summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-exynos/platsmp.c
blob: 98ffe1e62ad5d6debe7c087743d728d5730c26d3 (plain)
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
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
 /*
 * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 *
 * Cloned from linux/arch/arm/mach-vexpress/platsmp.c
 *
 *  Copyright (C) 2002 ARM Ltd.
 *  All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

#include <linux/init.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/soc/samsung/exynos-regs-pmu.h>

#include <asm/cacheflush.h>
#include <asm/cp15.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#include <asm/firmware.h>

#include <mach/map.h>

#include "common.h"

extern void exynos4_secondary_startup(void);

#ifdef CONFIG_HOTPLUG_CPU
static inline void cpu_leave_lowpower(u32 core_id)
{
	unsigned int v;

	asm volatile(
	"mrc	p15, 0, %0, c1, c0, 0\n"
	"	orr	%0, %0, %1\n"
	"	mcr	p15, 0, %0, c1, c0, 0\n"
	"	mrc	p15, 0, %0, c1, c0, 1\n"
	"	orr	%0, %0, %2\n"
	"	mcr	p15, 0, %0, c1, c0, 1\n"
	  : "=&r" (v)
	  : "Ir" (CR_C), "Ir" (0x40)
	  : "cc");
}

static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
{
	u32 mpidr = cpu_logical_map(cpu);
	u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);

	for (;;) {

		/* Turn the CPU off on next WFI instruction. */
		exynos_cpu_power_down(core_id);

		wfi();

		if (pen_release == core_id) {
			/*
			 * OK, proper wakeup, we're done
			 */
			break;
		}

		/*
		 * Getting here, means that we have come out of WFI without
		 * having been woken up - this shouldn't happen
		 *
		 * Just note it happening - when we're woken, we can report
		 * its occurrence.
		 */
		(*spurious)++;
	}
}
#endif /* CONFIG_HOTPLUG_CPU */

/**
 * exynos_core_power_down : power down the specified cpu
 * @cpu : the cpu to power down
 *
 * Power down the specified cpu. The sequence must be finished by a
 * call to cpu_do_idle()
 *
 */
void exynos_cpu_power_down(int cpu)
{
	u32 core_conf;

	if (cpu == 0 && (soc_is_exynos5420() || soc_is_exynos5800())) {
		/*
		 * Bypass power down for CPU0 during suspend. Check for
		 * the SYS_PWR_REG value to decide if we are suspending
		 * the system.
		 */
		int val = pmu_raw_readl(EXYNOS5_ARM_CORE0_SYS_PWR_REG);

		if (!(val & S5P_CORE_LOCAL_PWR_EN))
			return;
	}

	core_conf = pmu_raw_readl(EXYNOS_ARM_CORE_CONFIGURATION(cpu));
	core_conf &= ~S5P_CORE_LOCAL_PWR_EN;
	pmu_raw_writel(core_conf, EXYNOS_ARM_CORE_CONFIGURATION(cpu));
}

/**
 * exynos_cpu_power_up : power up the specified cpu
 * @cpu : the cpu to power up
 *
 * Power up the specified cpu
 */
void exynos_cpu_power_up(int cpu)
{
	u32 core_conf = S5P_CORE_LOCAL_PWR_EN;

	if (soc_is_exynos3250())
		core_conf |= S5P_CORE_AUTOWAKEUP_EN;

	pmu_raw_writel(core_conf,
			EXYNOS_ARM_CORE_CONFIGURATION(cpu));
}

/**
 * exynos_cpu_power_state : returns the power state of the cpu
 * @cpu : the cpu to retrieve the power state from
 *
 */
int exynos_cpu_power_state(int cpu)
{
	return (pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(cpu)) &
			S5P_CORE_LOCAL_PWR_EN);
}

/**
 * exynos_cluster_power_down : power down the specified cluster
 * @cluster : the cluster to power down
 */
void exynos_cluster_power_down(int cluster)
{
	pmu_raw_writel(0, EXYNOS_COMMON_CONFIGURATION(cluster));
}

/**
 * exynos_cluster_power_up : power up the specified cluster
 * @cluster : the cluster to power up
 */
void exynos_cluster_power_up(int cluster)
{
	pmu_raw_writel(S5P_CORE_LOCAL_PWR_EN,
			EXYNOS_COMMON_CONFIGURATION(cluster));
}

