intel/skylake: disable heci1 if psf is unlocked

This patch adds support for disabling the heci1 device
at the end of boot sequence. Prior to this, FSP would have
sent the end of post message to ME and initiated the d0i3 bit.

This uses the Psf unlock policy and the p2sb device to disable
the heci1 device, then lock the configuration and hide the device.

BRANCH=none
BUG=chrome-os-partner:45618
TEST=build for kunimitsu or glados board. set the hecienabled policy
to 0 and check for heci 1 device status in kernel lspci.

CQ-DEPEND=CL:*238451

Change-Id: I26b145231f8ed0c140af42d378b222e857d9aff6
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: fe184b8baf1bea9bcd0af1841785a4d763af9358
Original-Change-Id: I3b435491aeea0f2ca36b7877e942dc940560e4dd
Original-Signed-off-by: Archana Patni <archana.patni@intel.com>
Original-Signed-off-by: Subramony Sesha <subramony.sesha@intel.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/311912
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/12976
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

5 files changed, 80 insertions, 0 deletions

diff --git a/src/soc/intel/skylake/chip.c b/src/soc/intel/skylake/chip.c
index e6eb537fc5..f4dc4a729f 100644
--- a/src/soc/intel/skylake/chip.c
+++ b/src/soc/intel/skylake/chip.c
@@ -347,6 +347,18 @@ void soc_silicon_init_params(SILICON_INIT_UPD *params)
 
 	params->SkipMpInit = config->SkipMpInit;
 
+	/*
+	 * To disable Heci, the Psf needs to be left unlocked
+	 * by FSP after end of post sequence. Based on the devicetree
+	 * setting, we set the appropriate PsfUnlock policy in Fsp,
+	 * do the changes and then lock it back in Coreboot
+	 *
+	 */
+	if (config->HeciEnabled == 0)
+		params->PsfUnlock = 1;
+	else
+		params->PsfUnlock = 0;
+
 	for (i = 0; i < ARRAY_SIZE(config->domain_vr_config); i++) {
 		params->VrConfigEnable[i] =
 			config->domain_vr_config[i].vr_config_enable;
diff --git a/src/soc/intel/skylake/chip.h b/src/soc/intel/skylake/chip.h
index 1ff1fcfc1c..1c45470b9f 100644
--- a/src/soc/intel/skylake/chip.h
+++ b/src/soc/intel/skylake/chip.h
@@ -331,6 +331,11 @@ struct soc_intel_skylake_config {
 	 * 3 = GT unsliced,  4 = GT sliced
 	 */
 	struct vr_config domain_vr_config[NUM_VR_DOMAINS];
+	/*
+	 * HeciEnabled decides the state of Heci1 at end of boot
+	 * Setting to 0 (default) disables Heci1 and hides the device from OS
+	 */
+	u8 HeciEnabled;
 };
 
 typedef struct soc_intel_skylake_config config_t;
diff --git a/src/soc/intel/skylake/finalize.c b/src/soc/intel/skylake/finalize.c
index e2577aadeb..8069b405e8 100644
--- a/src/soc/intel/skylake/finalize.c
+++ b/src/soc/intel/skylake/finalize.c
@@ -31,6 +31,55 @@
 #include <soc/spi.h>
 #include <soc/systemagent.h>
 #include <device/pci.h>
+#include <chip.h>
+
+#define PCH_P2SB_EPMASK0		0xB0
+#define PCH_P2SB_EPMASK(mask_number) 	PCH_P2SB_EPMASK0 + (mask_number * 4)
+
+#define PCH_P2SB_E0			0xE0
+
+static void pch_configure_endpoints(device_t dev, int epmask_id, uint32_t mask)
+{
+	uint32_t reg32;
+
+	reg32 = pci_read_config32(dev, PCH_P2SB_EPMASK(epmask_id));
+	pci_write_config32(dev, PCH_P2SB_EPMASK(epmask_id), reg32 | mask);
+}
+
+static void pch_disable_heci(void)
+{
+	device_t dev;
+	u8 reg8;
+	uint32_t mask;
+
+	dev = PCH_DEV_P2SB;
+
+	/*
+	 * if p2sb device 1f.1 is not present or hidden in devicetree
+	 * p2sb device becomes NULL
+	 */
+	if (!dev)
+		return;
+
+	/* unhide p2sb device */
+	pci_write_config8(dev, PCH_P2SB_E0 + 1, 0);
+
+	/* disable heci */
+	pcr_andthenor32(PID_PSF1, PSF_BASE_ADDRESS + PCH_PCR_PSFX_T0_SHDW_PCIEN,
+				~0, PCH_PCR_PSFX_T0_SHDW_PCIEN_FUNDIS);
+
+	/* Remove the host accessing right to PSF register range. */
+	/* Set p2sb PCI offset EPMASK5 C4h [29, 28, 27, 26] to [1, 1, 1, 1] */
+	mask = (1 << 29) | (1 << 28) | (1 << 27)  | (1 << 26);
+	pch_configure_endpoints(dev, 5, mask);
+
+	/* Set the "Endpoint Mask Lock!", P2SB PCI offset E2h bit[1] to 1. */
+	reg8 = pci_read_config8(dev, PCH_P2SB_E0 + 2);
+	pci_write_config8(dev, PCH_P2SB_E0 + 2, reg8 | (1 << 1));
+
+	/* hide p2sb device */
+	pci_write_config8(dev, PCH_P2SB_E0 + 1, 1);
+}
 
