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-rw-r--r--arch/arm/Kconfig2
-rw-r--r--arch/arm/mach-realview/Makefile2
-rw-r--r--arch/arm/mach-realview/core.c2
-rw-r--r--arch/arm/mach-realview/hotplug.c138
-rw-r--r--arch/arm/mach-realview/localtimer.c130
-rw-r--r--arch/arm/mach-realview/platsmp.c5
6 files changed, 277 insertions, 2 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 3bfef0934c9d..ec77721507cb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -358,7 +358,7 @@ config HOTPLUG_CPU
358 358
359config LOCAL_TIMERS 359config LOCAL_TIMERS
360 bool "Use local timer interrupts" 360 bool "Use local timer interrupts"
361 depends on SMP && n 361 depends on SMP && REALVIEW_MPCORE
362 default y 362 default y
363 help 363 help
364 Enable support for local timers on SMP platforms, rather then the 364 Enable support for local timers on SMP platforms, rather then the
diff --git a/arch/arm/mach-realview/Makefile b/arch/arm/mach-realview/Makefile
index 011a85c10627..36e76ba937fc 100644
--- a/arch/arm/mach-realview/Makefile
+++ b/arch/arm/mach-realview/Makefile
@@ -5,3 +5,5 @@
5obj-y := core.o clock.o 5obj-y := core.o clock.o
6obj-$(CONFIG_MACH_REALVIEW_EB) += realview_eb.o 6obj-$(CONFIG_MACH_REALVIEW_EB) += realview_eb.o
7obj-$(CONFIG_SMP) += platsmp.o headsmp.o 7obj-$(CONFIG_SMP) += platsmp.o headsmp.o
8obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
9obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o
diff --git a/arch/arm/mach-realview/core.c b/arch/arm/mach-realview/core.c
index 4ea60d8b6e36..e2c6fa23d3cd 100644
--- a/arch/arm/mach-realview/core.c
+++ b/arch/arm/mach-realview/core.c
@@ -550,7 +550,7 @@ static irqreturn_t realview_timer_interrupt(int irq, void *dev_id, struct pt_reg
550 550
551 timer_tick(regs); 551 timer_tick(regs);
552 552
553#ifdef CONFIG_SMP 553#if defined(CONFIG_SMP) && !defined(CONFIG_LOCAL_TIMERS)
554 smp_send_timer(); 554 smp_send_timer();
555 update_process_times(user_mode(regs)); 555 update_process_times(user_mode(regs));
556#endif 556#endif
diff --git a/arch/arm/mach-realview/hotplug.c b/arch/arm/mach-realview/hotplug.c
new file mode 100644
index 000000000000..09748cbcd10e
--- /dev/null
+++ b/arch/arm/mach-realview/hotplug.c
@@ -0,0 +1,138 @@
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#include <linux/completion.h>
15
16extern volatile int pen_release;
17
18static DECLARE_COMPLETION(cpu_killed);
19
20static inline void cpu_enter_lowpower(void)
21{
22 unsigned int v;
23
24 asm volatile( "mcr p15, 0, %1, c7, c14, 0\n"
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, #0x20\n"
32 " mcr p15, 0, %0, c1, c0, 1\n"
33 " mrc p15, 0, %0, c1, c0, 0\n"
34 " bic %0, %0, #0x04\n"
35 " mcr p15, 0, %0, c1, c0, 0\n"
36 : "=&r" (v)
37 : "r" (0)
38 : "cc");
39}
40
41static inline void cpu_leave_lowpower(void)
42{
43 unsigned int v;
44
45 asm volatile( "mrc p15, 0, %0, c1, c0, 0\n"
46 " orr %0, %0, #0x04\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 :
53 : "cc");
54}
55
56static inline void platform_do_lowpower(unsigned int cpu)
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 * The trouble is, letting people know about this is not really
84 * possible, since we are currently running incoherently, and
85 * therefore cannot safely call printk() or anything else
86 */
87#ifdef DEBUG
88 printk("CPU%u: spurious wakeup call\n", cpu);
89#endif
90 }
91}
92
93int platform_cpu_kill(unsigned int cpu)
94{
95 return wait_for_completion_timeout(&cpu_killed, 5000);
96}
97
98/*
99 * platform-specific code to shutdown a CPU
100 *
101 * Called with IRQs disabled
102 */
103void platform_cpu_die(unsigned int cpu)
104{
105#ifdef DEBUG
106 unsigned int this_cpu = hard_smp_processor_id();
107
108 if (cpu != this_cpu) {
109 printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n",
110 this_cpu, cpu);
111 BUG();
112 }
113#endif
114
115 printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
116 complete(&cpu_killed);
117
118 /*
119 * we're ready for shutdown now, so do it
120 */
121 cpu_enter_lowpower();
122 platform_do_lowpower(cpu);
123
124 /*
125 * bring this CPU back into the world of cache
126 * coherency, and then restore interrupts
127 */
128 cpu_leave_lowpower();
129}
130
131int mach_cpu_disable(unsigned int cpu)
132{
133 /*
134 * we don't allow CPU 0 to be shutdown (it is still too special
135 * e.g. clock tick interrupts)
136 */
137 return cpu == 0 ? -EPERM : 0;
138}
diff --git a/arch/arm/mach-realview/localtimer.c b/arch/arm/mach-realview/localtimer.c
new file mode 100644
index 000000000000..5e917e37d095
--- /dev/null
+++ b/arch/arm/mach-realview/localtimer.c
@@ -0,0 +1,130 @@
1/*
2 * linux/arch/arm/mach-realview/localtimer.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/init.h>
12#include <linux/kernel.h>
13#include <linux/delay.h>
14#include <linux/device.h>
15#include <linux/smp.h>
16
17#include <asm/mach/time.h>
18#include <asm/hardware/arm_twd.h>
19#include <asm/hardware/gic.h>
20#include <asm/hardware.h>
21#include <asm/io.h>
22#include <asm/irq.h>
23
24#include "core.h"
25
26#define TWD_BASE(cpu) (__io_address(REALVIEW_TWD_BASE) + \
27 ((cpu) * REALVIEW_TWD_SIZE))
28
29static unsigned long mpcore_timer_rate;
30
31/*
32 * local_timer_ack: checks for a local timer interrupt.
