[coreboot-gerrit] Change in coreboot[master]: soc/intel/common/p2sb: Add helper function to determine p2sb state

[Arthur Heymans (Code Review)]

Arthur Heymans has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/47530 )

Change subject: soc/intel/common/p2sb: Add helper function to determine p2sb state
......................................................................

soc/intel/common/p2sb: Add helper function to determine p2sb state

Change-Id: I1d6f9c18160806e289e98c2fa5d290c61434112f
Signed-off-by: Arthur Heymans 
---
M src/soc/intel/common/block/p2sb/p2sb.c
1 file changed, 16 insertions(+), 4 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/30/47530/1

diff --git a/src/soc/intel/common/block/p2sb/p2sb.c b/src/soc/intel/common/block/p2sb/p2sb.c
index d97cd8d..b5f9a07 100644
--- a/src/soc/intel/common/block/p2sb/p2sb.c
+++ b/src/soc/intel/common/block/p2sb/p2sb.c
@@ -15,6 +15,20 @@

#define HIDE_BIT (1 << 0)

+static bool p2sb_is_hiden(void)
+{
+	bool valid_vid = pci_read_config16(PCH_DEV_P2SB, PCI_VENDOR_ID) ==
+		PCI_VENDOR_ID_INTEL;
+	bool read_ones = pci_read_config16(PCH_DEV_P2SB, PCI_VENDOR_ID) == 0xffff;
+
+	if (read_ones)
+		return true;
+	if (valid_vid)
+		return false;
+	printk(BIOS_ERR, "P2SB PCI_VENDOR_ID is invalid, unknown if hidden\n");
+	return true;
+}
+
 void p2sb_enable_bar(void)
 {
    /* Enable PCR Base address in PCH */
@@ -59,8 +73,7 @@
 {
    p2sb_set_hide_bit(0);

-	if (pci_read_config16(PCH_DEV_P2SB, PCI_VENDOR_ID) !=
-			PCI_VENDOR_ID_INTEL)
+	if (p2sb_is_hiden())
    	die_with_post_code(POST_HW_INIT_FAILURE,
    			   "Unable to unhide PCH_DEV_P2SB device !\n");
 }
@@ -69,8 +82,7 @@
 {
    p2sb_set_hide_bit(1);

-	if (pci_read_config16(PCH_DEV_P2SB, PCI_VENDOR_ID) !=
-			0xFFFF)
+	if (!p2sb_is_hiden())
    	die_with_post_code(POST_HW_INIT_FAILURE,
    			   "Unable to hide PCH_DEV_P2SB device !\n");
 }