xref: /openbmc/linux/arch/sparc/kernel/leon_smp.c (revision 4f6cce39)
1 /* leon_smp.c: Sparc-Leon SMP support.
2  *
3  * based on sun4m_smp.c
4  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
5  * Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
6  * Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
7  */
8 
9 #include <asm/head.h>
10 
11 #include <linux/kernel.h>
12 #include <linux/sched/mm.h>
13 #include <linux/threads.h>
14 #include <linux/smp.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel_stat.h>
17 #include <linux/of.h>
18 #include <linux/init.h>
19 #include <linux/spinlock.h>
20 #include <linux/mm.h>
21 #include <linux/swap.h>
22 #include <linux/profile.h>
23 #include <linux/pm.h>
24 #include <linux/delay.h>
25 #include <linux/gfp.h>
26 #include <linux/cpu.h>
27 #include <linux/clockchips.h>
28 
29 #include <asm/cacheflush.h>
30 #include <asm/tlbflush.h>
31 
32 #include <asm/ptrace.h>
33 #include <linux/atomic.h>
34 #include <asm/irq_regs.h>
35 #include <asm/traps.h>
36 
37 #include <asm/delay.h>
38 #include <asm/irq.h>
39 #include <asm/page.h>
40 #include <asm/pgalloc.h>
41 #include <asm/pgtable.h>
42 #include <asm/oplib.h>
43 #include <asm/cpudata.h>
44 #include <asm/asi.h>
45 #include <asm/leon.h>
46 #include <asm/leon_amba.h>
47 #include <asm/timer.h>
48 
49 #include "kernel.h"
50 
51 #include "irq.h"
52 
53 extern ctxd_t *srmmu_ctx_table_phys;
54 static int smp_processors_ready;
55 extern volatile unsigned long cpu_callin_map[NR_CPUS];
56 extern cpumask_t smp_commenced_mask;
57 void leon_configure_cache_smp(void);
58 static void leon_ipi_init(void);
59 
60 /* IRQ number of LEON IPIs */
61 int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
62 
63 static inline unsigned long do_swap(volatile unsigned long *ptr,
64 				    unsigned long val)
65 {
66 	__asm__ __volatile__("swapa [%2] %3, %0\n\t" : "=&r"(val)
67 			     : "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
68 			     : "memory");
69 	return val;
70 }
71 
72 void leon_cpu_pre_starting(void *arg)
73 {
74 	leon_configure_cache_smp();
75 }
76 
77 void leon_cpu_pre_online(void *arg)
78 {
79 	int cpuid = hard_smp_processor_id();
80 
81 	/* Allow master to continue. The master will then give us the
82 	 * go-ahead by setting the smp_commenced_mask and will wait without
83 	 * timeouts until our setup is completed fully (signified by
84 	 * our bit being set in the cpu_online_mask).
85 	 */
86 	do_swap(&cpu_callin_map[cpuid], 1);
87 
88 	local_ops->cache_all();
89 	local_ops->tlb_all();
90 
91 	/* Fix idle thread fields. */
92 	__asm__ __volatile__("ld [%0], %%g6\n\t" : : "r"(&current_set[cpuid])
93 			     : "memory" /* paranoid */);
94 
95 	/* Attach to the address space of init_task. */
96 	mmgrab(&init_mm);
97 	current->active_mm = &init_mm;
98 
99 	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
100 		mb();
101 }
102 
103 /*
104  *	Cycle through the processors asking the PROM to start each one.
105  */
106 
107 extern struct linux_prom_registers smp_penguin_ctable;
108 
109 void leon_configure_cache_smp(void)
110 {
111 	unsigned long cfg = sparc_leon3_get_dcachecfg();
112 	int me = smp_processor_id();
113 
114 	if (ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg) > 4) {
115 		printk(KERN_INFO "Note: SMP with snooping only works on 4k cache, found %dk(0x%x) on cpu %d, disabling caches\n",
116 		     (unsigned int)ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg),
117 		     (unsigned int)cfg, (unsigned int)me);
118 		sparc_leon3_disable_cache();
119 	} else {
120 		if (cfg & ASI_LEON3_SYSCTRL_CFG_SNOOPING) {
121 			sparc_leon3_enable_snooping();
122 		} else {
123 			printk(KERN_INFO "Note: You have to enable snooping in the vhdl model cpu %d, disabling caches\n",
124 			     me);
125 			sparc_leon3_disable_cache();
126 		}
127 	}
128 
129 	local_ops->cache_all();
130 	local_ops->tlb_all();
131 }
132 
133 static void leon_smp_setbroadcast(unsigned int mask)
134 {
135 	int broadcast =
136 	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
137 	      LEON3_IRQMPSTATUS_BROADCAST) & 1);
138 	if (!broadcast) {
139 		prom_printf("######## !!!! The irqmp-ctrl must have broadcast enabled, smp wont work !!!!! ####### nr cpus: %d\n",
140 		     leon_smp_nrcpus());
141 		if (leon_smp_nrcpus() > 1) {
142 			BUG();
143 		} else {
144 			prom_printf("continue anyway\n");
145 			return;
146 		}
147 	}
148 	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), mask);
149 }
150 
151 int leon_smp_nrcpus(void)
152 {
153 	int nrcpu =
154 	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
155 	      LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
156 	return nrcpu;
157 }
158 
159 void __init leon_boot_cpus(void)
160 {
161 	int nrcpu = leon_smp_nrcpus();
162 	int me = smp_processor_id();
163 
164 	/* Setup IPI */
165 	leon_ipi_init();
166 
167 	printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
168 	       (unsigned int)nrcpu, (unsigned int)NR_CPUS,
169 	       (unsigned int)&(leon3_irqctrl_regs->mpstatus));
170 
171 	leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
172 	leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
173 	leon_enable_irq_cpu(leon_ipi_irq, me);
174 
175 	leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
176 
177 	leon_configure_cache_smp();
178 	local_ops->cache_all();
179 
180 }
181 
182 int leon_boot_one_cpu(int i, struct task_struct *idle)
183 {
184 	int timeout;
185 
186 	current_set[i] = task_thread_info(idle);
187 
188 	/* See trampoline.S:leon_smp_cpu_startup for details...
