xref: /openbmc/linux/arch/sparc/kernel/leon_smp.c (revision 27ab1c1c)
1 // SPDX-License-Identifier: GPL-2.0
2 /* leon_smp.c: Sparc-Leon SMP support.
3  *
4  * based on sun4m_smp.c
5  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
6  * Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
7  * Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
8  */
9 
10 #include <asm/head.h>
11 
12 #include <linux/kernel.h>
13 #include <linux/sched/mm.h>
14 #include <linux/threads.h>
15 #include <linux/smp.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel_stat.h>
18 #include <linux/of.h>
19 #include <linux/init.h>
20 #include <linux/spinlock.h>
21 #include <linux/mm.h>
22 #include <linux/swap.h>
23 #include <linux/profile.h>
24 #include <linux/pm.h>
25 #include <linux/delay.h>
26 #include <linux/gfp.h>
27 #include <linux/cpu.h>
28 #include <linux/clockchips.h>
29 
30 #include <asm/cacheflush.h>
31 #include <asm/tlbflush.h>
32 
33 #include <asm/ptrace.h>
34 #include <linux/atomic.h>
35 #include <asm/irq_regs.h>
36 #include <asm/traps.h>
37 
38 #include <asm/delay.h>
39 #include <asm/irq.h>
40 #include <asm/page.h>
41 #include <asm/oplib.h>
42 #include <asm/cpudata.h>
43 #include <asm/asi.h>
44 #include <asm/leon.h>
45 #include <asm/leon_amba.h>
46 #include <asm/timer.h>
47 
48 #include "kernel.h"
49 
50 #include "irq.h"
51 
52 extern ctxd_t *srmmu_ctx_table_phys;
53 static int smp_processors_ready;
54 extern volatile unsigned long cpu_callin_map[NR_CPUS];
55 extern cpumask_t smp_commenced_mask;
56 void leon_configure_cache_smp(void);
57 static void leon_ipi_init(void);
58 
59 /* IRQ number of LEON IPIs */
60 int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
61 
62 static inline unsigned long do_swap(volatile unsigned long *ptr,
63 				    unsigned long val)
64 {
65 	__asm__ __volatile__("swapa [%2] %3, %0\n\t" : "=&r"(val)
66 			     : "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
67 			     : "memory");
68 	return val;
69 }
70 
71 void leon_cpu_pre_starting(void *arg)
72 {
73 	leon_configure_cache_smp();
74 }
75 
76 void leon_cpu_pre_online(void *arg)
77 {
78 	int cpuid = hard_smp_processor_id();
79 
80 	/* Allow master to continue. The master will then give us the
81 	 * go-ahead by setting the smp_commenced_mask and will wait without
82 	 * timeouts until our setup is completed fully (signified by
83 	 * our bit being set in the cpu_online_mask).
84 	 */
85 	do_swap(&cpu_callin_map[cpuid], 1);
86 
87 	local_ops->cache_all();
88 	local_ops->tlb_all();
89 
90 	/* Fix idle thread fields. */
91 	__asm__ __volatile__("ld [%0], %%g6\n\t" : : "r"(&current_set[cpuid])
92 			     : "memory" /* paranoid */);
93 
94 	/* Attach to the address space of init_task. */
95 	mmgrab(&init_mm);
96 	current->active_mm = &init_mm;
97 
98 	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
99 		mb();
100 }
101 
102 /*
103  *	Cycle through the processors asking the PROM to start each one.
104  */
105 
106 extern struct linux_prom_registers smp_penguin_ctable;
107 
108 void leon_configure_cache_smp(void)
109 {
110 	unsigned long cfg = sparc_leon3_get_dcachecfg();
111 	int me = smp_processor_id();
112 
113 	if (ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg) > 4) {
114 		printk(KERN_INFO "Note: SMP with snooping only works on 4k cache, found %dk(0x%x) on cpu %d, disabling caches\n",
115 		     (unsigned int)ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg),
116 		     (unsigned int)cfg, (unsigned int)me);
117 		sparc_leon3_disable_cache();
118 	} else {
119 		if (cfg & ASI_LEON3_SYSCTRL_CFG_SNOOPING) {
120 			sparc_leon3_enable_snooping();
121 		} else {
122 			printk(KERN_INFO "Note: You have to enable snooping in the vhdl model cpu %d, disabling caches\n",
123 			     me);
124 			sparc_leon3_disable_cache();
125 		}
126 	}
127 
128 	local_ops->cache_all();
129 	local_ops->tlb_all();
130 }
131 
132 static void leon_smp_setbroadcast(unsigned int mask)
133 {
134 	int broadcast =
135 	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
136 	      LEON3_IRQMPSTATUS_BROADCAST) & 1);
137 	if (!broadcast) {
138 		prom_printf("######## !!!! The irqmp-ctrl must have broadcast enabled, smp wont work !!!!! ####### nr cpus: %d\n",
139 		     leon_smp_nrcpus());
140 		if (leon_smp_nrcpus() > 1) {
141 			BUG();
142 		} else {
143 			prom_printf("continue anyway\n");
144 			return;
145 		}
146 	}
147 	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), mask);
148 }
149 
150 int leon_smp_nrcpus(void)
151 {
152 	int nrcpu =
153 	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
154 	      LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
155 	return nrcpu;
156 }
157 
158 void __init leon_boot_cpus(void)
159 {
160 	int nrcpu = leon_smp_nrcpus();
161 	int me = smp_processor_id();
162 
163 	/* Setup IPI */
164 	leon_ipi_init();
165 
166 	printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
167 	       (unsigned int)nrcpu, (unsigned int)NR_CPUS,
168 	       (unsigned int)&(leon3_irqctrl_regs->mpstatus));
169 
170 	leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
171 	leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
172 	leon_enable_irq_cpu(leon_ipi_irq, me);
173 
174 	leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
175 
176 	leon_configure_cache_smp();
177 	local_ops->cache_all();
178 
179 }
180 
181 int leon_boot_one_cpu(int i, struct task_struct *idle)
182 {
183 	int timeout;
184 
185 	current_set[i] = task_thread_info(idle);
186 
187 	/* See trampoline.S:leon_smp_cpu_startup for details...
