soc/intel/fsp_broadwell_de: Implement SystemAgent TSEG functions

Implement sa_get_tseg_base and sa_get_tseg_size.

Used by Intel TXT and the new SMM API.

Tested on OCP/Wedge100S.

Change-Id: I22123cbf8d65b25a77fbf72ae8411b23b10c13b4
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33418
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/soc/intel/fsp_broadwell_de/include/soc/broadwell_de.h

@@ -18,6 +18,9 @@
 #ifndef _SOC_BROADWELL_DE_H_
 #define _SOC_BROADWELL_DE_H_
 
+uintptr_t sa_get_tseg_base(void);
+size_t sa_get_tseg_size(void);
+
 #define VTBAR_OFFSET		0x180
 #define VTBAR_MASK		0xffffe000
 #define VTBAR_ENABLED		0x01

src/soc/intel/fsp_broadwell_de/memmap.c

@@ -14,10 +14,40 @@
  * GNU General Public License for more details.
  */
 
+#define __SIMPLE_DEVICE__
+
 #include <cbmem.h>
 #include <drivers/intel/fsp1_0/fsp_util.h>
+#include <soc/broadwell_de.h>
+#include <soc/pci_devs.h>
+#include <device/pci_ops.h>
 
 void *cbmem_top(void)
 {
 	return find_fsp_reserved_mem(*(void **)CBMEM_FSP_HOB_PTR);
 }
+
+/*
+ * Get TSEG base.
+ */
+uintptr_t sa_get_tseg_base(void)
+{
+	const pci_devfn_t dev = PCI_DEV(BUS0, VTD_DEV, VTD_FUNC);
+
+	/* All regions concerned for have 1 MiB alignment. */
+	return ALIGN_DOWN(pci_read_config32(dev, TSEG_BASE), 1 * MiB);
+}
+
+size_t sa_get_tseg_size(void)
+{
+	const pci_devfn_t dev = PCI_DEV(BUS0, VTD_DEV, VTD_FUNC);
+
+	/* All regions concerned for have 1 MiB alignment. */
+	size_t ret = ALIGN_DOWN(pci_read_config32(dev, TSEG_LIMIT), 1 * MiB);
+
+	/* Lower 20bit of TSEG_LIMIT are don't care, need to add 1MiB */
+	ret += 1 * MiB;
+
+	/* Subtract base to get the size */
+	return ret - sa_get_tseg_base();
+}