xref: /openbmc/linux/arch/mips/loongson64/smp.c (revision 52cdded0)
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/time.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 #define LS_IPI_IRQ (MIPS_CPU_IRQ_BASE + 6)
29 
30 static void *ipi_set0_regs[16];
31 static void *ipi_clear0_regs[16];
32 static void *ipi_status0_regs[16];
33 static void *ipi_en0_regs[16];
34 static void *ipi_mailbox_buf[16];
35 static uint32_t core0_c0count[NR_CPUS];
36 
37 /* read a 32bit value from ipi register */
38 #define loongson3_ipi_read32(addr) readl(addr)
39 /* read a 64bit value from ipi register */
40 #define loongson3_ipi_read64(addr) readq(addr)
41 /* write a 32bit value to ipi register */
42 #define loongson3_ipi_write32(action, addr)	\
43 	do {					\
44 		writel(action, addr);		\
45 		__wbflush();			\
46 	} while (0)
47 /* write a 64bit value to ipi register */
48 #define loongson3_ipi_write64(action, addr)	\
49 	do {					\
50 		writeq(action, addr);		\
51 		__wbflush();			\
52 	} while (0)
53 
54 u32 (*ipi_read_clear)(int cpu);
55 void (*ipi_write_action)(int cpu, u32 action);
56 
57 static u32 csr_ipi_read_clear(int cpu)
58 {
59 	u32 action;
60 
61 	/* Load the ipi register to figure out what we're supposed to do */
62 	action = csr_readl(LOONGSON_CSR_IPI_STATUS);
63 	/* Clear the ipi register to clear the interrupt */
64 	csr_writel(action, LOONGSON_CSR_IPI_CLEAR);
65 
66 	return action;
67 }
68 
69 static void csr_ipi_write_action(int cpu, u32 action)
70 {
71 	unsigned int irq = 0;
72 
73 	while ((irq = ffs(action))) {
74 		uint32_t val = CSR_IPI_SEND_BLOCK;
75 		val |= (irq - 1);
76 		val |= (cpu << CSR_IPI_SEND_CPU_SHIFT);
77 		csr_writel(val, LOONGSON_CSR_IPI_SEND);
78 		action &= ~BIT(irq - 1);
79 	}
80 }
81 
82 static u32 legacy_ipi_read_clear(int cpu)
83 {
84 	u32 action;
85 
86 	/* Load the ipi register to figure out what we're supposed to do */
87 	action = loongson3_ipi_read32(ipi_status0_regs[cpu_logical_map(cpu)]);
88 	/* Clear the ipi register to clear the interrupt */
89 	loongson3_ipi_write32(action, ipi_clear0_regs[cpu_logical_map(cpu)]);
90 
91 	return action;
92 }
93 
94 static void legacy_ipi_write_action(int cpu, u32 action)
95 {
96 	loongson3_ipi_write32((u32)action, ipi_set0_regs[cpu]);
97 }
98 
99 static void csr_ipi_probe(void)
100 {
101 	if (cpu_has_csr() && csr_readl(LOONGSON_CSR_FEATURES) & LOONGSON_CSRF_IPI) {
102 		ipi_read_clear = csr_ipi_read_clear;
103 		ipi_write_action = csr_ipi_write_action;
104 	} else {
105 		ipi_read_clear = legacy_ipi_read_clear;
106 		ipi_write_action = legacy_ipi_write_action;
107 	}
108 }
109 
110 static void ipi_set0_regs_init(void)
111 {
112 	ipi_set0_regs[0] = (void *)
113 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + SET0);
114 	ipi_set0_regs[1] = (void *)
115 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + SET0);
116 	ipi_set0_regs[2] = (void *)
117 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + SET0);
118 	ipi_set0_regs[3] = (void *)
119 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + SET0);
120 	ipi_set0_regs[4] = (void *)
121 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + SET0);
122 	ipi_set0_regs[5] = (void *)
123 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + SET0);
124 	ipi_set0_regs[6] = (void *)
125 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + SET0);
126 	ipi_set0_regs[7] = (void *)
127 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + SET0);
128 	ipi_set0_regs[8] = (void *)
129 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + SET0);
130 	ipi_set0_regs[9] = (void *)
131 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + SET0);
132 	ipi_set0_regs[10] = (void *)
133 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + SET0);
134 	ipi_set0_regs[11] = (void *)