/**
 * exynos_cluster_power_state : returns the power state of the cluster
 * @cluster : the cluster to retrieve the power state from
 *
 */
int exynos_cluster_power_state(int cluster)
{
	return (pmu_raw_readl(EXYNOS_COMMON_STATUS(cluster)) &
		S5P_CORE_LOCAL_PWR_EN);
}

static void __iomem *cpu_boot_reg_base(void)
{
	if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1)
		return pmu_base_addr + S5P_INFORM5;
	return sysram_base_addr;
}

static inline void __iomem *cpu_boot_reg(int cpu)
{
	void __iomem *boot_reg;

	boot_reg = cpu_boot_reg_base();
	if (!boot_reg)
		return IOMEM_ERR_PTR(-ENODEV);
	if (soc_is_exynos4412())
		boot_reg += 4*cpu;
	else if (soc_is_exynos5420() || soc_is_exynos5800())
		boot_reg += 4;
	return boot_reg;
}

/*
 * Set wake up by local power mode and execute software reset for given core.
 *
 * Currently this is needed only when booting secondary CPU on Exynos3250.
 */
void exynos_core_restart(u32 core_id)
{
	u32 val;

	if (!of_machine_is_compatible("samsung,exynos3250"))
		return;

	while (!pmu_raw_readl(S5P_PMU_SPARE2))
		udelay(10);
	udelay(10);

	val = pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(core_id));
	val |= S5P_CORE_WAKEUP_FROM_LOCAL_CFG;
	pmu_raw_writel(val, EXYNOS_ARM_CORE_STATUS(core_id));

	pmu_raw_writel(EXYNOS_CORE_PO_RESET(core_id), EXYNOS_SWRESET);
}

/*
 * Write pen_release in a way that is guaranteed to be visible to all
 * observers, irrespective of whether they're taking part in coherency
 * or not.  This is necessary for the hotplug code to work reliably.
 */
static void write_pen_release(int val)
{
	pen_release = val;
	smp_wmb();
	sync_cache_w(&pen_release);
}

static void __iomem *scu_base_addr(void)
{
	return (void __iomem *)(S5P_VA_SCU);
}

static DEFINE_SPINLOCK(boot_lock);

static void exynos_secondary_init(unsigned int cpu)
{
	/*
	 * let the primary processor know we're out of the
	 * pen, then head off into the C entry point
	 */
	write_pen_release(-1);

	/*
	 * Synchronise with the boot thread.
	 */
	spin_lock(&boot_lock);
	spin_unlock(&boot_lock);
}

int exynos_set_boot_addr(u32 core_id, unsigned long boot_addr)
{
	int ret;

	/*
	 * Try to set boot address using firmware first
	 * and fall back to boot register if it fails.
	 */
	ret = call_firmware_op(set_cpu_boot_addr, core_id, boot_addr);
	if (ret && ret != -ENOSYS)
		goto fail;
	if (ret == -ENOSYS) {
		void __iomem *boot_reg = cpu_boot_reg(core_id);

		if (IS_ERR(boot_reg)) {
			ret = PTR_ERR(boot_reg);
			goto fail;
		}
		writel_relaxed(boot_addr, boot_reg);
		ret = 0;
	}
fail:
	return ret;
}

int exynos_get_boot_addr(u32 core_id, unsigned long *boot_addr)
{
	int ret;

	/*
	 * Try to get boot address using firmware first
	 * and fall back to boot register if it fails.
	 */
	ret = call_firmware_op(get_cpu_boot_addr, core_id, boot_addr);
	if (ret && ret != -ENOSYS)
		goto fail;
	if (ret == -ENOSYS) {
		void __iomem *boot_reg = cpu_boot_reg(core_id);

		if (IS_ERR(boot_reg)) {
			ret = PTR_ERR(boot_reg);
			goto fail;
		}
		*boot_addr = readl_relaxed(boot_reg);
		ret = 0;
	}
fail:
	return ret;
}

static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
	unsigned long timeout;
	u32 mpidr = cpu_logical_map(cpu);
	u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
	int ret = -ENOSYS;

	/*
	 * Set synchronisation state between this boot processor
	 * and the secondary one
	 */
	spin_lock(&boot_lock);

	/*
	 * The secondary processor is waiting to be released from
	 * the holding pen - release it, then wait for it to flag
	 * that it has been released by resetting pen_release.
	 *
	 * Note that "pen_release" is the hardware CPU core ID, whereas
	 * "cpu" is Linux's internal ID.
	 */
	write_pen_release(core_id);

	if (!exynos_cpu_power_state(core_id)) {
		exynos_cpu_power_up(core_id);
		timeout = 10;

