xref: /openbmc/linux/arch/mips/cavium-octeon/smp.c (revision 874b8d42)
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 irqreturn_t mailbox_interrupt(int irq, void *dev_id)
34 {
35 	const int coreid = cvmx_get_core_num();
36 	uint64_t action;
37 
38 	/* Load the mailbox register to figure out what we're supposed to do */
39 	action = cvmx_read_csr(CVMX_CIU_MBOX_CLRX(coreid)) & 0xffff;
40 
41 	/* Clear the mailbox to clear the interrupt */
42 	cvmx_write_csr(CVMX_CIU_MBOX_CLRX(coreid), action);
43 
44 	if (action & SMP_CALL_FUNCTION)
45 		smp_call_function_interrupt();
46 	if (action & SMP_RESCHEDULE_YOURSELF)
47 		scheduler_ipi();
48 
49 	/* Check if we've been told to flush the icache */
50 	if (action & SMP_ICACHE_FLUSH)
51 		asm volatile ("synci 0($0)\n");
52 	return IRQ_HANDLED;
53 }
54 
55 /**
56  * Cause the function described by call_data to be executed on the passed
57  * cpu.	 When the function has finished, increment the finished field of
58  * call_data.
59  */
60 void octeon_send_ipi_single(int cpu, unsigned int action)
61 {
62 	int coreid = cpu_logical_map(cpu);
63 	/*
64 	pr_info("SMP: Mailbox send cpu=%d, coreid=%d, action=%u\n", cpu,
65 	       coreid, action);
66 	*/
67 	cvmx_write_csr(CVMX_CIU_MBOX_SETX(coreid), action);
68 }
69 
70 static inline void octeon_send_ipi_mask(const struct cpumask *mask,
71 					unsigned int action)
72 {
73 	unsigned int i;
74 
75 	for_each_cpu_mask(i, *mask)
76 		octeon_send_ipi_single(i, action);
77 }
78 
79 /**
80  * Detect available CPUs, populate cpu_possible_mask
81  */
82 static void octeon_smp_hotplug_setup(void)
83 {
84 #ifdef CONFIG_HOTPLUG_CPU
85 	struct linux_app_boot_info *labi;
86 
87 	labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
88 	if (labi->labi_signature != LABI_SIGNATURE)
89 		panic("The bootloader version on this board is incorrect.");
90 
91 	octeon_bootloader_entry_addr = labi->InitTLBStart_addr;
92 #endif
93 }
94 
95 static void octeon_smp_setup(void)
96 {
97 	const int coreid = cvmx_get_core_num();
98 	int cpus;
99 	int id;
100 	int core_mask = octeon_get_boot_coremask();
101 #ifdef CONFIG_HOTPLUG_CPU
102 	unsigned int num_cores = cvmx_octeon_num_cores();
103 #endif
104 
105 	/* The present CPUs are initially just the boot cpu (CPU 0). */
106 	for (id = 0; id < NR_CPUS; id++) {
107 		set_cpu_possible(id, id == 0);
108 		set_cpu_present(id, id == 0);
109 	}
110 
111 	__cpu_number_map[coreid] = 0;
112 	__cpu_logical_map[0] = coreid;
113 
114 	/* The present CPUs get the lowest CPU numbers. */
115 	cpus = 1;
116 	for (id = 0; id < NR_CPUS; id++) {
117 		if ((id != coreid) && (core_mask & (1 << id))) {
118 			set_cpu_possible(cpus, true);
119 			set_cpu_present(cpus, true);
120 			__cpu_number_map[id] = cpus;
121 			__cpu_logical_map[cpus] = id;
122 			cpus++;
123 		}
124 	}
125 
126 #ifdef CONFIG_HOTPLUG_CPU
127 	/*
128 	 * The possible CPUs are all those present on the chip.	 We
129 	 * will assign CPU numbers for possible cores as well.	Cores
130 	 * are always consecutively numberd from 0.
