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1/*
2 * linux/arch/arm/mach-spear13xx/hotplug.c
3 *
4 * Copyright (C) 2012 ST Microelectronics Ltd.
5 * Deepak Sikri <deepak.sikri@st.com>
6 *
7 * based upon linux/arch/arm/mach-realview/hotplug.c
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13#include <linux/kernel.h>
14#include <linux/errno.h>
15#include <linux/smp.h>
16#include <asm/cp15.h>
17#include <asm/smp_plat.h>
18
19static inline void cpu_enter_lowpower(void)
20{
21 unsigned int v;
22
23 asm volatile(
24 " mcr p15, 0, %1, c7, c5, 0\n"
25 " dsb\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", "memory");
38}
39
40static inline void cpu_leave_lowpower(void)
41{
42 unsigned int v;
43
44 asm volatile("mrc p15, 0, %0, c1, c0, 0\n"
45 " orr %0, %0, %1\n"
46 " mcr p15, 0, %0, c1, c0, 0\n"
47 " mrc p15, 0, %0, c1, c0, 1\n"
48 " orr %0, %0, #0x20\n"
49 " mcr p15, 0, %0, c1, c0, 1\n"
50 : "=&r" (v)
51 : "Ir" (CR_C)
52 : "cc");
53}
54
55static inline void spear13xx_do_lowpower(unsigned int cpu, int *spurious)
56{
57 for (;;) {
58 wfi();
59
60 if (pen_release == cpu) {
61 /*
62 * OK, proper wakeup, we're done
63 */
64 break;
65 }
66
67 /*
68 * Getting here, means that we have come out of WFI without
69 * having been woken up - this shouldn't happen
70 *
71 * Just note it happening - when we're woken, we can report
72 * its occurrence.
73 */
74 (*spurious)++;
75 }
76}
77
78/*
79 * platform-specific code to shutdown a CPU
80 *
81 * Called with IRQs disabled
82 */
83void __ref spear13xx_cpu_die(unsigned int cpu)
84{
85 int spurious = 0;
86
87 /*
88 * we're ready for shutdown now, so do it
89 */
90 cpu_enter_lowpower();
91 spear13xx_do_lowpower(cpu, &spurious);
92
93 /*
94 * bring this CPU back into the world of cache
95 * coherency, and then restore interrupts
96 */
97 cpu_leave_lowpower();
98
99 if (spurious)
100 pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
101}
1/*
2 * linux/arch/arm/mach-spear13xx/hotplug.c
3 *
4 * Copyright (C) 2012 ST Microelectronics Ltd.
5 * Deepak Sikri <deepak.sikri@st.com>
6 *
7 * based upon linux/arch/arm/mach-realview/hotplug.c
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13#include <linux/kernel.h>
14#include <linux/errno.h>
15#include <linux/smp.h>
16#include <asm/cp15.h>
17#include <asm/smp_plat.h>
18
19static inline void cpu_enter_lowpower(void)
20{
21 unsigned int v;
22
23 asm volatile(
24 " mcr p15, 0, %1, c7, c5, 0\n"
25 " dsb\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", "memory");
38}
39
40static inline void cpu_leave_lowpower(void)
41{
42 unsigned int v;
43
44 asm volatile("mrc p15, 0, %0, c1, c0, 0\n"
45 " orr %0, %0, %1\n"
46 " mcr p15, 0, %0, c1, c0, 0\n"
47 " mrc p15, 0, %0, c1, c0, 1\n"
48 " orr %0, %0, #0x20\n"
49 " mcr p15, 0, %0, c1, c0, 1\n"
50 : "=&r" (v)
51 : "Ir" (CR_C)
52 : "cc");
53}
54
55static inline void spear13xx_do_lowpower(unsigned int cpu, int *spurious)
56{
57 for (;;) {
58 wfi();
59
60 if (pen_release == cpu) {
61 /*
62 * OK, proper wakeup, we're done
63 */
64 break;
65 }
66
67 /*
68 * Getting here, means that we have come out of WFI without
69 * having been woken up - this shouldn't happen
70 *
71 * Just note it happening - when we're woken, we can report
72 * its occurrence.
73 */
74 (*spurious)++;
75 }
76}
77
78/*
79 * platform-specific code to shutdown a CPU
80 *
81 * Called with IRQs disabled
82 */
83void spear13xx_cpu_die(unsigned int cpu)
84{
85 int spurious = 0;
86
87 /*
88 * we're ready for shutdown now, so do it
89 */
90 cpu_enter_lowpower();
91 spear13xx_do_lowpower(cpu, &spurious);
92
93 /*
94 * bring this CPU back into the world of cache
95 * coherency, and then restore interrupts
96 */
97 cpu_leave_lowpower();
98
99 if (spurious)
100 pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
101}