Free Electrons

Embedded Linux Experts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
/* Sparc SS1000/SC2000 SMP support.
 *
 * Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 *
 * Based on sun4m's smp.c, which is:
 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
 */

#include <linux/interrupt.h>
#include <linux/profile.h>
#include <linux/delay.h>
#include <linux/cpu.h>

#include <asm/sbi.h>
#include <asm/mmu.h>
#include <asm/tlbflush.h>
#include <asm/switch_to.h>
#include <asm/cacheflush.h>

#include "kernel.h"
#include "irq.h"

#define IRQ_CROSS_CALL		15

static volatile int smp_processors_ready;
static int smp_highest_cpu;

static inline unsigned long sun4d_swap(volatile unsigned long *ptr, unsigned long val)
{
	__asm__ __volatile__("swap [%1], %0\n\t" :
			     "=&r" (val), "=&r" (ptr) :
			     "0" (val), "1" (ptr));
	return val;
}

static void smp4d_ipi_init(void);
static void smp_setup_percpu_timer(void);

static unsigned char cpu_leds[32];

static inline void show_leds(int cpuid)
{
	cpuid &= 0x1e;
	__asm__ __volatile__ ("stba %0, [%1] %2" : :
			      "r" ((cpu_leds[cpuid] << 4) | cpu_leds[cpuid+1]),
			      "r" (ECSR_BASE(cpuid) | BB_LEDS),
			      "i" (ASI_M_CTL));
}

void __cpuinit smp4d_callin(void)
{
	int cpuid = hard_smp4d_processor_id();
	unsigned long flags;

	/* Show we are alive */
	cpu_leds[cpuid] = 0x6;
	show_leds(cpuid);

	/* Enable level15 interrupt, disable level14 interrupt for now */
	cc_set_imsk((cc_get_imsk() & ~0x8000) | 0x4000);

	local_flush_cache_all();
	local_flush_tlb_all();

	notify_cpu_starting(cpuid);
	/*
	 * Unblock the master CPU _only_ when the scheduler state
	 * of all secondary CPUs will be up-to-date, so after
	 * the SMP initialization the master will be just allowed
	 * to call the scheduler code.
	 */
	/* Get our local ticker going. */
	smp_setup_percpu_timer();

	calibrate_delay();
	smp_store_cpu_info(cpuid);
	local_flush_cache_all();
	local_flush_tlb_all();

	/* Allow master to continue. */
	sun4d_swap((unsigned long *)&cpu_callin_map[cpuid], 1);
	local_flush_cache_all();
	local_flush_tlb_all();

	while ((unsigned long)current_set[cpuid] < PAGE_OFFSET)
		barrier();

	while (current_set[cpuid]->cpu != cpuid)
		barrier();

	/* Fix idle thread fields. */
	__asm__ __volatile__("ld [%0], %%g6\n\t"
			     : : "r" (&current_set[cpuid])
			     : "memory" /* paranoid */);

	cpu_leds[cpuid] = 0x9;
	show_leds(cpuid);

	/* Attach to the address space of init_task. */
	atomic_inc(&init_mm.mm_count);
	current->active_mm = &init_mm;

	local_flush_cache_all();
	local_flush_tlb_all();

	local_irq_enable();	/* We don't allow PIL 14 yet */

	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
		barrier();

	spin_lock_irqsave(&sun4d_imsk_lock, flags);
	cc_set_imsk(cc_get_imsk() & ~0x4000); /* Allow PIL 14 as well */
	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
	set_cpu_online(cpuid, true);

}

/*
 *	Cycle through the processors asking the PROM to start each one.
 */
void __init smp4d_boot_cpus(void)
{
	smp4d_ipi_init();
	if (boot_cpu_id)
		current_set[0] = NULL;
	smp_setup_percpu_timer();
	local_flush_cache_all();
}

int __cpuinit smp4d_boot_one_cpu(int i)
{
	unsigned long *entry = &sun4d_cpu_startup;
	struct task_struct *p;
	int timeout;
	int cpu_node;

	cpu_find_by_instance(i, &cpu_node, NULL);
	/* Cook up an idler for this guy. */
	p = fork_idle(i);
	current_set[i] = task_thread_info(p);

	/*
	 * Initialize the contexts table
	 * Since the call to prom_startcpu() trashes the structure,
	 * we need to re-initialize it for each cpu
	 */
	smp_penguin_ctable.which_io = 0;
	smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys;
	smp_penguin_ctable.reg_size = 0;

