1/*
 2 * OMAP4 SMP cpu-hotplug support
 3 *
 4 * Copyright (C) 2010 Texas Instruments, Inc.
 5 * Author:
 6 *      Santosh Shilimkar <santosh.shilimkar@ti.com>
 7 *
 8 * Platform file needed for the OMAP4 SMP. This file is based on arm
 9 * realview smp platform.
10 * Copyright (c) 2002 ARM Limited.
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16
17#include <linux/kernel.h>
18#include <linux/errno.h>
19#include <linux/smp.h>
 
20
21#include <asm/cacheflush.h>
22
23#include "common.h"
24
25#include "powerdomain.h"
26
27int platform_cpu_kill(unsigned int cpu)
28{
29	return 1;
30}
31
32/*
33 * platform-specific code to shutdown a CPU
34 * Called with IRQs disabled
35 */
36void __ref platform_cpu_die(unsigned int cpu)
37{
38	unsigned int this_cpu;
39
40	flush_cache_all();
41	dsb();
42
43	/*
44	 * we're ready for shutdown now, so do it
45	 */
46	if (omap_modify_auxcoreboot0(0x0, 0x200) != 0x0)
47		pr_err("Secure clear status failed\n");
 
 
 
 
 
48
49	for (;;) {
50		/*
51		 * Enter into low power state
52		 */
53		omap4_hotplug_cpu(cpu, PWRDM_POWER_OFF);
54		this_cpu = smp_processor_id();
55		if (omap_read_auxcoreboot0() == this_cpu) {
 
 
 
 
 
 
56			/*
57			 * OK, proper wakeup, we're done
58			 */
59			break;
60		}
61		pr_debug("CPU%u: spurious wakeup call\n", cpu);
62	}
63}
64
65int platform_cpu_disable(unsigned int cpu)
 
66{
67	/*
68	 * we don't allow CPU 0 to be shutdown (it is still too special
69	 * e.g. clock tick interrupts)
70	 */
71	return cpu == 0 ? -EPERM : 0;
72}

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * OMAP4 SMP cpu-hotplug support
 4 *
 5 * Copyright (C) 2010 Texas Instruments, Inc.
 6 * Author:
 7 *      Santosh Shilimkar <santosh.shilimkar@ti.com>
 8 *
 9 * Platform file needed for the OMAP4 SMP. This file is based on arm
10 * realview smp platform.
11 * Copyright (c) 2002 ARM Limited.
 
 
 
 
12 */
13
14#include <linux/kernel.h>
15#include <linux/errno.h>
16#include <linux/smp.h>
17#include <linux/io.h>
18
19#include "omap-wakeupgen.h"
 
20#include "common.h"
 
21#include "powerdomain.h"
22
 
 
 
 
 
23/*
24 * platform-specific code to shutdown a CPU
25 * Called with IRQs disabled
26 */
27void omap4_cpu_die(unsigned int cpu)
28{
29	unsigned int boot_cpu = 0;
30	void __iomem *base = omap_get_wakeupgen_base();
 
 
31
32	/*
33	 * we're ready for shutdown now, so do it
34	 */
35	if (omap_secure_apis_support()) {
36		if (omap_modify_auxcoreboot0(0x0, 0x200) != 0x0)
37			pr_err("Secure clear status failed\n");
38	} else {
39		writel_relaxed(0, base + OMAP_AUX_CORE_BOOT_0);
40	}
41
42
43	for (;;) {
44		/*
45		 * Enter into low power state
46		 */
47		omap4_hotplug_cpu(cpu, PWRDM_POWER_OFF);
48
49		if (omap_secure_apis_support())
50			boot_cpu = omap_read_auxcoreboot0() >> 9;
51		else
52			boot_cpu =
53				readl_relaxed(base + OMAP_AUX_CORE_BOOT_0) >> 5;
54
55		if (boot_cpu == smp_processor_id()) {
56			/*
57			 * OK, proper wakeup, we're done
58			 */
59			break;
60		}
61		pr_debug("CPU%u: spurious wakeup call\n", cpu);
62	}
63}
64
65/* Needed by kexec and platform_can_cpu_hotplug() */
66int omap4_cpu_kill(unsigned int cpu)
67{
68	return 1;
 
 
 
 
69}