soc/intel/alderlake/romstage: Do initial SoC commit till romstage

List of changes:
1. Add required SoC programming till romstage
2. Include only required headers into include/soc
3. Add SA EDS document number and chapter number
4. Fill required FSP-M UPD to call FSP-M API

Change-Id: I4473aed27363c22e92e66cc6770cb55aae83e75c
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45192
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/src/soc/intel/alderlake/p2sb.c b/src/soc/intel/alderlake/p2sb.c
new file mode 100644
index 0000000000..7eba1144d7
--- /dev/null
+++ b/src/soc/intel/alderlake/p2sb.c
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+/*
+ * This file is created based on Intel Alder Lake Processor PCH Datasheet
+ * Document number: 621483
+ * Chapter number: 3
+ */
+
+#include <console/console.h>
+#include <intelblocks/p2sb.h>
+
+void p2sb_soc_get_sb_mask(uint32_t *ep_mask, size_t count)
+{
+	uint32_t mask;
+
+	if (count != P2SB_EP_MASK_MAX_REG) {
+		printk(BIOS_ERR, "Unable to program EPMASK registers\n");
+		return;
+	}
+
+	/* Remove the host accessing right to PSF register range.
+	 * Set p2sb PCI offset EPMASK5 [29, 28, 27, 26] to disable Sideband
+	 * access for PCI Root Bridge.
+	 */
+	mask = (1 << 29) | (1 << 28) | (1 << 27)  | (1 << 26);
+
+	ep_mask[P2SB_EP_MASK_5_REG] = mask;
+
+	/*
+	 * Set p2sb PCI offset EPMASK7 [31, 30] to disable Sideband
+	 * access for Broadcast and Multicast.
+	 */
+	mask = (1 << 31) | (1 << 30);
+
+	ep_mask[P2SB_EP_MASK_7_REG] = mask;
+}