intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs

Support C-states for the Airmont core in the Cherrytrail and Braswell SOCs.
The states are similar to those of Silvermont in Baytrail,
except both flavors of C6 states are faster.

Signed-off-by: Len Brown <len.brown@intel.com>
Cc: Kumar P Mahesh <mahesh.kumar.p@intel.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/idle/intel_idle.c

@@ -253,6 +253,51 @@ static struct cpuidle_state byt_cstates[] = {
 		.enter = NULL }
 };
 
+static struct cpuidle_state cht_cstates[] = {
+	{
+		.name = "C1-CHT",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 1,
+		.target_residency = 1,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6N-CHT",
+		.desc = "MWAIT 0x58",
+		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 80,
+		.target_residency = 275,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6S-CHT",
+		.desc = "MWAIT 0x52",
+		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 200,
+		.target_residency = 560,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C7-CHT",
+		.desc = "MWAIT 0x60",
+		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 1200,
+		.target_residency = 4000,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C7S-CHT",
+		.desc = "MWAIT 0x64",
+		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 10000,
+		.target_residency = 20000,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+
 static struct cpuidle_state ivb_cstates[] = {
 	{
 		.name = "C1-IVB",
@@ -740,6 +785,12 @@ static const struct idle_cpu idle_cpu_byt = {
 	.byt_auto_demotion_disable_flag = true,
 };
 
+static const struct idle_cpu idle_cpu_cht = {
+	.state_table = cht_cstates,
+	.disable_promotion_to_c1e = true,
+	.byt_auto_demotion_disable_flag = true,
+};
+
 static const struct idle_cpu idle_cpu_ivb = {
 	.state_table = ivb_cstates,
 	.disable_promotion_to_c1e = true,
@@ -782,6 +833,7 @@ static const struct x86_cpu_id intel_idle_ids[] = {
 	ICPU(0x2d, idle_cpu_snb),
 	ICPU(0x36, idle_cpu_atom),
 	ICPU(0x37, idle_cpu_byt),
+	ICPU(0x4c, idle_cpu_cht),
 	ICPU(0x3a, idle_cpu_ivb),
 	ICPU(0x3e, idle_cpu_ivt),
 	ICPU(0x3c, idle_cpu_hsw),