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authorPaul Mackerras <paulus@samba.org>2005-11-04 13:28:58 +1100
committerPaul Mackerras <paulus@samba.org>2005-11-04 13:28:58 +1100
commit8ad200d7b7c8fac77cf705831e90e889360d7030 (patch)
treec954352ca3cd8c64e913ceb4a5a082ce7e98f8cd /arch/ppc64/kernel/smp-tbsync.c
parentd3ab57ebdc6457543b346255fa47b0ecd7671136 (diff)
powerpc: Merge smp-tbsync.c (the generic timebase sync routine)
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/ppc64/kernel/smp-tbsync.c')
-rw-r--r--arch/ppc64/kernel/smp-tbsync.c179
1 files changed, 0 insertions, 179 deletions
diff --git a/arch/ppc64/kernel/smp-tbsync.c b/arch/ppc64/kernel/smp-tbsync.c
deleted file mode 100644
index 7d8ec9996b3..00000000000
--- a/arch/ppc64/kernel/smp-tbsync.c
+++ /dev/null
@@ -1,179 +0,0 @@
-/*
- * Smp timebase synchronization for ppc.
- *
- * Copyright (C) 2003 Samuel Rydh (samuel@ibrium.se)
- *
- */
-
-#include <linux/config.h>
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/smp.h>
-#include <linux/unistd.h>
-#include <linux/init.h>
-#include <asm/atomic.h>
-#include <asm/smp.h>
-#include <asm/time.h>
-
-#define NUM_ITER 300
-
-enum {
- kExit=0, kSetAndTest, kTest
-};
-
-static struct {
- volatile long tb;
- volatile long mark;
- volatile int cmd;
- volatile int handshake;
- int filler[3];
-
- volatile int ack;
- int filler2[7];
-
- volatile int race_result;
-} *tbsync;
-
-static volatile int running;
-
-static void __devinit
-enter_contest( long mark, long add )
-{
- while( (long)(mftb() - mark) < 0 )
- tbsync->race_result = add;
-}
-
-void __devinit
-smp_generic_take_timebase( void )
-{
- int cmd;
- long tb;
-
- local_irq_disable();
- while( !running )
- ;
- rmb();
-
- for( ;; ) {
- tbsync->ack = 1;
- while( !tbsync->handshake )
- ;
- rmb();
-
- cmd = tbsync->cmd;
- tb = tbsync->tb;
- tbsync->ack = 0;
- if( cmd == kExit )
- return;
-
- if( cmd == kSetAndTest ) {
- while( tbsync->handshake )
- ;
- asm volatile ("mttbl %0" :: "r" (tb & 0xfffffffful) );
- asm volatile ("mttbu %0" :: "r" (tb >> 32) );
- } else {
- while( tbsync->handshake )
- ;
- }
- enter_contest( tbsync->mark, -1 );
- }
- local_irq_enable();
-}
-
-static int __devinit
-start_contest( int cmd, long offset, long num )
-{
- int i, score=0;
- long tb, mark;
-
- tbsync->cmd = cmd;
-
- local_irq_disable();
- for( i=-3; i<num; ) {
- tb = (long)mftb() + 400;
- tbsync->tb = tb + offset;
- tbsync->mark = mark = tb + 400;
-
- wmb();
-
- tbsync->handshake = 1;
- while( tbsync->ack )
- ;
-
- while( (long)(mftb() - tb) <= 0 )
- ;
- tbsync->handshake = 0;
- enter_contest( mark, 1 );
-
- while( !tbsync->ack )
- ;
-
- if ((tbsync->tb ^ (long)mftb()) & 0x8000000000000000ul)
- continue;
- if( i++ > 0 )
- score += tbsync->race_result;
- }
- local_irq_enable();
- return score;
-}
-
-void __devinit
-smp_generic_give_timebase( void )
-{
- int i, score, score2, old, min=0, max=5000, offset=1000;
-
- printk("Synchronizing timebase\n");
-
- /* if this fails then this kernel won't work anyway... */
- tbsync = kmalloc( sizeof(*tbsync), GFP_KERNEL );
- memset( tbsync, 0, sizeof(*tbsync) );
- mb();
- running = 1;
-
- while( !tbsync->ack )
- ;
-
- printk("Got ack\n");
-
- /* binary search */
- for( old=-1 ; old != offset ; offset=(min+max)/2 ) {
- score = start_contest( kSetAndTest, offset, NUM_ITER );
-
- printk("score %d, offset %d\n", score, offset );
-
- if( score > 0 )
- max = offset;
- else
- min = offset;
- old = offset;
- }
- score = start_contest( kSetAndTest, min, NUM_ITER );
- score2 = start_contest( kSetAndTest, max, NUM_ITER );
-
- printk( "Min %d (score %d), Max %d (score %d)\n", min, score, max, score2 );
- score = abs( score );
- score2 = abs( score2 );
- offset = (score < score2) ? min : max;
-
- /* guard against inaccurate mttb */
- for( i=0; i<10; i++ ) {
- start_contest( kSetAndTest, offset, NUM_ITER/10 );
-
- if( (score2=start_contest(kTest, offset, NUM_ITER)) < 0 )
- score2 = -score2;
- if( score2 <= score || score2 < 20 )
- break;
- }
- printk("Final offset: %d (%d/%d)\n", offset, score2, NUM_ITER );
-
- /* exiting */
- tbsync->cmd = kExit;
- wmb();
- tbsync->handshake = 1;
- while( tbsync->ack )
- ;
- tbsync->handshake = 0;
- kfree( tbsync );
- tbsync = NULL;
- running = 0;
-}