soc/intel/apollolake/acpi.c: Add RMRRs after all DRHDs

The VT-d architecture specification (Doc. D51397-011, Rev. 3.1) says:

 BIOS implementations must report these remapping structure types in
 numerical order. i.e., All remapping structures of type 0 (DRHD)
 enumerated before remapping structures of type 1 (RMRR), and so forth.

So, update the corresponding code to adhere to the specification.

Change-Id: I4ee3ae6c45e2a2c921fbccbb62b853e4a141a58d
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44110
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>

1 files changed, 13 insertions, 8 deletions

diff --git a/src/soc/intel/apollolake/acpi.c b/src/soc/intel/apollolake/acpi.c
index 96a142a89e..ee1a543728 100644
--- a/src/soc/intel/apollolake/acpi.c
+++ b/src/soc/intel/apollolake/acpi.c
@@ -171,19 +171,15 @@ static unsigned long soc_fill_dmar(unsigned long current)
 	unsigned long tmp;
 
 	/* IGD has to be enabled, GFXVTBAR set and enabled. */
-	if (is_dev_enabled(igfx_dev) && gfxvtbar && gfxvten) {
+	const bool emit_igd = is_dev_enabled(igfx_dev) && gfxvtbar && gfxvten;
+
+	/* First, add DRHD entries */
+	if (emit_igd) {
 		tmp = current;
 
 		current += acpi_create_dmar_drhd(current, 0, 0, gfxvtbar);
 		current += acpi_create_dmar_ds_pci(current, 0, 2, 0);
 		acpi_dmar_drhd_fixup(tmp, current);
-
-		/* Add RMRR entry */
-		tmp = current;
-		current += acpi_create_dmar_rmrr(current, 0,
-				sa_get_gsm_base(), sa_get_tolud_base() - 1);
-		current += acpi_create_dmar_ds_pci(current, 0, 2, 0);
-		acpi_dmar_rmrr_fixup(tmp, current);
 	}
 
 	/* DEFVTBAR has to be set and enabled. */
@@ -210,6 +206,15 @@ static unsigned long soc_fill_dmar(unsigned long current)
 		acpi_dmar_drhd_fixup(tmp, current);
 	}
 
+	/* Then, add RMRR entries after all DRHD entries */
+	if (emit_igd) {
+		tmp = current;
+		current += acpi_create_dmar_rmrr(current, 0,
+				sa_get_gsm_base(), sa_get_tolud_base() - 1);
+		current += acpi_create_dmar_ds_pci(current, 0, 2, 0);
+		acpi_dmar_rmrr_fixup(tmp, current);
+	}
+
 	return current;
 }