xref: /openbmc/linux/arch/mips/cavium-octeon/smp.c (revision b38269ec)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2004-2008, 2009, 2010 Cavium Networks
7  */
8 #include <linux/cpu.h>
9 #include <linux/delay.h>
10 #include <linux/smp.h>
11 #include <linux/interrupt.h>
12 #include <linux/kernel_stat.h>
13 #include <linux/sched.h>
14 #include <linux/sched/hotplug.h>
15 #include <linux/sched/task_stack.h>
16 #include <linux/init.h>
17 #include <linux/export.h>
18 #include <linux/kexec.h>
19 
20 #include <asm/mmu_context.h>
21 #include <asm/time.h>
22 #include <asm/setup.h>
23 
24 #include <asm/octeon/octeon.h>
25 
26 #include "octeon_boot.h"
27 
28 volatile unsigned long octeon_processor_boot = 0xff;
29 volatile unsigned long octeon_processor_sp;
30 volatile unsigned long octeon_processor_gp;
31 #ifdef CONFIG_RELOCATABLE
32 volatile unsigned long octeon_processor_relocated_kernel_entry;
33 #endif /* CONFIG_RELOCATABLE */
34 
35 #ifdef CONFIG_HOTPLUG_CPU
36 uint64_t octeon_bootloader_entry_addr;
37 EXPORT_SYMBOL(octeon_bootloader_entry_addr);
38 #endif
39 
40 extern void kernel_entry(unsigned long arg1, ...);
41 
42 static void octeon_icache_flush(void)
43 {
44 	asm volatile ("synci 0($0)\n");
45 }
46 
47 static void (*octeon_message_functions[8])(void) = {
48 	scheduler_ipi,
49 	generic_smp_call_function_interrupt,
50 	octeon_icache_flush,
51 };
52 
53 static irqreturn_t mailbox_interrupt(int irq, void *dev_id)
54 {
55 	u64 mbox_clrx = CVMX_CIU_MBOX_CLRX(cvmx_get_core_num());
56 	u64 action;
57 	int i;
58 
59 	/*
60 	 * Make sure the function array initialization remains
61 	 * correct.
62 	 */
63 	BUILD_BUG_ON(SMP_RESCHEDULE_YOURSELF != (1 << 0));
64 	BUILD_BUG_ON(SMP_CALL_FUNCTION       != (1 << 1));
65 	BUILD_BUG_ON(SMP_ICACHE_FLUSH        != (1 << 2));
66 
67 	/*
68 	 * Load the mailbox register to figure out what we're supposed
69 	 * to do.
70 	 */
71 	action = cvmx_read_csr(mbox_clrx);
72 
73 	if (OCTEON_IS_MODEL(OCTEON_CN68XX))
74 		action &= 0xff;
75 	else
76 		action &= 0xffff;
77 
78 	/* Clear the mailbox to clear the interrupt */
79 	cvmx_write_csr(mbox_clrx, action);
80 
81 	for (i = 0; i < ARRAY_SIZE(octeon_message_functions) && action;) {
82 		if (action & 1) {
83 			void (*fn)(void) = octeon_message_functions[i];
84 
85 			if (fn)
86 				fn();
87 		}
88 		action >>= 1;
89 		i++;
90 	}
91 	return IRQ_HANDLED;
92 }
93 
94 /*
95  * Cause the function described by call_data to be executed on the passed
96  * cpu.	 When the function has finished, increment the finished field of
97  * call_data.