131 	 */
132 	for (id = 0; id < num_cores && id < NR_CPUS; id++) {
133 		if (!(core_mask & (1 << id))) {
134 			set_cpu_possible(cpus, true);
135 			__cpu_number_map[id] = cpus;
136 			__cpu_logical_map[cpus] = id;
137 			cpus++;
138 		}
139 	}
140 #endif
141 
142 	octeon_smp_hotplug_setup();
143 }
144 
145 /**
146  * Firmware CPU startup hook
147  *
148  */
149 static void octeon_boot_secondary(int cpu, struct task_struct *idle)
150 {
151 	int count;
152 
153 	pr_info("SMP: Booting CPU%02d (CoreId %2d)...\n", cpu,
154 		cpu_logical_map(cpu));
155 
156 	octeon_processor_sp = __KSTK_TOS(idle);
157 	octeon_processor_gp = (unsigned long)(task_thread_info(idle));
158 	octeon_processor_boot = cpu_logical_map(cpu);
159 	mb();
160 
161 	count = 10000;
162 	while (octeon_processor_sp && count) {
163 		/* Waiting for processor to get the SP and GP */
164 		udelay(1);
165 		count--;
166 	}
167 	if (count == 0)
168 		pr_err("Secondary boot timeout\n");
169 }
170 
171 /**
172  * After we've done initial boot, this function is called to allow the
173  * board code to clean up state, if needed
174  */
175 static void octeon_init_secondary(void)
176 {
177 	unsigned int sr;
178 
179 	sr = set_c0_status(ST0_BEV);
180 	write_c0_ebase((u32)ebase);
181 	write_c0_status(sr);
182 
183 	octeon_check_cpu_bist();
184 	octeon_init_cvmcount();
185 
186 	octeon_irq_setup_secondary();
187 }
188 
189 /**
190  * Callout to firmware before smp_init
191  *
192  */
193 void octeon_prepare_cpus(unsigned int max_cpus)
194 {
195 #ifdef CONFIG_HOTPLUG_CPU
196 	struct linux_app_boot_info *labi;
197 
198 	labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
199 
200 	if (labi->labi_signature != LABI_SIGNATURE)
201 		panic("The bootloader version on this board is incorrect.");
202 #endif
203 	/*
204 	 * Only the low order mailbox bits are used for IPIs, leave
205 	 * the other bits alone.
206 	 */
207 	cvmx_write_csr(CVMX_CIU_MBOX_CLRX(cvmx_get_core_num()), 0xffff);
208 	if (request_irq(OCTEON_IRQ_MBOX0, mailbox_interrupt,
209 			IRQF_PERCPU | IRQF_NO_THREAD, "SMP-IPI",
210 			mailbox_interrupt)) {
211 		panic("Cannot request_irq(OCTEON_IRQ_MBOX0)");
212 	}
213 }
214 
215 /**
216  * Last chance for the board code to finish SMP initialization before
217  * the CPU is "online".
218  */
219 static void octeon_smp_finish(void)
220 {
221 #ifdef CONFIG_CAVIUM_GDB
222 	unsigned long tmp;
223 	/* Pulse MCD0 signal on Ctrl-C to stop all the cores. Also set the MCD0
224 	   to be not masked by this core so we know the signal is received by
225 	   someone */
226 	asm volatile ("dmfc0 %0, $22\n"
227 		      "ori   %0, %0, 0x9100\n" "dmtc0 %0, $22\n" : "=r" (tmp));
228 #endif
229 
230 	octeon_user_io_init();
231 
232 	/* to generate the first CPU timer interrupt */
233 	write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
234 	local_irq_enable();
235 }
236 
237 /**
238  * Hook for after all CPUs are online
239  */
240 static void octeon_cpus_done(void)
241 {
242 #ifdef CONFIG_CAVIUM_GDB
243 	unsigned long tmp;
244 	/* Pulse MCD0 signal on Ctrl-C to stop all the cores. Also set the MCD0
245 	   to be not masked by this core so we know the signal is received by
246 	   someone */
247 	asm volatile ("dmfc0 %0, $22\n"
248 		      "ori   %0, %0, 0x9100\n" "dmtc0 %0, $22\n" : "=r" (tmp));
249 #endif
250 }
251 
252 #ifdef CONFIG_HOTPLUG_CPU
253 
254 /* State of each CPU. */
255 DEFINE_PER_CPU(int, cpu_state);
256 
257 static int octeon_cpu_disable(void)
258 {
259 	unsigned int cpu = smp_processor_id();
260 
261 	if (cpu == 0)
262 		return -EBUSY;
263 
264 	set_cpu_online(cpu, false);
265 	cpu_clear(cpu, cpu_callin_map);
266 	local_irq_disable();
267 	octeon_fixup_irqs();
268 	local_irq_enable();
269 
270 	flush_cache_all();
271 	local_flush_tlb_all();
272 
273 	return 0;
274 }
275 
276 static void octeon_cpu_die(unsigned int cpu)
277 {
278 	int coreid = cpu_logical_map(cpu);
279 	uint32_t mask, new_mask;
280 	const struct cvmx_bootmem_named_block_desc *block_desc;
281 
