Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 380 insertions, 0 deletions

diff --git a/arch/ppc64/kernel/idle.c b/arch/ppc64/kernel/idle.c
new file mode 100644
index 00000000000..6abc621d3ba
--- /dev/null
+++ b/arch/ppc64/kernel/idle.c
@@ -0,0 +1,380 @@
+/*
+ * Idle daemon for PowerPC.  Idle daemon will handle any action
+ * that needs to be taken when the system becomes idle.
+ *
+ * Originally Written by Cort Dougan (cort@cs.nmt.edu)
+ *
+ * iSeries supported added by Mike Corrigan <mikejc@us.ibm.com>
+ *
+ * Additional shared processor, SMT, and firmware support
+ *    Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/cpu.h>
+#include <linux/module.h>
+#include <linux/sysctl.h>
+#include <linux/smp.h>
+
+#include <asm/system.h>
+#include <asm/processor.h>
+#include <asm/mmu.h>
+#include <asm/cputable.h>
+#include <asm/time.h>
+#include <asm/iSeries/HvCall.h>
+#include <asm/iSeries/ItLpQueue.h>
+#include <asm/plpar_wrappers.h>
+#include <asm/systemcfg.h>
+
+extern void power4_idle(void);
+
+static int (*idle_loop)(void);
+
+#ifdef CONFIG_PPC_ISERIES
+static unsigned long maxYieldTime = 0;
+static unsigned long minYieldTime = 0xffffffffffffffffUL;
+
+static void yield_shared_processor(void)
+{
+	unsigned long tb;
+	unsigned long yieldTime;
+
+	HvCall_setEnabledInterrupts(HvCall_MaskIPI |
+				    HvCall_MaskLpEvent |
+				    HvCall_MaskLpProd |
+				    HvCall_MaskTimeout);
+
+	tb = get_tb();
+	/* Compute future tb value when yield should expire */
+	HvCall_yieldProcessor(HvCall_YieldTimed, tb+tb_ticks_per_jiffy);
+
+	yieldTime = get_tb() - tb;
+	if (yieldTime > maxYieldTime)
+		maxYieldTime = yieldTime;
+
+	if (yieldTime < minYieldTime)
+		minYieldTime = yieldTime;
+	
+	/*
+	 * The decrementer stops during the yield.  Force a fake decrementer
+	 * here and let the timer_interrupt code sort out the actual time.
+	 */
+	get_paca()->lppaca.int_dword.fields.decr_int = 1;
+	process_iSeries_events();
+}
+
+static int iSeries_idle(void)
+{
+	struct paca_struct *lpaca;
+	long oldval;
+	unsigned long CTRL;
+
+	/* ensure iSeries run light will be out when idle */
+	clear_thread_flag(TIF_RUN_LIGHT);
+	CTRL = mfspr(CTRLF);
+	CTRL &= ~RUNLATCH;
+	mtspr(CTRLT, CTRL);
+
+	lpaca = get_paca();
+
+	while (1) {
+		if (lpaca->lppaca.shared_proc) {
+			if (ItLpQueue_isLpIntPending(lpaca->lpqueue_ptr))
+				process_iSeries_events();
+			if (!need_resched())
+				yield_shared_processor();
+		} else {
+			oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
+
+			if (!oldval) {
+				set_thread_flag(TIF_POLLING_NRFLAG);
+
+				while (!need_resched()) {
+					HMT_medium();
+					if (ItLpQueue_isLpIntPending(lpaca->lpqueue_ptr))
+						process_iSeries_events();
+					HMT_low();
+				}
+
+				HMT_medium();
+				clear_thread_flag(TIF_POLLING_NRFLAG);
+			} else {
+				set_need_resched();
+			}
+		}
+
+		schedule();
+	}
+
+	return 0;
+}
+
+#else
+
+static int default_idle(void)
+{
+	long oldval;
+	unsigned int cpu = smp_processor_id();
+
+	while (1) {
+		oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
+
+		if (!oldval) {
+			set_thread_flag(TIF_POLLING_NRFLAG);
+
+			while (!need_resched() && !cpu_is_offline(cpu)) {
+				barrier();
+				/*
+				 * Go into low thread priority and possibly
+				 * low power mode.
+				 */
+				HMT_low();
+				HMT_very_low();
+			}
+
+			HMT_medium();
+			clear_thread_flag(TIF_POLLING_NRFLAG);
+		} else {
+			set_need_resched();
+		}
+
+		schedule();
+		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
+			cpu_die();
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PPC_PSERIES
+
+DECLARE_PER_CPU(unsigned long, smt_snooze_delay);
+
+int dedicated_idle(void)
+{
+	long oldval;
+	struct paca_struct *lpaca = get_paca(), *ppaca;
+	unsigned long start_snooze;
+	unsigned long *smt_snooze_delay = &__get_cpu_var(smt_snooze_delay);
+	unsigned int cpu = smp_processor_id();
+
+	ppaca = &paca[cpu ^ 1];
+
+	while (1) {
+		/*
+		 * Indicate to the HV that we are idle. Now would be
+		 * a good time to find other work to dispatch.
+		 */
+		lpaca->lppaca.idle = 1;
+
+		oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
+		if (!oldval) {
+			set_thread_flag(TIF_POLLING_NRFLAG);
+			start_snooze = __get_tb() +
+				*smt_snooze_delay * tb_ticks_per_usec;
+			while (!need_resched() && !cpu_is_offline(cpu)) {
+				/*
+				 * Go into low thread priority and possibly
+				 * low power mode.
