thread_info(idle);
458 	startargs[3] = 0;
459 
460 	pr_debug("CPU#%d, func_pc=%lx, sp=%lx, gp=%lx\n",
461 			cpu, startargs[0], startargs[1], startargs[2]);
462 
463 	loongson3_ipi_write64(startargs[3],
464 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x18);
465 	loongson3_ipi_write64(startargs[2],
466 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x10);
467 	loongson3_ipi_write64(startargs[1],
468 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x8);
469 	loongson3_ipi_write64(startargs[0],
470 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x0);
471 	return 0;
472 }
473 
474 #ifdef CONFIG_HOTPLUG_CPU
475 
476 static int loongson3_cpu_disable(void)
477 {
478 	unsigned long flags;
479 	unsigned int cpu = smp_processor_id();
480 
481 	if (cpu == 0)
482 		return -EBUSY;
483 
484 	set_cpu_online(cpu, false);
485 	calculate_cpu_foreign_map();
486 	local_irq_save(flags);
487 	fixup_irqs();
488 	local_irq_restore(flags);
489 	local_flush_tlb_all();
490 
491 	return 0;
492 }
493 
494 
495 static void loongson3_cpu_die(unsigned int cpu)
496 {
497 	while (per_cpu(cpu_state, cpu) != CPU_DEAD)
498 		cpu_relax();
499 
500 	mb();
501 }
502 
503 /* To shutdown a core in Loongson 3, the target core should go to CKSEG1 and
504  * flush all L1 entries at first. Then, another core (usually Core 0) can
505  * safely disable the clock of the target core. loongson3_play_dead() is
506  * called via CKSEG1 (uncached and unmmaped) */
507 static void loongson3_type1_play_dead(int *state_addr)
508 {
509 	register int val;
510 	register long cpuid, core, node, count;
511 	register void *addr, *base, *initfunc;
512 
513 	__asm__ __volatile__(
514 		"   .set push                     \n"
515 		"   .set noreorder                \n"
516 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
517 		"1: cache 0, 0(%[addr])           \n" /* flush L1 ICache */
518 		"   cache 0, 1(%[addr])           \n"
519 		"   cache 0, 2(%[addr])           \n"
520 		"   cache 0, 3(%[addr])           \n"
521 		"   cache 1, 0(%[addr])           \n" /* flush L1 DCache */
522 		"   cache 1, 1(%[addr])           \n"
523 		"   cache 1, 2(%[addr])           \n"
524 		"   cache 1, 3(%[addr])           \n"
525 		"   addiu %[sets], %[sets], -1    \n"
526 		"   bnez  %[sets], 1b             \n"
527 		"   addiu %[addr], %[addr], 0x20  \n"
528 		"   li    %[val], 0x7             \n" /* *state_addr = CPU_DEAD; */
529 		"   sw    %[val], (%[state_addr]) \n"
530 		"   sync                          \n"
531 		"   cache 21, (%[state_addr])     \n" /* flush entry of *state_addr */
532 		"   .set pop                      \n"
533 		: [addr] "=&r" (addr), [val] "=&r" (val)
534 		: [state_addr] "r" (state_addr),
535 		  [sets] "r" (cpu_data[smp_processor_id()].dcache.sets));
536 
537 	__asm__ __volatile__(
538 		"   .set push                         \n"
539 		"   .set noreorder                    \n"
540 		"   .set mips64                       \n"
541 		"   mfc0  %[cpuid], $15, 1            \n"
542 		"   andi  %[cpuid], 0x3ff             \n"
543 		"   dli   %[base], 0x900000003ff01000 \n"
544 		"   andi  %[core], %[cpuid], 0x3      \n"
545 		"   sll   %[core], 8                  \n" /* get core id */
546 		"   or    %[base], %[base], %[core]   \n"
547 		"   andi  %[node], %[cpuid], 0xc      \n"
548 		"   dsll  %[node], 42                 \n" /* get node id */
549 		"   or    %[base], %[base], %[node]   \n"
550 		"1: li    %[count], 0x100             \n" /* wait for init loop */
551 		"2: bnez  %[count], 2b                \n" /* limit mailbox access */