188 	 * Initialize the contexts table
189 	 * Since the call to prom_startcpu() trashes the structure,
190 	 * we need to re-initialize it for each cpu
191 	 */
192 	smp_penguin_ctable.which_io = 0;
193 	smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
194 	smp_penguin_ctable.reg_size = 0;
195 
196 	/* whirrr, whirrr, whirrrrrrrrr... */
197 	printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)\n", (unsigned int)i,
198 	       (unsigned int)&leon3_irqctrl_regs->mpstatus);
199 	local_ops->cache_all();
200 
201 	/* Make sure all IRQs are of from the start for this new CPU */
202 	LEON_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[i], 0);
203 
204 	/* Wake one CPU */
205 	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);
206 
207 	/* wheee... it's going... */
208 	for (timeout = 0; timeout < 10000; timeout++) {
209 		if (cpu_callin_map[i])
210 			break;
211 		udelay(200);
212 	}
213 	printk(KERN_INFO "Started CPU %d\n", (unsigned int)i);
214 
215 	if (!(cpu_callin_map[i])) {
216 		printk(KERN_ERR "Processor %d is stuck.\n", i);
217 		return -ENODEV;
218 	} else {
219 		leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
220 		leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
221 		leon_enable_irq_cpu(leon_ipi_irq, i);
222 	}
223 
224 	local_ops->cache_all();
225 	return 0;
226 }
227 
228 void __init leon_smp_done(void)
229 {
230 
231 	int i, first;
232 	int *prev;
233 
234 	/* setup cpu list for irq rotation */
235 	first = 0;
236 	prev = &first;
237 	for (i = 0; i < NR_CPUS; i++) {
238 		if (cpu_online(i)) {
239 			*prev = i;
240 			prev = &cpu_data(i).next;
241 		}
242 	}
243 	*prev = first;
244 	local_ops->cache_all();
245 
246 	/* Free unneeded trap tables */
247 	if (!cpu_present(1)) {
248 		free_reserved_page(virt_to_page(&trapbase_cpu1));
249 	}
250 	if (!cpu_present(2)) {
251 		free_reserved_page(virt_to_page(&trapbase_cpu2));
252 	}
253 	if (!cpu_present(3)) {
254 		free_reserved_page(virt_to_page(&trapbase_cpu3));
255 	}
256 	/* Ok, they are spinning and ready to go. */
257 	smp_processors_ready = 1;
258 
259 }
260 
261 struct leon_ipi_work {
262 	int single;
263 	int msk;
264 	int resched;
265 };
266 
267 static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);
268 
269 /* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
270  * is used for all three types of IPIs.
