[PATCH 09/10] drm/sun4i: Add a dedicated ioctl call for allocating tiled buffers

[Paul Kocialkowski <paul.kocialkowski@bootlin.com>]

This introduces a dedicated ioctl for allocating tiled buffers in the
Allwinner MB32 format, that comes with a handful of specific
constraints. In particular, the stride of the buffers is expected to be
aligned to 32 bytes.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
---
 drivers/gpu/drm/sun4i/sun4i_drv.c | 96 +++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/sun4i/sun4i_drv.h |  2 +
 include/uapi/drm/sun4i_drm.h      | 42 +++++++++++++++++
 3 files changed, 140 insertions(+)
 create mode 100644 include/uapi/drm/sun4i_drm.h

diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
index d374bb61c565..e9cb03d34b44 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -21,11 +21,18 @@
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_of.h>
+#include <drm/sun4i_drm.h>
 
 #include "sun4i_drv.h"
 #include "sun4i_frontend.h"
 #include "sun4i_framebuffer.h"
 #include "sun4i_tcon.h"
+#include "sun4i_format.h"
+
+static const struct drm_ioctl_desc sun4i_drv_ioctls[] = {
+	DRM_IOCTL_DEF_DRV(SUN4I_GEM_CREATE_TILED, drm_sun4i_gem_create_tiled,
+			  DRM_AUTH | DRM_RENDER_ALLOW),
+};
 
 DEFINE_DRM_GEM_CMA_FOPS(sun4i_drv_fops);
 
@@ -34,6 +41,8 @@ static struct drm_driver sun4i_drv_driver = {
 
 	/* Generic Operations */
 	.lastclose		= drm_fb_helper_lastclose,
+	.ioctls			= sun4i_drv_ioctls,
+	.num_ioctls		= ARRAY_SIZE(sun4i_drv_ioctls),
 	.fops			= &sun4i_drv_fops,
 	.name			= "sun4i-drm",
 	.desc			= "Allwinner sun4i Display Engine",
@@ -69,6 +78,93 @@ int drm_sun4i_gem_dumb_create(struct drm_file *file_priv,
 	return drm_gem_cma_dumb_create_internal(file_priv, drm, args);
 }
 
+int drm_sun4i_gem_create_tiled(struct drm_device *drm, void *data,
+			       struct drm_file *file_priv)
+{
+	struct drm_sun4i_gem_create_tiled *args = data;
+	struct drm_gem_cma_object *cma_obj;
+	struct drm_gem_object *gem_obj;
+	uint32_t luma_stride, chroma_stride;
+	uint32_t luma_height, chroma_height;
+	int ret;
+
+	if (!sun4i_format_supports_tiling(args->format))
+		return -EINVAL;
+
+	memset(args->pitches, 0, sizeof(args->pitches));
+	memset(args->offsets, 0, sizeof(args->offsets));
+
+	/* Stride and height are aligned to 32 bytes for MB32 tiled format. */
+	luma_stride = ALIGN(args->width, 32);
+	luma_height = ALIGN(args->height, 32);
+
+	if (sun4i_format_is_semiplanar(args->format)) {
+		chroma_stride = luma_stride;
+
+		if (sun4i_format_is_yuv420(args->format))
+			chroma_height = ALIGN(DIV_ROUND_UP(args->height, 2), 32);
+		else if (sun4i_format_is_yuv422(args->format))
+			chroma_height = luma_height;
+		else
+			return -EINVAL;
+
+		args->pitches[0] = luma_stride;
+		args->pitches[1] = chroma_stride;
+
+		args->offsets[0] = 0;
+		args->offsets[1] = luma_stride * luma_height;
+
+		args->size = luma_stride * luma_height +
+			     chroma_stride * chroma_height;
+	} else if (sun4i_format_is_planar(args->format)) {
+		if (sun4i_format_is_yuv411(args->format)) {
+			chroma_stride = ALIGN(DIV_ROUND_UP(args->width, 4), 32);
+			chroma_height = luma_height;
+		} if (sun4i_format_is_yuv420(args->format)) {
+			chroma_stride = ALIGN(DIV_ROUND_UP(args->width, 2), 32);
+			chroma_height = ALIGN(DIV_ROUND_UP(args->height, 2), 32);
+		} else if (sun4i_format_is_yuv422(args->format)) {
+			chroma_stride = ALIGN(DIV_ROUND_UP(args->width, 2), 32);
+			chroma_height = luma_height;
+		} else {
+			return -EINVAL;
+		}
+
+		args->pitches[0] = luma_stride;
+		args->pitches[1] = chroma_stride;
+		args->pitches[2] = chroma_stride;
+
+		args->offsets[0] = 0;
+		args->offsets[1] = luma_stride * luma_height;
+		args->offsets[2] = luma_stride * luma_height +
+				   chroma_stride * chroma_height;
+
+		args->size = luma_stride * luma_height +
+			     chroma_stride * chroma_height * 2;
+	} else {
+		/* No support for packed formats in tiled mode. */
+		return -EINVAL;
+	}
+
+	cma_obj = drm_gem_cma_create(drm, args->size);
+	if (IS_ERR(cma_obj))
+		return PTR_ERR(cma_obj);
+
+	gem_obj = &cma_obj->base;
+
+	/*
+	 * allocate a id of idr table where the obj is registered
+	 * and handle has the id what user can see.
+	 */
+	ret = drm_gem_handle_create(file_priv, gem_obj, &args->handle);
+	/* drop reference from allocate - handle holds it now. */
+	drm_gem_object_put_unlocked(gem_obj);
+	if (ret)
+		return ret;
+
+	return PTR_ERR_OR_ZERO(cma_obj);
+}
+
 static void sun4i_remove_framebuffers(void)
 {
 	struct apertures_struct *ap;
diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.h b/drivers/gpu/drm/sun4i/sun4i_drv.h
index 47969711a889..308ff4bfcdd5 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.h
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.h
@@ -26,5 +26,7 @@ struct sun4i_drv {
 int drm_sun4i_gem_dumb_create(struct drm_file *file_priv,
 			      struct drm_device *drm,
 			      struct drm_mode_create_dumb *args);
+int drm_sun4i_gem_create_tiled(struct drm_device *dev, void *data,
+			       struct drm_file *file_priv);
 
 #endif /* _SUN4I_DRV_H_ */
diff --git a/include/uapi/drm/sun4i_drm.h b/include/uapi/drm/sun4i_drm.h
new file mode 100644
index 000000000000..2c77584b057b
--- /dev/null
+++ b/include/uapi/drm/sun4i_drm.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/* sun4i_drm.h
+ *
+ * Copyright (C) 2018 Paul Kocialkowski <paul.kocialkowski@bootlin.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#ifndef _UAPI_SUN4I_DRM_H_
+#define _UAPI_SUN4I_DRM_H_
+
+#include "drm.h"
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+struct drm_sun4i_gem_create_tiled {
+	__u32 height;
+	__u32 width;
+	__u32 format;
+	/* handle, offsets, pitches, size will be returned */
+	__u32 handle;
+	__u32 pitches[4];
+	__u32 offsets[4];
+	__u64 size;
+};
+
+#define DRM_SUN4I_GEM_CREATE_TILED	0x00
+
+#define DRM_IOCTL_SUN4I_GEM_CREATE_TILED \
+	DRM_IOWR(DRM_COMMAND_BASE + DRM_SUN4I_GEM_CREATE_TILED, \
+		 struct drm_sun4i_gem_create_tiled)
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* _UAPI_SUN4I_DRM_H_ */
-- 
2.16.2