135 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + SET0);
136 	ipi_set0_regs[12] = (void *)
137 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + SET0);
138 	ipi_set0_regs[13] = (void *)
139 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + SET0);
140 	ipi_set0_regs[14] = (void *)
141 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + SET0);
142 	ipi_set0_regs[15] = (void *)
143 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + SET0);
144 }
145 
146 static void ipi_clear0_regs_init(void)
147 {
148 	ipi_clear0_regs[0] = (void *)
149 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + CLEAR0);
150 	ipi_clear0_regs[1] = (void *)
151 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + CLEAR0);
152 	ipi_clear0_regs[2] = (void *)
153 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + CLEAR0);
154 	ipi_clear0_regs[3] = (void *)
155 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + CLEAR0);
156 	ipi_clear0_regs[4] = (void *)
157 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + CLEAR0);
158 	ipi_clear0_regs[5] = (void *)
159 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + CLEAR0);
160 	ipi_clear0_regs[6] = (void *)
161 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + CLEAR0);
162 	ipi_clear0_regs[7] = (void *)
163 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + CLEAR0);
164 	ipi_clear0_regs[8] = (void *)
165 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + CLEAR0);
166 	ipi_clear0_regs[9] = (void *)
167 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + CLEAR0);
168 	ipi_clear0_regs[10] = (void *)
169 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + CLEAR0);
170 	ipi_clear0_regs[11] = (void *)
171 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + CLEAR0);
172 	ipi_clear0_regs[12] = (void *)
173 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + CLEAR0);
174 	ipi_clear0_regs[13] = (void *)
175 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + CLEAR0);
176 	ipi_clear0_regs[14] = (void *)
177 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + CLEAR0);
178 	ipi_clear0_regs[15] = (void *)
179 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + CLEAR0);
180 }
181 
182 static void ipi_status0_regs_init(void)
183 {
184 	ipi_status0_regs[0] = (void *)
185 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + STATUS0);
186 	ipi_status0_regs[1] = (void *)
187 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + STATUS0);
188 	ipi_status0_regs[2] = (void *)
189 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + STATUS0);
190 	ipi_status0_regs[3] = (void *)
191 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + STATUS0);
192 	ipi_status0_regs[4] = (void *)
193 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + STATUS0);
194 	ipi_status0_regs[5] = (void *)
195 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + STATUS0);
196 	ipi_status0_regs[6] = (void *)
197 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + STATUS0);
198 	ipi_status0_regs[7] = (void *)
199 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + STATUS0);
200 	ipi_status0_regs[8] = (void *)
201 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + STATUS0);
202 	ipi_status0_regs[9] = (void *)
203 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + STATUS0);
204 	ipi_status0_regs[10] = (void *)
205 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + STATUS0);
206 	ipi_status0_regs[11] = (void *)
207 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + STATUS0);
208 	ipi_status0_regs[12] = (void *)
209 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + STATUS0);
210 	ipi_status0_regs[13] = (void *)
211 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + STATUS0);
212 	ipi_status0_regs[14] = (void *)
213 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + STATUS0);