189 	 * Initialize the contexts table
190 	 * Since the call to prom_startcpu() trashes the structure,
191 	 * we need to re-initialize it for each cpu
192 	 */
193 	smp_penguin_ctable.which_io = 0;
194 	smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
195 	smp_penguin_ctable.reg_size = 0;
196 
197 	/* whirrr, whirrr, whirrrrrrrrr... */
198 	printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)\n", (unsigned int)i,
199 	       (unsigned int)&leon3_irqctrl_regs->mpstatus);
200 	local_ops->cache_all();
201 
202 	/* Make sure all IRQs are of from the start for this new CPU */
203 	LEON_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[i], 0);
204 
205 	/* Wake one CPU */
206 	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);
207 
208 	/* wheee... it's going... */
209 	for (timeout = 0; timeout < 10000; timeout++) {
210 		if (cpu_callin_map[i])
211 			break;
212 		udelay(200);
213 	}
214 	printk(KERN_INFO "Started CPU %d\n", (unsigned int)i);
215 
216 	if (!(cpu_callin_map[i])) {
217 		printk(KERN_ERR "Processor %d is stuck.\n", i);
218 		return -ENODEV;
219 	} else {
220 		leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
221 		leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
222 		leon_enable_irq_cpu(leon_ipi_irq, i);
223 	}
224 
225 	local_ops->cache_all();
226 	return 0;
227 }
228 
229 void __init leon_smp_done(void)
230 {
231 
232 	int i, first;
233 	int *prev;
234 
235 	/* setup cpu list for irq rotation */
236 	first = 0;
237 	prev = &first;
238 	for (i = 0; i < NR_CPUS; i++) {
239 		if (cpu_online(i)) {
240 			*prev = i;
241 			prev = &cpu_data(i).next;
242 		}
243 	}
244 	*prev = first;
245 	local_ops->cache_all();
246 
247 	/* Free unneeded trap tables */
248 	if (!cpu_present(1)) {
249 		free_reserved_page(virt_to_page(&trapbase_cpu1));
250 	}
251 	if (!cpu_present(2)) {
252 		free_reserved_page(virt_to_page(&trapbase_cpu2));
253 	}
254 	if (!cpu_present(3)) {
255 		free_reserved_page(virt_to_page(&trapbase_cpu3));
256 	}
257 	/* Ok, they are spinning and ready to go. */
258 	smp_processors_ready = 1;
259 
260 }
261 
262 struct leon_ipi_work {
263 	int single;
264 	int msk;
265 	int resched;
266 };
267 
268 static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);
269 
270 /* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
271  * is used for all three types of IPIs.