552 		"   addiu %[count], -1                \n"
553 		"   ld    %[initfunc], 0x20(%[base])  \n" /* get PC via mailbox */
554 		"   beqz  %[initfunc], 1b             \n"
555 		"   nop                               \n"
556 		"   ld    $sp, 0x28(%[base])          \n" /* get SP via mailbox */
557 		"   ld    $gp, 0x30(%[base])          \n" /* get GP via mailbox */
558 		"   ld    $a1, 0x38(%[base])          \n"
559 		"   jr    %[initfunc]                 \n" /* jump to initial PC */
560 		"   nop                               \n"
561 		"   .set pop                          \n"
562 		: [core] "=&r" (core), [node] "=&r" (node),
563 		  [base] "=&r" (base), [cpuid] "=&r" (cpuid),
564 		  [count] "=&r" (count), [initfunc] "=&r" (initfunc)
565 		: /* No Input */
566 		: "a1");
567 }
568 
569 static void loongson3_type2_play_dead(int *state_addr)
570 {
571 	register int val;
572 	register long cpuid, core, node, count;
573 	register void *addr, *base, *initfunc;
574 
575 	__asm__ __volatile__(
576 		"   .set push                     \n"
577 		"   .set noreorder                \n"
578 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
579 		"1: cache 0, 0(%[addr])           \n" /* flush L1 ICache */
580 		"   cache 0, 1(%[addr])           \n"
581 		"   cache 0, 2(%[addr])           \n"
582 		"   cache 0, 3(%[addr])           \n"
583 		"   cache 1, 0(%[addr])           \n" /* flush L1 DCache */
584 		"   cache 1, 1(%[addr])           \n"
585 		"   cache 1, 2(%[addr])           \n"
586 		"   cache 1, 3(%[addr])           \n"
587 		"   addiu %[sets], %[sets], -1    \n"
588 		"   bnez  %[sets], 1b             \n"
589 		"   addiu %[addr], %[addr], 0x20  \n"
590 		"   li    %[val], 0x7             \n" /* *state_addr = CPU_DEAD; */
591 		"   sw    %[val], (%[state_addr]) \n"
592 		"   sync                          \n"
593 		"   cache 21, (%[state_addr])     \n" /* flush entry of *state_addr */
594 		"   .set pop                      \n"
595 		: [addr] "=&r" (addr), [val] "=&r" (val)
596 		: [state_addr] "r" (state_addr),
597 		  [sets] "r" (cpu_data[smp_processor_id()].dcache.sets));
598 
599 	__asm__ __volatile__(
600 		"   .set push                         \n"
601 		"   .set noreorder                    \n"
602 		"   .set mips64                       \n"
603 		"   mfc0  %[cpuid], $15, 1            \n"
604 		"   andi  %[cpuid], 0x3ff             \n"
605 		"   dli   %[base], 0x900000003ff01000 \n"
606 		"   andi  %[core], %[cpuid], 0x3      \n"
607 		"   sll   %[core], 8                  \n" /* get core id */
608 		"   or    %[base], %[base], %[core]   \n"
609 		"   andi  %[node], %[cpuid], 0xc      \n"
610 		"   dsll  %[node], 42                 \n" /* get node id */
611 		"   or    %[base], %[base], %[node]   \n"
612 		"   dsrl  %[node], 30                 \n" /* 15:14 */
613 		"   or    %[base], %[base], %[node]   \n"
614 		"1: li    %[count], 0x100             \n" /* wait for init loop */
615 		"2: bnez  %[count], 2b                \n" /* limit mailbox access */
616 		"   addiu %[count], -1                \n"
617 		"   ld    %[initfunc], 0x20(%[base])  \n" /* get PC via mailbox */
618 		"   beqz  %[initfunc], 1b             \n"
619 		"   nop                               \n"
620 		"   ld    $sp, 0x28(%[base])          \n" /* get SP via mailbox */
621 		"   ld    $gp, 0x30(%[base])          \n" /* get GP via mailbox */
622 		"   ld    $a1, 0x38(%[base])          \n"
623 		"   jr    %[initfunc]                 \n" /* jump to initial PC */
624 		"   nop                               \n"
625 		"   .set pop                          \n"
