From 251f971259714ef07cc4642f145bfb4ce552eb0e Mon Sep 17 00:00:00 2001
From: Yongcong Du <ycdu.vmcore@gmail.com>
Date: Thu, 5 Jul 2012 00:09:35 +0800
Subject: [PATCH] cpuidle: add intel native cpuidle module

Currently, it only supports intel sandy bridge processors.

Signed-off-by: Yongcong Du <ycdu.vmcore@gmail.com>
Signed-off-by: Fredrik Holmqvist <fredrik.holmqvist@gmail.com>
---
 src/add-ons/kernel/idle/Jamfile               |   1 +
 src/add-ons/kernel/idle/cpuidles/Jamfile      |   3 +
 .../idle/cpuidles/intel_cpuidle/Jamfile       |   7 +
 .../cpuidles/intel_cpuidle/intel_cpuidle.cpp  | 148 ++++++++++++++++++
 4 files changed, 159 insertions(+)
 create mode 100644 src/add-ons/kernel/idle/cpuidles/Jamfile
 create mode 100644 src/add-ons/kernel/idle/cpuidles/intel_cpuidle/Jamfile
 create mode 100644 src/add-ons/kernel/idle/cpuidles/intel_cpuidle/intel_cpuidle.cpp

diff --git a/src/add-ons/kernel/idle/Jamfile b/src/add-ons/kernel/idle/Jamfile
index 27f0864029..878fd5cc5e 100644
--- a/src/add-ons/kernel/idle/Jamfile
+++ b/src/add-ons/kernel/idle/Jamfile
@@ -1,3 +1,4 @@
 SubDir HAIKU_TOP src add-ons kernel idle ;
 
+SubInclude HAIKU_TOP src add-ons kernel idle cpuidles ;
 SubInclude HAIKU_TOP src add-ons kernel idle generic ;
diff --git a/src/add-ons/kernel/idle/cpuidles/Jamfile b/src/add-ons/kernel/idle/cpuidles/Jamfile
new file mode 100644
index 0000000000..03a6a3c860
--- /dev/null
+++ b/src/add-ons/kernel/idle/cpuidles/Jamfile
@@ -0,0 +1,3 @@
+SubDir HAIKU_TOP src add-ons kernel idle cpuidles ;
+
+SubInclude HAIKU_TOP src add-ons kernel idle cpuidles intel_cpuidle ;
diff --git a/src/add-ons/kernel/idle/cpuidles/intel_cpuidle/Jamfile b/src/add-ons/kernel/idle/cpuidles/intel_cpuidle/Jamfile
new file mode 100644
index 0000000000..4b74f09e92
--- /dev/null
+++ b/src/add-ons/kernel/idle/cpuidles/intel_cpuidle/Jamfile
@@ -0,0 +1,7 @@
+SubDir HAIKU_TOP src add-ons kernel idle cpuidles intel_cpuidle ;
+
+UsePrivateKernelHeaders ;
+
+KernelAddon intel_cpuidle :
+	intel_cpuidle.cpp
+	;
diff --git a/src/add-ons/kernel/idle/cpuidles/intel_cpuidle/intel_cpuidle.cpp b/src/add-ons/kernel/idle/cpuidles/intel_cpuidle/intel_cpuidle.cpp
new file mode 100644
index 0000000000..a2bba81463
--- /dev/null
+++ b/src/add-ons/kernel/idle/cpuidles/intel_cpuidle/intel_cpuidle.cpp
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2012, Haiku, Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT License.
+ *
+ * Authors:
+ *		Yongcong Du <ycdu.vmcore@gmail.com>
+ */
+
+#include <KernelExport.h>
+#include <stdio.h>
+
+#include <cpu.h>
+#include <arch_system_info.h>
+#include <cpuidle.h>
+
+
+static status_t std_ops(int32 op, ...);
+
+
+static inline void
+x86_monitor(const void *addr, unsigned long ecx, unsigned long edx)
+{
+	asm volatile("monitor"
+		:: "a" (addr), "c" (ecx), "d"(edx));
+}
+
+
+static inline void
+x86_mwait(unsigned long eax, unsigned long ecx)
+{
+	asm volatile("mwait"
+		:: "a" (eax), "c" (ecx));
+}
+
+
+static void *kMwaitEax[] = {
+	// C0, we never use it
+	(void *)0x00,
+	// MWAIT C1
+	(void *)0x00,
+	// MWAIT C2
+	(void *)0x10,
+	// MWAIT C3
+	(void *)0x20,
+	// MWAIT C4
+	(void *)0x30,
+	// MWAIT C5
+	(void *)0x40,
+	// MWAIT C6, 0x2 is used to fully shrink L2 cache
+	(void *)0x52
+};
+
+
+static int32
+IntelCstateIdleEnter(int32 state, CpuidleCstate *cstate)
+{
+	cpu_ent *cpu = get_cpu_struct();
+	if (cpu->invoke_scheduler)
+		return 0;
+
+	x86_monitor((void *)&cpu->invoke_scheduler, 0, 0);
+	if (!cpu->invoke_scheduler)
+		x86_mwait((unsigned long)cstate->pData, 1);
+
+	return state;
+}
+
+
+static CpuidleCstate kSnbcStates[CPUIDLE_CSTATE_MAX] = {
+	{},
+	{
+		"C1-SNB",
+		1,
+		IntelCstateIdleEnter,
+	},
+	{
+		"C3-SNB",
+		80,
+		IntelCstateIdleEnter,
+	},
+	{
+		"C6-SNB",
+		104,
+		IntelCstateIdleEnter,
+	},
+	{
+		"C7-SNB",
+		109,
+		IntelCstateIdleEnter,
+	},
+};
+
+
+static CpuidleModuleInfo sIntelidleModule = {
+	{
+		"idle/cpuidles/intel_cpuidle/v1",
+		0,
+		std_ops
+	},
+
+};
+
+
+static status_t
+std_ops(int32 op, ...)
+{
+	switch (op) {
+		case B_MODULE_INIT:
+		{
+			cpuid_info cpuid;
+			get_current_cpuid(&cpuid, 5);
+			/* ecx[0] monitor/mwait extension supported
+			 * ecx[1] support for treating interrupts as break-events for mwait
+			 * edx number of sub-states
+			 */
+			if (!((cpuid.regs.ecx & 0x1) && (cpuid.regs.ecx & 0x2) &&
+				cpuid.regs.edx)) {
+				return B_ERROR;
+			}
+
+			sIntelidleModule.cStateCount = 1;
+			for (int32 i = 1; i < CPUIDLE_CSTATE_MAX; i++) {
+				int32 subStates = (cpuid.regs.edx >> ((i) * 4)) & 0xf;
+				// no sub-states means the state is not available
+				if (!subStates)
+					continue;
+				sIntelidleModule.cStates[sIntelidleModule.cStateCount] =
+					kSnbcStates[i];
+				sIntelidleModule.cStates[sIntelidleModule.cStateCount].pData =
+					kMwaitEax[i];
+				sIntelidleModule.cStateCount++;
+			}
+			dprintf("intel idle init\n");
+			return B_OK;
+		}
+		case B_MODULE_UNINIT:
+			dprintf("intel idle uninit\n");
+			return B_OK;
+	}
+
+	return B_ERROR;
+}
+
+
+module_info *modules[] = {
+	(module_info *)&sIntelidleModule,
+	NULL
+};