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Commit 87fa05ae authored by Sam Ravnborg's avatar Sam Ravnborg Committed by Thomas Gleixner
Browse files

sparc: Use generic idle loop 



Add generic cpu_idle support

sparc32:
- replace call to cpu_idle() with cpu_startup_entry()
- add arch_cpu_idle()

sparc64:
- smp_callin() now include cpu_startup_entry() call so we can
  skip calling cpu_idle from assembler
- add arch_cpu_idle() and arch_cpu_idle_dead()

Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
Reviewed-by: default avatar"Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: torvalds@linux-foundation.org
Cc: rusty@rustcorp.com.au
Cc: paulmck@linux.vnet.ibm.com
Cc: peterz@infradead.org
Cc: magnus.damm@gmail.com
Acked-by: default avatarDavid Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20130411193850.GA2330@merkur.ravnborg.org


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 781b0e87

arch/sparc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ config SPARC 
	select GENERIC_SMP_IDLE_THREAD

	select GENERIC_CMOS_UPDATE

	select GENERIC_CLOCKEVENTS

	select GENERIC_IDLE_LOOP

	select GENERIC_STRNCPY_FROM_USER

	select GENERIC_STRNLEN_USER

	select MODULES_USE_ELF_RELA

arch/sparc/kernel/hvtramp.S

+1 −2
Original line number Diff line number Diff line
@@ -128,8 +128,7 @@ hv_cpu_startup: 


	call		smp_callin

	 nop

	call		cpu_idle

	 mov		0, %o0



	call		cpu_panic

	 nop

arch/sparc/kernel/process_32.c

+5 −16
Original line number Diff line number Diff line
@@ -64,23 +64,12 @@ extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *); 
struct task_struct *last_task_used_math = NULL;

struct thread_info *current_set[NR_CPUS];



/*

 * the idle loop on a Sparc... ;)

 */

void cpu_idle(void)

/* Idle loop support. */

void arch_cpu_idle(void)

{

	set_thread_flag(TIF_POLLING_NRFLAG);



	/* endless idle loop with no priority at all */

	for (;;) {

		while (!need_resched()) {

	if (sparc_idle)

		(*sparc_idle)();

			else

				cpu_relax();

		}

		schedule_preempt_disabled();

	}

	local_irq_enable();

}



/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */

arch/sparc/kernel/process_64.c

+13 −36
Original line number Diff line number Diff line
@@ -52,20 +52,17 @@ 


#include "kstack.h"



static void sparc64_yield(int cpu)

/* Idle loop support on sparc64. */

void arch_cpu_idle(void)

{

	if (tlb_type != hypervisor) {

		touch_nmi_watchdog();

		return;

	}



	clear_thread_flag(TIF_POLLING_NRFLAG);

	smp_mb__after_clear_bit();



	while (!need_resched() && !cpu_is_offline(cpu)) {

	} else {

		unsigned long pstate;



		/* Disable interrupts. */

                /* The sun4v sleeping code requires that we have PSTATE.IE cleared over

                 * the cpu sleep hypervisor call.

                 */

		__asm__ __volatile__(

			"rdpr %%pstate, %0\n\t"

			"andn %0, %1, %0\n\t"
@@ -73,7 +70,7 @@ static void sparc64_yield(int cpu) 
			: "=&r" (pstate)

			: "i" (PSTATE_IE));



		if (!need_resched() && !cpu_is_offline(cpu))

		if (!need_resched() && !cpu_is_offline(smp_processor_id()))

			sun4v_cpu_yield();



		/* Re-enable interrupts. */
@@ -84,36 +81,16 @@ static void sparc64_yield(int cpu) 
			: "=&r" (pstate)

			: "i" (PSTATE_IE));

	}



	set_thread_flag(TIF_POLLING_NRFLAG);

	local_irq_enable();

}



/* The idle loop on sparc64. */

void cpu_idle(void)

{

	int cpu = smp_processor_id();



	set_thread_flag(TIF_POLLING_NRFLAG);



	while(1) {

		tick_nohz_idle_enter();

		rcu_idle_enter();



		while (!need_resched() && !cpu_is_offline(cpu))

			sparc64_yield(cpu);



		rcu_idle_exit();

		tick_nohz_idle_exit();



#ifdef CONFIG_HOTPLUG_CPU

		if (cpu_is_offline(cpu)) {

void arch_cpu_idle_dead()

{

	sched_preempt_enable_no_resched();

	cpu_play_dead();

}

#endif

		schedule_preempt_disabled();

	}

}



#ifdef CONFIG_COMPAT

static void show_regwindow32(struct pt_regs *regs)

arch/sparc/kernel/smp_32.c

+1 −1
Original line number Diff line number Diff line
@@ -369,7 +369,7 @@ void __cpuinit sparc_start_secondary(void *arg) 
	local_irq_enable();



	wmb();

	cpu_idle();

	cpu_startup_entry(CPUHP_ONLINE);



	/* We should never reach here! */

	BUG();