+				 */
+				HMT_low();
+				HMT_very_low();
+
+				if (*smt_snooze_delay == 0 ||
+				    __get_tb() < start_snooze)
+					continue;
+
+				HMT_medium();
+
+				if (!(ppaca->lppaca.idle)) {
+					local_irq_disable();
+
+					/*
+					 * We are about to sleep the thread
+					 * and so wont be polling any
+					 * more.
+					 */
+					clear_thread_flag(TIF_POLLING_NRFLAG);
+
+					/*
+					 * SMT dynamic mode. Cede will result
+					 * in this thread going dormant, if the
+					 * partner thread is still doing work.
+					 * Thread wakes up if partner goes idle,
+					 * an interrupt is presented, or a prod
+					 * occurs.  Returning from the cede
+					 * enables external interrupts.
+					 */
+					if (!need_resched())
+						cede_processor();
+					else
+						local_irq_enable();
+				} else {
+					/*
+					 * Give the HV an opportunity at the
+					 * processor, since we are not doing
+					 * any work.
+					 */
+					poll_pending();
+				}
+			}
+
+			clear_thread_flag(TIF_POLLING_NRFLAG);
+		} else {
+			set_need_resched();
+		}
+
+		HMT_medium();
+		lpaca->lppaca.idle = 0;
+		schedule();
+		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
+			cpu_die();
+	}
+	return 0;
+}
+
+static int shared_idle(void)
+{
+	struct paca_struct *lpaca = get_paca();
+	unsigned int cpu = smp_processor_id();
+
+	while (1) {
+		/*
+		 * Indicate to the HV that we are idle. Now would be
+		 * a good time to find other work to dispatch.
+		 */
+		lpaca->lppaca.idle = 1;
+
+		while (!need_resched() && !cpu_is_offline(cpu)) {
+			local_irq_disable();
+
+			/*
+			 * Yield the processor to the hypervisor.  We return if
+			 * an external interrupt occurs (which are driven prior
+			 * to returning here) or if a prod occurs from another 
+			 * processor. When returning here, external interrupts
+			 * are enabled.
+			 *
+			 * Check need_resched() again with interrupts disabled
+			 * to avoid a race.
+			 */
+			if (!need_resched())
+				cede_processor();
+			else
+				local_irq_enable();
+		}
+
+		HMT_medium();
+		lpaca->lppaca.idle = 0;
+		schedule();
+		if (cpu_is_offline(smp_processor_id()) &&
+		    system_state == SYSTEM_RUNNING)
+			cpu_die();
+	}
+
+	return 0;
+}
+
+#endif /* CONFIG_PPC_PSERIES */
+
+static int native_idle(void)
+{
+	while(1) {
+		/* check CPU type here */
+		if (!need_resched())
+			power4_idle();
+		if (need_resched())
+			schedule();
+
+		if (cpu_is_offline(_smp_processor_id()) &&
+		    system_state == SYSTEM_RUNNING)
+			cpu_die();
+	}
+	return 0;
+}
+
+#endif /* CONFIG_PPC_ISERIES */
+
+void cpu_idle(void)
+{
+	idle_loop();
+}
+
+int powersave_nap;
+
+#ifdef CONFIG_SYSCTL
+/*
+ * Register the sysctl to set/clear powersave_nap.
+ */
+static ctl_table powersave_nap_ctl_table[]={
+	{
+		.ctl_name	= KERN_PPC_POWERSAVE_NAP,
+		.procname	= "powersave-nap",
+		.data		= &powersave_nap,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{ 0, },
+};
+static ctl_table powersave_nap_sysctl_root[] = {
+	{ 1, "kernel", NULL, 0, 0755, powersave_nap_ctl_table, },
+ 	{ 0,},
+};
+
+static int __init
+register_powersave_nap_sysctl(void)
+{
+	register_sysctl_table(powersave_nap_sysctl_root, 0);
+
+	return 0;
+}
+__initcall(register_powersave_nap_sysctl);
+#endif
+
+int idle_setup(void)
+{
+	/*
+	 * Move that junk to each platform specific file, eventually define
+	 * a pSeries_idle for shared processor stuff
+	 */
+#ifdef CONFIG_PPC_ISERIES
+	idle_loop = iSeries_idle;
+	return 1;
+#else
+	idle_loop = default_idle;
+#endif
+#ifdef CONFIG_PPC_PSERIES
+	if (systemcfg->platform & PLATFORM_PSERIES) {
+		if (cur_cpu_spec->firmware_features & FW_FEATURE_SPLPAR) {
+			if (get_paca()->lppaca.shared_proc) {
+				printk(KERN_INFO "Using shared processor idle loop\n");
+				idle_loop = shared_idle;
+			} else {
+				printk(KERN_INFO "Using dedicated idle loop\n");
+				idle_loop = dedicated_idle;
+			}
+		} else {
+			printk(KERN_INFO "Using default idle loop\n");
+			idle_loop = default_idle;
+		}
+	}
+#endif /* CONFIG_PPC_PSERIES */
+#ifndef CONFIG_PPC_ISERIES
+	if (systemcfg->platform == PLATFORM_POWERMAC ||
+	    systemcfg->platform == PLATFORM_MAPLE) {
+		printk(KERN_INFO "Using native/NAP idle loop\n");
+		idle_loop = native_idle;
+	}
+#endif /* CONFIG_PPC_ISERIES */
+
+	return 1;
+}