staging: vboxvideo: Add vboxvideo to drivers/staging

This commit adds the vboxvideo drm/kms driver for the virtual graphics
card used in Virtual Box virtual machines to drivers/staging.

Why drivers/staging? This driver is already being patched into the kernel
by several distros, thus it is good to get this driver upstream soon, so
that work on the driver can be easily shared.

At the same time we want to take our time to get this driver properly
cleaned up (mainly converted to the new atomic modesetting APIs) before
submitting it as a normal driver under drivers/gpu/drm, putting this
driver in staging for now allows both.

Note this driver has already been significantly cleaned up, when I started
working on this the files under /usr/src/vboxguest/vboxvideo as installed
by Virtual Box 5.1.18 Guest Additions had a total linecount of 52681
lines. The version in this commit has 4874 lines.

Cc: vbox-dev@virtualbox.org
Cc: Michael Thayer <michael.thayer@oracle.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Michael Thayer <michael.thayer@oracle.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 233 insertions, 0 deletions

diff --git a/drivers/staging/vboxvideo/vbva_base.c b/drivers/staging/vboxvideo/vbva_base.c
new file mode 100644
index 000000000000..c10c782f94e1
--- /dev/null
+++ b/drivers/staging/vboxvideo/vbva_base.c
@@ -0,0 +1,233 @@
+/*
+ * Copyright (C) 2006-2017 Oracle Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "vbox_drv.h"
+#include "vbox_err.h"
+#include "vboxvideo_guest.h"
+#include "hgsmi_channels.h"
+
+/*
+ * There is a hardware ring buffer in the graphics device video RAM, formerly
+ * in the VBox VMMDev PCI memory space.
+ * All graphics commands go there serialized by vbva_buffer_begin_update.
+ * and vbva_buffer_end_update.
+ *
+ * free_offset is writing position. data_offset is reading position.
+ * free_offset == data_offset means buffer is empty.
+ * There must be always gap between data_offset and free_offset when data
+ * are in the buffer.
+ * Guest only changes free_offset, host changes data_offset.
+ */
+
+static u32 vbva_buffer_available(const struct vbva_buffer *vbva)
+{
+	s32 diff = vbva->data_offset - vbva->free_offset;
+
+	return diff > 0 ? diff : vbva->data_len + diff;
+}
+
+static void vbva_buffer_place_data_at(struct vbva_buf_ctx *vbva_ctx,
+				      const void *p, u32 len, u32 offset)
+{
+	struct vbva_buffer *vbva = vbva_ctx->vbva;
+	u32 bytes_till_boundary = vbva->data_len - offset;
+	u8 *dst = &vbva->data[offset];
+	s32 diff = len - bytes_till_boundary;
+
+	if (diff <= 0) {
+		/* Chunk will not cross buffer boundary. */
+		memcpy(dst, p, len);
+	} else {
+		/* Chunk crosses buffer boundary. */
+		memcpy(dst, p, bytes_till_boundary);
+		memcpy(&vbva->data[0], (u8 *)p + bytes_till_boundary, diff);
+	}
+}
+
+static void vbva_buffer_flush(struct gen_pool *ctx)
+{
+	struct vbva_flush *p;
+
+	p = hgsmi_buffer_alloc(ctx, sizeof(*p), HGSMI_CH_VBVA, VBVA_FLUSH);
+	if (!p)
+		return;
+
+	p->reserved = 0;
+
+	hgsmi_buffer_submit(ctx, p);
+	hgsmi_buffer_free(ctx, p);
+}
+
+bool vbva_write(struct vbva_buf_ctx *vbva_ctx, struct gen_pool *ctx,
+		const void *p, u32 len)
+{
+	struct vbva_record *record;
+	struct vbva_buffer *vbva;
+	u32 available;
+
+	vbva = vbva_ctx->vbva;
+	record = vbva_ctx->record;
+
+	if (!vbva || vbva_ctx->buffer_overflow ||
+	    !record || !(record->len_and_flags & VBVA_F_RECORD_PARTIAL))
+		return false;
+
+	available = vbva_buffer_available(vbva);
