soc/intel/xeon_sp/uncore: Read VtdBar

Read the VtdBar and add it to the resources of the host bridge PCI
device. The BAR is already marked as PciResourceMem32 in the parent
PCI domain.
This allows easy probing for VTD devices with enabled VtdBars in the
next commit, without the need to look up the stack HOB.

Change-Id: Id579a94e653473f3dd0dccea6e33dc64f792d028
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80550
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

1 files changed, 16 insertions, 4 deletions

diff --git a/src/soc/intel/xeon_sp/uncore.c b/src/soc/intel/xeon_sp/uncore.c
index d43b20959168..952ca4db70eb 100644
--- a/src/soc/intel/xeon_sp/uncore.c
+++ b/src/soc/intel/xeon_sp/uncore.c
@@ -45,6 +45,7 @@ enum {
 	ME_LIMIT_REG,
 	TSEG_BASE_REG,
 	TSEG_LIMIT_REG,
+	VTDBAR_REG,
 	/* Must be last. */
 	NUM_MAP_ENTRIES
 };
@@ -64,6 +65,7 @@ static struct map_entry memory_map[NUM_MAP_ENTRIES] = {
 #endif
 		[TSEG_BASE_REG] = MAP_ENTRY_BASE_32(VTD_TSEG_BASE_CSR, "TSEGMB_BASE"),
 		[TSEG_LIMIT_REG] = MAP_ENTRY_LIMIT_32(VTD_TSEG_LIMIT_CSR, 20, "TSEGMB_LIMIT"),
+		[VTDBAR_REG] = MAP_ENTRY_BASE_32(VTD_BAR_CSR, "VTD_BAR"),
 };
 
 static void read_map_entry(struct device *dev, struct map_entry *entry,
@@ -76,6 +78,11 @@ static void read_map_entry(struct device *dev, struct map_entry *entry,
 		*result = 0;
 		return;
 	}
+	if (entry->reg == VTD_BAR_CSR && !(pci_read_config32(dev, entry->reg) & 1)) {
+		/* VTDBAR is not enabled */
+		*result = 0;
+		return;
+	}
 
 	mask = ((1ULL << entry->mask_bits) - 1);
 	mask = ~mask;
@@ -198,14 +205,19 @@ static void mc_add_dram_resources(struct device *dev, int *res_count)
 	int index = *res_count;
 	struct range_entry fsp_mem;
 
-	/* Only add dram resources once. */
-	if (dev->upstream->secondary != 0 || dev->upstream->segment_group != 0)
-		return;
-
 	/* Read in the MAP registers and report their values. */
 	mc_read_map_entries(dev, &mc_values[0]);
 	mc_report_map_entries(dev, &mc_values[0]);
 
+	if (mc_values[VTDBAR_REG]) {
+		res = mmio_range(dev, VTD_BAR_CSR, mc_values[VTDBAR_REG], 8 * KiB);
+		LOG_RESOURCE("vtd_bar", dev, res);
+	}
+
+	/* Only add dram resources once. */
+	if (dev->upstream->secondary != 0 || dev->upstream->segment_group != 0)
+		return;
+
 	/* Conventional Memory (DOS region, 0x0 to 0x9FFFF) */
 	res = ram_from_to(dev, index++, 0, 0xa0000);
 	LOG_RESOURCE("legacy_ram", dev, res);