214 	ipi_status0_regs[15] = (void *)
215 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + STATUS0);
216 }
217 
218 static void ipi_en0_regs_init(void)
219 {
220 	ipi_en0_regs[0] = (void *)
221 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + EN0);
222 	ipi_en0_regs[1] = (void *)
223 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + EN0);
224 	ipi_en0_regs[2] = (void *)
225 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + EN0);
226 	ipi_en0_regs[3] = (void *)
227 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + EN0);
228 	ipi_en0_regs[4] = (void *)
229 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + EN0);
230 	ipi_en0_regs[5] = (void *)
231 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + EN0);
232 	ipi_en0_regs[6] = (void *)
233 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + EN0);
234 	ipi_en0_regs[7] = (void *)
235 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + EN0);
236 	ipi_en0_regs[8] = (void *)
237 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + EN0);
238 	ipi_en0_regs[9] = (void *)
239 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + EN0);
240 	ipi_en0_regs[10] = (void *)
241 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + EN0);
242 	ipi_en0_regs[11] = (void *)
243 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + EN0);
244 	ipi_en0_regs[12] = (void *)
245 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + EN0);
246 	ipi_en0_regs[13] = (void *)
247 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + EN0);
248 	ipi_en0_regs[14] = (void *)
249 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + EN0);
250 	ipi_en0_regs[15] = (void *)
251 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + EN0);
252 }
253 
254 static void ipi_mailbox_buf_init(void)
255 {
256 	ipi_mailbox_buf[0] = (void *)
257 		(SMP_CORE_GROUP0_BASE + SMP_CORE0_OFFSET + BUF);
258 	ipi_mailbox_buf[1] = (void *)
259 		(SMP_CORE_GROUP0_BASE + SMP_CORE1_OFFSET + BUF);
260 	ipi_mailbox_buf[2] = (void *)
261 		(SMP_CORE_GROUP0_BASE + SMP_CORE2_OFFSET + BUF);
262 	ipi_mailbox_buf[3] = (void *)
263 		(SMP_CORE_GROUP0_BASE + SMP_CORE3_OFFSET + BUF);
264 	ipi_mailbox_buf[4] = (void *)
265 		(SMP_CORE_GROUP1_BASE + SMP_CORE0_OFFSET + BUF);
266 	ipi_mailbox_buf[5] = (void *)
267 		(SMP_CORE_GROUP1_BASE + SMP_CORE1_OFFSET + BUF);
268 	ipi_mailbox_buf[6] = (void *)
269 		(SMP_CORE_GROUP1_BASE + SMP_CORE2_OFFSET + BUF);
270 	ipi_mailbox_buf[7] = (void *)
271 		(SMP_CORE_GROUP1_BASE + SMP_CORE3_OFFSET + BUF);
272 	ipi_mailbox_buf[8] = (void *)
273 		(SMP_CORE_GROUP2_BASE + SMP_CORE0_OFFSET + BUF);
274 	ipi_mailbox_buf[9] = (void *)
275 		(SMP_CORE_GROUP2_BASE + SMP_CORE1_OFFSET + BUF);
276 	ipi_mailbox_buf[10] = (void *)
277 		(SMP_CORE_GROUP2_BASE + SMP_CORE2_OFFSET + BUF);
278 	ipi_mailbox_buf[11] = (void *)
279 		(SMP_CORE_GROUP2_BASE + SMP_CORE3_OFFSET + BUF);
280 	ipi_mailbox_buf[12] = (void *)
281 		(SMP_CORE_GROUP3_BASE + SMP_CORE0_OFFSET + BUF);
282 	ipi_mailbox_buf[13] = (void *)
283 		(SMP_CORE_GROUP3_BASE + SMP_CORE1_OFFSET + BUF);
284 	ipi_mailbox_buf[14] = (void *)
285 		(SMP_CORE_GROUP3_BASE + SMP_CORE2_OFFSET + BUF);
286 	ipi_mailbox_buf[15] = (void *)
287 		(SMP_CORE_GROUP3_BASE + SMP_CORE3_OFFSET + BUF);
288 }
289 
290 /*
291  * Simple enough, just poke the appropriate ipi register
292  */
293 static void loongson3_send_ipi_single(int cpu, unsigned int action)
294 {
295 	ipi_write_action(cpu_logical_map(cpu), (u32)action);
296 }
297 
298 static void
299 loongson3_send_ipi_mask(const struct cpumask *mask, unsigned int action)
300 {
301 	unsigned int i;
302 
303 	for_each_cpu(i, mask)
304 		ipi_write_action(cpu_logical_map(i), (u32)action);
305 }
306 
307 
308 static irqreturn_t loongson3_ipi_interrupt(int irq, void *dev_id)
309 {
