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authorLinus Torvalds <torvalds@linux-foundation.org>2009-06-22 17:56:13 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-22 17:56:13 -0400
commit9e268beb92ee3a853b3946e84b10358207e2085f (patch)
treedec36344c8b16d53e56763aa174dd7ea806b653f /arch/arm/kernel/process.c
parent2e8b5a09ebf1f98f02c1988a48415e89d4c25168 (diff)
parent9ccdac3662dbf3c75e8f8851a214bdf7d365a4bd (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: (49 commits) [ARM] idle: clean up pm_idle calling, obey hlt_counter [ARM] S3C: Fix gpio-config off-by-one bug [ARM] S3C64XX: add to_irq() support for EINT() GPIO [ARM] S3C64XX: clock.c: fix typo in usb-host clock ctrlbit [ARM] S3C64XX: fix HCLK gate defines [ARM] Update mach-types [ARM] wire up rt_tgsigqueueinfo and perf_counter_open OMAP2 clock/powerdomain: off by 1 error in loop timeout comparisons OMAP3 SDRC: set FIXEDDELAY when disabling SDRC DLL OMAP3: Add support for DPLL3 divisor values higher than 2 OMAP3 SRAM: convert SRAM code to use macros rather than magic numbers OMAP3 SRAM: add more comments on the SRAM code OMAP3 clock/SDRC: program SDRC_MR register during SDRC clock change OMAP3 clock: add a short delay when lowering CORE clk rate OMAP3 clock: initialize SDRC timings at kernel start OMAP3 clock: remove wait for DPLL3 M2 clock to stabilize [ARM] Add old Feroceon support to compressed/head.S [ARM] 5559/1: Limit the stack unwinding caused by a kthread exit [ARM] 5558/1: Add extra checks to ARM unwinder to avoid tracing corrupt stacks [ARM] 5557/1: Discard some ARM.ex*.*exit.text sections when !HOTPLUG or !HOTPLUG_CPU ...
Diffstat (limited to 'arch/arm/kernel/process.c')
-rw-r--r--arch/arm/kernel/process.c77
1 files changed, 50 insertions, 27 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 1585423699ee..39196dff478c 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -114,9 +114,6 @@ void arm_machine_restart(char mode, const char *cmd)
114/* 114/*
115 * Function pointers to optional machine specific functions 115 * Function pointers to optional machine specific functions
116 */ 116 */
117void (*pm_idle)(void);
118EXPORT_SYMBOL(pm_idle);
119
120void (*pm_power_off)(void); 117void (*pm_power_off)(void);
121EXPORT_SYMBOL(pm_power_off); 118EXPORT_SYMBOL(pm_power_off);
122 119
@@ -130,20 +127,19 @@ EXPORT_SYMBOL_GPL(arm_pm_restart);
130 */ 127 */
131static void default_idle(void) 128static void default_idle(void)
132{ 129{
133 if (hlt_counter) 130 if (!need_resched())
134 cpu_relax(); 131 arch_idle();
135 else { 132 local_irq_enable();
136 local_irq_disable();
137 if (!need_resched())
138 arch_idle();
139 local_irq_enable();
140 }
141} 133}
142 134
135void (*pm_idle)(void) = default_idle;
136EXPORT_SYMBOL(pm_idle);
137
143/* 138/*
144 * The idle thread. We try to conserve power, while trying to keep 139 * The idle thread, has rather strange semantics for calling pm_idle,
145 * overall latency low. The architecture specific idle is passed 140 * but this is what x86 does and we need to do the same, so that
146 * a value to indicate the level of "idleness" of the system. 141 * things like cpuidle get called in the same way. The only difference
142 * is that we always respect 'hlt_counter' to prevent low power idle.
147 */ 143 */
148void cpu_idle(void) 144void cpu_idle(void)
149{ 145{
@@ -151,21 +147,31 @@ void cpu_idle(void)
151 147
152 /* endless idle loop with no priority at all */ 148 /* endless idle loop with no priority at all */
153 while (1) { 149 while (1) {
154 void (*idle)(void) = pm_idle; 150 tick_nohz_stop_sched_tick(1);
155 151 leds_event(led_idle_start);
152 while (!need_resched()) {
156#ifdef CONFIG_HOTPLUG_CPU 153#ifdef CONFIG_HOTPLUG_CPU
157 if (cpu_is_offline(smp_processor_id())) { 154 if (cpu_is_offline(smp_processor_id()))
158 leds_event(led_idle_start); 155 cpu_die();
159 cpu_die();
160 }
161#endif 156#endif
162 157
163 if (!idle) 158 local_irq_disable();
164 idle = default_idle; 159 if (hlt_counter) {
165 leds_event(led_idle_start); 160 local_irq_enable();
166 tick_nohz_stop_sched_tick(1); 161 cpu_relax();
167 while (!need_resched()) 162 } else {
168 idle(); 163 stop_critical_timings();
164 pm_idle();
165 start_critical_timings();
166 /*
167 * This will eventually be removed - pm_idle
168 * functions should always return with IRQs
169 * enabled.
170 */
171 WARN_ON(irqs_disabled());
172 local_irq_enable();
173 }
174 }
169 leds_event(led_idle_end); 175 leds_event(led_idle_end);
170 tick_nohz_restart_sched_tick(); 176 tick_nohz_restart_sched_tick();
171 preempt_enable_no_resched(); 177 preempt_enable_no_resched();
@@ -352,6 +358,23 @@ asm( ".section .text\n"
352" .size kernel_thread_helper, . - kernel_thread_helper\n" 358" .size kernel_thread_helper, . - kernel_thread_helper\n"
353" .previous"); 359" .previous");
354 360
361#ifdef CONFIG_ARM_UNWIND
362extern void kernel_thread_exit(long code);
363asm( ".section .text\n"
364" .align\n"
365" .type kernel_thread_exit, #function\n"
366"kernel_thread_exit:\n"
367" .fnstart\n"
368" .cantunwind\n"
369" bl do_exit\n"
370" nop\n"
371" .fnend\n"
372" .size kernel_thread_exit, . - kernel_thread_exit\n"
373" .previous");
374#else
375#define kernel_thread_exit do_exit
376#endif
377
355/* 378/*
356 * Create a kernel thread. 379 * Create a kernel thread.
357 */ 380 */
@@ -363,7 +386,7 @@ pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
363 386
364 regs.ARM_r1 = (unsigned long)arg; 387 regs.ARM_r1 = (unsigned long)arg;
365 regs.ARM_r2 = (unsigned long)fn; 388 regs.ARM_r2 = (unsigned long)fn;
366 regs.ARM_r3 = (unsigned long)do_exit; 389 regs.ARM_r3 = (unsigned long)kernel_thread_exit;
367 regs.ARM_pc = (unsigned long)kernel_thread_helper; 390 regs.ARM_pc = (unsigned long)kernel_thread_helper;
368 regs.ARM_cpsr = SVC_MODE | PSR_ENDSTATE; 391 regs.ARM_cpsr = SVC_MODE | PSR_ENDSTATE;
369 392