summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-omap2/omap-smp.c
blob: 361677983af0ea07d84667cd36da407317d684b8 (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
/*
 * OMAP4 SMP source file. It contains platform specific fucntions
 * needed for the linux smp kernel.
 *
 * Copyright (C) 2009 Texas Instruments, Inc.
 *
 * Author:
 *      Santosh Shilimkar <santosh.shilimkar@ti.com>
 *
 * Platform file needed for the OMAP4 SMP. This file is based on arm
 * realview smp platform.
 * * Copyright (c) 2002 ARM Limited.
 *
 * 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/device.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/irqchip/arm-gic.h>

#include <asm/cacheflush.h>
#include <asm/smp_scu.h>

#include "omap-secure.h"
#include "omap-wakeupgen.h"
#include <asm/cputype.h>

#include "soc.h"
#include "iomap.h"
#include "common.h"
#include "clockdomain.h"
#include "pm.h"

#define CPU_MASK		0xff0ffff0
#define CPU_CORTEX_A9		0x410FC090
#define CPU_CORTEX_A15		0x410FC0F0

#define OMAP5_CORE_COUNT	0x2

u16 pm44xx_errata;

/* SCU base address */
static void __iomem *scu_base;

static DEFINE_SPINLOCK(boot_lock);

void __iomem *omap4_get_scu_base(void)
{
	return scu_base;
}

static void __cpuinit omap4_secondary_init(unsigned int cpu)
{
	/*
	 * Configure ACTRL and enable NS SMP bit access on CPU1 on HS device.
	 * OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA
	 * init and for CPU1, a secure PPA API provided. CPU0 must be ON
	 * while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+.
	 * OMAP443X GP devices- SMP bit isn't accessible.
	 * OMAP446X GP devices - SMP bit access is enabled on both CPUs.
	 */
	if (cpu_is_omap443x() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
		omap_secure_dispatcher(OMAP4_PPA_CPU_ACTRL_SMP_INDEX,
							4, 0, 0, 0, 0, 0);

	/*
	 * If any interrupts are already enabled for the primary
	 * core (e.g. timer irq), then they will not have been enabled
	 * for us: do so
	 */
	gic_secondary_init(0);

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

static int __cpuinit omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
	static struct clockdomain *cpu1_clkdm;
	static bool booted;
	void __iomem *base = omap_get_wakeupgen_base();

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

	/*
	 * Update the AuxCoreBoot0 with boot state for secondary core.
	 * omap_secondary_startup() routine will hold the secondary core till
	 * the AuxCoreBoot1 register is updated with cpu state
	 * A barrier is added to ensure that write buffer is drained
	 */
	if (omap_secure_apis_support())
		omap_modify_auxcoreboot0(0x200, 0xfffffdff);
	else
		__raw_writel(0x20, base + OMAP_AUX_CORE_BOOT_0);

	flush_cache_all();
	smp_wmb();

	if (!cpu1_clkdm)
		cpu1_clkdm = clkdm_lookup("mpu1_clkdm");

	/*
	 * The SGI(Software Generated Interrupts) are not wakeup capable
	 * from low power states. This is known limitation on OMAP4 and
	 * needs to be worked around by using software forced clockdomain
	 * wake-up. To wakeup CPU1, CPU0 forces the CPU1 clockdomain to
	 * software force wakeup. The clockdomain is then put back to
	 * hardware supervised mode.
	 * More details can be found in OMAP4430 TRM - Version J
	 * Section :
	 *	4.3.4.2 Power States of CPU0 and CPU1
	 */
	if (booted) {
		/*
		 * GIC distributor control register has changed between
		 * CortexA9 r1pX and r2pX. The Control Register secure
		 * banked version is now composed of 2 bits:
		 * bit 0 == Secure Enable
		 * bit 1 == Non-Secure Enable
		 * The Non-Secure banked register has not changed
		 * Because the ROM Code is based on the r1pX GIC, the CPU1
		 * GIC restoration will cause a problem to CPU0 Non-Secure SW.
		 * The workaround must be:
		 * 1) Before doing the CPU1 wakeup, CPU0 must disable
		 * the GIC distributor
		 * 2) CPU1 must re-enable the GIC distributor on
		 * it's wakeup path.
		 */
		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
			local_irq_disable();
			gic_dist_disable();
		}

		clkdm_wakeup(cpu1_clkdm);
		clkdm_allow_idle(cpu1_clkdm);

		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
			while (gic_dist_disabled()) {
				udelay(1);
				cpu_relax();
			}
			gic_timer_retrigger();
			local_irq_enable();
		}
	} else {
		dsb_sev();
		booted = true;
	}

	arch_send_wakeup_ipi_mask(cpumask_of(cpu));

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

	return 0;
}

static void __init wakeup_secondary(void)
{
	void *startup_addr = omap_secondary_startup;
	void __iomem *base = omap_get_wakeupgen_base();

	if (cpu_is_omap446x()) {
		startup_addr = omap_secondary_startup_4460;
		pm44xx_errata |= PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD;
	}

	/*
	 * Write the address of secondary startup routine into the
	 * AuxCoreBoot1 where ROM code will jump and start executing
	 * on secondary core once out of WFE
	 * A barrier is added to ensure that write buffer is drained
	 */
	if (omap_secure_apis_support())
		omap_auxcoreboot_addr(virt_to_phys(startup_addr));
	else
		__raw_writel(virt_to_phys(omap5_secondary_startup),
						base + OMAP_AUX_CORE_BOOT_1);

	smp_wmb();

	/*
	 * Send a 'sev' to wake the secondary core from WFE.
	 * Drain the outstanding writes to memory
	 */
	dsb_sev();
	mb();
}

/*
 * Initialise the CPU possible map early - this describes the CPUs
 * which may be present or become present in the system.
 */
static void __init omap4_smp_init_cpus(void)
{
	unsigned int i = 0, ncores = 1, cpu_id;

	/* Use ARM cpuid check here, as SoC detection will not work so early */
	cpu_id = read_cpuid(CPUID_ID) & CPU_MASK;
	if (cpu_id == CPU_CORTEX_A9) {
		/*
		 * Currently we can't call ioremap here because
		 * SoC detection won't work until after init_early.
		 */
		scu_base =  OMAP2_L4_IO_ADDRESS(OMAP44XX_SCU_BASE);
		BUG_ON(!scu_base);
		ncores = scu_get_core_count(scu_base);
	} else if (cpu_id == CPU_CORTEX_A15) {
		ncores = OMAP5_CORE_COUNT;
	}

	/* 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 omap4_smp_prepare_cpus(unsigned int max_cpus)
{

	/*
	 * Initialise the SCU and wake up the secondary core using
	 * wakeup_secondary().
	 */
	if (scu_base)
		scu_enable(scu_base);
	wakeup_secondary();
}

struct smp_operations omap4_smp_ops __initdata = {
	.smp_init_cpus		= omap4_smp_init_cpus,
	.smp_prepare_cpus	= omap4_smp_prepare_cpus,
	.smp_secondary_init	= omap4_secondary_init,
	.smp_boot_secondary	= omap4_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
	.cpu_die		= omap4_cpu_die,
#endif
};
OpenPOWER on IntegriCloud