 static void pch_finalize_script(void)
 {
@@ -40,6 +89,7 @@ static void pch_finalize_script(void)
 	u16 tcobase;
 	u16 tcocnt;
 	uint8_t *pmcbase;
+	config_t *config;
 	u32 pmsyncreg;
 
 	/* Set SPI opcode menu */
@@ -69,6 +119,11 @@ static void pch_finalize_script(void)
 	pmsyncreg = read32(pmcbase + PMSYNC_TPR_CFG);
 	pmsyncreg |= PMSYNC_LOCK;
 	write32(pmcbase + PMSYNC_TPR_CFG, pmsyncreg);
+
+	/* we should disable Heci1 based on the devicetree policy */
+	config = dev->chip_info;
+	if (config->HeciEnabled == 0)
+		pch_disable_heci();
 }
 
 static void soc_lockdown(void)
diff --git a/src/soc/intel/skylake/include/soc/pci_devs.h b/src/soc/intel/skylake/include/soc/pci_devs.h
index 5ce2136a8c..2dba3dec20 100644
--- a/src/soc/intel/skylake/include/soc/pci_devs.h
+++ b/src/soc/intel/skylake/include/soc/pci_devs.h
@@ -127,6 +127,7 @@
 
 #define PCH_DEV_SLOT_LPC	0x1f
 #define  PCH_DEVFN_LPC		_PCH_DEVFN(LPC, 0)
+#define  PCH_DEVFN_P2SB         _PCH_DEVFN(LPC, 1)
 #define  PCH_DEVFN_PMC		_PCH_DEVFN(LPC, 2)
 #define  PCH_DEVFN_HDA		_PCH_DEVFN(LPC, 3)
 #define  PCH_DEVFN_SMBUS	_PCH_DEVFN(LPC, 4)
@@ -134,6 +135,7 @@
 #define  PCH_DEVFN_GBE		_PCH_DEVFN(LPC, 6)
 #define  PCH_DEVFN_TRACEHUB		_PCH_DEVFN(LPC, 7)
 #define  PCH_DEV_LPC		_PCH_DEV(LPC, 0)
+#define  PCH_DEV_P2SB		_PCH_DEV(LPC, 1)
 #define  PCH_DEV_PMC		_PCH_DEV(LPC, 2)
 #define  PCH_DEV_HDA		_PCH_DEV(LPC, 3)
 #define  PCH_DEV_SMBUS		_PCH_DEV(LPC, 4)
diff --git a/src/soc/intel/skylake/include/soc/pcr.h b/src/soc/intel/skylake/include/soc/pcr.h
index cb64af6578..8a46cd1e5e 100644
--- a/src/soc/intel/skylake/include/soc/pcr.h
+++ b/src/soc/intel/skylake/include/soc/pcr.h
@@ -83,6 +83,7 @@
 #define PID_GPIOCOM2	0xAD
 #define PID_GPIOCOM1	0xAE
 #define PID_GPIOCOM0	0xAF
+#define PID_PSF1	0xBA
 #define PID_SCS		0xC0
 #define PID_RTC		0xC3
 #define PID_ITSS	0xC4
@@ -90,6 +91,11 @@
 #define PID_SERIALIO	0xCB
 #define PID_DMI		0xEF
 
+#define PCH_PCR_PSFX_T0_SHDW_PCIEN		0x1C
+
+#define PCH_PCR_PSFX_T0_SHDW_PCIEN_FUNDIS	(1 << 8)
+#define PSF_BASE_ADDRESS			0xA00
+
 #if !defined(__ASSEMBLER__) && !defined(__ACPI__)
 #include <stdint.h>