Commit 8536e02e authored by Vijay Kumar's avatar Vijay Kumar Committed by David S. Miller
Browse files

sparc64: Use CPU_POKE to resume idle cpu 



Use CPU_POKE hypervisor call to resume idle cpu if supported.

Signed-off-by: default avatarVijay Kumar <vijay.ac.kumar@oracle.com>
Reviewed-by: default avatarAnthony Yznaga <anthony.yznaga@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 28d43de7

arch/sparc/include/asm/smp_64.h

+5 −0
Original line number Diff line number Diff line
@@ -33,6 +33,9 @@ 
DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);

extern cpumask_t cpu_core_map[NR_CPUS];



void smp_init_cpu_poke(void);

void scheduler_poke(void);



void arch_send_call_function_single_ipi(int cpu);

void arch_send_call_function_ipi_mask(const struct cpumask *mask);
@@ -74,6 +77,8 @@ void __cpu_die(unsigned int cpu); 
#define smp_fetch_global_regs() do { } while (0)

#define smp_fetch_global_pmu() do { } while (0)

#define smp_fill_in_cpu_possible_map() do { } while (0)

#define smp_init_cpu_poke() do { } while (0)

#define scheduler_poke() do { } while (0)



#endif /* !(CONFIG_SMP) */

arch/sparc/kernel/hvapi.c

+1 −1
Original line number Diff line number Diff line
@@ -189,7 +189,7 @@ void __init sun4v_hvapi_init(void) 


	group = HV_GRP_CORE;

	major = 1;

	minor = 1;

	minor = 6;

	if (sun4v_hvapi_register(group, major, &minor))

		goto bad;

arch/sparc/kernel/process_64.c

+6 −1
Original line number Diff line number Diff line
@@ -77,8 +77,13 @@ void arch_cpu_idle(void) 
			: "=&r" (pstate)

			: "i" (PSTATE_IE));



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

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

			sun4v_cpu_yield();

			/* If resumed by cpu_poke then we need to explicitly

			 * call scheduler_ipi().

			 */

			scheduler_poke();

		}



		/* Re-enable interrupts. */

		__asm__ __volatile__(

arch/sparc/kernel/setup_64.c

+1 −0
Original line number Diff line number Diff line
@@ -356,6 +356,7 @@ void __init start_early_boot(void) 
	check_if_starfire();

	per_cpu_patch();

	sun4v_patch();

	smp_init_cpu_poke();



	cpu = hard_smp_processor_id();

	if (cpu >= NR_CPUS) {

arch/sparc/kernel/smp_64.c

+77 −3
Original line number Diff line number Diff line
@@ -74,6 +74,9 @@ EXPORT_SYMBOL(cpu_core_sib_cache_map); 


static cpumask_t smp_commenced_mask;



static DEFINE_PER_CPU(bool, poke);

static bool cpu_poke;



void smp_info(struct seq_file *m)

{

	int i;
@@ -1439,15 +1442,86 @@ void __init smp_cpus_done(unsigned int max_cpus) 
{

}



static void send_cpu_ipi(int cpu)

{

	xcall_deliver((u64) &xcall_receive_signal,

			0, 0, cpumask_of(cpu));

}



void scheduler_poke(void)

{

	if (!cpu_poke)

		return;



	if (!__this_cpu_read(poke))

		return;



	__this_cpu_write(poke, false);

	set_softint(1 << PIL_SMP_RECEIVE_SIGNAL);

}



static unsigned long send_cpu_poke(int cpu)

{

	unsigned long hv_err;



	per_cpu(poke, cpu) = true;

	hv_err = sun4v_cpu_poke(cpu);

	if (hv_err != HV_EOK) {

		per_cpu(poke, cpu) = false;

		pr_err_ratelimited("%s: sun4v_cpu_poke() fails err=%lu\n",

				    __func__, hv_err);

	}



	return hv_err;

}



void smp_send_reschedule(int cpu)

{

	if (cpu == smp_processor_id()) {

		WARN_ON_ONCE(preemptible());

		set_softint(1 << PIL_SMP_RECEIVE_SIGNAL);

	} else {

		xcall_deliver((u64) &xcall_receive_signal,

			      0, 0, cpumask_of(cpu));

		return;

	}



	/* Use cpu poke to resume idle cpu if supported. */

	if (cpu_poke && idle_cpu(cpu)) {

		unsigned long ret;



		ret = send_cpu_poke(cpu);

		if (ret == HV_EOK)

			return;

	}



	/* Use IPI in following cases:

	 * - cpu poke not supported

	 * - cpu not idle

	 * - send_cpu_poke() returns with error

	 */

	send_cpu_ipi(cpu);

}



void smp_init_cpu_poke(void)

{

	unsigned long major;

	unsigned long minor;

	int ret;



	if (tlb_type != hypervisor)

		return;



	ret = sun4v_hvapi_get(HV_GRP_CORE, &major, &minor);

	if (ret) {

		pr_debug("HV_GRP_CORE is not registered\n");

		return;

	}



	if (major == 1 && minor >= 6) {

		/* CPU POKE is registered. */

		cpu_poke = true;

		return;

	}



	pr_debug("CPU_POKE not supported\n");

}



void __irq_entry smp_receive_signal_client(int irq, struct pt_regs *regs)