282 	while (per_cpu(cpu_state, cpu) != CPU_DEAD)
283 		cpu_relax();
284 
285 	/*
286 	 * This is a bit complicated strategics of getting/settig available
287 	 * cores mask, copied from bootloader
288 	 */
289 
290 	mask = 1 << coreid;
291 	/* LINUX_APP_BOOT_BLOCK is initialized in bootoct binary */
292 	block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
293 
294 	if (!block_desc) {
295 		struct linux_app_boot_info *labi;
296 
297 		labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
298 
299 		labi->avail_coremask |= mask;
300 		new_mask = labi->avail_coremask;
301 	} else {		       /* alternative, already initialized */
302 		uint32_t *p = (uint32_t *)PHYS_TO_XKSEG_CACHED(block_desc->base_addr +
303 							       AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK);
304 		*p |= mask;
305 		new_mask = *p;
306 	}
307 
308 	pr_info("Reset core %d. Available Coremask = 0x%x \n", coreid, new_mask);
309 	mb();
310 	cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
311 	cvmx_write_csr(CVMX_CIU_PP_RST, 0);
312 }
313 
314 void play_dead(void)
315 {
316 	int cpu = cpu_number_map(cvmx_get_core_num());
317 
318 	idle_task_exit();
319 	octeon_processor_boot = 0xff;
320 	per_cpu(cpu_state, cpu) = CPU_DEAD;
321 
322 	mb();
323 
324 	while (1)	/* core will be reset here */
325 		;
326 }
327 
328 extern void kernel_entry(unsigned long arg1, ...);
329 
330 static void start_after_reset(void)
331 {
332 	kernel_entry(0, 0, 0);	/* set a2 = 0 for secondary core */
333 }
334 
335 static int octeon_update_boot_vector(unsigned int cpu)
336 {
337 
338 	int coreid = cpu_logical_map(cpu);
339 	uint32_t avail_coremask;
340 	const struct cvmx_bootmem_named_block_desc *block_desc;
341 	struct boot_init_vector *boot_vect =
342 		(struct boot_init_vector *)PHYS_TO_XKSEG_CACHED(BOOTLOADER_BOOT_VECTOR);
343 
344 	block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
345 
346 	if (!block_desc) {
347 		struct linux_app_boot_info *labi;
348 
349 		labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
350 
351 		avail_coremask = labi->avail_coremask;
352 		labi->avail_coremask &= ~(1 << coreid);
353 	} else {		       /* alternative, already initialized */
354 		avail_coremask = *(uint32_t *)PHYS_TO_XKSEG_CACHED(
355 			block_desc->base_addr + AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK);
356 	}
357 
358 	if (!(avail_coremask & (1 << coreid))) {
359 		/* core not available, assume, that catched by simple-executive */
360 		cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
361 		cvmx_write_csr(CVMX_CIU_PP_RST, 0);
362 	}
363 
364 	boot_vect[coreid].app_start_func_addr =
365 		(uint32_t) (unsigned long) start_after_reset;
366 	boot_vect[coreid].code_addr = octeon_bootloader_entry_addr;
367 
368 	mb();
369 
370 	cvmx_write_csr(CVMX_CIU_NMI, (1 << coreid) & avail_coremask);
371 
372 	return 0;
373 }
374 
375 static int octeon_cpu_callback(struct notifier_block *nfb,
376 	unsigned long action, void *hcpu)
377 {
378 	unsigned int cpu = (unsigned long)hcpu;
379 
380 	switch (action) {
381 	case CPU_UP_PREPARE:
382 		octeon_update_boot_vector(cpu);
383 		break;
384 	case CPU_ONLINE:
385 		pr_info("Cpu %d online\n", cpu);
386 		break;
387 	case CPU_DEAD:
388 		break;
389 	}
390 
391 	return NOTIFY_OK;
392 }
393 
394 static int register_cavium_notifier(void)
395 {
396 	hotcpu_notifier(octeon_cpu_callback, 0);
397 	return 0;
398 }
399 late_initcall(register_cavium_notifier);
400 
401 #endif	/* CONFIG_HOTPLUG_CPU */
402 
403 struct plat_smp_ops octeon_smp_ops = {
404 	.send_ipi_single	= octeon_send_ipi_single,
405 	.send_ipi_mask		= octeon_send_ipi_mask,
406 	.init_secondary		= octeon_init_secondary,
407 	.smp_finish		= octeon_smp_finish,
408 	.cpus_done		= octeon_cpus_done,
409 	.boot_secondary		= octeon_boot_secondary,
410 	.smp_setup		= octeon_smp_setup,
411 	.prepare_cpus		= octeon_prepare_cpus,
412 #ifdef CONFIG_HOTPLUG_CPU
413 	.cpu_disable		= octeon_cpu_disable,
414 	.cpu_die		= octeon_cpu_die,
415 #endif
416 };
417