626 		: [core] "=&r" (core), [node] "=&r" (node),
627 		  [base] "=&r" (base), [cpuid] "=&r" (cpuid),
628 		  [count] "=&r" (count), [initfunc] "=&r" (initfunc)
629 		: /* No Input */
630 		: "a1");
631 }
632 
633 static void loongson3_type3_play_dead(int *state_addr)
634 {
635 	register int val;
636 	register long cpuid, core, node, count;
637 	register void *addr, *base, *initfunc;
638 
639 	__asm__ __volatile__(
640 		"   .set push                     \n"
641 		"   .set noreorder                \n"
642 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
643 		"1: cache 0, 0(%[addr])           \n" /* flush L1 ICache */
644 		"   cache 0, 1(%[addr])           \n"
645 		"   cache 0, 2(%[addr])           \n"
646 		"   cache 0, 3(%[addr])           \n"
647 		"   cache 1, 0(%[addr])           \n" /* flush L1 DCache */
648 		"   cache 1, 1(%[addr])           \n"
649 		"   cache 1, 2(%[addr])           \n"
650 		"   cache 1, 3(%[addr])           \n"
651 		"   addiu %[sets], %[sets], -1    \n"
652 		"   bnez  %[sets], 1b             \n"
653 		"   addiu %[addr], %[addr], 0x40  \n"
654 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
655 		"2: cache 2, 0(%[addr])           \n" /* flush L1 VCache */
656 		"   cache 2, 1(%[addr])           \n"
657 		"   cache 2, 2(%[addr])           \n"
658 		"   cache 2, 3(%[addr])           \n"
659 		"   cache 2, 4(%[addr])           \n"
660 		"   cache 2, 5(%[addr])           \n"
661 		"   cache 2, 6(%[addr])           \n"
662 		"   cache 2, 7(%[addr])           \n"
663 		"   cache 2, 8(%[addr])           \n"
664 		"   cache 2, 9(%[addr])           \n"
665 		"   cache 2, 10(%[addr])          \n"
666 		"   cache 2, 11(%[addr])          \n"
667 		"   cache 2, 12(%[addr])          \n"
668 		"   cache 2, 13(%[addr])          \n"
669 		"   cache 2, 14(%[addr])          \n"
670 		"   cache 2, 15(%[addr])          \n"
671 		"   addiu %[vsets], %[vsets], -1  \n"
672 		"   bnez  %[vsets], 2b            \n"
673 		"   addiu %[addr], %[addr], 0x40  \n"
674 		"   li    %[val], 0x7             \n" /* *state_addr = CPU_DEAD; */
675 		"   sw    %[val], (%[state_addr]) \n"
676 		"   sync                          \n"
677 		"   cache 21, (%[state_addr])     \n" /* flush entry of *state_addr */
678 		"   .set pop                      \n"
679 		: [addr] "=&r" (addr), [val] "=&r" (val)
680 		: [state_addr] "r" (state_addr),
681 		  [sets] "r" (cpu_data[smp_processor_id()].dcache.sets),
682 		  [vsets] "r" (cpu_data[smp_processor_id()].vcache.sets));
683 
684 	__asm__ __volatile__(
685 		"   .set push                         \n"
686 		"   .set noreorder                    \n"
687 		"   .set mips64                       \n"
688 		"   mfc0  %[cpuid], $15, 1            \n"
689 		"   andi  %[cpuid], 0x3ff             \n"
690 		"   dli   %[base], 0x900000003ff01000 \n"
691 		"   andi  %[core], %[cpuid], 0x3      \n"
692 		"   sll   %[core], 8                  \n" /* get core id */
693 		"   or    %[base], %[base], %[core]   \n"
694 		"   andi  %[node], %[cpuid], 0xc      \n"
695 		"   dsll  %[node], 42                 \n" /* get node id */
696 		"   or    %[base], %[base], %[node]   \n"
697 		"1: li    %[count], 0x100             \n" /* wait for init loop */
698 		"2: bnez  %[count], 2b                \n" /* limit mailbox access */
699 		"   addiu %[count], -1                \n"
700 		"   ld    %[initfunc], 0x20(%[base])  \n" /* get PC via mailbox */
701 		"   beqz  %[initfunc], 1b             \n"
702 		"   nop                               \n"
703 		"   ld    $sp, 0x28(%[base])          \n" /* get SP via mailbox */
