[PATCH v10 4/8] drm/i915/bios: de/allocate VS/PE-O buffers for each port

["Michał Grzelak" <michal.grzelak@intel.com>]

Every devdata needs a VS/PE-O dedicated buffers since each port can
request an override. Add intel_ddi_buf_trans{,_entry} pointers into
intel_bios_encoder_data.

Allocate struct intel_ddi_buf_trans{,_entry} for the port if VS/PE-O was
requested and is supported. Keep NULL in vspeo if any allocation failed
or VS/PE-O was not requested. It will be used later for checking if
override should actually take place.

Note that we theoretically could store intel_ddi_buf_trans_entry inside
`entries` field of newly allocated intel_ddi_buf_trans. However it will
be impossible to overwrite the buffer during intel_ddi_get_buf_trans()
without discarding const qualifier of `entries` field. This would
involve either void casting or deconstifying entries field and in turn
all predefined tables as well. Thus add a separate non-const qualified
field into intel_bios_encoder_data for the buffer, which after
overwriting will be promoted to be const qualified.

Deallocate the buffer as well as entries if requested.

v9->v10
- add separate non-const field for `entries` caching
- cache `entries` into const field after data is overwritten (Jani)

v4->v5
- set devdata->vspeo->num_entries in intel_bios.c

Signed-off-by: Michał Grzelak <michal.grzelak@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
---
 drivers/gpu/drm/i915/display/intel_bios.c | 32 +++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index 9610b794bc14..a491b8500611 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -34,6 +34,7 @@
 #include <drm/drm_fixed.h>
 #include <drm/drm_print.h>
 
+#include "intel_ddi_buf_trans.h"
 #include "intel_display.h"
 #include "intel_display_core.h"
 #include "intel_display_rpm.h"
@@ -72,6 +73,8 @@
 struct intel_bios_encoder_data {
 	struct intel_display *display;
 
+	struct intel_ddi_buf_trans *vspeo;
+	union intel_ddi_buf_trans_entry *entries;
 	struct child_device_config child;
 	struct dsc_compression_parameters_entry *dsc;
 	struct list_head node;
@@ -2648,6 +2651,29 @@ static void sanitize_device_type(struct intel_bios_encoder_data *devdata,
 	devdata->child.device_type |= DEVICE_TYPE_NOT_HDMI_OUTPUT;
 }
 
+static void allocate_vswing_preemph_override(struct intel_bios_encoder_data *devdata)
+{
+	int num_rows = devdata->display->vbt.vspeo.num_rows;
+	union intel_ddi_buf_trans_entry *entries;
+	struct intel_ddi_buf_trans *vspeo;
+
+	if (!intel_bios_encoder_requests_vspeo(devdata))
+		return;
+
+	vspeo = kzalloc_obj(*vspeo);
+	if (!vspeo)
+		return;
+
+	entries = kzalloc_objs(*entries, num_rows);
+	if (!entries) {
+		kfree(vspeo);
+		return;
+	}
+
+	devdata->vspeo = vspeo;
+	devdata->entries = entries;
+}
+
 static void sanitize_hdmi_level_shift(struct intel_bios_encoder_data *devdata,
 				      enum port port)
 {
@@ -2866,6 +2892,7 @@ static void parse_ddi_port(struct intel_bios_encoder_data *devdata)
 	sanitize_dedicated_external(devdata, port);
 	sanitize_device_type(devdata, port);
 	sanitize_hdmi_level_shift(devdata, port);
+	allocate_vswing_preemph_override(devdata);
 }
 
 static bool has_ddi_port_info(struct intel_display *display)
@@ -3403,6 +3430,11 @@ void intel_bios_driver_remove(struct intel_display *display)
 	list_for_each_entry_safe(devdata, nd, &display->vbt.display_devices,
 				 node) {
 		list_del(&devdata->node);
+
+		if (devdata->vspeo)
+			kfree(devdata->vspeo->entries);
+
+		kfree(devdata->vspeo);
 		kfree(devdata->dsc);
 		kfree(devdata);
 	}
-- 
2.45.2