33 *
34 * If a local timer interrupt has occured, acknowledge and return 1.
35 * Otherwise, return 0.
36 */
37int local_timer_ack(void)
38{
39 void __iomem *base = TWD_BASE(smp_processor_id());
40
41 if (__raw_readl(base + TWD_TIMER_INTSTAT)) {
42 __raw_writel(1, base + TWD_TIMER_INTSTAT);
43 return 1;
44 }
45
46 return 0;
47}
48
49void __cpuinit local_timer_setup(unsigned int cpu)
50{
51 void __iomem *base = TWD_BASE(cpu);
52 unsigned int load, offset;
53 u64 waitjiffies;
54 unsigned int count;
55
56 /*
57 * If this is the first time round, we need to work out how fast
58 * the timer ticks
59 */
60 if (mpcore_timer_rate == 0) {
61 printk("Calibrating local timer... ");
62
63 /* Wait for a tick to start */
64 waitjiffies = get_jiffies_64() + 1;
65
66 while (get_jiffies_64() < waitjiffies)
67 udelay(10);
68
69 /* OK, now the tick has started, let's get the timer going */
70 waitjiffies += 5;
71
72 /* enable, no interrupt or reload */
73 __raw_writel(0x1, base + TWD_TIMER_CONTROL);
74
75 /* maximum value */
76 __raw_writel(0xFFFFFFFFU, base + TWD_TIMER_COUNTER);
77
78 while (get_jiffies_64() < waitjiffies)
79 udelay(10);
80
81 count = __raw_readl(base + TWD_TIMER_COUNTER);
82
83 mpcore_timer_rate = (0xFFFFFFFFU - count) * (HZ / 5);
84
85 printk("%lu.%02luMHz.\n", mpcore_timer_rate / 1000000,
86 (mpcore_timer_rate / 100000) % 100);
87 }
88
89 load = mpcore_timer_rate / HZ;
90
91 __raw_writel(load, base + TWD_TIMER_LOAD);
92 __raw_writel(0x7, base + TWD_TIMER_CONTROL);
93
94 /*
95 * Now maneuver our local tick into the right part of the jiffy.
96 * Start by working out where within the tick our local timer
97 * interrupt should go.
98 */
99 offset = ((mpcore_timer_rate / HZ) / (NR_CPUS + 1)) * (cpu + 1);
100
101 /*
102 * gettimeoffset() will return a number of us since the last tick.
103 * Convert this number of us to a local timer tick count.
104 * Be careful of integer overflow whilst keeping maximum precision.
105 *
106 * with HZ=100 and 1MHz (fpga) ~ 1GHz processor:
107 * load = 1 ~ 10,000
108 * mpcore_timer_rate/10000 = 100 ~ 100,000
109 *
110 * so the multiply value will be less than 10^9 always.
111 */
112 load = (system_timer->offset() * (mpcore_timer_rate / 10000)) / 100;
113
114 /* Add on our offset to get the load value */
115 load = (load + offset) % (mpcore_timer_rate / HZ);
116
117 __raw_writel(load, base + TWD_TIMER_COUNTER);
118
119 /* Make sure our local interrupt controller has this enabled */
120 __raw_writel(1 << IRQ_LOCALTIMER,
121 __io_address(REALVIEW_GIC_DIST_BASE) + GIC_DIST_ENABLE_SET);
122}
123
124/*
125 * take a local timer down
126 */
127void __cpuexit local_timer_stop(unsigned int cpu)
128{
129 __raw_writel(0, TWD_BASE(cpu) + TWD_TIMER_CONTROL);
130}
diff --git a/arch/arm/mach-realview/platsmp.c b/arch/arm/mach-realview/platsmp.c
index 09b35f62247a..0c7d4ac9a7b3 100644
--- a/arch/arm/mach-realview/platsmp.c
+++ b/arch/arm/mach-realview/platsmp.c
@@ -175,6 +175,11 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
175 max_cpus = ncores; 175 max_cpus = ncores;
176 176
177 /* 177 /*
178 * Enable the local timer for primary CPU
179 */
180 local_timer_setup(cpu);
181
182 /*
178 * Initialise the possible/present maps. 183 * Initialise the possible/present maps.
179 * cpu_possible_map describes the set of CPUs which may be present 184 * cpu_possible_map describes the set of CPUs which may be present
180 * cpu_present_map describes the set of CPUs populated 185 * cpu_present_map describes the set of CPUs populated
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-12 10:48:21 -0500