310 	int i, cpu = smp_processor_id();
311 	unsigned int action, c0count;
312 
313 	action = ipi_read_clear(cpu);
314 
315 	if (action & SMP_RESCHEDULE_YOURSELF)
316 		scheduler_ipi();
317 
318 	if (action & SMP_CALL_FUNCTION) {
319 		irq_enter();
320 		generic_smp_call_function_interrupt();
321 		irq_exit();
322 	}
323 
324 	if (action & SMP_ASK_C0COUNT) {
325 		BUG_ON(cpu != 0);
326 		c0count = read_c0_count();
327 		c0count = c0count ? c0count : 1;
328 		for (i = 1; i < nr_cpu_ids; i++)
329 			core0_c0count[i] = c0count;
330 		__wbflush(); /* Let others see the result ASAP */
331 	}
332 
333 	return IRQ_HANDLED;
334 }
335 
336 #define MAX_LOOPS 800
337 /*
338  * SMP init and finish on secondary CPUs
339  */
340 static void loongson3_init_secondary(void)
341 {
342 	int i;
343 	uint32_t initcount;
344 	unsigned int cpu = smp_processor_id();
345 	unsigned int imask = STATUSF_IP7 | STATUSF_IP6 |
346 			     STATUSF_IP3 | STATUSF_IP2;
347 
348 	/* Set interrupt mask, but don't enable */
349 	change_c0_status(ST0_IM, imask);
350 
351 	for (i = 0; i < num_possible_cpus(); i++)
352 		loongson3_ipi_write32(0xffffffff, ipi_en0_regs[cpu_logical_map(i)]);
353 
354 	per_cpu(cpu_state, cpu) = CPU_ONLINE;
355 	cpu_set_core(&cpu_data[cpu],
356 		     cpu_logical_map(cpu) % loongson_sysconf.cores_per_package);
357 	cpu_data[cpu].package =
358 		cpu_logical_map(cpu) / loongson_sysconf.cores_per_package;
359 
360 	i = 0;
361 	core0_c0count[cpu] = 0;
362 	loongson3_send_ipi_single(0, SMP_ASK_C0COUNT);
363 	while (!core0_c0count[cpu]) {
364 		i++;
365 		cpu_relax();
366 	}
367 
368 	if (i > MAX_LOOPS)
369 		i = MAX_LOOPS;
370 	if (cpu_data[cpu].package)
371 		initcount = core0_c0count[cpu] + i;
372 	else /* Local access is faster for loops */
373 		initcount = core0_c0count[cpu] + i/2;
374 
375 	write_c0_count(initcount);
376 }
377 
378 static void loongson3_smp_finish(void)
379 {
380 	int cpu = smp_processor_id();
381 
382 	write_c0_compare(read_c0_count() + mips_hpt_frequency/HZ);
383 	local_irq_enable();
384 	loongson3_ipi_write64(0,
385 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x0);
386 	pr_info("CPU#%d finished, CP0_ST=%x\n",
387 			smp_processor_id(), read_c0_status());
388 }
389 
390 static void __init loongson3_smp_setup(void)
391 {
392 	int i = 0, num = 0; /* i: physical id, num: logical id */
393 
394 	init_cpu_possible(cpu_none_mask);
395 
396 	/* For unified kernel, NR_CPUS is the maximum possible value,
397 	 * loongson_sysconf.nr_cpus is the really present value */
398 	while (i < loongson_sysconf.nr_cpus) {
399 		if (loongson_sysconf.reserved_cpus_mask & (1<<i)) {
400 			/* Reserved physical CPU cores */
401 			__cpu_number_map[i] = -1;
402 		} else {
403 			__cpu_number_map[i] = num;
404 			__cpu_logical_map[num] = i;
405 			set_cpu_possible(num, true);
406 			num++;
407 		}
408 		i++;
409 	}
410 	pr_info("Detected %i available CPU(s)\n", num);
411 
412 	while (num < loongson_sysconf.nr_cpus) {
413 		__cpu_logical_map[num] = -1;
414 		num++;
415 	}
416 
417 	csr_ipi_probe();
418 	ipi_set0_regs_init();
419 	ipi_clear0_regs_init();
420 	ipi_status0_regs_init();
421 	ipi_en0_regs_init();
422 	ipi_mailbox_buf_init();
423 	cpu_set_core(&cpu_data[0],
424 		     cpu_logical_map(0) % loongson_sysconf.cores_per_package);
425 	cpu_data[0].package = cpu_logical_map(0) / loongson_sysconf.cores_per_package;
426 }
427 
428 static void __init loongson3_prepare_cpus(unsigned int max_cpus)
429 {
430 	if (request_irq(LS_IPI_IRQ, loongson3_ipi_interrupt,
431 			IRQF_PERCPU | IRQF_NO_SUSPEND, "SMP_IPI", NULL))
432 		pr_err("Failed to request IPI IRQ\n");
433 	init_cpu_present(cpu_possible_mask);
434 	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
435 }
436 
437 /*
438  * Setup the PC, SP, and GP of a secondary processor and start it runing!