	/* whirrr, whirrr, whirrrrrrrrr... */
	printk(KERN_INFO "Starting CPU %d at %p\n", i, entry);
	local_flush_cache_all();
	prom_startcpu(cpu_node,
		      &smp_penguin_ctable, 0, (char *)entry);

	printk(KERN_INFO "prom_startcpu returned :)\n");

	/* wheee... it's going... */
	for (timeout = 0; timeout < 10000; timeout++) {
		if (cpu_callin_map[i])
			break;
		udelay(200);
	}

	if (!(cpu_callin_map[i])) {
		printk(KERN_ERR "Processor %d is stuck.\n", i);
		return -ENODEV;

	}
	local_flush_cache_all();
	return 0;
}

void __init smp4d_smp_done(void)
{
	int i, first;
	int *prev;

	/* setup cpu list for irq rotation */
	first = 0;
	prev = &first;
	for_each_online_cpu(i) {
		*prev = i;
		prev = &cpu_data(i).next;
	}
	*prev = first;
	local_flush_cache_all();

	/* Ok, they are spinning and ready to go. */
	smp_processors_ready = 1;
	sun4d_distribute_irqs();
}

/* Memory structure giving interrupt handler information about IPI generated */
struct sun4d_ipi_work {
	int single;
	int msk;
	int resched;
};

static DEFINE_PER_CPU_SHARED_ALIGNED(struct sun4d_ipi_work, sun4d_ipi_work);

/* Initialize IPIs on the SUN4D SMP machine */
static void __init smp4d_ipi_init(void)
{
	int cpu;
	struct sun4d_ipi_work *work;

	printk(KERN_INFO "smp4d: setup IPI at IRQ %d\n", SUN4D_IPI_IRQ);

	for_each_possible_cpu(cpu) {
		work = &per_cpu(sun4d_ipi_work, cpu);
		work->single = work->msk = work->resched = 0;
	}
}

void sun4d_ipi_interrupt(void)
{
	struct sun4d_ipi_work *work = &__get_cpu_var(sun4d_ipi_work);

	if (work->single) {
		work->single = 0;
		smp_call_function_single_interrupt();
	}
	if (work->msk) {
		work->msk = 0;
		smp_call_function_interrupt();
	}
	if (work->resched) {
		work->resched = 0;
		smp_resched_interrupt();
	}
}

static void smp4d_ipi_single(int cpu)
{
	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);

	/* Mark work */
	work->single = 1;

	/* Generate IRQ on the CPU */
	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
}

static void smp4d_ipi_mask_one(int cpu)
{
	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);

	/* Mark work */
	work->msk = 1;

	/* Generate IRQ on the CPU */
	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
}

static void smp4d_ipi_resched(int cpu)
{
	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);

	/* Mark work */
	work->resched = 1;

	/* Generate IRQ on the CPU (any IRQ will cause resched) */
	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
}

static struct smp_funcall {
	smpfunc_t func;
	unsigned long arg1;
	unsigned long arg2;
	unsigned long arg3;
	unsigned long arg4;
	unsigned long arg5;
	unsigned char processors_in[NR_CPUS];  /* Set when ipi entered. */
	unsigned char processors_out[NR_CPUS]; /* Set when ipi exited. */
} ccall_info __attribute__((aligned(8)));

static DEFINE_SPINLOCK(cross_call_lock);

/* Cross calls must be serialized, at least currently. */
static void smp4d_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
			     unsigned long arg2, unsigned long arg3,
			     unsigned long arg4)
{
	if (smp_processors_ready) {
		register int high = smp_highest_cpu;
		unsigned long flags;

		spin_lock_irqsave(&cross_call_lock, flags);

		{
			/*
			 * If you make changes here, make sure
			 * gcc generates proper code...
			 */
			register smpfunc_t f asm("i0") = func;
			register unsigned long a1 asm("i1") = arg1;
			register unsigned long a2 asm("i2") = arg2;
			register unsigned long a3 asm("i3") = arg3;
			register unsigned long a4 asm("i4") = arg4;
			register unsigned long a5 asm("i5") = 0;

			__asm__ __volatile__(
				"std %0, [%6]\n\t"
				"std %2, [%6 + 8]\n\t"
				"std %4, [%6 + 16]\n\t" : :
				"r"(f), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5),
				"r" (&ccall_info.func));
		}

