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Commit c388cfeb authored by Olof Johansson's avatar Olof Johansson Committed by Paul Mackerras
Browse files

[POWERPC] pasemi: SMP timebase sync 



Timebase update is simple on PA6T, since global updates can be done from
one core by writing to an SPR.

Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent f620be99

arch/powerpc/platforms/pasemi/setup.c

+25 −2
Original line number Diff line number Diff line
@@ -48,13 +48,36 @@ static void pas_restart(char *cmd) 
}



#ifdef CONFIG_SMP

static DEFINE_SPINLOCK(timebase_lock);



static void __devinit pas_give_timebase(void)

{

	unsigned long tb;



	spin_lock(&timebase_lock);

	mtspr(SPRN_TBCTL, TBCTL_FREEZE);

	tb = mftb();

	mtspr(SPRN_TBCTL, TBCTL_UPDATE_LOWER | (tb & 0xffffffff));

	mtspr(SPRN_TBCTL, TBCTL_UPDATE_UPPER | (tb >> 32));

	mtspr(SPRN_TBCTL, TBCTL_RESTART);

	spin_unlock(&timebase_lock);

	pr_debug("pas_give_timebase: cpu %d gave tb %lx\n",

		 smp_processor_id(), tb);

}



static void __devinit pas_take_timebase(void)

{

	pr_debug("pas_take_timebase: cpu %d has tb %lx\n",

		 smp_processor_id(), mftb());

}



struct smp_ops_t pas_smp_ops = {

	.probe		= smp_mpic_probe,

	.message_pass	= smp_mpic_message_pass,

	.kick_cpu	= smp_generic_kick_cpu,

	.setup_cpu	= smp_mpic_setup_cpu,

	.give_timebase	= smp_generic_give_timebase,

	.take_timebase	= smp_generic_take_timebase,

	.give_timebase	= pas_give_timebase,

	.take_timebase	= pas_take_timebase,

};

#endif /* CONFIG_SMP */

include/asm-powerpc/reg.h

+6 −0
Original line number Diff line number Diff line
@@ -392,6 +392,12 @@ 
#define SPRN_HSRR0	0x13A	/* Save/Restore Register 0 */

#define SPRN_HSRR1	0x13B	/* Save/Restore Register 1 */



#define SPRN_TBCTL	0x35f	/* PA6T Timebase control register */

#define   TBCTL_FREEZE		0x0000000000000000ull /* Freeze all tbs */

#define   TBCTL_RESTART		0x0000000100000000ull /* Restart all tbs */

#define   TBCTL_UPDATE_UPPER	0x0000000200000000ull /* Set upper 32 bits */

#define   TBCTL_UPDATE_LOWER	0x0000000300000000ull /* Set lower 32 bits */



#ifndef SPRN_SVR

#define SPRN_SVR	0x11E	/* System Version Register */

#endif