439  */
440 static int loongson3_boot_secondary(int cpu, struct task_struct *idle)
441 {
442 	unsigned long startargs[4];
443 
444 	pr_info("Booting CPU#%d...\n", cpu);
445 
446 	/* startargs[] are initial PC, SP and GP for secondary CPU */
447 	startargs[0] = (unsigned long)&smp_bootstrap;
448 	startargs[1] = (unsigned long)__KSTK_TOS(idle);
449 	startargs[2] = (unsigned long)task_thread_info(idle);
450 	startargs[3] = 0;
451 
452 	pr_debug("CPU#%d, func_pc=%lx, sp=%lx, gp=%lx\n",
453 			cpu, startargs[0], startargs[1], startargs[2]);
454 
455 	loongson3_ipi_write64(startargs[3],
456 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x18);
457 	loongson3_ipi_write64(startargs[2],
458 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x10);
459 	loongson3_ipi_write64(startargs[1],
460 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x8);
461 	loongson3_ipi_write64(startargs[0],
462 			ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x0);
463 	return 0;
464 }
465 
466 #ifdef CONFIG_HOTPLUG_CPU
467 
468 static int loongson3_cpu_disable(void)
469 {
470 	unsigned long flags;
471 	unsigned int cpu = smp_processor_id();
472 
473 	if (cpu == 0)
474 		return -EBUSY;
475 
476 	set_cpu_online(cpu, false);
477 	calculate_cpu_foreign_map();
478 	local_irq_save(flags);
479 	irq_cpu_offline();
480 	clear_c0_status(ST0_IM);
481 	local_irq_restore(flags);
482 	local_flush_tlb_all();
483 
484 	return 0;
485 }
486 
487 
488 static void loongson3_cpu_die(unsigned int cpu)
489 {
490 	while (per_cpu(cpu_state, cpu) != CPU_DEAD)
491 		cpu_relax();
492 
493 	mb();
494 }
495 
496 /* To shutdown a core in Loongson 3, the target core should go to CKSEG1 and
497  * flush all L1 entries at first. Then, another core (usually Core 0) can
498  * safely disable the clock of the target core. loongson3_play_dead() is
499  * called via CKSEG1 (uncached and unmmaped) */
500 static void loongson3_type1_play_dead(int *state_addr)
501 {
502 	register int val;
503 	register long cpuid, core, node, count;
504 	register void *addr, *base, *initfunc;
505 
506 	__asm__ __volatile__(
507 		"   .set push                     \n"
508 		"   .set noreorder                \n"
509 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
510 		"1: cache 0, 0(%[addr])           \n" /* flush L1 ICache */
511 		"   cache 0, 1(%[addr])           \n"
512 		"   cache 0, 2(%[addr])           \n"
513 		"   cache 0, 3(%[addr])           \n"
514 		"   cache 1, 0(%[addr])           \n" /* flush L1 DCache */
515 		"   cache 1, 1(%[addr])           \n"
516 		"   cache 1, 2(%[addr])           \n"
517 		"   cache 1, 3(%[addr])           \n"
518 		"   addiu %[sets], %[sets], -1    \n"
519 		"   bnez  %[sets], 1b             \n"
520 		"   addiu %[addr], %[addr], 0x20  \n"
521 		"   li    %[val], 0x7             \n" /* *state_addr = CPU_DEAD; */
522 		"   sw    %[val], (%[state_addr]) \n"
523 		"   sync                          \n"
524 		"   cache 21, (%[state_addr])     \n" /* flush entry of *state_addr */
525 		"   .set pop                      \n"
526 		: [addr] "=&r" (addr), [val] "=&r" (val)
527 		: [state_addr] "r" (state_addr),
528 		  [sets] "r" (cpu_data[smp_processor_id()].dcache.sets));
529 
530 	__asm__ __volatile__(
531 		"   .set push                         \n"
532 		"   .set noreorder                    \n"
533 		"   .set mips64                       \n"
534 		"   mfc0  %[cpuid], $15, 1            \n"
535 		"   andi  %[cpuid], 0x3ff             \n"
536 		"   dli   %[base], 0x900000003ff01000 \n"
537 		"   andi  %[core], %[cpuid], 0x3      \n"
538 		"   sll   %[core], 8                  \n" /* get core id */
539 		"   or    %[base], %[base], %[core]   \n"
