[coreboot-gerrit] Change in coreboot[master]: soc/intel/cannonlake: Add back PM TIMER EMULATION

[Lijian Zhao (Code Review)]

Lijian Zhao has uploaded this change for review. ( https://review.coreboot.org/28937

Change subject: soc/intel/cannonlake: Add back PM TIMER EMULATION
......................................................................

soc/intel/cannonlake: Add back PM TIMER EMULATION

ACPI PM timer emulation will be added back as default FSP stops TCO count
for power saving, which will also stop ACPI PM timer within PCH. CPU PM TIMER
EMULATION will help UEFI payload pass, instead of endless loop wait for
ACPI PM timer counter to increase.

BUG=N/A
TEST=Build and boot up fine with whiskey lake rvp board into UEFI shell.

Change-Id: Ie069e815e6244c3f85fabf51e186311621d316fd
Signed-off-by: Lijian Zhao 
---
M src/soc/intel/cannonlake/cpu.c
M src/soc/intel/cannonlake/include/soc/cpu.h
M src/soc/intel/cannonlake/include/soc/msr.h
3 files changed, 30 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/37/28937/1

diff --git a/src/soc/intel/cannonlake/cpu.c b/src/soc/intel/cannonlake/cpu.c
index ba87045..0e5b4bf 100644
--- a/src/soc/intel/cannonlake/cpu.c
+++ b/src/soc/intel/cannonlake/cpu.c
@@ -1,7 +1,7 @@
 /*
  * This file is part of the coreboot project.
  *
- * Copyright (C) 2017 Intel Corporation.
+ * Copyright (C) 2017-2018 Intel Corporation.
  *
  * 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
@@ -165,6 +165,27 @@
    wrmsr(MSR_C_STATE_LATENCY_CONTROL_5, msr);
 }

+/*
+ * The emulated ACPI timer allows disabling of the ACPI timer
+ * (PM1_TMR) to have no impart on the system.
+ */
+static void enable_pm_timer_emulation(void)
+{
+	/* ACPI PM timer emulation */
+	msr_t msr;
+	/*
+	 * The derived frequency is calculated as follows:
+	 *    (CTC_FREQ * msr[63:32]) >> 32 = target frequency.
+	 * Back solve the multiplier so the 3.579545MHz ACPI timer
+	 * frequency is used.
+	 */
+	msr.hi = (3579545ULL << 32) / CTC_FREQ;
+	/* Set PM1 timer IO port and enable*/
+	msr.lo = (EMULATE_DELAY_VALUE << EMULATE_DELAY_OFFSET_VALUE) |
+			EMULATE_PM_TMR_EN | (ACPI_BASE_ADDRESS + PM1_TMR);
+	wrmsr(MSR_EMULATE_PM_TMR, msr);
+}
+
 /* All CPUs including BSP will run the following function. */
 void soc_core_init(struct device *cpu)
 {
@@ -187,6 +208,9 @@
    /* Configure Intel Speed Shift */
    configure_isst();

+	/* Enable ACPI Timer Emulation via MSR 0x121 */
+	enable_pm_timer_emulation();
+
    /* Enable Direct Cache Access */
    configure_dca_cap();

diff --git a/src/soc/intel/cannonlake/include/soc/cpu.h b/src/soc/intel/cannonlake/include/soc/cpu.h
index dfc7183..1e3e2b4 100644
--- a/src/soc/intel/cannonlake/include/soc/cpu.h
+++ b/src/soc/intel/cannonlake/include/soc/cpu.h
@@ -37,6 +37,9 @@
 #define C9_POWER	0xc8
 #define C10_POWER	0xc8

+/* Common Timer Copy (CTC) frequency - 24MHz. */
+#define CTC_FREQ		24000000
+
 #define C_STATE_LATENCY_MICRO_SECONDS(limit, base) \
    (((1 << ((base)*5)) * (limit)) / 1000)
 #define C_STATE_LATENCY_FROM_LAT_REG(reg) \
diff --git a/src/soc/intel/cannonlake/include/soc/msr.h b/src/soc/intel/cannonlake/include/soc/msr.h
index c63c921..48db610 100644
--- a/src/soc/intel/cannonlake/include/soc/msr.h
+++ b/src/soc/intel/cannonlake/include/soc/msr.h
@@ -2,7 +2,7 @@
  * This file is part of the coreboot project.
  *
  * Copyright (C) 2014 Google Inc.
- * Copyright (C) 2017 Intel Corporation.
+ * Copyright (C) 2017-2018 Intel Corporation.
  *
  * 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
@@ -20,6 +20,7 @@
 #include <intelblocks/msr.h>

#define MSR_PIC_MSG_CONTROL		0x2e
+#define  EMULATE_DELAY_VALUE		0x13
 #define IA32_THERM_INTERRUPT		0x19b
 #define IA32_ENERGY_PERFORMANCE_BIAS	0x1b0
 #define  ENERGY_POLICY_PERFORMANCE	0