[Intel-gfx] [PATCH] drm/i915: Parsing VBT if size of VBT exceeds 6KB

[Deepak M]

Currently the iomap for VBT works only if the size of the
VBT is less than 6KB, but if the size of the VBT exceeds
6KB than the physical address and the size of the VBT to
be iomapped is specified in the mailbox3 and is iomapped
accordingly.

v3: -Splitted the patch into small ones
    -Handeled memory unmap in intel_opregion_fini
    -removed the new file created for opregion macro`s
v4: Moving the vbt assignment after the opregion fields are assigned

Cc: Mika Kahola <mika.kahola at intel.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Signed-off-by: Deepak M <m.deepak at intel.com>
---

 drivers/gpu/drm/i915/intel_opregion.c | 47 +++++++++++++++++++++++++----------
 1 file changed, 34 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
index 7908a1d..5116690 100644
--- a/drivers/gpu/drm/i915/intel_opregion.c
+++ b/drivers/gpu/drm/i915/intel_opregion.c
@@ -856,6 +856,8 @@ void intel_opregion_fini(struct drm_device *dev)
 	}
 
 	/* just clear all opregion memory pointers now */
+	if (opregion->header->opregion_ver >= 2 && opregion->asle->rvda)
+		memunmap(opregion->vbt);
 	memunmap(opregion->header);
 	opregion->header = NULL;
 	opregion->acpi = NULL;
@@ -933,7 +935,8 @@ int intel_opregion_setup(struct drm_device *dev)
 	char buf[sizeof(OPREGION_SIGNATURE)];
 	const struct vbt_header *vbt = NULL;
 	int err = 0;
-	void *base;
+	void *base, *vbt_base;
+	size_t size;
 
 	BUILD_BUG_ON(sizeof(struct opregion_header) != 0x100);
 	BUILD_BUG_ON(sizeof(struct opregion_acpi) != 0x100);
@@ -963,19 +966,7 @@ int intel_opregion_setup(struct drm_device *dev)
 		goto err_out;
 	}
 
-	vbt = validate_vbt(base + OPREGION_VBT_OFFSET,
-				MAILBOX_4_SIZE, "OpRegion");
-
-	if (vbt == NULL) {
-		err = -EINVAL;
-		goto err_out;
-	}
-
-	vbt = (const struct vbt_header *)(base + OPREGION_VBT_OFFSET);
-	dev_priv->opregion.vbt_size = vbt->vbt_size;
-
 	opregion->header = base;
-	opregion->vbt = base + OPREGION_VBT_OFFSET;
 
 	opregion->lid_state = base + ACPI_CLID;
 	opregion->asle_ext = base + OPREGION_ASLE_EXT_OFFSET;
@@ -998,6 +989,36 @@ int intel_opregion_setup(struct drm_device *dev)
 		opregion->asle->ardy = ASLE_ARDY_NOT_READY;
 	}
 
+	/*
+	 * Non-zero value in rvda field is an indication to driver that a
+	 * valid Raw VBT is stored in that address and driver should not refer
+	 * to mailbox4 for getting VBT.
+	 */
+	if (opregion->header->opregion_ver >= 2 && opregion->asle->rvda) {
+		size = opregion->asle->rvds;
+		vbt_base = memremap(opregion->asle->rvda,
+				size, MEMREMAP_WB);
+	} else {
+		size = MAILBOX_4_SIZE;
+		vbt_base = base + OPREGION_VBT_OFFSET;
+	}
+
+	vbt = validate_vbt(vbt_base, size, "OpRegion");
+
+	if (vbt == NULL) {
+		err = -EINVAL;
+		goto err_out;
+	}
+
+	/* Assigning the vbt_size based on the VBT location */
+	if (opregion->header->opregion_ver >= 2 && opregion->asle->rvda)
+		dev_priv->opregion.vbt_size = opregion->asle->rvds;
+	else {
+		vbt = (const struct vbt_header *)(base + OPREGION_VBT_OFFSET);
+		dev_priv->opregion.vbt_size = vbt->vbt_size;
+	}
+
+	opregion->vbt = vbt_base;
 	return 0;
 
 err_out:
-- 
1.9.1