xref: /openbmc/linux/arch/mips/cavium-octeon/smp.c (revision e8e0929d)
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 Cavium Networks
7  */
8 #include <linux/cpu.h>
9 #include <linux/init.h>
10 #include <linux/delay.h>
11 #include <linux/smp.h>
12 #include <linux/interrupt.h>
13 #include <linux/kernel_stat.h>
14 #include <linux/sched.h>
15 #include <linux/module.h>
16 
17 #include <asm/mmu_context.h>
18 #include <asm/system.h>
19 #include <asm/time.h>
20 
21 #include <asm/octeon/octeon.h>
22 
23 #include "octeon_boot.h"
24 
25 volatile unsigned long octeon_processor_boot = 0xff;
26 volatile unsigned long octeon_processor_sp;
27 volatile unsigned long octeon_processor_gp;
28 
29 #ifdef CONFIG_HOTPLUG_CPU
30 static unsigned int InitTLBStart_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));
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 
47 	/* Check if we've been told to flush the icache */
48 	if (action & SMP_ICACHE_FLUSH)
49 		asm volatile ("synci 0($0)\n");
50 	return IRQ_HANDLED;
51 }
52 
53 /**
54  * Cause the function described by call_data to be executed on the passed
55  * cpu.  When the function has finished, increment the finished field of
56  * call_data.
57  */
58 void octeon_send_ipi_single(int cpu, unsigned int action)
59 {
60 	int coreid = cpu_logical_map(cpu);
61 	/*
62 	pr_info("SMP: Mailbox send cpu=%d, coreid=%d, action=%u\n", cpu,
63 	       coreid, action);
64 	*/
65 	cvmx_write_csr(CVMX_CIU_MBOX_SETX(coreid), action);
66 }
67 
68 static inline void octeon_send_ipi_mask(cpumask_t mask, unsigned int action)
69 {
70 	unsigned int i;
71 
72 	for_each_cpu_mask(i, mask)
73 		octeon_send_ipi_single(i, action);
74 }
75 
76 /**
77  * Detect available CPUs, populate cpu_possible_map
78  */
79 static void octeon_smp_hotplug_setup(void)
80 {
81 #ifdef CONFIG_HOTPLUG_CPU
82 	uint32_t labi_signature;
83 
84 	labi_signature =
85 		cvmx_read64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
86 					LABI_ADDR_IN_BOOTLOADER +
87 					offsetof(struct linux_app_boot_info,
88 						    labi_signature)));
89 	if (labi_signature != LABI_SIGNATURE)
90 		pr_err("The bootloader version on this board is incorrect\n");
91 	InitTLBStart_addr =
92 		cvmx_read64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
93 				   LABI_ADDR_IN_BOOTLOADER +
94 					   offsetof(struct linux_app_boot_info,
95 						    InitTLBStart_addr)));
96 #endif
97 }
98 
99 static void octeon_smp_setup(void)
100 {
101 	const int coreid = cvmx_get_core_num();
102 	int cpus;
103 	int id;
104 
105 	int core_mask = octeon_get_boot_coremask();
106 
107 	cpus_clear(cpu_possible_map);
108 	__cpu_number_map[coreid] = 0;
109 	__cpu_logical_map[0] = coreid;
110 	cpu_set(0, cpu_possible_map);
111 
112 	cpus = 1;
113 	for (id = 0; id < 16; id++) {
114 		if ((id != coreid) && (core_mask & (1 << id))) {
115 			cpu_set(cpus, cpu_possible_map);
116 			__cpu_number_map[id] = cpus;
117 			__cpu_logical_map[cpus] = id;
