xref: /linux/arch/mips/cavium-octeon/smp.c (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
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/module.h>
15 
16 #include <asm/mmu_context.h>
17 #include <asm/time.h>
18 #include <asm/setup.h>
19 
20 #include <asm/octeon/octeon.h>
21 
22 #include "octeon_boot.h"
23 
24 volatile unsigned long octeon_processor_boot = 0xff;
25 volatile unsigned long octeon_processor_sp;
26 volatile unsigned long octeon_processor_gp;
27 
28 #ifdef CONFIG_HOTPLUG_CPU
29 uint64_t octeon_bootloader_entry_addr;
30 EXPORT_SYMBOL(octeon_bootloader_entry_addr);
31 #endif
32 
33 static void octeon_icache_flush(void)
34 {
35 	asm volatile ("synci 0($0)\n");
36 }
37 
38 static void (*octeon_message_functions[8])(void) = {
39 	scheduler_ipi,
40 	generic_smp_call_function_interrupt,
41 	octeon_icache_flush,
42 };
43 
44 static irqreturn_t mailbox_interrupt(int irq, void *dev_id)
45 {
46 	u64 mbox_clrx = CVMX_CIU_MBOX_CLRX(cvmx_get_core_num());
47 	u64 action;
48 	int i;
49 
50 	/*
51 	 * Make sure the function array initialization remains
52 	 * correct.
53 	 */
54 	BUILD_BUG_ON(SMP_RESCHEDULE_YOURSELF != (1 << 0));
55 	BUILD_BUG_ON(SMP_CALL_FUNCTION       != (1 << 1));
56 	BUILD_BUG_ON(SMP_ICACHE_FLUSH        != (1 << 2));
57 
58 	/*
59 	 * Load the mailbox register to figure out what we're supposed
60 	 * to do.
61 	 */
62 	action = cvmx_read_csr(mbox_clrx);
63 
64 	if (OCTEON_IS_MODEL(OCTEON_CN68XX))
65 		action &= 0xff;
66 	else
67 		action &= 0xffff;
68 
69 	/* Clear the mailbox to clear the interrupt */
70 	cvmx_write_csr(mbox_clrx, action);
71 
72 	for (i = 0; i < ARRAY_SIZE(octeon_message_functions) && action;) {
73 		if (action & 1) {
74 			void (*fn)(void) = octeon_message_functions[i];
75 
76 			if (fn)
77 				fn();
78 		}
79 		action >>= 1;
80 		i++;
81 	}
82 	return IRQ_HANDLED;
83 }
84 
85 /**
86  * Cause the function described by call_data to be executed on the passed
87  * cpu.	 When the function has finished, increment the finished field of
88  * call_data.
89  */
90 void octeon_send_ipi_single(int cpu, unsigned int action)
91 {
92 	int coreid = cpu_logical_map(cpu);
93 	/*
94 	pr_info("SMP: Mailbox send cpu=%d, coreid=%d, action=%u\n", cpu,
95 	       coreid, action);
96 	*/
97 	cvmx_write_csr(CVMX_CIU_MBOX_SETX(coreid), action);
98 }
99 
100 static inline void octeon_send_ipi_mask(const struct cpumask *mask,
101 					unsigned int action)
102 {
103 	unsigned int i;
104 
105 	for_each_cpu(i, mask)
106 		octeon_send_ipi_single(i, action);
107 }
108 
109 /**
110  * Detect available CPUs, populate cpu_possible_mask
111  */
112 static void octeon_smp_hotplug_setup(void)
113 {
114 #ifdef CONFIG_HOTPLUG_CPU
115 	struct linux_app_boot_info *labi;
116 
117 	if (!setup_max_cpus)
118 		return;
119 
120 	labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
121 	if (labi->labi_signature != LABI_SIGNATURE) {
122 		pr_info("The bootloader on this board does not support HOTPLUG_CPU.");
123 		return;
124 	}
125 
126 	octeon_bootloader_entry_addr = labi->InitTLBStart_addr;
127 #endif
128 }
129 
130 static void __init octeon_smp_setup(void)
131 {
132 	const int coreid = cvmx_get_core_num();
133 	int cpus;
134 	int id;
135 	struct cvmx_sysinfo *sysinfo = cvmx_sysinfo_get();
136 
137 #ifdef CONFIG_HOTPLUG_CPU
138 	int core_mask = octeon_get_boot_coremask();
139 	unsigned int num_cores = cvmx_octeon_num_cores();
140 #endif
141 
142 	/* The present CPUs are initially just the boot cpu (CPU 0). */
143 	for (id = 0; id < NR_CPUS; id++) {
144 		set_cpu_possible(id, id == 0);
145 		set_cpu_present(id, id == 0);
146 	}
147 
148 	__cpu_number_map[coreid] = 0;
149 	__cpu_logical_map[0] = coreid;
150 
151 	/* The present CPUs get the lowest CPU numbers. */
152 	cpus = 1;
153 	for (id = 0; id < NR_CPUS; id++) {
154 		if ((id != coreid) && cvmx_coremask_is_core_set(&sysinfo->core_mask, id)) {
155 			set_cpu_possible(cpus, true);
156 			set_cpu_present(cpus, true);
157 			__cpu_number_map[id] = cpus;
158 			__cpu_logical_map[cpus] = id;
159 			cpus++;
160 		}
161 	}
162 
163 #ifdef CONFIG_HOTPLUG_CPU
164 	/*
165 	 * The possible CPUs are all those present on the chip.	 We
166 	 * will assign CPU numbers for possible cores as well.	Cores
167 	 * are always consecutively numberd from 0.
