soc/intel/broadwell: add support for Intel GMA OpRegion

Add global/ACPI nvs variables required for IGD OpRegion.
Add functions necessary to generate ACPI OpRegion, save the
table address in ASLB, and restore table address upon S3 resume.

Implementation largely based on existing Haswell/Lynxpoint code.

Test: boot Windows 10 on google/lulu with Tianocore payload and
GOP display init, observe display driver loaded and functional,
display not black screen when resuming from S3 suspend.

Change-Id: I024f4f0784df3cbbb9977692e9ef0ff9c3552725
Signed-off-by: CoolStar <coolstarorganization@gmail.com>
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/25094
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
diff --git a/src/soc/intel/broadwell/igd.c b/src/soc/intel/broadwell/igd.c
index 0b6e416..23c650a 100644
--- a/src/soc/intel/broadwell/igd.c
+++ b/src/soc/intel/broadwell/igd.c
@@ -24,8 +24,11 @@
 #include <stdlib.h>
 #include <string.h>
 #include <reg_script.h>
+#include <cbmem.h>
 #include <drivers/intel/gma/i915_reg.h>
+#include <drivers/intel/gma/opregion.h>
 #include <soc/cpu.h>
+#include <soc/nvs.h>
 #include <soc/pm.h>
 #include <soc/ramstage.h>
 #include <soc/systemagent.h>
@@ -479,6 +482,19 @@
 	gtt_rmw(0x64810, 0xfffff800, dpdiv);
 }
 
+uintptr_t gma_get_gnvs_aslb(const void *gnvs)
+{
+	const global_nvs_t *gnvs_ptr = gnvs;
+	return (uintptr_t)(gnvs_ptr ? gnvs_ptr->aslb : 0);
+}
+
+void gma_set_gnvs_aslb(void *gnvs, uintptr_t aslb)
+{
+	global_nvs_t *gnvs_ptr = gnvs;
+	if (gnvs_ptr)
+		gnvs_ptr->aslb = aslb;
+}
+
 static void igd_init(struct device *dev)
 {
 	int is_broadwell = !!(cpu_family_model() == BROADWELL_FAMILY_ULT);
@@ -555,6 +571,33 @@
 		gtt_write(DDI_BUF_CTL_A, DDI_BUF_IS_IDLE | DDI_A_4_LANES |
 			  DDI_INIT_DISPLAY_DETECTED);
 	}
+
+	intel_gma_restore_opregion();
+}
+
+static unsigned long
+gma_write_acpi_tables(struct device *const dev, unsigned long current,
+		struct acpi_rsdp *const rsdp)
+{
+	igd_opregion_t *opregion = (igd_opregion_t *)current;
+	global_nvs_t *gnvs;
+
+	if (intel_gma_init_igd_opregion(opregion) != CB_SUCCESS)
+		return current;
+
+	current += sizeof(igd_opregion_t);
+
+	/* GNVS has been already set up */
+	gnvs = cbmem_find(CBMEM_ID_ACPI_GNVS);
+	if (gnvs) {
+		/* IGD OpRegion Base Address */
+		gma_set_gnvs_aslb(gnvs, (uintptr_t)opregion);
+	} else {
+		printk(BIOS_ERR, "Error: GNVS table not found.\n");
+	}
+
+	current = acpi_align_current(current);
+	return current;
 }
 
 static struct device_operations igd_ops = {
@@ -563,6 +606,7 @@
 	.enable_resources	= &pci_dev_enable_resources,
 	.init			= &igd_init,
 	.ops_pci		= &broadwell_pci_ops,
+	.write_acpi_tables	= gma_write_acpi_tables,
 };
 
 static const unsigned short pci_device_ids[] = {