118 			cpus++;
119 		}
120 	}
121 	cpu_present_map = cpu_possible_map;
122 
123 	octeon_smp_hotplug_setup();
124 }
125 
126 /**
127  * Firmware CPU startup hook
128  *
129  */
130 static void octeon_boot_secondary(int cpu, struct task_struct *idle)
131 {
132 	int count;
133 
134 	pr_info("SMP: Booting CPU%02d (CoreId %2d)...\n", cpu,
135 		cpu_logical_map(cpu));
136 
137 	octeon_processor_sp = __KSTK_TOS(idle);
138 	octeon_processor_gp = (unsigned long)(task_thread_info(idle));
139 	octeon_processor_boot = cpu_logical_map(cpu);
140 	mb();
141 
142 	count = 10000;
143 	while (octeon_processor_sp && count) {
144 		/* Waiting for processor to get the SP and GP */
145 		udelay(1);
146 		count--;
147 	}
148 	if (count == 0)
149 		pr_err("Secondary boot timeout\n");
150 }
151 
152 /**
153  * After we've done initial boot, this function is called to allow the
154  * board code to clean up state, if needed
155  */
156 static void octeon_init_secondary(void)
157 {
158 	const int coreid = cvmx_get_core_num();
159 	union cvmx_ciu_intx_sum0 interrupt_enable;
160 
161 #ifdef CONFIG_HOTPLUG_CPU
162 	unsigned int cur_exception_base;
163 
164 	cur_exception_base = cvmx_read64_uint32(
165 		CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
166 			     LABI_ADDR_IN_BOOTLOADER +
167 			     offsetof(struct linux_app_boot_info,
168 				      cur_exception_base)));
169 	/* cur_exception_base is incremented in bootloader after setting */
170 	write_c0_ebase((unsigned int)(cur_exception_base - EXCEPTION_BASE_INCR));
171 #endif
172 	octeon_check_cpu_bist();
173 	octeon_init_cvmcount();
174 	/*
175 	pr_info("SMP: CPU%d (CoreId %lu) started\n", cpu, coreid);
176 	*/
177 	/* Enable Mailbox interrupts to this core. These are the only
178 	   interrupts allowed on line 3 */
179 	cvmx_write_csr(CVMX_CIU_MBOX_CLRX(coreid), 0xffffffff);
180 	interrupt_enable.u64 = 0;
181 	interrupt_enable.s.mbox = 0x3;
182 	cvmx_write_csr(CVMX_CIU_INTX_EN0((coreid * 2)), interrupt_enable.u64);
183 	cvmx_write_csr(CVMX_CIU_INTX_EN0((coreid * 2 + 1)), 0);
184 	cvmx_write_csr(CVMX_CIU_INTX_EN1((coreid * 2)), 0);
185 	cvmx_write_csr(CVMX_CIU_INTX_EN1((coreid * 2 + 1)), 0);
186 	/* Enable core interrupt processing for 2,3 and 7 */
187 	set_c0_status(0x8c01);
188 }
189 
190 /**
191  * Callout to firmware before smp_init
192  *
193  */
194 void octeon_prepare_cpus(unsigned int max_cpus)
195 {
196 	cvmx_write_csr(CVMX_CIU_MBOX_CLRX(cvmx_get_core_num()), 0xffffffff);
197 	if (request_irq(OCTEON_IRQ_MBOX0, mailbox_interrupt, IRQF_DISABLED,
198 			"mailbox0", mailbox_interrupt)) {
199 		panic("Cannot request_irq(OCTEON_IRQ_MBOX0)\n");
200 	}
201 	if (request_irq(OCTEON_IRQ_MBOX1, mailbox_interrupt, IRQF_DISABLED,
202 			"mailbox1", mailbox_interrupt)) {
203 		panic("Cannot request_irq(OCTEON_IRQ_MBOX1)\n");
204 	}
205 }
206 
207 /**
208  * Last chance for the board code to finish SMP initialization before
209  * the CPU is "online".