168 	 */
169 	for (id = 0; setup_max_cpus && octeon_bootloader_entry_addr &&
170 		     id < num_cores && id < NR_CPUS; id++) {
171 		if (!(core_mask & (1 << id))) {
172 			set_cpu_possible(cpus, true);
173 			__cpu_number_map[id] = cpus;
174 			__cpu_logical_map[cpus] = id;
175 			cpus++;
176 		}
177 	}
178 #endif
179 
180 	octeon_smp_hotplug_setup();
181 }
182 
183 /**
184  * Firmware CPU startup hook
185  *
186  */
187 static void octeon_boot_secondary(int cpu, struct task_struct *idle)
188 {
189 	int count;
190 
191 	pr_info("SMP: Booting CPU%02d (CoreId %2d)...\n", cpu,
192 		cpu_logical_map(cpu));
193 
194 	octeon_processor_sp = __KSTK_TOS(idle);
195 	octeon_processor_gp = (unsigned long)(task_thread_info(idle));
196 	octeon_processor_boot = cpu_logical_map(cpu);
197 	mb();
198 
199 	count = 10000;
200 	while (octeon_processor_sp && count) {
201 		/* Waiting for processor to get the SP and GP */
202 		udelay(1);
203 		count--;
204 	}
205 	if (count == 0)
206 		pr_err("Secondary boot timeout\n");
207 }
208 
209 /**
210  * After we've done initial boot, this function is called to allow the
211  * board code to clean up state, if needed
212  */
213 static void octeon_init_secondary(void)
214 {
215 	unsigned int sr;
216 
217 	sr = set_c0_status(ST0_BEV);
218 	write_c0_ebase((u32)ebase);
219 	write_c0_status(sr);
220 
221 	octeon_check_cpu_bist();
222 	octeon_init_cvmcount();
223 
224 	octeon_irq_setup_secondary();
225 }
226 
227 /**
228  * Callout to firmware before smp_init
229  *
230  */
231 static void __init octeon_prepare_cpus(unsigned int max_cpus)
232 {
233 	/*
234 	 * Only the low order mailbox bits are used for IPIs, leave
235 	 * the other bits alone.
236 	 */
237 	cvmx_write_csr(CVMX_CIU_MBOX_CLRX(cvmx_get_core_num()), 0xffff);
238 	if (request_irq(OCTEON_IRQ_MBOX0, mailbox_interrupt,
239 			IRQF_PERCPU | IRQF_NO_THREAD, "SMP-IPI",
240 			mailbox_interrupt)) {
241 		panic("Cannot request_irq(OCTEON_IRQ_MBOX0)");
242 	}
243 }
244 
245 /**
246  * Last chance for the board code to finish SMP initialization before
247  * the CPU is "online".