98  */
99 void octeon_send_ipi_single(int cpu, unsigned int action)
100 {
101 	int coreid = cpu_logical_map(cpu);
102 	/*
103 	pr_info("SMP: Mailbox send cpu=%d, coreid=%d, action=%u\n", cpu,
104 	       coreid, action);
105 	*/
106 	cvmx_write_csr(CVMX_CIU_MBOX_SETX(coreid), action);
107 }
108 
109 static inline void octeon_send_ipi_mask(const struct cpumask *mask,
110 					unsigned int action)
111 {
112 	unsigned int i;
113 
114 	for_each_cpu(i, mask)
115 		octeon_send_ipi_single(i, action);
116 }
117 
118 /*
119  * Detect available CPUs, populate cpu_possible_mask
120  */
121 static void octeon_smp_hotplug_setup(void)
122 {
123 #ifdef CONFIG_HOTPLUG_CPU
124 	struct linux_app_boot_info *labi;
125 
126 	if (!setup_max_cpus)
127 		return;
128 
129 	labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
130 	if (labi->labi_signature != LABI_SIGNATURE) {
131 		pr_info("The bootloader on this board does not support HOTPLUG_CPU.");
132 		return;
133 	}
134 
135 	octeon_bootloader_entry_addr = labi->InitTLBStart_addr;
136 #endif
137 }
138 
139 static void __init octeon_smp_setup(void)
140 {
141 	const int coreid = cvmx_get_core_num();
142 	int cpus;
143 	int id;
144 	struct cvmx_sysinfo *sysinfo = cvmx_sysinfo_get();
145 
146 #ifdef CONFIG_HOTPLUG_CPU
147 	int core_mask = octeon_get_boot_coremask();
148 	unsigned int num_cores = cvmx_octeon_num_cores();
149 #endif
150 
151 	/* The present CPUs are initially just the boot cpu (CPU 0). */
152 	for (id = 0; id < NR_CPUS; id++) {
153 		set_cpu_possible(id, id == 0);
154 		set_cpu_present(id, id == 0);
155 	}
156 
157 	__cpu_number_map[coreid] = 0;
158 	__cpu_logical_map[0] = coreid;
159 
160 	/* The present CPUs get the lowest CPU numbers. */
161 	cpus = 1;
162 	for (id = 0; id < NR_CPUS; id++) {
163 		if ((id != coreid) && cvmx_coremask_is_core_set(&sysinfo->core_mask, id)) {
164 			set_cpu_possible(cpus, true);
165 			set_cpu_present(cpus, true);
166 			__cpu_number_map[id] = cpus;
167 			__cpu_logical_map[cpus] = id;
168 			cpus++;
169 		}
170 	}
171 
172 #ifdef CONFIG_HOTPLUG_CPU
173 	/*
174 	 * The possible CPUs are all those present on the chip.	 We
175 	 * will assign CPU numbers for possible cores as well.	Cores
176 	 * are always consecutively numberd from 0.
177 	 */
178 	for (id = 0; setup_max_cpus && octeon_bootloader_entry_addr &&
179 		     id < num_cores && id < NR_CPUS; id++) {
180 		if (!(core_mask & (1 << id))) {
181 			set_cpu_possible(cpus, true);
182 			__cpu_number_map[id] = cpus;
183 			__cpu_logical_map[cpus] = id;
184 			cpus++;
185 		}
186 	}
187 #endif
188 
189 	octeon_smp_hotplug_setup();
190 }
191 
192 
193 #ifdef CONFIG_RELOCATABLE
194 int plat_post_relocation(long offset)
195 {
196 	unsigned long entry = (unsigned long)kernel_entry;
197 
198 	/* Send secondaries into relocated kernel */
199 	octeon_processor_relocated_kernel_entry = entry + offset;
200 
201 	return 0;
202 }
203 #endif /* CONFIG_RELOCATABLE */
204 
205 /*
206  * Firmware CPU startup hook
207  */
208 static int octeon_boot_secondary(int cpu, struct task_struct *idle)
209 {
210 	int count;
211 
212 	pr_info("SMP: Booting CPU%02d (CoreId %2d)...\n", cpu,
213 		cpu_logical_map(cpu));
214 
215 	octeon_processor_sp = __KSTK_TOS(idle);
216 	octeon_processor_gp = (unsigned long)(task_thread_info(idle));
217 	octeon_processor_boot = cpu_logical_map(cpu);
218 	mb();
219 
220 	count = 10000;
221 	while (octeon_processor_sp && count) {
222 		/* Waiting for processor to get the SP and GP */
223 		udelay(1);
224 		count--;
225 	}
226 	if (count == 0) {
227 		pr_err("Secondary boot timeout\n");
228 		return -ETIMEDOUT;
229 	}
230 
231 	return 0;
232 }
233 
234 /*
235  * After we've done initial boot, this function is called to allow the
236  * board code to clean up state, if needed
237  */
238 static void octeon_init_secondary(void)
239 {
240 	unsigned int sr;
241 
242 	sr = set_c0_status(ST0_BEV);
243 	write_c0_ebase((u32)ebase);
244 	write_c0_status(sr);
245 
246 	octeon_check_cpu_bist();
247 	octeon_init_cvmcount();
248 
249 	octeon_irq_setup_secondary();
250 }
251 
252 /*
253  * Callout to firmware before smp_init
254  */
255 static void __init octeon_prepare_cpus(unsigned int max_cpus)
256 {
257 	/*
258 	 * Only the low order mailbox bits are used for IPIs, leave
259 	 * the other bits alone.
260 	 */
261 	cvmx_write_csr(CVMX_CIU_MBOX_CLRX(cvmx_get_core_num()), 0xffff);
262 	if (request_irq(OCTEON_IRQ_MBOX0, mailbox_interrupt,
263 			IRQF_PERCPU | IRQF_NO_THREAD, "SMP-IPI",
264 			mailbox_interrupt)) {
265 		panic("Cannot request_irq(OCTEON_IRQ_MBOX0)");
266 	}
267 }
268 
269 /*
270  * Last chance for the board code to finish SMP initialization before
271  * the CPU is "online".
