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authorLinus Torvalds <torvalds@linux-foundation.org>2011-01-06 19:50:35 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-06 19:50:35 -0500
commit3c0cb7c31c206aaedb967e44b98442bbeb17a6c4 (patch)
tree3ecba45d7ffae4fba4a5aafaef4af5b0b1105bde /arch/arm/mach-vexpress/hotplug.c
parentf70f5b9dc74ca7d0a64c4ead3fb28da09dc1b234 (diff)
parent404a02cbd2ae8bf256a2fa1169bdfe86bb5ebb34 (diff)
Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (416 commits) ARM: DMA: add support for DMA debugging ARM: PL011: add DMA burst threshold support for ST variants ARM: PL011: Add support for transmit DMA ARM: PL011: Ensure IRQs are disabled in UART interrupt handler ARM: PL011: Separate hardware FIFO size from TTY FIFO size ARM: PL011: Allow better handling of vendor data ARM: PL011: Ensure error flags are clear at startup ARM: PL011: include revision number in boot-time port printk ARM: vexpress: add sched_clock() for Versatile Express ARM i.MX53: Make MX53 EVK bootable ARM i.MX53: Some bug fix about MX53 MSL code ARM: 6607/1: sa1100: Update platform device registration ARM: 6606/1: sa1100: Fix platform device registration ARM i.MX51: rename IPU irqs ARM i.MX51: Add ipu clock support ARM: imx/mx27_3ds: Add PMIC support ARM: DMA: Replace page_to_dma()/dma_to_page() with pfn_to_dma()/dma_to_pfn() mx51: fix usb clock support MX51: Add support for usb host 2 arch/arm/plat-mxc/ehci.c: fix errors/typos ...
Diffstat (limited to 'arch/arm/mach-vexpress/hotplug.c')
-rw-r--r--arch/arm/mach-vexpress/hotplug.c128
1 files changed, 128 insertions, 0 deletions
diff --git a/arch/arm/mach-vexpress/hotplug.c b/arch/arm/mach-vexpress/hotplug.c
new file mode 100644
index 000000000000..ea4cbfb90a66
--- /dev/null
+++ b/arch/arm/mach-vexpress/hotplug.c
@@ -0,0 +1,128 @@
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
17extern volatile int pen_release;
18
19static inline void cpu_enter_lowpower(void)
20{
21 unsigned int v;
22
23 flush_cache_all();
24 asm volatile(
25 "mcr p15, 0, %1, c7, c5, 0\n"
26 " mcr p15, 0, %1, c7, c10, 4\n"
27 /*
28 * Turn off coherency
29 */
30 " mrc p15, 0, %0, c1, c0, 1\n"
31 " bic %0, %0, %3\n"
32 " mcr p15, 0, %0, c1, c0, 1\n"
33 " mrc p15, 0, %0, c1, c0, 0\n"
34 " bic %0, %0, %2\n"
35 " mcr p15, 0, %0, c1, c0, 0\n"
36 : "=&r" (v)
37 : "r" (0), "Ir" (CR_C), "Ir" (0x40)
38 : "cc");
39}
40
41static inline void cpu_leave_lowpower(void)
42{
43 unsigned int v;
44
45 asm volatile(
46 "mrc p15, 0, %0, c1, c0, 0\n"
47 " orr %0, %0, %1\n"
48 " mcr p15, 0, %0, c1, c0, 0\n"
49 " mrc p15, 0, %0, c1, c0, 1\n"
50 " orr %0, %0, %2\n"
51 " mcr p15, 0, %0, c1, c0, 1\n"
52 : "=&r" (v)
53 : "Ir" (CR_C), "Ir" (0x40)
54 : "cc");
55}
56
57static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
58{
59 /*
60 * there is no power-control hardware on this platform, so all
61 * we can do is put the core into WFI; this is safe as the calling
62 * code will have already disabled interrupts
63 */
64 for (;;) {
65 /*
66 * here's the WFI
67 */
68 asm(".word 0xe320f003\n"
69 :
70 :
71 : "memory", "cc");
72
73 if (pen_release == cpu) {
74 /*
75 * OK, proper wakeup, we're done
76 */
77 break;
78 }
79
80 /*
81 * Getting here, means that we have come out of WFI without
82 * having been woken up - this shouldn't happen
83 *
84 * Just note it happening - when we're woken, we can report
85 * its occurrence.
86 */
87 (*spurious)++;
88 }
89}
90
91int platform_cpu_kill(unsigned int cpu)
92{
93 return 1;
94}
95
96/*
97 * platform-specific code to shutdown a CPU
98 *
99 * Called with IRQs disabled
100 */
101void platform_cpu_die(unsigned int cpu)
102{
103 int spurious = 0;
104
105 /*
106 * we're ready for shutdown now, so do it
107 */
108 cpu_enter_lowpower();
109 platform_do_lowpower(cpu, &spurious);
110
111 /*
112 * bring this CPU back into the world of cache
113 * coherency, and then restore interrupts
114 */
115 cpu_leave_lowpower();
116
117 if (spurious)
118 pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
119}
120
121int platform_cpu_disable(unsigned int cpu)
122{
123 /*
124 * we don't allow CPU 0 to be shutdown (it is still too special
125 * e.g. clock tick interrupts)
126 */
127 return cpu == 0 ? -EPERM : 0;
128}