Commit 8ad200d7 authored by Paul Mackerras's avatar Paul Mackerras

powerpc: Merge smp-tbsync.c (the generic timebase sync routine)

Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent d3ab57eb
......@@ -300,6 +300,7 @@ config PPC_PMAC64
bool
depends on PPC_PMAC && POWER4
select U3_DART
select GENERIC_TBSYNC
default y
config PPC_PREP
......@@ -314,6 +315,7 @@ config PPC_MAPLE
bool " Maple 970FX Evaluation Board"
select U3_DART
select MPIC_BROKEN_U3
select GENERIC_TBSYNC
default n
help
This option enables support for the Maple 970FX Evaluation Board.
......@@ -386,6 +388,11 @@ config PPC_MPC106
bool
default n
config GENERIC_TBSYNC
bool
default y if CONFIG_PPC32 && CONFIG_SMP
default n
source "drivers/cpufreq/Kconfig"
config CPU_FREQ_PMAC
......
......@@ -21,6 +21,7 @@ obj-$(CONFIG_PPC_RTAS) += rtas.o
obj-$(CONFIG_RTAS_FLASH) += rtas_flash.o
obj-$(CONFIG_RTAS_PROC) += rtas-proc.o
obj-$(CONFIG_IBMVIO) += vio.o
obj-$(CONFIG_GENERIC_TBSYNC) += smp-tbsync.o
ifeq ($(CONFIG_PPC_MERGE),y)
......
......@@ -22,11 +22,11 @@ enum {
};
static struct {
volatile long tb;
volatile long mark;
volatile u64 tb;
volatile u64 mark;
volatile int cmd;
volatile int handshake;
int filler[3];
int filler[2];
volatile int ack;
int filler2[7];
......@@ -36,89 +36,80 @@ static struct {
static volatile int running;
static void __devinit
enter_contest( long mark, long add )
static void __devinit enter_contest(u64 mark, long add)
{
while( (long)(mftb() - mark) < 0 )
while (get_tb() < mark)
tbsync->race_result = add;
}
void __devinit
smp_generic_take_timebase( void )
void __devinit smp_generic_take_timebase(void)
{
int cmd;
long tb;
u64 tb;
local_irq_disable();
while( !running )
;
while (!running)
barrier();
rmb();
for( ;; ) {
for (;;) {
tbsync->ack = 1;
while( !tbsync->handshake )
;
while (!tbsync->handshake)
barrier();
rmb();
cmd = tbsync->cmd;
tb = tbsync->tb;
mb();
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 );
if (cmd == kExit)
break;
while (tbsync->handshake)
barrier();
if (cmd == kSetAndTest)
set_tb(tb >> 32, tb & 0xfffffffful);
enter_contest(tbsync->mark, -1);
}
local_irq_enable();
}
static int __devinit
start_contest( int cmd, long offset, long num )
static int __devinit start_contest(int cmd, long offset, int num)
{
int i, score=0;
long tb, mark;
u64 tb;
long mark;
tbsync->cmd = cmd;
local_irq_disable();
for( i=-3; i<num; ) {
tb = (long)mftb() + 400;
for (i = -3; i < num; ) {
tb = get_tb() + 400;
tbsync->tb = tb + offset;
tbsync->mark = mark = tb + 400;
wmb();
tbsync->handshake = 1;
while( tbsync->ack )
;
while (tbsync->ack)
barrier();
while( (long)(mftb() - tb) <= 0 )
;
while (get_tb() <= tb)
barrier();
tbsync->handshake = 0;
enter_contest( mark, 1 );
enter_contest(mark, 1);
while( !tbsync->ack )
;
while (!tbsync->ack)
barrier();
if ((tbsync->tb ^ (long)mftb()) & 0x8000000000000000ul)
continue;
if( i++ > 0 )
if (i++ > 0)
score += tbsync->race_result;
}
local_irq_enable();
return score;
}
void __devinit
smp_generic_give_timebase( void )
void __devinit smp_generic_give_timebase(void)
{
int i, score, score2, old, min=0, max=5000, offset=1000;
......@@ -130,14 +121,14 @@ smp_generic_give_timebase( void )
mb();
running = 1;
while( !tbsync->ack )
;
while (!tbsync->ack)
barrier();
printk("Got ack\n");
/* binary search */
for( old=-1 ; old != offset ; offset=(min+max)/2 ) {
score = start_contest( kSetAndTest, offset, NUM_ITER );
for (old = -1; old != offset ; offset = (min+max) / 2) {
score = start_contest(kSetAndTest, offset, NUM_ITER);
printk("score %d, offset %d\n", score, offset );
......@@ -147,21 +138,22 @@ smp_generic_give_timebase( void )
min = offset;
old = offset;
}
score = start_contest( kSetAndTest, min, NUM_ITER );
score2 = start_contest( kSetAndTest, max, NUM_ITER );
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 );
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 );
for (i = 0; i < 10; i++) {
start_contest(kSetAndTest, offset, NUM_ITER/10);
if( (score2=start_contest(kTest, offset, NUM_ITER)) < 0 )
if ((score2 = start_contest(kTest, offset, NUM_ITER)) < 0)
score2 = -score2;
if( score2 <= score || score2 < 20 )
if (score2 <= score || score2 < 20)
break;
}
printk("Final offset: %d (%d/%d)\n", offset, score2, NUM_ITER );
......@@ -170,10 +162,10 @@ smp_generic_give_timebase( void )
tbsync->cmd = kExit;
wmb();
tbsync->handshake = 1;
while( tbsync->ack )
;
while (tbsync->ack)
barrier();
tbsync->handshake = 0;
kfree( tbsync );
kfree(tbsync);
tbsync = NULL;
running = 0;
}
......@@ -89,12 +89,14 @@ config PPC_PMAC
bool " Apple G5 based machines"
default y
select U3_DART
select GENERIC_TBSYNC
config PPC_MAPLE
depends on PPC_MULTIPLATFORM
bool " Maple 970FX Evaluation Board"
select U3_DART
select MPIC_BROKEN_U3
select GENERIC_TBSYNC
default n
help
This option enables support for the Maple 970FX Evaluation Board.
......@@ -182,6 +184,9 @@ config MPIC_BROKEN_U3
depends on PPC_MAPLE
default y
config GENERIC_TBSYNC
def_bool n
config PPC_PMAC64
bool
depends on PPC_PMAC
......
......@@ -51,11 +51,6 @@ obj-$(CONFIG_PPC_PMAC) += udbg_scc.o
obj-$(CONFIG_PPC_MAPLE) += udbg_16550.o
ifdef CONFIG_SMP
obj-$(CONFIG_PPC_PMAC) += smp-tbsync.o
obj-$(CONFIG_PPC_MAPLE) += smp-tbsync.o
endif
obj-$(CONFIG_KPROBES) += kprobes.o
CFLAGS_ioctl32.o += -Ifs/
......
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