210  */
211 static void octeon_smp_finish(void)
212 {
213 #ifdef CONFIG_CAVIUM_GDB
214 	unsigned long tmp;
215 	/* Pulse MCD0 signal on Ctrl-C to stop all the cores. Also set the MCD0
216 	   to be not masked by this core so we know the signal is received by
217 	   someone */
218 	asm volatile ("dmfc0 %0, $22\n"
219 		      "ori   %0, %0, 0x9100\n" "dmtc0 %0, $22\n" : "=r" (tmp));
220 #endif
221 
222 	octeon_user_io_init();
223 
224 	/* to generate the first CPU timer interrupt */
225 	write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
226 }
227 
228 /**
229  * Hook for after all CPUs are online
230  */
231 static void octeon_cpus_done(void)
232 {
233 #ifdef CONFIG_CAVIUM_GDB
234 	unsigned long tmp;
235 	/* Pulse MCD0 signal on Ctrl-C to stop all the cores. Also set the MCD0
236 	   to be not masked by this core so we know the signal is received by
237 	   someone */
238 	asm volatile ("dmfc0 %0, $22\n"
239 		      "ori   %0, %0, 0x9100\n" "dmtc0 %0, $22\n" : "=r" (tmp));
240 #endif
241 }
242 
243 #ifdef CONFIG_HOTPLUG_CPU
244 
245 /* State of each CPU. */
246 DEFINE_PER_CPU(int, cpu_state);
247 
248 extern void fixup_irqs(void);
249 
250 static DEFINE_SPINLOCK(smp_reserve_lock);
251 
252 static int octeon_cpu_disable(void)
253 {
254 	unsigned int cpu = smp_processor_id();
255 
256 	if (cpu == 0)
257 		return -EBUSY;
258 
259 	spin_lock(&smp_reserve_lock);
260 
261 	cpu_clear(cpu, cpu_online_map);
262 	cpu_clear(cpu, cpu_callin_map);
263 	local_irq_disable();
264 	fixup_irqs();
265 	local_irq_enable();
266 
267 	flush_cache_all();
268 	local_flush_tlb_all();
269 
270 	spin_unlock(&smp_reserve_lock);
271 
272 	return 0;
273 }
274 
275 static void octeon_cpu_die(unsigned int cpu)
276 {
277 	int coreid = cpu_logical_map(cpu);
278 	uint32_t avail_coremask;
279 	struct cvmx_bootmem_named_block_desc *block_desc;
280 
281 #ifdef CONFIG_CAVIUM_OCTEON_WATCHDOG
282 	/* Disable the watchdog */
283 	cvmx_ciu_wdogx_t ciu_wdog;
284 	ciu_wdog.u64 = cvmx_read_csr(CVMX_CIU_WDOGX(cpu));
285 	ciu_wdog.s.mode = 0;
286 	cvmx_write_csr(CVMX_CIU_WDOGX(cpu), ciu_wdog.u64);
287 #endif
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 	/* LINUX_APP_BOOT_BLOCK is initialized in bootoct binary */
297 	block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
298 
299 	if (!block_desc) {
300 		avail_coremask =
301 			cvmx_read64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
302 						   LABI_ADDR_IN_BOOTLOADER +
303 						   offsetof
304 						   (struct linux_app_boot_info,
305 						    avail_coremask)));
306 	} else {		       /* alternative, already initialized */
307 	       avail_coremask =
308 		   cvmx_read64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
309 						   block_desc->base_addr +
310 						  AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK));
311 	}
312 
313 	avail_coremask |= 1 << coreid;
314 
315 	/* Setting avail_coremask for bootoct binary */
316 	if (!block_desc) {
317 		cvmx_write64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
318 						LABI_ADDR_IN_BOOTLOADER +
319 						offsetof(struct linux_app_boot_info,
320 							 avail_coremask)),
321 				   avail_coremask);
322 	} else {
323 		cvmx_write64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
324 						block_desc->base_addr +
325 						AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK),
326 				   avail_coremask);