540 		"   andi  %[node], %[cpuid], 0xc      \n"
541 		"   dsll  %[node], 42                 \n" /* get node id */
542 		"   or    %[base], %[base], %[node]   \n"
543 		"1: li    %[count], 0x100             \n" /* wait for init loop */
544 		"2: bnez  %[count], 2b                \n" /* limit mailbox access */
545 		"   addiu %[count], -1                \n"
546 		"   ld    %[initfunc], 0x20(%[base])  \n" /* get PC via mailbox */
547 		"   beqz  %[initfunc], 1b             \n"
548 		"   nop                               \n"
549 		"   ld    $sp, 0x28(%[base])          \n" /* get SP via mailbox */
550 		"   ld    $gp, 0x30(%[base])          \n" /* get GP via mailbox */
551 		"   ld    $a1, 0x38(%[base])          \n"
552 		"   jr    %[initfunc]                 \n" /* jump to initial PC */
553 		"   nop                               \n"
554 		"   .set pop                          \n"
555 		: [core] "=&r" (core), [node] "=&r" (node),
556 		  [base] "=&r" (base), [cpuid] "=&r" (cpuid),
557 		  [count] "=&r" (count), [initfunc] "=&r" (initfunc)
558 		: /* No Input */
559 		: "a1");
560 }
561 
562 static void loongson3_type2_play_dead(int *state_addr)
563 {
564 	register int val;
565 	register long cpuid, core, node, count;
566 	register void *addr, *base, *initfunc;
567 
568 	__asm__ __volatile__(
569 		"   .set push                     \n"
570 		"   .set noreorder                \n"
571 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
572 		"1: cache 0, 0(%[addr])           \n" /* flush L1 ICache */
573 		"   cache 0, 1(%[addr])           \n"
574 		"   cache 0, 2(%[addr])           \n"
575 		"   cache 0, 3(%[addr])           \n"
576 		"   cache 1, 0(%[addr])           \n" /* flush L1 DCache */
577 		"   cache 1, 1(%[addr])           \n"
578 		"   cache 1, 2(%[addr])           \n"
579 		"   cache 1, 3(%[addr])           \n"
580 		"   addiu %[sets], %[sets], -1    \n"
581 		"   bnez  %[sets], 1b             \n"
582 		"   addiu %[addr], %[addr], 0x20  \n"
583 		"   li    %[val], 0x7             \n" /* *state_addr = CPU_DEAD; */
584 		"   sw    %[val], (%[state_addr]) \n"
585 		"   sync                          \n"
586 		"   cache 21, (%[state_addr])     \n" /* flush entry of *state_addr */
587 		"   .set pop                      \n"
588 		: [addr] "=&r" (addr), [val] "=&r" (val)
589 		: [state_addr] "r" (state_addr),
590 		  [sets] "r" (cpu_data[smp_processor_id()].dcache.sets));
591 
592 	__asm__ __volatile__(
593 		"   .set push                         \n"
594 		"   .set noreorder                    \n"
595 		"   .set mips64                       \n"
596 		"   mfc0  %[cpuid], $15, 1            \n"
597 		"   andi  %[cpuid], 0x3ff             \n"
598 		"   dli   %[base], 0x900000003ff01000 \n"
599 		"   andi  %[core], %[cpuid], 0x3      \n"
600 		"   sll   %[core], 8                  \n" /* get core id */
601 		"   or    %[base], %[base], %[core]   \n"
602 		"   andi  %[node], %[cpuid], 0xc      \n"
603 		"   dsll  %[node], 42                 \n" /* get node id */
604 		"   or    %[base], %[base], %[node]   \n"
605 		"   dsrl  %[node], 30                 \n" /* 15:14 */
606 		"   or    %[base], %[base], %[node]   \n"
607 		"1: li    %[count], 0x100             \n" /* wait for init loop */
608 		"2: bnez  %[count], 2b                \n" /* limit mailbox access */
609 		"   addiu %[count], -1                \n"
610 		"   ld    %[initfunc], 0x20(%[base])  \n" /* get PC via mailbox */
611 		"   beqz  %[initfunc], 1b             \n"
612 		"   nop                               \n"
613 		"   ld    $sp, 0x28(%[base])          \n" /* get SP via mailbox */
614 		"   ld    $gp, 0x30(%[base])          \n" /* get GP via mailbox */
