Change in coreboot[master]: soc/intel/skylake: detect if IGD is present

[Alexander Couzens (Code Review)]

Attention is currently required from: Patrick Rudolph.
Alexander Couzens has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/51332 )

Change subject: soc/intel/skylake: detect if IGD is present
......................................................................

soc/intel/skylake: detect if IGD is present

When enabling IGD on a CPU which doesn't have an IGD, the
FSP-S will hang indefinitive.

Signed-off-by: Alexander Couzens 
Change-Id: Ife6e6157db0df772b48a9cb95a0f1494ae21c250
---
M src/soc/intel/skylake/bootblock/report_platform.c
M src/soc/intel/skylake/chip.c
M src/soc/intel/skylake/romstage/fsp_params.c
M src/soc/intel/skylake/romstage/systemagent.c
M src/soc/intel/skylake/systemagent.c
5 files changed, 22 insertions(+), 4 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/32/51332/1

diff --git a/src/soc/intel/skylake/bootblock/report_platform.c b/src/soc/intel/skylake/bootblock/report_platform.c
index 99b5ba1..d83de73 100644
--- a/src/soc/intel/skylake/bootblock/report_platform.c
+++ b/src/soc/intel/skylake/bootblock/report_platform.c
@@ -224,6 +224,11 @@
    uint16_t igdid = get_dev_id(dev);
    const char *igd_type = "Unknown";

+	if (pci_read_config16(dev, PCI_VENDOR_ID) != 0x8086) {
+		printk(BIOS_DEBUG, "IGD: device is not present\n");
+		return;
+	}
+
    for (i = 0; i < ARRAY_SIZE(igd_table); i++) {
    	if (igd_table[i].igdid == igdid) {
    		igd_type = igd_table[i].name;
diff --git a/src/soc/intel/skylake/chip.c b/src/soc/intel/skylake/chip.c
index 0ae98a9..4b35b8b 100644
--- a/src/soc/intel/skylake/chip.c
+++ b/src/soc/intel/skylake/chip.c
@@ -7,6 +7,7 @@
 #include <console/console.h>
 #include <device/device.h>
 #include <device/pci_ids.h>
+#include <device/pci_ops.h>
 #include <fsp/util.h>
 #include <gpio.h>
 #include <intelblocks/cfg.h>
@@ -532,7 +533,8 @@
    }

dev = pcidev_path_on_root(SA_DEVFN_IGD);
-	if (CONFIG(RUN_FSP_GOP) && dev && dev->enabled)
+	if (CONFIG(RUN_FSP_GOP) && dev && dev->enabled && \
+			pci_read_config16(dev, PCI_VENDOR_ID) == 0x8086)
    	params->PeiGraphicsPeimInit = 1;
    else
    	params->PeiGraphicsPeimInit = 0;
diff --git a/src/soc/intel/skylake/romstage/fsp_params.c b/src/soc/intel/skylake/romstage/fsp_params.c
index 2793c2d..86f5af9 100644
--- a/src/soc/intel/skylake/romstage/fsp_params.c
+++ b/src/soc/intel/skylake/romstage/fsp_params.c
@@ -5,6 +5,7 @@
 #include <cpu/x86/msr.h>
 #include <fsp/util.h>
 #include <intelblocks/cpulib.h>
+#include <device/pci_ops.h>
 #include <soc/iomap.h>
 #include <soc/msr.h>
 #include <soc/pci_devs.h>
@@ -110,9 +111,16 @@
    			const struct soc_intel_skylake_config *config)
 {
    const struct device *dev;
+	bool igd = false;

dev = pcidev_path_on_root(SA_DEVFN_IGD);
-	m_cfg->InternalGfx = dev && dev->enabled;
+	if (dev && dev->enabled) {
+		igd = 0x8086 == pci_read_config16(SA_DEVFN_IGD, PCI_VENDOR_ID);
+		if (!igd)
+			printk(BIOS_INFO, "IGD is enabled but not present.\n");
+	}
+
+	m_cfg->InternalGfx = igd;

/*
     * If iGPU is enabled, set IGD stolen size to 64MB. The FBC
diff --git a/src/soc/intel/skylake/romstage/systemagent.c b/src/soc/intel/skylake/romstage/systemagent.c
index f22fd53..8535e97 100644
--- a/src/soc/intel/skylake/romstage/systemagent.c
+++ b/src/soc/intel/skylake/romstage/systemagent.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */

+#include <console/console.h>
 #include <device/device.h>
 #include <device/pci_ops.h>
 #include <intelblocks/systemagent.h>
@@ -28,8 +29,9 @@
    pci_write_config16(PCH_DEV_P2SB, PCH_P2SB_HBDF, V_DEFAULT_HBDF);
    pci_write_config16(PCH_DEV_P2SB, PCH_P2SB_IBDF, V_DEFAULT_IBDF);

-	if (igd_dev && igd_dev->enabled)
+	if (igd_dev && igd_dev->enabled && pci_read_config16(SA_DEVFN_IGD, PCI_VENDOR_ID) == 0x8086) {
    	sa_set_mch_bar(&soc_gfxvt_mmio_descriptor, 1);
+	}

sa_set_mch_bar(&soc_vtvc0_mmio_descriptor, 1);
 }
diff --git a/src/soc/intel/skylake/systemagent.c b/src/soc/intel/skylake/systemagent.c
index 785a5e6..e2b1443 100644
--- a/src/soc/intel/skylake/systemagent.c
+++ b/src/soc/intel/skylake/systemagent.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */

+#include <console/console.h>
 #include <cpu/x86/msr.h>
 #include <delay.h>
 #include <device/device.h>
@@ -45,7 +46,7 @@
    		ARRAY_SIZE(soc_fixed_resources));

if (!config->ignore_vtd && soc_is_vtd_capable()) {
-		if (igd_dev && igd_dev->enabled)
+		if (igd_dev && igd_dev->enabled && pci_read_config16(igd_dev, PCI_VENDOR_ID) == 0x8086)
    		sa_add_fixed_mmio_resources(dev, index,
    				&soc_gfxvt_mmio_descriptor, 1);