272  */
273 static void octeon_smp_finish(void)
274 {
275 	octeon_user_io_init();
276 
277 	/* to generate the first CPU timer interrupt */
278 	write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
279 	local_irq_enable();
280 }
281 
282 #ifdef CONFIG_HOTPLUG_CPU
283 
284 /* State of each CPU. */
285 static DEFINE_PER_CPU(int, cpu_state);
286 
287 static int octeon_cpu_disable(void)
288 {
289 	unsigned int cpu = smp_processor_id();
290 
291 	if (!octeon_bootloader_entry_addr)
292 		return -ENOTSUPP;
293 
294 	set_cpu_online(cpu, false);
295 	calculate_cpu_foreign_map();
296 	octeon_fixup_irqs();
297 
298 	__flush_cache_all();
299 	local_flush_tlb_all();
300 
301 	return 0;
302 }
303 
304 static void octeon_cpu_die(unsigned int cpu)
305 {
306 	int coreid = cpu_logical_map(cpu);
307 	uint32_t mask, new_mask;
308 	const struct cvmx_bootmem_named_block_desc *block_desc;
309 
310 	while (per_cpu(cpu_state, cpu) != CPU_DEAD)
311 		cpu_relax();
312 
313 	/*
314 	 * This is a bit complicated strategics of getting/settig available
315 	 * cores mask, copied from bootloader
316 	 */
317 
318 	mask = 1 << coreid;
319 	/* LINUX_APP_BOOT_BLOCK is initialized in bootoct binary */
320 	block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
321 
322 	if (!block_desc) {
323 		struct linux_app_boot_info *labi;
324 
325 		labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
326 
327 		labi->avail_coremask |= mask;
328 		new_mask = labi->avail_coremask;
329 	} else {		       /* alternative, already initialized */
330 		uint32_t *p = (uint32_t *)PHYS_TO_XKSEG_CACHED(block_desc->base_addr +
331 							       AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK);
332 		*p |= mask;
333 		new_mask = *p;
334 	}
335 
336 	pr_info("Reset core %d. Available Coremask = 0x%x \n", coreid, new_mask);
337 	mb();
338 	cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
339 	cvmx_write_csr(CVMX_CIU_PP_RST, 0);
340 }
341 
342 void play_dead(void)
343 {
344 	int cpu = cpu_number_map(cvmx_get_core_num());
345 
346 	idle_task_exit();
347 	octeon_processor_boot = 0xff;
348 	per_cpu(cpu_state, cpu) = CPU_DEAD;
349 
350 	mb();
351 
352 	while (1)	/* core will be reset here */
353 		;
354 }
355 
356 static void start_after_reset(void)
357 {
358 	kernel_entry(0, 0, 0);	/* set a2 = 0 for secondary core */
359 }
360 
361 static int octeon_update_boot_vector(unsigned int cpu)
362 {
363 
364 	int coreid = cpu_logical_map(cpu);
365 	uint32_t avail_coremask;
366 	const struct cvmx_bootmem_named_block_desc *block_desc;
367 	struct boot_init_vector *boot_vect =
368 		(struct boot_init_vector *)PHYS_TO_XKSEG_CACHED(BOOTLOADER_BOOT_VECTOR);
369 
370 	block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
371 
372 	if (!block_desc) {
373 		struct linux_app_boot_info *labi;
374 
375 		labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
376 
377 		avail_coremask = labi->avail_coremask;
378 		labi->avail_coremask &= ~(1 << coreid);
379 	} else {		       /* alternative, already initialized */
380 		avail_coremask = *(uint32_t *)PHYS_TO_XKSEG_CACHED(
381 			block_desc->base_addr + AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK);
382 	}
383 
384 	if (!(avail_coremask & (1 << coreid))) {
385 		/* core not available, assume, that caught by simple-executive */
386 		cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
387 		cvmx_write_csr(CVMX_CIU_PP_RST, 0);
388 	}
389 
390 	boot_vect[coreid].app_start_func_addr =
391 		(uint32_t) (unsigned long) start_after_reset;
392 	boot_vect[coreid].code_addr = octeon_bootloader_entry_addr;
393 