615 		"   ld    $a1, 0x38(%[base])          \n"
616 		"   jr    %[initfunc]                 \n" /* jump to initial PC */
617 		"   nop                               \n"
618 		"   .set pop                          \n"
619 		: [core] "=&r" (core), [node] "=&r" (node),
620 		  [base] "=&r" (base), [cpuid] "=&r" (cpuid),
621 		  [count] "=&r" (count), [initfunc] "=&r" (initfunc)
622 		: /* No Input */
623 		: "a1");
624 }
625 
626 static void loongson3_type3_play_dead(int *state_addr)
627 {
628 	register int val;
629 	register long cpuid, core, node, count;
630 	register void *addr, *base, *initfunc;
631 
632 	__asm__ __volatile__(
633 		"   .set push                     \n"
634 		"   .set noreorder                \n"
635 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
636 		"1: cache 0, 0(%[addr])           \n" /* flush L1 ICache */
637 		"   cache 0, 1(%[addr])           \n"
638 		"   cache 0, 2(%[addr])           \n"
639 		"   cache 0, 3(%[addr])           \n"
640 		"   cache 1, 0(%[addr])           \n" /* flush L1 DCache */
641 		"   cache 1, 1(%[addr])           \n"
642 		"   cache 1, 2(%[addr])           \n"
643 		"   cache 1, 3(%[addr])           \n"
644 		"   addiu %[sets], %[sets], -1    \n"
645 		"   bnez  %[sets], 1b             \n"
646 		"   addiu %[addr], %[addr], 0x40  \n"
647 		"   li %[addr], 0x80000000        \n" /* KSEG0 */
648 		"2: cache 2, 0(%[addr])           \n" /* flush L1 VCache */
649 		"   cache 2, 1(%[addr])           \n"
650 		"   cache 2, 2(%[addr])           \n"
651 		"   cache 2, 3(%[addr])           \n"
652 		"   cache 2, 4(%[addr])           \n"
653 		"   cache 2, 5(%[addr])           \n"
654 		"   cache 2, 6(%[addr])           \n"
655 		"   cache 2, 7(%[addr])           \n"
656 		"   cache 2, 8(%[addr])           \n"
657 		"   cache 2, 9(%[addr])           \n"
658 		"   cache 2, 10(%[addr])          \n"
659 		"   cache 2, 11(%[addr])          \n"
660 		"   cache 2, 12(%[addr])          \n"
661 		"   cache 2, 13(%[addr])          \n"
662 		"   cache 2, 14(%[addr])          \n"
663 		"   cache 2, 15(%[addr])          \n"
664 		"   addiu %[vsets], %[vsets], -1  \n"
665 		"   bnez  %[vsets], 2b            \n"
666 		"   addiu %[addr], %[addr], 0x40  \n"
667 		"   li    %[val], 0x7             \n" /* *state_addr = CPU_DEAD; */
668 		"   sw    %[val], (%[state_addr]) \n"
669 		"   sync                          \n"
670 		"   cache 21, (%[state_addr])     \n" /* flush entry of *state_addr */
671 		"   .set pop                      \n"
672 		: [addr] "=&r" (addr), [val] "=&r" (val)
673 		: [state_addr] "r" (state_addr),
674 		  [sets] "r" (cpu_data[smp_processor_id()].dcache.sets),
675 		  [vsets] "r" (cpu_data[smp_processor_id()].vcache.sets));
676 
677 	__asm__ __volatile__(
678 		"   .set push                         \n"
679 		"   .set noreorder                    \n"
680 		"   .set mips64                       \n"
681 		"   mfc0  %[cpuid], $15, 1            \n"
682 		"   andi  %[cpuid], 0x3ff             \n"
683 		"   dli   %[base], 0x900000003ff01000 \n"
684 		"   andi  %[core], %[cpuid], 0x3      \n"
685 		"   sll   %[core], 8                  \n" /* get core id */
686 		"   or    %[base], %[base], %[core]   \n"
687 		"   andi  %[node], %[cpuid], 0xc      \n"
688 		"   dsll  %[node], 42                 \n" /* get node id */
689 		"   or    %[base], %[base], %[node]   \n"
690 		"1: li    %[count], 0x100             \n" /* wait for init loop */
691 		"2: bnez  %[count], 2b                \n" /* limit mailbox access */
692 		"   addiu %[count], -1                \n"
693 		"   ld    %[initfunc], 0x20(%[base])  \n" /* get PC via mailbox */
694 		"   beqz  %[initfunc], 1b             \n"