271  */
272 static void __init leon_ipi_init(void)
273 {
274 	int cpu, len;
275 	struct leon_ipi_work *work;
276 	struct property *pp;
277 	struct device_node *rootnp;
278 	struct tt_entry *trap_table;
279 	unsigned long flags;
280 
281 	/* Find IPI IRQ or stick with default value */
282 	rootnp = of_find_node_by_path("/ambapp0");
283 	if (rootnp) {
284 		pp = of_find_property(rootnp, "ipi_num", &len);
285 		if (pp && (*(int *)pp->value))
286 			leon_ipi_irq = *(int *)pp->value;
287 	}
288 	printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);
289 
290 	/* Adjust so that we jump directly to smpleon_ipi */
291 	local_irq_save(flags);
292 	trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
293 	trap_table->inst_three += smpleon_ipi - real_irq_entry;
294 	local_ops->cache_all();
295 	local_irq_restore(flags);
296 
297 	for_each_possible_cpu(cpu) {
298 		work = &per_cpu(leon_ipi_work, cpu);
299 		work->single = work->msk = work->resched = 0;
300 	}
301 }
302 
303 static void leon_send_ipi(int cpu, int level)
304 {
305 	unsigned long mask;
306 	mask = leon_get_irqmask(level);
307 	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
308 }
309 
310 static void leon_ipi_single(int cpu)
311 {
312 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
313 
314 	/* Mark work */
315 	work->single = 1;
316 
317 	/* Generate IRQ on the CPU */
318 	leon_send_ipi(cpu, leon_ipi_irq);
319 }
320 
321 static void leon_ipi_mask_one(int cpu)
322 {
323 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
324 
325 	/* Mark work */
326 	work->msk = 1;
327 
328 	/* Generate IRQ on the CPU */
329 	leon_send_ipi(cpu, leon_ipi_irq);
330 }
331 
332 static void leon_ipi_resched(int cpu)
333 {
334 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
335 
336 	/* Mark work */
337 	work->resched = 1;
338 
339 	/* Generate IRQ on the CPU (any IRQ will cause resched) */
340 	leon_send_ipi(cpu, leon_ipi_irq);
341 }
342 
343 void leonsmp_ipi_interrupt(void)
344 {
345 	struct leon_ipi_work *work = this_cpu_ptr(&leon_ipi_work);
346 
347 	if (work->single) {
348 		work->single = 0;
349 		smp_call_function_single_interrupt();
350 	}
351 	if (work->msk) {
352 		work->msk = 0;
353 		smp_call_function_interrupt();
354 	}
355 	if (work->resched) {
356 		work->resched = 0;
357 		smp_resched_interrupt();
358 	}
359 }
360 
361 static struct smp_funcall {
362 	smpfunc_t func;
363 	unsigned long arg1;
364 	unsigned long arg2;
365 	unsigned long arg3;
366 	unsigned long arg4;
367 	unsigned long arg5;
368 	unsigned long processors_in[NR_CPUS];	/* Set when ipi entered. */
369 	unsigned long processors_out[NR_CPUS];	/* Set when ipi exited. */
370 } ccall_info __attribute__((aligned(8)));
371 
372 static DEFINE_SPINLOCK(cross_call_lock);
373 
374 /* Cross calls must be serialized, at least currently. */
375 static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
376 			    unsigned long arg2, unsigned long arg3,
377 			    unsigned long arg4)
378 {
379 	if (smp_processors_ready) {
380 		register int high = NR_CPUS - 1;
381 		unsigned long flags;
382 
383 		spin_lock_irqsave(&cross_call_lock, flags);
384 
385 		{
386 			/* If you make changes here, make sure gcc generates proper code... */
387 			register smpfunc_t f asm("i0") = func;
388 			register unsigned long a1 asm("i1") = arg1;
389 			register unsigned long a2 asm("i2") = arg2;
390 			register unsigned long a3 asm("i3") = arg3;
391 			register unsigned long a4 asm("i4") = arg4;
392 			register unsigned long a5 asm("i5") = 0;
393 
394 			__asm__ __volatile__("std %0, [%6]\n\t"
395 					     "std %2, [%6 + 8]\n\t"
396 					     "std %4, [%6 + 16]\n\t" : :
397 					     "r"(f), "r"(a1), "r"(a2), "r"(a3),
398 					     "r"(a4), "r"(a5),
399 					     "r"(&ccall_info.func));
400 		}
401 
402 		/* Init receive/complete mapping, plus fire the IPI's off. */
403 		{
404 			register int i;
405 
406 			cpumask_clear_cpu(smp_processor_id(), &mask);
407 			cpumask_and(&mask, cpu_online_mask, &mask);
408 			for (i = 0; i <= high; i++) {
409 				if (cpumask_test_cpu(i, &mask)) {
410 					ccall_info.processors_in[i] = 0;
411 					ccall_info.processors_out[i] = 0;
412 					leon_send_ipi(i, LEON3_IRQ_CROSS_CALL);
413 
414 				}
415 			}
416 		}
417 
418 		{
419 			register int i;
420 
421 			i = 0;
422 			do {
423 				if (!cpumask_test_cpu(i, &mask))
424 					continue;
425 
426 				while (!ccall_info.processors_in[i])
427 					barrier();
428 			} while (++i <= high);
429 
430 			i = 0;
431 			do {
432 				if (!cpumask_test_cpu(i, &mask))
433 					continue;
434 
435 				while (!ccall_info.processors_out[i])
436 					barrier();
437 			} while (++i <= high);
438 		}
439 
440 		spin_unlock_irqrestore(&cross_call_lock, flags);
441 	}
442 }
443 
444 /* Running cross calls. */
445 void leon_cross_call_irq(void)
446 {
447 	int i = smp_processor_id();
448 
449 	ccall_info.processors_in[i] = 1;
450 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
451 			ccall_info.arg4, ccall_info.arg5);
452 	ccall_info.processors_out[i] = 1;
453 }
454 
455 static const struct sparc32_ipi_ops leon_ipi_ops = {
456 	.cross_call = leon_cross_call,
457 	.resched    = leon_ipi_resched,
458 	.single     = leon_ipi_single,
459 	.mask_one   = leon_ipi_mask_one,
460 };
461 
462 void __init leon_init_smp(void)
463 {
464 	/* Patch ipi15 trap table */
465 	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
466 
467 	sparc32_ipi_ops = &leon_ipi_ops;
468 }
469