704 		"   ld    $gp, 0x30(%[base])          \n" /* get GP via mailbox */
705 		"   ld    $a1, 0x38(%[base])          \n"
706 		"   jr    %[initfunc]                 \n" /* jump to initial PC */
707 		"   nop                               \n"
708 		"   .set pop                          \n"
709 		: [core] "=&r" (core), [node] "=&r" (node),
710 		  [base] "=&r" (base), [cpuid] "=&r" (cpuid),
711 		  [count] "=&r" (count), [initfunc] "=&r" (initfunc)
712 		: /* No Input */
713 		: "a1");
714 }
715 
716 void play_dead(void)
717 {
718 	int prid_imp, prid_rev, *state_addr;
719 	unsigned int cpu = smp_processor_id();
720 	void (*play_dead_at_ckseg1)(int *);
721 
722 	idle_task_exit();
723 
724 	prid_imp = read_c0_prid() & PRID_IMP_MASK;
725 	prid_rev = read_c0_prid() & PRID_REV_MASK;
726 
727 	if (prid_imp == PRID_IMP_LOONGSON_64G) {
728 		play_dead_at_ckseg1 =
729 			(void *)CKSEG1ADDR((unsigned long)loongson3_type3_play_dead);
730 		goto out;
731 	}
732 
733 	switch (prid_rev) {
734 	case PRID_REV_LOONGSON3A_R1:
735 	default:
736 		play_dead_at_ckseg1 =
737 			(void *)CKSEG1ADDR((unsigned long)loongson3_type1_play_dead);
738 		break;
739 	case PRID_REV_LOONGSON3B_R1:
740 	case PRID_REV_LOONGSON3B_R2:
741 		play_dead_at_ckseg1 =
742 			(void *)CKSEG1ADDR((unsigned long)loongson3_type2_play_dead);
743 		break;
744 	case PRID_REV_LOONGSON3A_R2_0:
745 	case PRID_REV_LOONGSON3A_R2_1:
746 	case PRID_REV_LOONGSON3A_R3_0:
747 	case PRID_REV_LOONGSON3A_R3_1:
748 		play_dead_at_ckseg1 =
749 			(void *)CKSEG1ADDR((unsigned long)loongson3_type3_play_dead);
750 		break;
751 	}
752 
753 out:
754 	state_addr = &per_cpu(cpu_state, cpu);
755 	mb();
756 	play_dead_at_ckseg1(state_addr);
757 }
758 
759 static int loongson3_disable_clock(unsigned int cpu)
760 {
761 	uint64_t core_id = cpu_core(&cpu_data[cpu]);
762 	uint64_t package_id = cpu_data[cpu].package;
763 
764 	if ((read_c0_prid() & PRID_REV_MASK) == PRID_REV_LOONGSON3A_R1) {
765 		LOONGSON_CHIPCFG(package_id) &= ~(1 << (12 + core_id));
766 	} else {
767 		if (!(loongson_sysconf.workarounds & WORKAROUND_CPUHOTPLUG))
768 			LOONGSON_FREQCTRL(package_id) &= ~(1 << (core_id * 4 + 3));
769 	}
770 	return 0;
771 }
772 
773 static int loongson3_enable_clock(unsigned int cpu)
774 {
775 	uint64_t core_id = cpu_core(&cpu_data[cpu]);
776 	uint64_t package_id = cpu_data[cpu].package;
777 
778 	if ((read_c0_prid() & PRID_REV_MASK) == PRID_REV_LOONGSON3A_R1) {
779 		LOONGSON_CHIPCFG(package_id) |= 1 << (12 + core_id);
780 	} else {
781 		if (!(loongson_sysconf.workarounds & WORKAROUND_CPUHOTPLUG))
782 			LOONGSON_FREQCTRL(package_id) |= 1 << (core_id * 4 + 3);
783 	}
784 	return 0;
785 }
786 
787 static int register_loongson3_notifier(void)
788 {
789 	return cpuhp_setup_state_nocalls(CPUHP_MIPS_SOC_PREPARE,
790 					 "mips/loongson:prepare",
791 					 loongson3_enable_clock,
792 					 loongson3_disable_clock);
793 }
794 early_initcall(register_loongson3_notifier);
795 
796 #endif
797 
798 const struct plat_smp_ops loongson3_smp_ops = {
799 	.send_ipi_single = loongson3_send_ipi_single,
800 	.send_ipi_mask = loongson3_send_ipi_mask,
801 	.init_secondary = loongson3_init_secondary,
802 	.smp_finish = loongson3_smp_finish,
803 	.boot_secondary = loongson3_boot_secondary,
804 	.smp_setup = loongson3_smp_setup,
805 	.prepare_cpus = loongson3_prepare_cpus,
806 #ifdef CONFIG_HOTPLUG_CPU
807 	.cpu_disable = loongson3_cpu_disable,
808 	.cpu_die = loongson3_cpu_die,
809 #endif
810 #ifdef CONFIG_KEXEC
811 	.kexec_nonboot_cpu = kexec_nonboot_cpu_jump,
812 #endif
813 };
814