695 		"   nop                               \n"
696 		"   ld    $sp, 0x28(%[base])          \n" /* get SP via mailbox */
697 		"   ld    $gp, 0x30(%[base])          \n" /* get GP via mailbox */
698 		"   ld    $a1, 0x38(%[base])          \n"
699 		"   jr    %[initfunc]                 \n" /* jump to initial PC */
700 		"   nop                               \n"
701 		"   .set pop                          \n"
702 		: [core] "=&r" (core), [node] "=&r" (node),
703 		  [base] "=&r" (base), [cpuid] "=&r" (cpuid),
704 		  [count] "=&r" (count), [initfunc] "=&r" (initfunc)
705 		: /* No Input */
706 		: "a1");
707 }
708 
709 void play_dead(void)
710 {
711 	int prid_imp, prid_rev, *state_addr;
712 	unsigned int cpu = smp_processor_id();
713 	void (*play_dead_at_ckseg1)(int *);
714 
715 	idle_task_exit();
716 
717 	prid_imp = read_c0_prid() & PRID_IMP_MASK;
718 	prid_rev = read_c0_prid() & PRID_REV_MASK;
719 
720 	if (prid_imp == PRID_IMP_LOONGSON_64G) {
721 		play_dead_at_ckseg1 =
722 			(void *)CKSEG1ADDR((unsigned long)loongson3_type3_play_dead);
723 		goto out;
724 	}
725 
726 	switch (prid_rev) {
727 	case PRID_REV_LOONGSON3A_R1:
728 	default:
729 		play_dead_at_ckseg1 =
730 			(void *)CKSEG1ADDR((unsigned long)loongson3_type1_play_dead);
731 		break;
732 	case PRID_REV_LOONGSON3B_R1:
733 	case PRID_REV_LOONGSON3B_R2:
734 		play_dead_at_ckseg1 =
735 			(void *)CKSEG1ADDR((unsigned long)loongson3_type2_play_dead);
736 		break;
737 	case PRID_REV_LOONGSON3A_R2_0:
738 	case PRID_REV_LOONGSON3A_R2_1:
739 	case PRID_REV_LOONGSON3A_R3_0:
740 	case PRID_REV_LOONGSON3A_R3_1:
741 		play_dead_at_ckseg1 =
742 			(void *)CKSEG1ADDR((unsigned long)loongson3_type3_play_dead);
743 		break;
744 	}
745 
746 out:
747 	state_addr = &per_cpu(cpu_state, cpu);
748 	mb();
749 	play_dead_at_ckseg1(state_addr);
750 }
751 
752 static int loongson3_disable_clock(unsigned int cpu)
753 {
754 	uint64_t core_id = cpu_core(&cpu_data[cpu]);
755 	uint64_t package_id = cpu_data[cpu].package;
756 
757 	if ((read_c0_prid() & PRID_REV_MASK) == PRID_REV_LOONGSON3A_R1) {
758 		LOONGSON_CHIPCFG(package_id) &= ~(1 << (12 + core_id));
759 	} else {
760 		if (!(loongson_sysconf.workarounds & WORKAROUND_CPUHOTPLUG))
761 			LOONGSON_FREQCTRL(package_id) &= ~(1 << (core_id * 4 + 3));
762 	}
763 	return 0;
764 }
765 
766 static int loongson3_enable_clock(unsigned int cpu)
767 {
768 	uint64_t core_id = cpu_core(&cpu_data[cpu]);
769 	uint64_t package_id = cpu_data[cpu].package;
770 
771 	if ((read_c0_prid() & PRID_REV_MASK) == PRID_REV_LOONGSON3A_R1) {
772 		LOONGSON_CHIPCFG(package_id) |= 1 << (12 + core_id);
773 	} else {
774 		if (!(loongson_sysconf.workarounds & WORKAROUND_CPUHOTPLUG))
775 			LOONGSON_FREQCTRL(package_id) |= 1 << (core_id * 4 + 3);
776 	}
777 	return 0;
778 }
779 
780 static int register_loongson3_notifier(void)
781 {
782 	return cpuhp_setup_state_nocalls(CPUHP_MIPS_SOC_PREPARE,
783 					 "mips/loongson:prepare",
784 					 loongson3_enable_clock,
785 					 loongson3_disable_clock);
786 }
787 early_initcall(register_loongson3_notifier);
788 
789 #endif
790 
791 const struct plat_smp_ops loongson3_smp_ops = {
792 	.send_ipi_single = loongson3_send_ipi_single,
793 	.send_ipi_mask = loongson3_send_ipi_mask,
794 	.init_secondary = loongson3_init_secondary,
795 	.smp_finish = loongson3_smp_finish,
796 	.boot_secondary = loongson3_boot_secondary,
797 	.smp_setup = loongson3_smp_setup,
798 	.prepare_cpus = loongson3_prepare_cpus,
799 #ifdef CONFIG_HOTPLUG_CPU
800 	.cpu_disable = loongson3_cpu_disable,
801 	.cpu_die = loongson3_cpu_die,
802 #endif
803 #ifdef CONFIG_KEXEC
804 	.kexec_nonboot_cpu = kexec_nonboot_cpu_jump,
805 #endif
806 };
807