		/* Init receive/complete mapping, plus fire the IPI's off. */
		{
			register int i;

			cpumask_clear_cpu(smp_processor_id(), &mask);
			cpumask_and(&mask, cpu_online_mask, &mask);
			for (i = 0; i <= high; i++) {
				if (cpumask_test_cpu(i, &mask)) {
					ccall_info.processors_in[i] = 0;
					ccall_info.processors_out[i] = 0;
					sun4d_send_ipi(i, IRQ_CROSS_CALL);
				}
			}
		}

		{
			register int i;

			i = 0;
			do {
				if (!cpumask_test_cpu(i, &mask))
					continue;
				while (!ccall_info.processors_in[i])
					barrier();
			} while (++i <= high);

			i = 0;
			do {
				if (!cpumask_test_cpu(i, &mask))
					continue;
				while (!ccall_info.processors_out[i])
					barrier();
			} while (++i <= high);
		}

		spin_unlock_irqrestore(&cross_call_lock, flags);
	}
}

/* Running cross calls. */
void smp4d_cross_call_irq(void)
{
	int i = hard_smp4d_processor_id();

	ccall_info.processors_in[i] = 1;
	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
			ccall_info.arg4, ccall_info.arg5);
	ccall_info.processors_out[i] = 1;
}

void smp4d_percpu_timer_interrupt(struct pt_regs *regs)
{
	struct pt_regs *old_regs;
	int cpu = hard_smp4d_processor_id();
	static int cpu_tick[NR_CPUS];
	static char led_mask[] = { 0xe, 0xd, 0xb, 0x7, 0xb, 0xd };

	old_regs = set_irq_regs(regs);
	bw_get_prof_limit(cpu);
	bw_clear_intr_mask(0, 1);	/* INTR_TABLE[0] & 1 is Profile IRQ */

	cpu_tick[cpu]++;
	if (!(cpu_tick[cpu] & 15)) {
		if (cpu_tick[cpu] == 0x60)
			cpu_tick[cpu] = 0;
		cpu_leds[cpu] = led_mask[cpu_tick[cpu] >> 4];
		show_leds(cpu);
	}

	profile_tick(CPU_PROFILING);

	if (!--prof_counter(cpu)) {
		int user = user_mode(regs);

		irq_enter();
		update_process_times(user);
		irq_exit();

		prof_counter(cpu) = prof_multiplier(cpu);
	}
	set_irq_regs(old_regs);
}

static void __cpuinit smp_setup_percpu_timer(void)
{
	int cpu = hard_smp4d_processor_id();

	prof_counter(cpu) = prof_multiplier(cpu) = 1;
	load_profile_irq(cpu, lvl14_resolution);
}

void __init smp4d_blackbox_id(unsigned *addr)
{
	int rd = *addr & 0x3e000000;

	addr[0] = 0xc0800800 | rd;		/* lda [%g0] ASI_M_VIKING_TMP1, reg */
	addr[1] = 0x01000000;			/* nop */
	addr[2] = 0x01000000;			/* nop */
}

void __init smp4d_blackbox_current(unsigned *addr)
{
	int rd = *addr & 0x3e000000;

	addr[0] = 0xc0800800 | rd;		/* lda [%g0] ASI_M_VIKING_TMP1, reg */
	addr[2] = 0x81282002 | rd | (rd >> 11);	/* sll reg, 2, reg */
	addr[4] = 0x01000000;			/* nop */
}

void __init sun4d_init_smp(void)
{
	int i;

	/* Patch ipi15 trap table */
	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_sun4d - linux_trap_ipi15_sun4m);

	/* And set btfixup... */
	BTFIXUPSET_BLACKBOX(hard_smp_processor_id, smp4d_blackbox_id);
	BTFIXUPSET_BLACKBOX(load_current, smp4d_blackbox_current);
	BTFIXUPSET_CALL(smp_cross_call, smp4d_cross_call, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(__hard_smp_processor_id, __smp4d_processor_id, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(smp_ipi_resched, smp4d_ipi_resched, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(smp_ipi_single, smp4d_ipi_single, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(smp_ipi_mask_one, smp4d_ipi_mask_one, BTFIXUPCALL_NORM);

	for (i = 0; i < NR_CPUS; i++) {
		ccall_info.processors_in[i] = 1;
		ccall_info.processors_out[i] = 1;
	}
}