248  */
249 static void octeon_smp_finish(void)
250 {
251 	octeon_user_io_init();
252 
253 	/* to generate the first CPU timer interrupt */
254 	write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
255 	local_irq_enable();
256 }
257 
258 #ifdef CONFIG_HOTPLUG_CPU
259 
260 /* State of each CPU. */
261 DEFINE_PER_CPU(int, cpu_state);
262 
263 static int octeon_cpu_disable(void)
264 {
265 	unsigned int cpu = smp_processor_id();
266 
267 	if (cpu == 0)
268 		return -EBUSY;
269 
270 	if (!octeon_bootloader_entry_addr)
271 		return -ENOTSUPP;
272 
273 	set_cpu_online(cpu, false);
274 	cpumask_clear_cpu(cpu, &cpu_callin_map);
275 	octeon_fixup_irqs();
276 
277 	__flush_cache_all();
278 	local_flush_tlb_all();
279 
280 	return 0;
281 }
282 
283 static void octeon_cpu_die(unsigned int cpu)
284 {
285 	int coreid = cpu_logical_map(cpu);
286 	uint32_t mask, new_mask;
287 	const struct cvmx_bootmem_named_block_desc *block_desc;
288 
289 	while (per_cpu(cpu_state, cpu) != CPU_DEAD)
290 		cpu_relax();
291 
292 	/*
293 	 * This is a bit complicated strategics of getting/settig available
294 	 * cores mask, copied from bootloader
295 	 */
296 
297 	mask = 1 << coreid;
298 	/* LINUX_APP_BOOT_BLOCK is initialized in bootoct binary */
299 	block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
300 
301 	if (!block_desc) {
302 		struct linux_app_boot_info *labi;
303 
304 		labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
305 
306 		labi->avail_coremask |= mask;
307 		new_mask = labi->avail_coremask;
308 	} else {		       /* alternative, already initialized */
309 		uint32_t *p = (uint32_t *)PHYS_TO_XKSEG_CACHED(block_desc->base_addr +
310 							       AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK);
311 		*p |= mask;
312 		new_mask = *p;
313 	}
314 
315 	pr_info("Reset core %d. Available Coremask = 0x%x \n", coreid, new_mask);
316 	mb();
317 	cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
318 	cvmx_write_csr(CVMX_CIU_PP_RST, 0);
319 }
320 
321 void play_dead(void)
322 {
323 	int cpu = cpu_number_map(cvmx_get_core_num());
324 
325 	idle_task_exit();
326 	octeon_processor_boot = 0xff;
327 	per_cpu(cpu_state, cpu) = CPU_DEAD;
328 
329 	mb();
330 
331 	while (1)	/* core will be reset here */
332 		;
333 }
334 
335 extern void kernel_entry(unsigned long arg1, ...);
336 
337 static void start_after_reset(void)
338 {
339 	kernel_entry(0, 0, 0);	/* set a2 = 0 for secondary core */
340 }
341 
342 static int octeon_update_boot_vector(unsigned int cpu)
343 {
344 
345 	int coreid = cpu_logical_map(cpu);
346 	uint32_t avail_coremask;
347 	const struct cvmx_bootmem_named_block_desc *block_desc;
348 	struct boot_init_vector *boot_vect =
349 		(struct boot_init_vector *)PHYS_TO_XKSEG_CACHED(BOOTLOADER_BOOT_VECTOR);
350 
351 	block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
352 
353 	if (!block_desc) {
354 		struct linux_app_boot_info *labi;
355 
356 		labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
357 
358 		avail_coremask = labi->avail_coremask;
359 		labi->avail_coremask &= ~(1 << coreid);
360 	} else {		       /* alternative, already initialized */
361 		avail_coremask = *(uint32_t *)PHYS_TO_XKSEG_CACHED(
362 			block_desc->base_addr + AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK);
363 	}
364 
365 	if (!(avail_coremask & (1 << coreid))) {
366 		/* core not available, assume, that caught by simple-executive */
367 		cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
368 		cvmx_write_csr(CVMX_CIU_PP_RST, 0);
369 	}
370 
371 	boot_vect[coreid].app_start_func_addr =
372 		(uint32_t) (unsigned long) start_after_reset;
373 	boot_vect[coreid].code_addr = octeon_bootloader_entry_addr;
374 
375 	mb();
376 
