From 302eca184fb844670fb128c69e22a8a28bbce48a Mon Sep 17 00:00:00 2001 From: "arnd@arndb.de" Date: Tue, 24 Oct 2006 18:31:26 +0200 Subject: [PATCH] [POWERPC] cell: use ppc_md->power_save instead of cbe_idle_loop This moves the cell idle function to use the default cpu_idle with a special power_save callback, like all other platforms except iSeries already do. It also makes it possible to disable this power_save function with a new powerpc-specific boot option "powersave=off". Signed-off-by: Arnd Bergmann Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/idle.c | 7 +++ arch/powerpc/platforms/cell/pervasive.c | 96 ++++++++++----------------------- 2 files changed, 34 insertions(+), 69 deletions(-) diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c index 4180c39..8994af3 100644 --- a/arch/powerpc/kernel/idle.c +++ b/arch/powerpc/kernel/idle.c @@ -39,6 +39,13 @@ #define cpu_should_die() 0 #endif +static int __init powersave_off(char *arg) +{ + ppc_md.power_save = NULL; + return 0; +} +__setup("powersave=off", powersave_off); + /* * The body of the idle task. */ diff --git a/arch/powerpc/platforms/cell/pervasive.c b/arch/powerpc/platforms/cell/pervasive.c index fdcd89e..c68fabd 100644 --- a/arch/powerpc/platforms/cell/pervasive.c +++ b/arch/powerpc/platforms/cell/pervasive.c @@ -38,32 +38,16 @@ #include "pervasive.h" #include "cbe_regs.h" -static DEFINE_SPINLOCK(cbe_pervasive_lock); - -static void __init cbe_enable_pause_zero(void) +static void cbe_power_save(void) { - unsigned long thread_switch_control; - unsigned long temp_register; - struct cbe_pmd_regs __iomem *pregs; - - spin_lock_irq(&cbe_pervasive_lock); - pregs = cbe_get_cpu_pmd_regs(smp_processor_id()); - if (pregs == NULL) - goto out; - - pr_debug("Power Management: CPU %d\n", smp_processor_id()); - - /* Enable Pause(0) control bit */ - temp_register = in_be64(&pregs->pmcr); - - out_be64(&pregs->pmcr, - temp_register | CBE_PMD_PAUSE_ZERO_CONTROL); + unsigned long ctrl, thread_switch_control; + ctrl = mfspr(SPRN_CTRLF); /* Enable DEC and EE interrupt request */ thread_switch_control = mfspr(SPRN_TSC_CELL); thread_switch_control |= TSC_CELL_EE_ENABLE | TSC_CELL_EE_BOOST; - switch ((mfspr(SPRN_CTRLF) & CTRL_CT)) { + switch (ctrl & CTRL_CT) { case CTRL_CT0: thread_switch_control |= TSC_CELL_DEC_ENABLE_0; break; @@ -75,58 +59,21 @@ static void __init cbe_enable_pause_zero(void) __FUNCTION__); break; } - mtspr(SPRN_TSC_CELL, thread_switch_control); -out: - spin_unlock_irq(&cbe_pervasive_lock); -} - -static void cbe_idle(void) -{ - unsigned long ctrl; - - /* Why do we do that on every idle ? Couldn't that be done once for - * all or do we lose the state some way ? Also, the pmcr - * register setting, that can't be set once at boot ? We really want - * to move that away in order to implement a simple powersave + /* + * go into low thread priority, medium priority will be + * restored for us after wake-up. */ - cbe_enable_pause_zero(); - - while (1) { - if (!need_resched()) { - local_irq_disable(); - while (!need_resched()) { - /* go into low thread priority */ - HMT_low(); - - /* - * atomically disable thread execution - * and runlatch. - * External and Decrementer exceptions - * are still handled when the thread - * is disabled but now enter in - * cbe_system_reset_exception() - */ - ctrl = mfspr(SPRN_CTRLF); - ctrl &= ~(CTRL_RUNLATCH | CTRL_TE); - mtspr(SPRN_CTRLT, ctrl); - } - /* restore thread prio */ - HMT_medium(); - local_irq_enable(); - } + HMT_low(); - /* - * turn runlatch on again before scheduling the - * process we just woke up - */ - ppc64_runlatch_on(); - - preempt_enable_no_resched(); - schedule(); - preempt_disable(); - } + /* + * atomically disable thread execution and runlatch. + * External and Decrementer exceptions are still handled when the + * thread is disabled but now enter in cbe_system_reset_exception() + */ + ctrl &= ~(CTRL_RUNLATCH | CTRL_TE); + mtspr(SPRN_CTRLT, ctrl); } static int cbe_system_reset_exception(struct pt_regs *regs) @@ -158,9 +105,20 @@ static int cbe_system_reset_exception(struct pt_regs *regs) void __init cbe_pervasive_init(void) { + int cpu; if (!cpu_has_feature(CPU_FTR_PAUSE_ZERO)) return; - ppc_md.idle_loop = cbe_idle; + for_each_possible_cpu(cpu) { + struct cbe_pmd_regs __iomem *regs = cbe_get_cpu_pmd_regs(cpu); + if (!regs) + continue; + + /* Enable Pause(0) control bit */ + out_be64(®s->pmcr, in_be64(®s->pmcr) | + CBE_PMD_PAUSE_ZERO_CONTROL); + } + + ppc_md.power_save = cbe_power_save; ppc_md.system_reset_exception = cbe_system_reset_exception; } -- 2.7.4