		/* wait max 10 ms until cpu1 is on */
		while (exynos_cpu_power_state(core_id)
		       != S5P_CORE_LOCAL_PWR_EN) {
			if (timeout-- == 0)
				break;

			mdelay(1);
		}

		if (timeout == 0) {
			printk(KERN_ERR "cpu1 power enable failed");
			spin_unlock(&boot_lock);
			return -ETIMEDOUT;
		}
	}

	exynos_core_restart(core_id);

	/*
	 * Send the secondary CPU a soft interrupt, thereby causing
	 * the boot monitor to read the system wide flags register,
	 * and branch to the address found there.
	 */

	timeout = jiffies + (1 * HZ);
	while (time_before(jiffies, timeout)) {
		unsigned long boot_addr;

		smp_rmb();

		boot_addr = virt_to_phys(exynos4_secondary_startup);

		ret = exynos_set_boot_addr(core_id, boot_addr);
		if (ret)
			goto fail;

		call_firmware_op(cpu_boot, core_id);

		if (soc_is_exynos3250())
			dsb_sev();
		else
			arch_send_wakeup_ipi_mask(cpumask_of(cpu));

		if (pen_release == -1)
			break;

		udelay(10);
	}

	if (pen_release != -1)
		ret = -ETIMEDOUT;

	/*
	 * now the secondary core is starting up let it run its
	 * calibrations, then wait for it to finish
	 */
fail:
	spin_unlock(&boot_lock);

	return pen_release != -1 ? ret : 0;
}

/*
 * Initialise the CPU possible map early - this describes the CPUs
 * which may be present or become present in the system.
 */

static void __init exynos_smp_init_cpus(void)
{
	void __iomem *scu_base = scu_base_addr();
	unsigned int i, ncores;

	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
		ncores = scu_base ? scu_get_core_count(scu_base) : 1;
	else
		/*
		 * CPU Nodes are passed thru DT and set_cpu_possible
		 * is set by "arm_dt_init_cpu_maps".
		 */
		return;

	/* sanity check */
	if (ncores > nr_cpu_ids) {
		pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
			ncores, nr_cpu_ids);
		ncores = nr_cpu_ids;
	}

	for (i = 0; i < ncores; i++)
		set_cpu_possible(i, true);
}

static void __init exynos_smp_prepare_cpus(unsigned int max_cpus)
{
	int i;

	exynos_sysram_init();

	exynos_set_delayed_reset_assertion(true);

	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
		scu_enable(scu_base_addr());

	/*
	 * Write the address of secondary startup into the
	 * system-wide flags register. The boot monitor waits
	 * until it receives a soft interrupt, and then the
	 * secondary CPU branches to this address.
	 *
	 * Try using firmware operation first and fall back to
	 * boot register if it fails.
	 */
	for (i = 1; i < max_cpus; ++i) {
		unsigned long boot_addr;
		u32 mpidr;
		u32 core_id;
		int ret;

		mpidr = cpu_logical_map(i);
		core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
		boot_addr = virt_to_phys(exynos4_secondary_startup);

		ret = exynos_set_boot_addr(core_id, boot_addr);
		if (ret)
			break;
	}
}

#ifdef CONFIG_HOTPLUG_CPU
/*
 * platform-specific code to shutdown a CPU
 *
 * Called with IRQs disabled
 */
static void exynos_cpu_die(unsigned int cpu)
{
	int spurious = 0;
	u32 mpidr = cpu_logical_map(cpu);
	u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);

	v7_exit_coherency_flush(louis);

	platform_do_lowpower(cpu, &spurious);

	/*
	 * bring this CPU back into the world of cache
	 * coherency, and then restore interrupts
	 */
	cpu_leave_lowpower(core_id);

	if (spurious)
		pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
}
#endif /* CONFIG_HOTPLUG_CPU */

const struct smp_operations exynos_smp_ops __initconst = {
	.smp_init_cpus		= exynos_smp_init_cpus,
	.smp_prepare_cpus	= exynos_smp_prepare_cpus,
	.smp_secondary_init	= exynos_secondary_init,
	.smp_boot_secondary	= exynos_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
	.cpu_die		= exynos_cpu_die,
#endif
};