377 	cvmx_write_csr(CVMX_CIU_NMI, (1 << coreid) & avail_coremask);
378 
379 	return 0;
380 }
381 
382 static int octeon_cpu_callback(struct notifier_block *nfb,
383 	unsigned long action, void *hcpu)
384 {
385 	unsigned int cpu = (unsigned long)hcpu;
386 
387 	switch (action & ~CPU_TASKS_FROZEN) {
388 	case CPU_UP_PREPARE:
389 		octeon_update_boot_vector(cpu);
390 		break;
391 	case CPU_ONLINE:
392 		pr_info("Cpu %d online\n", cpu);
393 		break;
394 	case CPU_DEAD:
395 		break;
396 	}
397 
398 	return NOTIFY_OK;
399 }
400 
401 static int register_cavium_notifier(void)
402 {
403 	hotcpu_notifier(octeon_cpu_callback, 0);
404 	return 0;
405 }
406 late_initcall(register_cavium_notifier);
407 
408 #endif	/* CONFIG_HOTPLUG_CPU */
409 
410 struct plat_smp_ops octeon_smp_ops = {
411 	.send_ipi_single	= octeon_send_ipi_single,
412 	.send_ipi_mask		= octeon_send_ipi_mask,
413 	.init_secondary		= octeon_init_secondary,
414 	.smp_finish		= octeon_smp_finish,
415 	.boot_secondary		= octeon_boot_secondary,
416 	.smp_setup		= octeon_smp_setup,
417 	.prepare_cpus		= octeon_prepare_cpus,
418 #ifdef CONFIG_HOTPLUG_CPU
419 	.cpu_disable		= octeon_cpu_disable,
420 	.cpu_die		= octeon_cpu_die,
421 #endif
422 };
423 
424 static irqreturn_t octeon_78xx_reched_interrupt(int irq, void *dev_id)
425 {
426 	scheduler_ipi();
427 	return IRQ_HANDLED;
428 }
429 
430 static irqreturn_t octeon_78xx_call_function_interrupt(int irq, void *dev_id)
431 {
432 	generic_smp_call_function_interrupt();
433 	return IRQ_HANDLED;
434 }
435 
436 static irqreturn_t octeon_78xx_icache_flush_interrupt(int irq, void *dev_id)
437 {
438 	octeon_icache_flush();
439 	return IRQ_HANDLED;
440 }
441 
442 /*
443  * Callout to firmware before smp_init
444  */
445 static void octeon_78xx_prepare_cpus(unsigned int max_cpus)
446 {
447 	if (request_irq(OCTEON_IRQ_MBOX0 + 0,
448 			octeon_78xx_reched_interrupt,
449 			IRQF_PERCPU | IRQF_NO_THREAD, "Scheduler",
450 			octeon_78xx_reched_interrupt)) {
451 		panic("Cannot request_irq for SchedulerIPI");
452 	}
453 	if (request_irq(OCTEON_IRQ_MBOX0 + 1,
454 			octeon_78xx_call_function_interrupt,
455 			IRQF_PERCPU | IRQF_NO_THREAD, "SMP-Call",
456 			octeon_78xx_call_function_interrupt)) {
457 		panic("Cannot request_irq for SMP-Call");
458 	}
459 	if (request_irq(OCTEON_IRQ_MBOX0 + 2,
460 			octeon_78xx_icache_flush_interrupt,
461 			IRQF_PERCPU | IRQF_NO_THREAD, "ICache-Flush",
462 			octeon_78xx_icache_flush_interrupt)) {
463 		panic("Cannot request_irq for ICache-Flush");
464 	}
465 }
466 
467 static void octeon_78xx_send_ipi_single(int cpu, unsigned int action)
468 {
469 	int i;
470 
471 	for (i = 0; i < 8; i++) {
472 		if (action & 1)
473 			octeon_ciu3_mbox_send(cpu, i);
474 		action >>= 1;
475 	}
476 }
477 
478 static void octeon_78xx_send_ipi_mask(const struct cpumask *mask,
479 				      unsigned int action)
480 {
481 	unsigned int cpu;
482 
483 	for_each_cpu(cpu, mask)
484 		octeon_78xx_send_ipi_single(cpu, action);
485 }
486 
487 static struct plat_smp_ops octeon_78xx_smp_ops = {
488 	.send_ipi_single	= octeon_78xx_send_ipi_single,
489 	.send_ipi_mask		= octeon_78xx_send_ipi_mask,
490 	.init_secondary		= octeon_init_secondary,
491 	.smp_finish		= octeon_smp_finish,
492 	.boot_secondary		= octeon_boot_secondary,
493 	.smp_setup		= octeon_smp_setup,
494 	.prepare_cpus		= octeon_78xx_prepare_cpus,
495 #ifdef CONFIG_HOTPLUG_CPU
496 	.cpu_disable		= octeon_cpu_disable,
497 	.cpu_die		= octeon_cpu_die,
498 #endif
499 };
500 
501 void __init octeon_setup_smp(void)
502 {
503 	struct plat_smp_ops *ops;
504 
505 	if (octeon_has_feature(OCTEON_FEATURE_CIU3))
506 		ops = &octeon_78xx_smp_ops;
507 	else
508 		ops = &octeon_smp_ops;
509 
510 	register_smp_ops(ops);
511 }
512