272  */
273 static void __init leon_ipi_init(void)
274 {
275 	int cpu, len;
276 	struct leon_ipi_work *work;
277 	struct property *pp;
278 	struct device_node *rootnp;
279 	struct tt_entry *trap_table;
280 	unsigned long flags;
281 
282 	/* Find IPI IRQ or stick with default value */
283 	rootnp = of_find_node_by_path("/ambapp0");
284 	if (rootnp) {
285 		pp = of_find_property(rootnp, "ipi_num", &len);
286 		if (pp && (*(int *)pp->value))
287 			leon_ipi_irq = *(int *)pp->value;
288 	}
289 	printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);
290 
291 	/* Adjust so that we jump directly to smpleon_ipi */
292 	local_irq_save(flags);
293 	trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
294 	trap_table->inst_three += smpleon_ipi - real_irq_entry;
295 	local_ops->cache_all();
296 	local_irq_restore(flags);
297 
298 	for_each_possible_cpu(cpu) {
299 		work = &per_cpu(leon_ipi_work, cpu);
300 		work->single = work->msk = work->resched = 0;
301 	}
302 }
303 
304 static void leon_send_ipi(int cpu, int level)
305 {
306 	unsigned long mask;
307 	mask = leon_get_irqmask(level);
308 	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
309 }
310 
311 static void leon_ipi_single(int cpu)
312 {
313 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
314 
315 	/* Mark work */
316 	work->single = 1;
317 
318 	/* Generate IRQ on the CPU */
319 	leon_send_ipi(cpu, leon_ipi_irq);
320 }
321 
322 static void leon_ipi_mask_one(int cpu)
323 {
324 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
325 
326 	/* Mark work */
327 	work->msk = 1;
328 
329 	/* Generate IRQ on the CPU */
330 	leon_send_ipi(cpu, leon_ipi_irq);
331 }
332 
333 static void leon_ipi_resched(int cpu)
334 {
335 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
336 
337 	/* Mark work */
338 	work->resched = 1;
339 
340 	/* Generate IRQ on the CPU (any IRQ will cause resched) */
341 	leon_send_ipi(cpu, leon_ipi_irq);
342 }
343 
344 void leonsmp_ipi_interrupt(void)
345 {
346 	struct leon_ipi_work *work = this_cpu_ptr(&leon_ipi_work);
347 
348 	if (work->single) {
349 		work->single = 0;
350 		smp_call_function_single_interrupt();
351 	}
352 	if (work->msk) {
353 		work->msk = 0;
354 		smp_call_function_interrupt();
355 	}
356 	if (work->resched) {
357 		work->resched = 0;
358 		smp_resched_interrupt();
359 	}
360 }
361 
362 static struct smp_funcall {
363 	smpfunc_t func;
364 	unsigned long arg1;
365 	unsigned long arg2;
366 	unsigned long arg3;
367 	unsigned long arg4;
368 	unsigned long arg5;
369 	unsigned long processors_in[NR_CPUS];	/* Set when ipi entered. */
370 	unsigned long processors_out[NR_CPUS];	/* Set when ipi exited. */
371 } ccall_info __attribute__((aligned(8)));
372 
373 static DEFINE_SPINLOCK(cross_call_lock);
374 
375 /* Cross calls must be serialized, at least currently. */
376 static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
377 			    unsigned long arg2, unsigned long arg3,
378 			    unsigned long arg4)
379 {
380 	if (smp_processors_ready) {
381 		register int high = NR_CPUS - 1;
382 		unsigned long flags;
383 
384 		spin_lock_irqsave(&cross_call_lock, flags);
385 
386 		{
387 			/* If you make changes here, make sure gcc generates proper code... */
388 			register smpfunc_t f asm("i0") = func;
389 			register unsigned long a1 asm("i1") = arg1;
390 			register unsigned long a2 asm("i2") = arg2;
391 			register unsigned long a3 asm("i3") = arg3;
392 			register unsigned long a4 asm("i4") = arg4;
393 			register unsigned long a5 asm("i5") = 0;
394 
395 			__asm__ __volatile__("std %0, [%6]\n\t"
396 					     "std %2, [%6 + 8]\n\t"
397 					     "std %4, [%6 + 16]\n\t" : :
398 					     "r"(f), "r"(a1), "r"(a2), "r"(a3),
399 					     "r"(a4), "r"(a5),
400 					     "r"(&ccall_info.func));
401 		}
402 
403 		/* Init receive/complete mapping, plus fire the IPI's off. */
404 		{
405 			register int i;
406 
407 			cpumask_clear_cpu(smp_processor_id(), &mask);
408 			cpumask_and(&mask, cpu_online_mask, &mask);
409 			for (i = 0; i <= high; i++) {
410 				if (cpumask_test_cpu(i, &mask)) {
411 					ccall_info.processors_in[i] = 0;
412 					ccall_info.processors_out[i] = 0;
413 					leon_send_ipi(i, LEON3_IRQ_CROSS_CALL);
414 
415 				}
416 			}
417 		}
418 
419 		{
420 			register int i;
421 
422 			i = 0;
423 			do {
424 				if (!cpumask_test_cpu(i, &mask))
425 					continue;
426 
427 				while (!ccall_info.processors_in[i])
428 					barrier();
429 			} while (++i <= high);
430 
431 			i = 0;
432 			do {
433 				if (!cpumask_test_cpu(i, &mask))
434 					continue;
435 
436 				while (!ccall_info.processors_out[i])
437 					barrier();
438 			} while (++i <= high);
439 		}
440 
441 		spin_unlock_irqrestore(&cross_call_lock, flags);
442 	}
443 }
444 
445 /* Running cross calls. */
446 void leon_cross_call_irq(void)
447 {
448 	int i = smp_processor_id();
449 
450 	ccall_info.processors_in[i] = 1;
451 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
452 			ccall_info.arg4, ccall_info.arg5);
453 	ccall_info.processors_out[i] = 1;
454 }
455 
456 static const struct sparc32_ipi_ops leon_ipi_ops = {
457 	.cross_call = leon_cross_call,
458 	.resched    = leon_ipi_resched,
459 	.single     = leon_ipi_single,
460 	.mask_one   = leon_ipi_mask_one,
461 };
462 
463 void __init leon_init_smp(void)
464 {
465 	/* Patch ipi15 trap table */
466 	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
467 
468 	sparc32_ipi_ops = &leon_ipi_ops;
469 }
470