+
+	while (len > 0) {
+		u32 chunk = len;
+
+		if (chunk >= available) {
+			vbva_buffer_flush(ctx);
+			available = vbva_buffer_available(vbva);
+		}
+
+		if (chunk >= available) {
+			if (WARN_ON(available <= vbva->partial_write_tresh)) {
+				vbva_ctx->buffer_overflow = true;
+				return false;
+			}
+			chunk = available - vbva->partial_write_tresh;
+		}
+
+		vbva_buffer_place_data_at(vbva_ctx, p, chunk,
+					  vbva->free_offset);
+
+		vbva->free_offset = (vbva->free_offset + chunk) %
+				    vbva->data_len;
+		record->len_and_flags += chunk;
+		available -= chunk;
+		len -= chunk;
+		p += chunk;
+	}
+
+	return true;
+}
+
+static bool vbva_inform_host(struct vbva_buf_ctx *vbva_ctx,
+			     struct gen_pool *ctx, s32 screen, bool enable)
+{
+	struct vbva_enable_ex *p;
+	bool ret;
+
+	p = hgsmi_buffer_alloc(ctx, sizeof(*p), HGSMI_CH_VBVA, VBVA_ENABLE);
+	if (!p)
+		return false;
+
+	p->base.flags = enable ? VBVA_F_ENABLE : VBVA_F_DISABLE;
+	p->base.offset = vbva_ctx->buffer_offset;
+	p->base.result = VERR_NOT_SUPPORTED;
+	if (screen >= 0) {
+		p->base.flags |= VBVA_F_EXTENDED | VBVA_F_ABSOFFSET;
+		p->screen_id = screen;
+	}
+
+	hgsmi_buffer_submit(ctx, p);
+
+	if (enable)
+		ret = RT_SUCCESS(p->base.result);
+	else
+		ret = true;
+
+	hgsmi_buffer_free(ctx, p);
+
+	return ret;
+}
+
+bool vbva_enable(struct vbva_buf_ctx *vbva_ctx, struct gen_pool *ctx,
+		 struct vbva_buffer *vbva, s32 screen)
+{
+	bool ret = false;
+
+	memset(vbva, 0, sizeof(*vbva));
+	vbva->partial_write_tresh = 256;
+	vbva->data_len = vbva_ctx->buffer_length - sizeof(struct vbva_buffer);
+	vbva_ctx->vbva = vbva;
+
+	ret = vbva_inform_host(vbva_ctx, ctx, screen, true);
+	if (!ret)
+		vbva_disable(vbva_ctx, ctx, screen);
+
+	return ret;
+}
+
+void vbva_disable(struct vbva_buf_ctx *vbva_ctx, struct gen_pool *ctx,
+		  s32 screen)
+{
+	vbva_ctx->buffer_overflow = false;
+	vbva_ctx->record = NULL;
+	vbva_ctx->vbva = NULL;
+
+	vbva_inform_host(vbva_ctx, ctx, screen, false);
+}
+
+bool vbva_buffer_begin_update(struct vbva_buf_ctx *vbva_ctx,
+			      struct gen_pool *ctx)
+{
+	struct vbva_record *record;
+	u32 next;
+
+	if (!vbva_ctx->vbva ||
+	    !(vbva_ctx->vbva->host_flags.host_events & VBVA_F_MODE_ENABLED))
+		return false;
+
+	WARN_ON(vbva_ctx->buffer_overflow || vbva_ctx->record);
+
+	next = (vbva_ctx->vbva->record_free_index + 1) % VBVA_MAX_RECORDS;
+
+	/* Flush if all slots in the records queue are used */
+	if (next == vbva_ctx->vbva->record_first_index)
+		vbva_buffer_flush(ctx);
+
+	/* If even after flush there is no place then fail the request */
+	if (next == vbva_ctx->vbva->record_first_index)
+		return false;
+
+	record = &vbva_ctx->vbva->records[vbva_ctx->vbva->record_free_index];
+	record->len_and_flags = VBVA_F_RECORD_PARTIAL;
+	vbva_ctx->vbva->record_free_index = next;
+	/* Remember which record we are using. */
+	vbva_ctx->record = record;
+
+	return true;
+}
+
+void vbva_buffer_end_update(struct vbva_buf_ctx *vbva_ctx)
+{
+	struct vbva_record *record = vbva_ctx->record;
+
+	WARN_ON(!vbva_ctx->vbva || !record ||
+		!(record->len_and_flags & VBVA_F_RECORD_PARTIAL));
+
+	/* Mark the record completed. */
+	record->len_and_flags &= ~VBVA_F_RECORD_PARTIAL;
+
+	vbva_ctx->buffer_overflow = false;
+	vbva_ctx->record = NULL;
+}
+
+void vbva_setup_buffer_context(struct vbva_buf_ctx *vbva_ctx,
+			       u32 buffer_offset, u32 buffer_length)
+{
+	vbva_ctx->buffer_offset = buffer_offset;
+	vbva_ctx->buffer_length = buffer_length;
+}