[coreboot-gerrit] New patch to review for coreboot: [HACK] soc/apollolake: Hide P2SB after siliconi_init

[Lijian Zhao (lijian.zhao@intel.com)]

Lijian Zhao (lijian.zhao at intel.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/15167

-gerrit

commit 6c2b92d7b433fbc016a7c2411680502545ed5d44
Author: Alexandru Gagniuc <alexandrux.gagniuc at intel.com>
Date:   Wed May 18 16:20:19 2016 -0700

    [HACK] soc/apollolake: Hide P2SB after siliconi_init
    
    The hack is still needed for FSP 139_40
    
    Change-Id: I86c60792a60bbc0a6c1e59ad9e1e355e0f18d6c4
    Signed-off-by: Alexandru Gagniuc <alexandrux.gagniuc at intel.com>
    Reviewed-on: https://chromium.devtools.intel.com/7382
    Auto-Verified: chromeos <chromeos at intel.com>
    Tested-by: Zhao, Lijian <lijian.zhao at intel.com>
    Reviewed-by: Zhao, Lijian <lijian.zhao at intel.com>
    Reviewed-on: https://chromium.devtools.intel.com/7690
    CI-Queue: Petrov, Andrey <andrey.petrov at intel.com>
    Reviewed-by: Petrov, Andrey <andrey.petrov at intel.com>
    Tested-by: Petrov, Andrey <andrey.petrov at intel.com>
---
 src/soc/intel/apollolake/chip.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/src/soc/intel/apollolake/chip.c b/src/soc/intel/apollolake/chip.c
index 94a101f..a08063e 100644
--- a/src/soc/intel/apollolake/chip.c
+++ b/src/soc/intel/apollolake/chip.c
@@ -70,6 +70,30 @@ static void enable_dev(device_t dev)
 	}
 }
 
+static void hide_p2sb(void)
+{
+	uint8_t reg8;
+	uint16_t reg16;
+	struct device *dev = dev_find_slot(0, PCI_DEVFN(0x0d, 0));
+
+	if (!dev) {
+		printk(BIOS_ERR, "Could not locate P2SB device (0:0d.0)!\n");
+		return;
+	}
+
+	reg16 = pci_read_config16(dev, PCI_VENDOR_ID);
+	printk(BIOS_DEBUG, "Vendor ID is %x!\n", reg16);
+
+	printk(BIOS_DEBUG, "Will now attempt to hide P2SB PCI device!\n");
+	reg8 = pci_read_config8(dev, 0xe1);
+	reg8 |= 1 << 0;
+	pci_write_config8(dev, 0xe1, reg8);
+
+	reg16 = pci_read_config16(dev, PCI_VENDOR_ID);
+	printk(BIOS_DEBUG, "Vendor ID is now %x... %s\n", reg16,
+		(reg16 == 0xffff) ? "HIDDEN" : "FAILED!!!");
+}
+
 static void soc_init(void *data)
 {
 	struct range_entry range;
@@ -83,6 +107,7 @@ static void soc_init(void *data)
 	/* TODO: fix for S3 resume, as this would corrupt OS memory */
 	range_entry_init(&range, 0x200000, 4ULL*GiB, 0);
 	fsp_silicon_init(&range);
+	hide_p2sb();
 
 	/* Allocate ACPI NVS in CBMEM */
 	gnvs = cbmem_add(CBMEM_ID_ACPI_GNVS, sizeof(*gnvs));