Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f5f3cca3 authored by Catalin Marinas's avatar Catalin Marinas Committed by Joonwoo Park
Browse files

arm64: Remove boot thread synchronisation for spin-table release method 



The synchronisation with the boot thread already happens in __cpu_up()
via wait_for_completion_timeout(). In addition, __cpu_up() calls are
protected by the cpu_add_remove_lock mutex and already serialised.

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Git-commit: 6400111399e16a535231ebd76389c894ea1837ff
Signed-off-by: default avatarJoonwoo Park <joonwoop@codeaurora.org>
parent 4fdb4a98

arch/arm64/kernel/smp_spin_table.c

+1 −38
Original line number Diff line number Diff line
@@ -27,7 +27,6 @@ 
#include <asm/smp_plat.h>



static phys_addr_t cpu_release_addr[NR_CPUS];

static DEFINE_RAW_SPINLOCK(boot_lock);



/*

 * Write secondary_holding_pen_release in a way that is guaranteed to be
@@ -91,14 +90,6 @@ static int smp_spin_table_cpu_prepare(unsigned int cpu) 


static int smp_spin_table_cpu_boot(unsigned int cpu)

{

	unsigned long timeout;



	/*

	 * Set synchronisation state between this boot processor

	 * and the secondary one

	 */

	raw_spin_lock(&boot_lock);



	/*

	 * Update the pen release flag.

	 */
@@ -109,34 +100,7 @@ static int smp_spin_table_cpu_boot(unsigned int cpu) 
	 */

	sev();



	timeout = jiffies + (1 * HZ);

	while (time_before(jiffies, timeout)) {

		if (secondary_holding_pen_release == INVALID_HWID)

			break;

		udelay(10);

	}



	/*

	 * Now the secondary core is starting up let it run its

	 * calibrations, then wait for it to finish

	 */

	raw_spin_unlock(&boot_lock);



	return secondary_holding_pen_release != INVALID_HWID ? -ENOSYS : 0;

}



static void smp_spin_table_cpu_postboot(void)

{

	/*

	 * Let the primary processor know we're out of the pen.

	 */

	write_pen_release(INVALID_HWID);



	/*

	 * Synchronise with the boot thread.

	 */

	raw_spin_lock(&boot_lock);

	raw_spin_unlock(&boot_lock);

	return 0;

}



static const struct cpu_operations smp_spin_table_ops = {
@@ -144,6 +108,5 @@ static const struct cpu_operations smp_spin_table_ops = { 
	.cpu_init	= smp_spin_table_cpu_init,

	.cpu_prepare	= smp_spin_table_cpu_prepare,

	.cpu_boot	= smp_spin_table_cpu_boot,

	.cpu_postboot	= smp_spin_table_cpu_postboot,

};

CPU_METHOD_OF_DECLARE(spin_table, &smp_spin_table_ops);