394 	mb();
395 
396 	cvmx_write_csr(CVMX_CIU_NMI, (1 << coreid) & avail_coremask);
397 
398 	return 0;
399 }
400 
401 static int register_cavium_notifier(void)
402 {
403 	return cpuhp_setup_state_nocalls(CPUHP_MIPS_SOC_PREPARE,
404 					 "mips/cavium:prepare",
405 					 octeon_update_boot_vector, NULL);
406 }
407 late_initcall(register_cavium_notifier);
408 
409 #endif	/* CONFIG_HOTPLUG_CPU */
410 
411 static const struct plat_smp_ops octeon_smp_ops = {
412 	.send_ipi_single	= octeon_send_ipi_single,
413 	.send_ipi_mask		= octeon_send_ipi_mask,
414 	.init_secondary		= octeon_init_secondary,
415 	.smp_finish		= octeon_smp_finish,
416 	.boot_secondary		= octeon_boot_secondary,
417 	.smp_setup		= octeon_smp_setup,
418 	.prepare_cpus		= octeon_prepare_cpus,
419 #ifdef CONFIG_HOTPLUG_CPU
420 	.cpu_disable		= octeon_cpu_disable,
421 	.cpu_die		= octeon_cpu_die,
422 #endif
423 #ifdef CONFIG_KEXEC
424 	.kexec_nonboot_cpu	= kexec_nonboot_cpu_jump,
425 #endif
426 };
427 
428 static irqreturn_t octeon_78xx_reched_interrupt(int irq, void *dev_id)
429 {
430 	scheduler_ipi();
431 	return IRQ_HANDLED;
432 }
433 
434 static irqreturn_t octeon_78xx_call_function_interrupt(int irq, void *dev_id)
435 {
436 	generic_smp_call_function_interrupt();
437 	return IRQ_HANDLED;
438 }
439 
440 static irqreturn_t octeon_78xx_icache_flush_interrupt(int irq, void *dev_id)
441 {
442 	octeon_icache_flush();
443 	return IRQ_HANDLED;
444 }
445 
446 /*
447  * Callout to firmware before smp_init
448  */
449 static void octeon_78xx_prepare_cpus(unsigned int max_cpus)
450 {
451 	if (request_irq(OCTEON_IRQ_MBOX0 + 0,
452 			octeon_78xx_reched_interrupt,
453 			IRQF_PERCPU | IRQF_NO_THREAD, "Scheduler",
454 			octeon_78xx_reched_interrupt)) {
455 		panic("Cannot request_irq for SchedulerIPI");
456 	}
457 	if (request_irq(OCTEON_IRQ_MBOX0 + 1,
458 			octeon_78xx_call_function_interrupt,
459 			IRQF_PERCPU | IRQF_NO_THREAD, "SMP-Call",
460 			octeon_78xx_call_function_interrupt)) {
461 		panic("Cannot request_irq for SMP-Call");
462 	}
463 	if (request_irq(OCTEON_IRQ_MBOX0 + 2,
464 			octeon_78xx_icache_flush_interrupt,
465 			IRQF_PERCPU | IRQF_NO_THREAD, "ICache-Flush",
466 			octeon_78xx_icache_flush_interrupt)) {
467 		panic("Cannot request_irq for ICache-Flush");
468 	}
469 }
470 
471 static void octeon_78xx_send_ipi_single(int cpu, unsigned int action)
472 {
473 	int i;
474 
475 	for (i = 0; i < 8; i++) {
476 		if (action & 1)
477 			octeon_ciu3_mbox_send(cpu, i);
478 		action >>= 1;
479 	}
480 }
481 
482 static void octeon_78xx_send_ipi_mask(const struct cpumask *mask,
483 				      unsigned int action)
484 {
485 	unsigned int cpu;
486 
487 	for_each_cpu(cpu, mask)
488 		octeon_78xx_send_ipi_single(cpu, action);
489 }
490 
491 static const struct plat_smp_ops octeon_78xx_smp_ops = {
492 	.send_ipi_single	= octeon_78xx_send_ipi_single,
493 	.send_ipi_mask		= octeon_78xx_send_ipi_mask,
494 	.init_secondary		= octeon_init_secondary,
495 	.smp_finish		= octeon_smp_finish,
496 	.boot_secondary		= octeon_boot_secondary,
497 	.smp_setup		= octeon_smp_setup,
498 	.prepare_cpus		= octeon_78xx_prepare_cpus,
499 #ifdef CONFIG_HOTPLUG_CPU
500 	.cpu_disable		= octeon_cpu_disable,
501 	.cpu_die		= octeon_cpu_die,
502 #endif
503 #ifdef CONFIG_KEXEC
504 	.kexec_nonboot_cpu	= kexec_nonboot_cpu_jump,
505 #endif
506 };
507 
508 void __init octeon_setup_smp(void)
509 {
510 	const struct plat_smp_ops *ops;
511 
512 	if (octeon_has_feature(OCTEON_FEATURE_CIU3))
513 		ops = &octeon_78xx_smp_ops;
514 	else
515 		ops = &octeon_smp_ops;
516 
517 	register_smp_ops(ops);
518 }
519