From: Paul Mackerras Date: Fri, 4 Nov 2005 02:28:58 +0000 (+1100) Subject: powerpc: Merge smp-tbsync.c (the generic timebase sync routine) X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=8ad200d7b7c8fac77cf705831e90e889360d7030;p=deliverable%2Flinux.git powerpc: Merge smp-tbsync.c (the generic timebase sync routine) Signed-off-by: Paul Mackerras --- diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 3cf03ab46113..f4e25c648fbb 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -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 diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 7a3e1155ac9a..631149ea93db 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -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) diff --git a/arch/powerpc/kernel/smp-tbsync.c b/arch/powerpc/kernel/smp-tbsync.c new file mode 100644 index 000000000000..9adef3bddad4 --- /dev/null +++ b/arch/powerpc/kernel/smp-tbsync.c @@ -0,0 +1,171 @@ +/* + * Smp timebase synchronization for ppc. + * + * Copyright (C) 2003 Samuel Rydh (samuel@ibrium.se) + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define NUM_ITER 300 + +enum { + kExit=0, kSetAndTest, kTest +}; + +static struct { + volatile u64 tb; + volatile u64 mark; + volatile int cmd; + volatile int handshake; + int filler[2]; + + volatile int ack; + int filler2[7]; + + volatile int race_result; +} *tbsync; + +static volatile int running; + +static void __devinit enter_contest(u64 mark, long add) +{ + while (get_tb() < mark) + tbsync->race_result = add; +} + +void __devinit smp_generic_take_timebase(void) +{ + int cmd; + u64 tb; + + local_irq_disable(); + while (!running) + barrier(); + rmb(); + + for (;;) { + tbsync->ack = 1; + while (!tbsync->handshake) + barrier(); + rmb(); + + cmd = tbsync->cmd; + tb = tbsync->tb; + mb(); + tbsync->ack = 0; + 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, int num) +{ + int i, score=0; + u64 tb; + long mark; + + tbsync->cmd = cmd; + + local_irq_disable(); + 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) + barrier(); + + while (get_tb() <= tb) + barrier(); + tbsync->handshake = 0; + enter_contest(mark, 1); + + while (!tbsync->ack) + barrier(); + + 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) + barrier(); + + 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) + barrier(); + tbsync->handshake = 0; + kfree(tbsync); + tbsync = NULL; + running = 0; +} diff --git a/arch/ppc64/Kconfig b/arch/ppc64/Kconfig index 42677cc96508..b987164fca4c 100644 --- a/arch/ppc64/Kconfig +++ b/arch/ppc64/Kconfig @@ -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 diff --git a/arch/ppc64/kernel/Makefile b/arch/ppc64/kernel/Makefile index 430cb3900a07..f597c2954b71 100644 --- a/arch/ppc64/kernel/Makefile +++ b/arch/ppc64/kernel/Makefile @@ -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/ diff --git a/arch/ppc64/kernel/smp-tbsync.c b/arch/ppc64/kernel/smp-tbsync.c deleted file mode 100644 index 7d8ec9996b3e..000000000000 --- 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 -#include -#include -#include -#include -#include -#include -#include -#include - -#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; itb = 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; -}