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1/*
2 * linux/arch/arm/mach-realview/hotplug.c
3 *
4 * Copyright (C) 2002 ARM Ltd.
5 * All Rights Reserved
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11#include <linux/kernel.h>
12#include <linux/errno.h>
13#include <linux/smp.h>
14
15#include <asm/cacheflush.h>
16#include <asm/cp15.h>
17
18static inline void cpu_enter_lowpower(void)
19{
20 unsigned int v;
21
22 flush_cache_all();
23 asm volatile(
24 " mcr p15, 0, %1, c7, c5, 0\n"
25 " mcr p15, 0, %1, c7, c10, 4\n"
26 /*
27 * Turn off coherency
28 */
29 " mrc p15, 0, %0, c1, c0, 1\n"
30 " bic %0, %0, #0x20\n"
31 " mcr p15, 0, %0, c1, c0, 1\n"
32 " mrc p15, 0, %0, c1, c0, 0\n"
33 " bic %0, %0, %2\n"
34 " mcr p15, 0, %0, c1, c0, 0\n"
35 : "=&r" (v)
36 : "r" (0), "Ir" (CR_C)
37 : "cc");
38}
39
40static inline void cpu_leave_lowpower(void)
41{
42 unsigned int v;
43
44 asm volatile(
45 "mrc p15, 0, %0, c1, c0, 0\n"
46 " orr %0, %0, %1\n"
47 " mcr p15, 0, %0, c1, c0, 0\n"
48 " mrc p15, 0, %0, c1, c0, 1\n"
49 " orr %0, %0, #0x20\n"
50 " mcr p15, 0, %0, c1, c0, 1\n"
51 : "=&r" (v)
52 : "Ir" (CR_C)
53 : "cc");
54}
55
56static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
57{
58 /*
59 * there is no power-control hardware on this platform, so all
60 * we can do is put the core into WFI; this is safe as the calling
61 * code will have already disabled interrupts
62 */
63 for (;;) {
64 /*
65 * here's the WFI
66 */
67 asm(".word 0xe320f003\n"
68 :
69 :
70 : "memory", "cc");
71
72 /*if (pen_release == cpu) {*/
73 /*
74 * OK, proper wakeup, we're done
75 */
76 break;
77 /*}*/
78
79 /*
80 * Getting here, means that we have come out of WFI without
81 * having been woken up - this shouldn't happen
82 *
83 * Just note it happening - when we're woken, we can report
84 * its occurrence.
85 */
86 (*spurious)++;
87 }
88}
89
90int platform_cpu_kill(unsigned int cpu)
91{
92 return 1;
93}
94
95/*
96 * platform-specific code to shutdown a CPU
97 *
98 * Called with IRQs disabled
99 */
100void platform_cpu_die(unsigned int cpu)
101{
102 int spurious = 0;
103
104 /*
105 * we're ready for shutdown now, so do it
106 */
107 cpu_enter_lowpower();
108 platform_do_lowpower(cpu, &spurious);
109
110 /*
111 * bring this CPU back into the world of cache
112 * coherency, and then restore interrupts
113 */
114 cpu_leave_lowpower();
115
116 if (spurious)
117 pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
118}
119
120int platform_cpu_disable(unsigned int cpu)
121{
122 /*
123 * we don't allow CPU 0 to be shutdown (it is still too special
124 * e.g. clock tick interrupts)
125 */
126 return cpu == 0 ? -EPERM : 0;
127}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2002 ARM Ltd.
4 * All Rights Reserved
5 * Copyright (c) 2010, 2012-2013, NVIDIA Corporation. All rights reserved.
6 */
7
8#include <linux/clk/tegra.h>
9#include <linux/kernel.h>
10#include <linux/smp.h>
11
12#include <soc/tegra/common.h>
13#include <soc/tegra/fuse.h>
14
15#include <asm/smp_plat.h>
16
17#include "common.h"
18#include "sleep.h"
19
20static void (*tegra_hotplug_shutdown)(void);
21
22int tegra_cpu_kill(unsigned cpu)
23{
24 cpu = cpu_logical_map(cpu);
25
26 /* Clock gate the CPU */
27 tegra_wait_cpu_in_reset(cpu);
28 tegra_disable_cpu_clock(cpu);
29
30 return 1;
31}
32
33/*
34 * platform-specific code to shutdown a CPU
35 *
36 * Called with IRQs disabled
37 */
38void tegra_cpu_die(unsigned int cpu)
39{
40 if (!tegra_hotplug_shutdown) {
41 WARN(1, "hotplug is not yet initialized\n");
42 return;
43 }
44
45 /* Clean L1 data cache */
46 tegra_disable_clean_inv_dcache(TEGRA_FLUSH_CACHE_LOUIS);
47
48 /* Shut down the current CPU. */
49 tegra_hotplug_shutdown();
50
51 /* Should never return here. */
52 BUG();
53}
54
55static int __init tegra_hotplug_init(void)
56{
57 if (!IS_ENABLED(CONFIG_HOTPLUG_CPU))
58 return 0;
59
60 if (!soc_is_tegra())
61 return 0;
62
63 if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC) && tegra_get_chip_id() == TEGRA20)
64 tegra_hotplug_shutdown = tegra20_hotplug_shutdown;
65 if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) && tegra_get_chip_id() == TEGRA30)
66 tegra_hotplug_shutdown = tegra30_hotplug_shutdown;
67 if (IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) && tegra_get_chip_id() == TEGRA114)
68 tegra_hotplug_shutdown = tegra30_hotplug_shutdown;
69 if (IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC) && tegra_get_chip_id() == TEGRA124)
70 tegra_hotplug_shutdown = tegra30_hotplug_shutdown;
71
72 return 0;
73}
74pure_initcall(tegra_hotplug_init);