327 	}
328 
329 	pr_info("Reset core %d. Available Coremask = %x \n", coreid,
330 		avail_coremask);
331 	cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
332 	cvmx_write_csr(CVMX_CIU_PP_RST, 0);
333 }
334 
335 void play_dead(void)
336 {
337 	int coreid = cvmx_get_core_num();
338 
339 	idle_task_exit();
340 	octeon_processor_boot = 0xff;
341 	per_cpu(cpu_state, coreid) = CPU_DEAD;
342 
343 	while (1)	/* core will be reset here */
344 		;
345 }
346 
347 extern void kernel_entry(unsigned long arg1, ...);
348 
349 static void start_after_reset(void)
350 {
351 	kernel_entry(0, 0, 0);  /* set a2 = 0 for secondary core */
352 }
353 
354 int octeon_update_boot_vector(unsigned int cpu)
355 {
356 
357 	int coreid = cpu_logical_map(cpu);
358 	unsigned int avail_coremask;
359 	struct cvmx_bootmem_named_block_desc *block_desc;
360 	struct boot_init_vector *boot_vect =
361 		(struct boot_init_vector *) cvmx_phys_to_ptr(0x0 +
362 						  BOOTLOADER_BOOT_VECTOR);
363 
364 	block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
365 
366 	if (!block_desc) {
367 		avail_coremask =
368 			cvmx_read64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
369 					   LABI_ADDR_IN_BOOTLOADER +
370 						offsetof(struct linux_app_boot_info,
371 						avail_coremask)));
372 	} else {		       /* alternative, already initialized */
373 	       avail_coremask =
374 		   cvmx_read64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
375 						   block_desc->base_addr +
376 						   AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK));
377 	}
378 
379 	if (!(avail_coremask & (1 << coreid))) {
380 		/* core not available, assume, that catched by simple-executive */
381 		cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
382 		cvmx_write_csr(CVMX_CIU_PP_RST, 0);
383 	}
384 
385 	boot_vect[coreid].app_start_func_addr =
386 		(uint32_t) (unsigned long) start_after_reset;
387 	boot_vect[coreid].code_addr = InitTLBStart_addr;
388 
389 	CVMX_SYNC;
390 
391 	cvmx_write_csr(CVMX_CIU_NMI, (1 << coreid) & avail_coremask);
392 
393 	return 0;
394 }
395 
396 static int __cpuinit octeon_cpu_callback(struct notifier_block *nfb,
397 	unsigned long action, void *hcpu)
398 {
399 	unsigned int cpu = (unsigned long)hcpu;
400 
401 	switch (action) {
402 	case CPU_UP_PREPARE:
403 		octeon_update_boot_vector(cpu);
404 		break;
405 	case CPU_ONLINE:
406 		pr_info("Cpu %d online\n", cpu);
407 		break;
408 	case CPU_DEAD:
409 		break;
410 	}
411 
412 	return NOTIFY_OK;
413 }
414 
415 static struct notifier_block __cpuinitdata octeon_cpu_notifier = {
416 	.notifier_call = octeon_cpu_callback,
417 };
418 
419 static int __cpuinit register_cavium_notifier(void)
420 {
421 	register_hotcpu_notifier(&octeon_cpu_notifier);
422 
423 	return 0;
424 }
425 
426 late_initcall(register_cavium_notifier);
427 
428 #endif  /* CONFIG_HOTPLUG_CPU */
429 
430 struct plat_smp_ops octeon_smp_ops = {
431 	.send_ipi_single	= octeon_send_ipi_single,
432 	.send_ipi_mask		= octeon_send_ipi_mask,
433 	.init_secondary		= octeon_init_secondary,
434 	.smp_finish		= octeon_smp_finish,
435 	.cpus_done		= octeon_cpus_done,
436 	.boot_secondary		= octeon_boot_secondary,
437 	.smp_setup		= octeon_smp_setup,
438 	.prepare_cpus		= octeon_prepare_cpus,
439 #ifdef CONFIG_HOTPLUG_CPU
440 	.cpu_disable		= octeon_cpu_disable,
441 	.cpu_die		= octeon_cpu_die,
442 #endif
443 };
444