From e467ba95b017924b06f2f52a73ab5380d553543a Mon Sep 17 00:00:00 2001
From: Yongcong Du <ycdu.vmcore@gmail.com>
Date: Sat, 7 Jul 2012 21:52:56 +0800
Subject: [PATCH] cpuidle: add stats reporting support

Signed-off-by: Fredrik Holmqvist <fredrik.holmqvist@gmail.com>
---
 headers/os/drivers/cpuidle.h                  |  9 +++++
 src/add-ons/kernel/drivers/cpuidle/Jamfile    |  2 +
 .../kernel/drivers/cpuidle/cpuidle.cpp        | 39 +++++++++++++++++--
 src/add-ons/kernel/idle/generic/cpuidle.cpp   | 35 +++++++++++++++--
 4 files changed, 78 insertions(+), 7 deletions(-)

diff --git a/headers/os/drivers/cpuidle.h b/headers/os/drivers/cpuidle.h
index 7234429283..ed79be9622 100644
--- a/headers/os/drivers/cpuidle.h
+++ b/headers/os/drivers/cpuidle.h
@@ -44,6 +44,15 @@ struct CpuidleModuleInfo {
 };
 
 
+struct GenCpuidle {
+	module_info	info;
+	int32		(*GetIdleStateCount)(void);
+	char *		(*GetIdleStateName)(int32 state);
+	void		(*GetIdleStateInfo)(int32 cpu, int32 state,
+									CpuidleStat *stat);
+};
+
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/add-ons/kernel/drivers/cpuidle/Jamfile b/src/add-ons/kernel/drivers/cpuidle/Jamfile
index 50b92909b1..ce5f450017 100644
--- a/src/add-ons/kernel/drivers/cpuidle/Jamfile
+++ b/src/add-ons/kernel/drivers/cpuidle/Jamfile
@@ -1,5 +1,7 @@
 SubDir HAIKU_TOP src add-ons kernel drivers cpuidle ;
 
+UsePrivateKernelHeaders ;
+
 KernelAddon <driver>cpuidle :
 	cpuidle.cpp
 	;
diff --git a/src/add-ons/kernel/drivers/cpuidle/cpuidle.cpp b/src/add-ons/kernel/drivers/cpuidle/cpuidle.cpp
index 9440358dfe..82110c9253 100644
--- a/src/add-ons/kernel/drivers/cpuidle/cpuidle.cpp
+++ b/src/add-ons/kernel/drivers/cpuidle/cpuidle.cpp
@@ -6,6 +6,10 @@
  *		Yongcong Du <ycdu.vmcore@gmail.com>
  */
 
+#include <stdio.h>
+#include <string.h>
+#include <smp.h>
+
 #include <Drivers.h>
 #include <KernelExport.h>
 
@@ -15,7 +19,7 @@
 
 int32 api_version = B_CUR_DRIVER_API_VERSION;
 
-CpuidleModuleInfo *sCpuidleModule;
+static GenCpuidle *sGenCpuidle;
 
 static status_t
 cpuidle_open(const char *name, uint32 flags, void **cookie)
@@ -49,7 +53,36 @@ cpuidle_ioctl(void *cookie, uint32 op, void *buffer, size_t length)
 static status_t
 cpuidle_read(void *cookie, off_t pos, void *buffer, size_t *length)
 {
-	*length = 0;
+	if (pos != 0) {
+		*length = 0;
+		return B_OK;
+	}
+	char *str = (char *)buffer;
+	size_t max_len = *length;
+	int32 stateCount = sGenCpuidle->GetIdleStateCount();
+	int32 bytes = snprintf(str, max_len, "C-STATE COUNT: %"B_PRId32"\n", stateCount);
+	max_len-= bytes;
+	str += bytes;
+	int32 cpu = smp_get_num_cpus();
+
+	for (int32 i = 0; i < cpu; i++) {
+		bytes = snprintf(str, max_len, "CPU%"B_PRId32"\n", i);
+		max_len-= bytes;
+		str += bytes;
+		for (int32 j = 1; j < stateCount; j++) {
+			CpuidleStat stat;
+			bytes = snprintf(str, max_len, "%s\n", sGenCpuidle->GetIdleStateName(j));
+			max_len-= bytes;
+			str += bytes;
+			sGenCpuidle->GetIdleStateInfo(i, j, &stat);
+			bytes = snprintf(str, max_len, "%lld %lldus\n",
+							stat.usageCount, stat.usageTime);
+			max_len-= bytes;
+			str += bytes;
+		}
+	}
+	*length = strlen((char *)buffer);
+
 	return B_OK;
 }
 
@@ -102,7 +135,7 @@ init_driver(void)
 {
 	status_t err;
 
-	err = get_module(B_CPUIDLE_MODULE_NAME, (module_info **)&sCpuidleModule);
+	err = get_module(B_CPUIDLE_MODULE_NAME, (module_info **)&sGenCpuidle);
 	if (err != B_OK) {
 		dprintf("can't load "B_CPUIDLE_MODULE_NAME"\n");
 	}
diff --git a/src/add-ons/kernel/idle/generic/cpuidle.cpp b/src/add-ons/kernel/idle/generic/cpuidle.cpp
index 4338a16835..041b7298ca 100644
--- a/src/add-ons/kernel/idle/generic/cpuidle.cpp
+++ b/src/add-ons/kernel/idle/generic/cpuidle.cpp
@@ -106,10 +106,37 @@ std_ops(int32 op, ...)
 }
 
 
-static module_info sModule = {
-	B_CPUIDLE_MODULE_NAME,
-	0,
-	std_ops
+static char *
+GetIdleStateName(int32 state)
+{
+	return sCpuidleModule->cStates[state].name;
+}
+
+
+static int32
+GetIdleStateCount(void)
+{
+	return sCpuidleModule->cStateCount;
+}
+
+
+static void
+GetIdleStateInfo(int32 cpu, int32 state, CpuidleStat *stat)
+{
+	memcpy(stat, &sPerCPU[cpu].stats[state], sizeof(CpuidleStat));
+}
+
+
+static GenCpuidle sModule = {
+	{
+		B_CPUIDLE_MODULE_NAME,
+		0,
+		std_ops
+	},
+
+	GetIdleStateCount,
+	GetIdleStateName,
+	GetIdleStateInfo
 };