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Date:	Fri,  8 Feb 2013 20:08:05 -0500
From:	Len Brown <lenb@...nel.org>
To:	linux-pm@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, Len Brown <len.brown@...el.com>
Subject: [PATCH 01/16] intel_idle: stop using driver_data for static flags

From: Len Brown <len.brown@...el.com>

The commit, 4202735e8ab6ecfb0381631a0d0b58fefe0bd4e2
(cpuidle: Split cpuidle_state structure and move per-cpu statistics fields)
observed that the MWAIT flags for Cn on every processor to date were the
same, and created get_driver_data() to supply them.

Unfortunately, that assumption is false, going forward.
So here we restore the MWAIT flags to the cpuidle_state table.
However, instead restoring the old "driver_data" field,
we put the flags into the existing "flags" field,
where they probalby should have lived all along.

This patch does not change any operation.

This patch removes 1 of the 3 users of cpuidle_state_usage.driver_data.
Perhaps some day we'll get rid of the other 2.

Signed-off-by: Len Brown <len.brown@...el.com>
---
 drivers/idle/intel_idle.c | 75 ++++++++++++++++-------------------------------
 1 file changed, 26 insertions(+), 49 deletions(-)

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 2df9414..b2cf489 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -109,6 +109,16 @@ static struct cpuidle_state *cpuidle_state_table;
 #define CPUIDLE_FLAG_TLB_FLUSHED	0x10000
 
 /*
+ * MWAIT takes an 8-bit "hint" in EAX "suggesting"
+ * the C-state (top nibble) and sub-state (bottom nibble)
+ * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
+ *
+ * We store the hint at the top of our "flags" for each state.
+ */
+#define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
+#define MWAIT2flg(eax) ((eax & 0xFF) << 24)
+
+/*
  * States are indexed by the cstate number,
  * which is also the index into the MWAIT hint array.
  * Thus C0 is a dummy.
@@ -118,21 +128,21 @@ static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = {
 	{ /* MWAIT C1 */
 		.name = "C1-NHM",
 		.desc = "MWAIT 0x00",
-		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_TIME_VALID,
 		.exit_latency = 3,
 		.target_residency = 6,
 		.enter = &intel_idle },
 	{ /* MWAIT C2 */
 		.name = "C3-NHM",
 		.desc = "MWAIT 0x10",
-		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
+		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 20,
 		.target_residency = 80,
 		.enter = &intel_idle },
 	{ /* MWAIT C3 */
 		.name = "C6-NHM",
 		.desc = "MWAIT 0x20",
-		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
+		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 200,
 		.target_residency = 800,
 		.enter = &intel_idle },
@@ -143,28 +153,28 @@ static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = {
 	{ /* MWAIT C1 */
 		.name = "C1-SNB",
 		.desc = "MWAIT 0x00",
-		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_TIME_VALID,
 		.exit_latency = 1,
 		.target_residency = 1,
 		.enter = &intel_idle },
 	{ /* MWAIT C2 */
 		.name = "C3-SNB",
 		.desc = "MWAIT 0x10",
-		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
+		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 80,
 		.target_residency = 211,
 		.enter = &intel_idle },
 	{ /* MWAIT C3 */
 		.name = "C6-SNB",
 		.desc = "MWAIT 0x20",
-		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
+		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 104,
 		.target_residency = 345,
 		.enter = &intel_idle },
 	{ /* MWAIT C4 */
 		.name = "C7-SNB",
 		.desc = "MWAIT 0x30",
-		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
+		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 109,
 		.target_residency = 345,
 		.enter = &intel_idle },
@@ -175,28 +185,28 @@ static struct cpuidle_state ivb_cstates[MWAIT_MAX_NUM_CSTATES] = {
 	{ /* MWAIT C1 */
 		.name = "C1-IVB",
 		.desc = "MWAIT 0x00",
-		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_TIME_VALID,
 		.exit_latency = 1,
 		.target_residency = 1,
 		.enter = &intel_idle },
 	{ /* MWAIT C2 */
 		.name = "C3-IVB",
 		.desc = "MWAIT 0x10",
-		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
+		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 59,
 		.target_residency = 156,
 		.enter = &intel_idle },
 	{ /* MWAIT C3 */
 		.name = "C6-IVB",
 		.desc = "MWAIT 0x20",
-		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
+		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 80,
 		.target_residency = 300,
 		.enter = &intel_idle },
 	{ /* MWAIT C4 */
 		.name = "C7-IVB",
 		.desc = "MWAIT 0x30",
-		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
+		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 87,
 		.target_residency = 300,
 		.enter = &intel_idle },
@@ -207,14 +217,14 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = {
 	{ /* MWAIT C1 */
 		.name = "C1-ATM",
 		.desc = "MWAIT 0x00",
-		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_TIME_VALID,
 		.exit_latency = 1,
 		.target_residency = 4,
 		.enter = &intel_idle },
 	{ /* MWAIT C2 */
 		.name = "C2-ATM",
 		.desc = "MWAIT 0x10",
-		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TIME_VALID,
 		.exit_latency = 20,
 		.target_residency = 80,
 		.enter = &intel_idle },
@@ -222,7 +232,7 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = {
 	{ /* MWAIT C4 */
 		.name = "C4-ATM",
 		.desc = "MWAIT 0x30",
-		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
+		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 100,
 		.target_residency = 400,
 		.enter = &intel_idle },
@@ -230,41 +240,12 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = {
 	{ /* MWAIT C6 */
 		.name = "C6-ATM",
 		.desc = "MWAIT 0x52",
-		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
+		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 140,
 		.target_residency = 560,
 		.enter = &intel_idle },
 };
 
-static long get_driver_data(int cstate)
-{
-	int driver_data;
-	switch (cstate) {
-
-	case 1:	/* MWAIT C1 */
-		driver_data = 0x00;
-		break;
-	case 2:	/* MWAIT C2 */
-		driver_data = 0x10;
-		break;
-	case 3:	/* MWAIT C3 */
-		driver_data = 0x20;
-		break;
-	case 4:	/* MWAIT C4 */
-		driver_data = 0x30;
-		break;
-	case 5:	/* MWAIT C5 */
-		driver_data = 0x40;
-		break;
-	case 6:	/* MWAIT C6 */
-		driver_data = 0x52;
-		break;
-	default:
-		driver_data = 0x00;
-	}
-	return driver_data;
-}
-
 /**
  * intel_idle
  * @dev: cpuidle_device
@@ -278,8 +259,7 @@ static int intel_idle(struct cpuidle_device *dev,
 {
 	unsigned long ecx = 1; /* break on interrupt flag */
 	struct cpuidle_state *state = &drv->states[index];
-	struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
-	unsigned long eax = (unsigned long)cpuidle_get_statedata(state_usage);
+	unsigned long eax = flg2MWAIT(state->flags);
 	unsigned int cstate;
 	int cpu = smp_processor_id();
 
@@ -558,9 +538,6 @@ static int intel_idle_cpu_init(int cpu)
 		if (cpuidle_state_table[cstate].enter == NULL)
 			continue;
 
-		dev->states_usage[dev->state_count].driver_data =
-			(void *)get_driver_data(cstate);
-
 		dev->state_count += 1;
 	}
 
-- 
1.8.1.3.535.ga923c31

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